August/September 2005 by Tim Walker

Volume 19 No. 4 â&#x20AC;&#x201C; August/September 2005

Eel breeding breakthrough At last, new Eden mussel leases Bathurst Island barra farm Rice and yabbies together Bass and mullet hatchery How, when and why feed yabbies Equity capital buys ornamentals Forging ahead with salmon

August/September 2005

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Editor-in-chief Dr Tim Walker Regular contributors David O'Sullivan John Mosig Dave Field Subscription/editorial Austasia Aquaculture PO Box 658, Rosny, Tas. 7018 Ph: 03 6245 0064 Fax: 03 6245 0068 Email: AustasiaAquaculture@ netspace.net.au Advertising Megan Farrer Graphic design Beverly Waldie Printing The Franklin Press 91 Albert Road, Moonah, Tas. 7009 Copyright © by Austasia Aquaculture. Contents cannot be reproduced without permission. Statements made or opinions expressed are not necessarily those of Turtle Press Pty Ltd (ABN 98 506 165 857).

FA R M P R O F I L E S Wetlands secure water for boutique salmon farm

Equity capital fund buys largest ornamental fish wholesaler in Australia

Eden Mussel expansion finally approved

Marine Harvest, barramundi farming the Bathurst Island way

NSW Native Fish Hatchery – fingerlings by the millions

Rice and yabbies – the perfect companions

Saltas forges ahead

Aussie bass and sea mullet from SE Qld hatchery

Tathra Oysters win more Sydney Royal Show awards

F E AT U R E Feeding yabbies

TECHNOLOGY High Density Continuous Rotifer Culture Systems

Barclay Oysters outstanding success with Aquapurse

Datacall: Remote Transmitter Unit

Twenty one years and still flowing strongly

RESEARCH Austasia Aquaculture magazine (ISSN: 0818 552) is published by Turtle Press Pty Ltd (ABN 98 506 165 857) for the promotion of aquaculture in the Australasian and Asian regions – inclusive of farming in marine, freshwater, brackish and hypersaline waters. Reader's contributions are encouraged on the clear understanding they will be subject to editorial control and, if accepted, will appear in both printed and online versions.

Cover photo: Selection of photos from Rob McCormack, the author of a new book on commercial yabby farming (see page 48).

Kiwi ingenuity and Iraqi skill hatches eels for the first time

FISHENEWS

August/September 2005

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Photographs by A Pyka.

FARM PROFILE

Wetlands secure water for boutique salmon farm Siggi Pyka and his wife Angelika have come a long way with their boutique salmon farm in north west Tasmania. When the farm was set up two years ago it had no electricity and a marginal water supply. Now remnant wetlands on their property have been expanded allowing for recycling of water during the summer when water availability can become critical. They have also opened their farm as a unique eco-tourism attraction. Siggi Pyka, his wife Angelika and son Ben have been busy with their recent expansions to their 41º South Aquaculture (they were featured in the April-May ’03 Vol 17 Issue 3 of AAM). The property, located near Deloraine, is an old quarry and needed considerable rehabilitation when the Pykas first moved there. The rehabilitation works were extended with a Natural Resource Innovation Grant – matched on a dollar for dollar basis – that allowed Siggi to remove around 4.5ha of willow trees and replace this area with an artificial wetland. While Siggi and Angelika put in a lot of time into the project, they also sold their nearby house and property to provide cash funds for the expansion. Siggi and Angelika now live in a 2 bedroom unit above their new visitors centre. “Living at the farm is great, as it is easy to get to work,” explains Siggi. “However, it is really hard to get a holiday – I just had a day off this week and it is the first day I have had off in a year!” However, all the work has been worth it as the Pykas have been able to improve production of Atlantic salmon (Salmo salar) with expanding markets for their value-added produce. Water security Since starting the farm, one of Siggi’s biggest problems has been that of water security. Good water flows are essential as the farm primarily relies on flowthrough water. The water flow in Western Creek – the main water source for

the farm – is good during winter but summer flow is low. “Our licence stipulates how much water we can take from the river and we are careful not too exceed this as it is important that the river maintains good environmental flows to ensure its health,” he says. “In order to secure our water we decided that we needed to have some way to reuse our water but were not sure how we could do this.” After looking at the internet and talking with other farmers, Siggi decided on using a constructed or artificial wetland. “It makes a lot of sense to me to use nature in the form of an artificial wetland to revitalise the water for reuse. It also allows the creation of habitat for a range of other wildlife as well.” The wetlands were developed in an area of the property adjacent to his water source. The area was always water logged in winter and covered in willow trees. The wetlands are constructed as a series of ponds that are inter-connected with channels. The problem with constructing them was working out how to lay out the ponds so that water would flow between them. This was solved largely by using the natural contours in the land to dictate the pond and channel shapes. A variety of aquatic and semi-aquatic plants are being encouraged to grow in the channels and ponds. These are the ‘filters’ of the system and absorb nutrients from the water after it has passed through the fish tanks. “We have a

Effluent channel for water from the main culture tanks. The u-shaped pipe configuration helps to maintain water levels in the tanks.

Ziggi holding a market sized fish – the culmination of around 2 years hard work!

Tanks are harvested and graded by large dip nets. These fish are being harvested for grading which is important for maintaining growth of fish.

Ziggi still runs his water-wheel that he originally used to generate power before electricity was connected.

Ziggi installing the new pumps for recirculating water from the wetlands.

Austasia Aquaculture | August/September 2005 3

FARM PROFILE

Performance Criteria To allow inter-farm comparisons, each AAM farm profile details a number of system performance criteria. Except for the comments under ‘Key Management Decisions’ which are prepared by Dos, the information has been supplied by the farmer: • Key Management Decisions for 41O South Aquaculture include: – Expanded remnant wetlands to bio-remediate water for re-use. – Opened wetlands and farm as ecotourism, good for selling onfarm produce as well as cash flow – Value added processing of salmon used to significantly increase farm profits – Use of effluent to grow other crops (Ginseng and Wasabi). • Growth rate (from stocking to market): <4 months (100g to 500g). • Survival rate: 95% from first stocking to harvest size. • Av. stocking density: 3 kg/m3 (range is 1kg to 8kg). • Water use: 73,000 L per kg produced per year (extensive culture with). • FCR: 1.2 kg (number of kg of food to produce 1kg stock). • Production rate: 13.5 kg per 1,000m3 (growout system volume) per year. • Productivity: 5 tonne per man year (240 days, 48wk X 40hr/8hr). • Production cost: $10/kg.

wide variety of plants including native sedges and rushes that filter the water,” Siggi continues. “I thought we would have to spend thousands of dollars on plants but after the excavation work was completed the plants began to grow everywhere, and within 3-4 weeks the wetlands had sprung to life. I can’t wait to see what it looks like after a year.” The water stays in the wetlands for several weeks before reaching the return channel. “After passing through the wetlands the water is so clean you can drink it; it (the wetlands) just acts like a giant biofilter.” From the return channel, water can pass back into Western Creek or it can be pumped back to the top of the farm. There are two 3 kilowatt pumps that can each deliver 25 litres per second but which have been frequency regulated to allow them to be slowed down to reduce pumping costs. Siggi plans to leave one pump operating all year round, while the second pump will be used for six months of the year over summer when water availability is reduced. Between the pumps and river, Siggi has approximately 75 litres of water per second to recycle through the farm, ample for the stocking rates being used. The fish are stocked in 5m diameter concrete tanks a metre deep, with a volume of approximately 20,000 litres. The tanks were poured by hand and the concrete was delivered by a truck. “We had to pour the concrete by bucket from wheelbarrows to the tanks so it was really hard work. My son Ben likes to

break records though and each tank we poured was quicker. The last tank only took 24 minutes to pour,” Siggi recalls. Each tank is supplied with water through a 100 mm PVC pipe from the main supply channel at 4-5 litres per second. Each is also covered by netting to prevent bird predation and, more importantly, to stop fish from jumping out. Atlantic salmon are very prone to jumping. The fish are sourced from Tasmanian hatcheries such as Mountain Stream Fishery and Springfield Hatcheries and normally stocked in April to June at a size of 2-10 grams. They take between 16 months to 2 years to grow to size. Siggi had originally intended to produce one kilo fish but changed this due to market demand. “Our customers liked the product but the fish were too big. Restaurants, such as Cradle Mountain Lodge, want a fish around 600 grams, while retail customers want a 400 to 500 gram fish. So we began to produce 400 to 600 gram fish.” With careful grading and feeding Siggi is now able to do a partial harvest every two months to maintain supply of his product amidst growing demand. Feeding with Skretting salmon diets is done primarily by hand although Siggi has recently installed automatic feeders to reduce the weekend workload. Hand feeding is done to satiation 1-3 times per day depending on temperature and weather conditions. “Feeding by hand is better as the fish are the best indicator of how much food they want but I also use the Skretting feed tables as an indication of how much food I should be feeding.” Siggi is currently getting a Food Conversion Ratio of slightly better than 1.2:1. The other major job is that of grading. This is done by crowding fish, netting them out and putting them through an adjustable grader basket. Eco-tourism Senator Richard Colbeck, a great supporter of the Pykas who helped them to get the electricity connected, recently opened their new eco-tourism attraction. Senator Colbeck says, “It shows if you think outside the square what is possible and what you can

4 Austasia Aquaculture | August/September 2005

FARM PROFILE

achieve… It is a testament to the Pykas’ passion for business.” The eco-tourism experience includes a tour of the fish farm; the Pykas explain how the fish are grown and tourists can see various farming operations such as feeding and grading take place. While the farm is obviously the main attraction, tourists are also able to walk around the wetlands which are now host to a variety of wildlife including frogs, birds, fish and even a family of platypus. “Probably half of the visitors coming to the farm see our platypus. They are magnificent animals and obviously enjoy our wetlands,” says Siggi. He also hopes that as the wetlands expand that it will grow into a unique tourist attraction in northern Tasmania. Senator Colbeck agrees with this. “The business has the potential to become a significant drawcard and could rival the Salmon Ponds facility in the south of Tasmania (near New Norfolk).” Siggi hopes that tourists take the opportunity to wander around the farm and relax and then sample some food from their shop. The shop offers free samples of their smoked salmon and also of their Rillettes – a coarse pate with salmon flakes.

Marketing and Value-adding Siggi aims to continue producing around 10 tonnes of ‘baby’ Atlantic Salmon per year for local and interstate gourmet markets. “You do not have to produce huge volumes of fish to make money. All you need to be is smart and market your product the right way,” he says. The fish are processed locally and undergo a range of value-adding activities. The salmon are hot smoked, using a ‘recipe’ based on German methods, while other fish are used to produce the Rillettes. Siggi and Angelika first started to sell their products at local markets direct to the public. “Direct sales to the public allow you to get a much higher price for the product and also get feedback from customers,” Siggi explains. After refining their product Siggi and Angelika were able to approach local gourmet butcher shops, delicatessens and restaurants. And demand keeps growing. “We’re now finding it hard to keep up with orders!” Future Directions Production has already reached the maximum allowed under the license (10 tonnes per annum) so Siggi does not plan to expand the harvest any fur-

ther. However, a small processing facility will be built later in the year. Expansion is more likely to come from activities on the site. In keeping with the Pykas’ theme of eco-tourism and production of gourmet produce, Siggi is continuing to expand his Ginseng production and looking at production of Wasabi. The Ginseng that Siggi grows is some of the best quality grown outside of Asia. “Tasmania has the best climate in the world for Ginseng and it is becoming more popular in the western world. I originally had the fish farm to finance my Ginseng production but the salmon has taken over.” However, the salmon production compliments production of Ginseng and Wasabi, as the farm effluent water is used to irrigate them. Siggi is still experimenting with this and hopes to continue to expand production of these crops in the future. By Shane Willis For more information contact Siggi Pyka, 41O South Aquaculture, 323 Montana Rd, Deloraine, Tasmania, 7304. Tel: 03 6362 4130, email: 41south@mynewsat.com, website: www.41south-aquaculture.com

The Commercial Yabby Farmer Robert B McCormack The most complete and comprehensive book ever written on yabbies and yabby farming. Compiling all you need to know on the latest research and commercial farming methods this book is a complete A-Z of how to commercially semi intensively farm yabbies. An absolute must for everyone in the industry or anybody contemplating entering. In depth coverage of constructing a yabby hatchery, constructing yabby ponds, pond and water quality management, feeding, harvesting, hybrids, genetic selection, predators, diseases, production returns, purging, packaging and marketing, etc. ISBN: 0 9578524 1 X • 256 pages • $49.50 • Includes Postage and Handling Australia & New Zealand. Add $3.30 extra postage for every extra book. (All other countries add $18 extra postage, add $13.50 postage every extra book.) Order form Name: Address: Postcode: Phone:

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Austasia Aquaculture | August/September 2005 5

FARM PROFILE

Equity capital fund buys largest ornamental fish wholesaler in Australia These goldfish are a small sample of the tens of thousands of fish held at any time at Aquarium Industries Pty Ltd. Photo by Shane Willis

Crescent Capital made its first aquaculture investment earlier this year buying Aquarium Industries (AI) Pty Ltd, the largest ornamental fish wholesaler in Australia. Following the first quarter of trading as the new owner of AI, the investor is happy with how things are shaping up, with big plans for future expansion of the business but intention to change the culture of the business. Aquarium Industries Pty Ltd (last story in August-September ’03 issue of AAM Vol 17 No 5) is Australia’s largest importer and wholesaler of ornamental fish selling in excess of 7 million fish to over 1,000 retail customers around Australia. The fish, sourced from a variety of local Australian producers and international suppliers, are held in ‘state of the art’ facilities at Epping near Melbourne airport. Former owner, Rick Datodi, started the company from scratch 36 years ago and built it to be the dominate supplier in the Australian ornamental fish market. However, given changed circum-

stances with some key senior personnel and a desire to slow down a bit, Rick decided to sell the company late last year. Rick’s decision was not made lightly, his major concern being the job security of his staff and a need to pass on the operation to safe hands. “My staff have been very loyal to me and I was determined that in any takeover that their jobs should not be threatened. I also wanted to make sure the business would be well looked after – after all it is my baby,” he says. Thus far, he’s well satisfied and is staying on with the company on a parttime basis to help with technical and

6 Austasia Aquaculture | August/September 2005

marketing matters. Crescent Capital, an equity capital fund based in Sydney with funding from superannuation funds and private equity, specialises in purchasing companies valued at $10 million or more. It uses superior business skills and capital injections to significantly grow that business. As with most of its ilk, it is very fussy in its choice of target; there needs to be a sustained record of growth and productivity, a fine reputation and with excellent future prospects. Crescent Capital began looking for opportunities in aquaculture some time ago but nothing available met the crite-

FARM PROFILE

ria. Until AI came up. And when it did, whilst the company’s sound economics and good business operations were most attractive, Crescent Capital did have some questions about its ability to operate in the sector without prior experience. Fortunately, an in-depth examination revealed just how big the ornamental fish industry is and, given AI’s success in meeting all of the other investment criteria, a deal was done. “We had no idea how big the pet industry is,” says Greg Brigden, the new CEO of Aquarium Industries. “In fact it is worth more than $2 billion per annum and growing fast. The opportunity to invest in one of the largest operators in the sector was timely for us and I think we have made a really good decision. It gives us a sound foundation to grow and develop further opportunities in this sector. Aquarium Industries met all our criteria, having had sustained growth over 35 years, profitability and potential for growth. However, the factor that attracted us most was the culture and ethics of the business. Rick Datodi (the former owner) has built a great team of people over the years and we have no intention of breaking up this team.” Growing the business Greg has only been in his current job for 12 weeks and being new to the industry is still finding his feet and learning about the industry. However, he has big plans for future expansion. “We need to continue growing the business and the best way to achieve that is to nurture the retail sector so it can grow too. “To achieve that we need enough scale to be able to assist the retail industry with marketing and promotion of the industry, technical assistance, shop design and layout and various other support services,” he continues. Greg does not intend to change the fish operations side of the business quite yet. “I used to have a fish tank, but managed to kill the fish so that is not my strong point. I believe that Aquarium Industries operations are World Best Practice and I have no intention of upsetting this.”

A steel gantry supports the biological filtration system for the goldfish recirculating system consisting of 100 by 1,000 litre tanks. Photo by Shane Willis.

However, as his and Crescent’s expertise grows in this area there may be changes in business operations and strategic management – Crescent Capital’s strengths. “We intend to make some internal changes to operational aspects such as accounting, computer systems and stock inventory management but

these will be largely back office issues and will only improve our ability to service our customers,” says Greg. Another area that is being overhauled is that of Professional Development of staff. AI has had an in-house training program operating for many years but Greg is looking to build on this. “I think

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FARM PROFILE

The main packing bench has been ergonomically designed to allow for easy and fast packing of fish. Photo by Shane Willis.

it important that staff be given the right training to do the job but it is also vital that there be opportunities for career development and a professional development program will help this happen.” Discussions with the National Aquaculture Training Institute are currently focussed on workplace training options within the Seafood Industry and Com-

panion Animal (Rural) Training Packages. Greg sees this as a vital step in plans for future expansion with several key staff members to begin their training soon; the remaining staff will complete theirs over the next 18 months to 2 years. Greg’s also looking to improve the ornamental fish supply chain which he sees as fairly inefficient. Timeliness of

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supply is a major concern for most operators but so too is freight, a major cost. As AI’s expertise is in distributing livestock, Greg says the company will be looking at options to supply other lines of livestock. However, he’s not planning to begin selling dry goods (accessories such as food, tanks, lights, pumps, food and chemicals used for the maintenance of livestock) again. Expanding capacity As Aquarium Industries’ facility has nearly reached full capacity, options for boosting fish holding and quarantining capacity are being drawn up. One option is to build a new facility in Sydney, allowing for a reduction in freight costs by distributing product directly into the lucrative Sydney market – the country’s largest. No major national distributor is currently based there. Better customer service is another benefit. “We have massive market share in Victoria – particularly in Melbourne,” Greg explains. “Many Mel-

FARM PROFILE

Key Management Decisions • – – – – • Aquarium Industries’ new warehouse in Epping. The building is a concrete slab building with the fish rooms contained within ‘freezer panel’ rooms. Photo by Shane Willis

Most fish are kept in 200L glass aquaria that are supported on cantilevered steel supports. Each tank has its own internal filtration system for water quality control. Photo by Shane Willis

Investment criteria Sustained growth over a long period Possibility of future growth Profitability Good business practices Development of new facility in Sydney to expand market share and reduce market access costs • Professional Development program and career pathways for staff • Expanded support for industry to help industry expand

bourne customers visit us regularly to select fish and talk to our staff about various problems they are having.” Customers are also able to see the facility and deal direct with staff to build personal relationships which are important in business to business sales. He’d like to give the same service to Sydney customers. Freight costs for distributing fish are also on the rise and unlikely to fall in the future. Crescent Capital are currently busy on building AI and consolidating its position as market leader in the industry. Greg says: “Our first priority is to make Aquarium Industries a very defensible national business, able to withstand any foreseeable problems that the industry may face.” Once this is achieved, he suggests it is likely that Crescent Capital will be looking at other investment opportunities in the aquaculture or pet industry. “We are always looking for good investment opportunities but potential companies must meet our selection criteria. We not interested in start-ups or high risk ventures. We only look for solid investment opportunities that have the potential for further growth.” By Shane Willis.

Some of the 1,000 litre tanks in the goldfish recirculating system which is maintained at ambient temperatures. The main fish rooms are contained within the freezer panelled room at the right of the picture. Photo by Shane Willis.

For more information contact Greg Brigden, Aquarium Industries Pty Ltd, Lot 26 Shirley Way, Epping, Vic 3076. Tel: 03 9409-9300, fax: 03 9401-3455, email: gregb@aquariumindustries.com.au

Austasia Aquaculture | August/September 2005 9

FARM PROFILE

Map showing the existing and planned mussel leases. Courtesy of O’Hanlon Design.

Eden Mussel expansion finally approved Plans for the expansion of mussel farming in Twofold Bay, on the Southern NSW coast, have been on the drawing board for almost a decade. Despite a comprehensive Environmental Impact Study, regular monitoring of the seabed under the existing mussel farms and even a recent Visual Impact Assessment, opposition continued to the expansion. Fortunately the NSW Government has seen the process through and recently, Ian Macdonald, Minster for Primary Industries, signed off on the approvals for the larger second stage of the expansion (Stage 1 was approved in 1998).

10 Austasia Aquaculture | August/September 2005

After considering community submissions on the issue, the NSW Minister for Primary Industries, Ian Macdonald, announced on February 22 (2005) that he had approved the (2nd stage) expansion of mussels farms in Twofold Bay from 15.5 hectares to 49.5 hectares. “This is part of the Government’s plan to develop aquaculture along the NSW coast, as a vital means of easing the pressure on fish stocks,” Mr Macdonald said. “It follows 13 years of consultation between the local community, Local Council and State Government, starting from when the original mussel farming proposal was advertised in 1992.” In a state where population pressures on the coastline are extreme, it is significant that the NSW Government will allow what can become a world-class mussel farming industry to develop. “The Government has struck a balance between local jobs, industry, the environment and the economy,” Mr MacDonald continued. “Based on detailed, independent assessments, I am satisfied the mussel farm does not pose a significant risk to the environment. Ongoing monitoring will ensure the health of the local waterways remains the highest priority. “The farms’ expansion will inject up to $800,000 into the region in capital investment, plus up to $600,000 each year by creating 17 full-time jobs and extra casual positions. But importantly, it will still only cover a total 1.5% of the Bay’s area – leaving space for recreational and sporting activities.” Mr Macdonald also stated that other concerns had been addressed, including the potential entanglement of dolphins and other marine mammals, navigational hazards, yachting regattas and environmental impacts. 30 Years of Farming Eden Shellfish has been operating a blue mussel (Mytilus edulis planulatus) farm in Twofold Bay off Eden, 6.5 hours drive south of Sydney, for almost 30 years. It is a business owned and operated by the Bamford family, with Mike and son Adam out on the lease, and wife/mother Nola handling much of the paperwork and orders.

FARM PROFILE

View from Onan Point showing one of the rafts (centre left) and several long lines (left back). Photo courtesy of O’Hanlon Design.

Mike sees mussel farming as a great improvement on wild fishing. “We converted trawler the Rikara Star as our work vessel. With that, and two delivery trucks and our work ute, our total fuel bill is only around $1,000 per month. A trawler could spend the same amount in a day and still not be guaranteed they would catch their quota. I know what I’d prefer to be doing.” Adam has two helpers on the boat, Terry and Tony. All three have spent time away fishing over many nights. All agree that a five to six minute run out to the lease makes for a lot more enjoyable work. “As part of the Stage 1 expansion, we were given an additional 6ha of Consolidated Crown Lease area in 1998, which added to our raft farm area gave us a total of 13.5ha,” Mike explains. “As part of the Stage 2 we will get another 4ha.” Eden Mussels have their leases around 200 meters offshore adjacent to Cocora Point in the north-western end of Twofold Bay; this is overlooked by part of the township of Eden. Originally a farm of eight wooden raft systems, ten 160m long lines have been installed since 1998, substantially increasing the farm’s productivity. In 1998 a pilot lease of 2ha was also given to the NSW Cultured Mussel Growers Association (NSW MGA) to test culture systems before the Stage 2 expansion. Two 100m longlines were installed over at Mutries Reef (adjacent to Torarago Point) in the south western

View south from Onan Point towards the Eden wharf with rafts (foreground) and longlines (background). Photo courtesy of O’Hanlon Design.

end of the Bay. In that area the proposed Stage 2 development is an 18 hectare extension on the western side of Torarago Point and another 12 hectares on the eastern side of Torarago Point. All would involve the use of longlines rather than floating rafts. Environmental protection remains an important focus. Mike and the NSW CMGA have had to undertake a $151,000 Biodiversity Survey as part of

his permit conditions. “We contracted Professor Mike Underwood from Sydney University to take more than 240 samples,” Mike explains. “The aim was to see if the mussel farming was having any impact on the infauna, those animals living in the top 80mm of sediment. The study has shown there has been no impact from the mussel lines, but we will keep doing it to a lesser degree. “We are not making big changes to the environment. Look at the $50 million multi-purpose Wharf (built on the southern end of the Bay). They had to dredge the bottom (100,000m3 of sand had to be shifted) to allow the bigger ships to get in. That structure is over 620m long and 200 wide (at the end of the wharf), enough to turn a semi-trailer in. What environmental work do they have to keep doing?” However, now that the Fisheries Minister has given the go-ahead, all the Mike’s ‘blood, sweat and tears’ have been worth it. “We have got our final 4ha, and the Mussel Growers Association got their new area, so that is good. But even then, that only adds up to less than 50ha in the Bay; it is still a tiny area.”

Austasia Aquaculture | August/September 2005 11

FARM PROFILE

Key Performance Indicators (KPIs) To allow inter-farm comparisons, each AAM farm profile details a number of key performance indicators for different aquaculture systems. Except for the comments under ‘Key Management Decisions’ which are prepared by Dos, the information has been supplied by the farmer: • Key Management Decisions include: – Move from raft culture to sub-surface longlines – Use of the rafts to collect large quantities of high quality mussel seed – Use of ice and the canvas deck screen to keep the product cool and fresh • Culture System utilised: subsurface longlines with surface buoys and dropper ropes • Growth rate (from stocking to market): <10 months (0.5g to 40g) • Survival rate: 80% from first settlement to sale size, includes those striped off, overcatch • Av. stocking density: 5-7kg per metre of dropper rope (range is 0kg to 10kg) of market product • Annual harvest: 20-70 tonnes • Productivity: 10-30tonnes per Effective Fulltime Unit (240 days, 48wk X 40hr) • Sale price: $6/kg

Stage 2 Expansion Plans are underway for the pilot lease area to be expanded at Mutries Reef into a lease of 32ha. Chris Boyton, Secretary/Treasurer of the NSW CMGA, says that he expects all members will band together to form one company to develop and farm the site. “This would offer us the economies of scale

in production and marketing. We’ll look to maintain the level of quality already started by Michael (Bamford).” Chris says that their site is a little more exposed than that occupied by the Eden Mussels. “We are looking at more rigid buoys and stronger springers and lines.” He too is very relieved with the Minister’s decision. “If the Minister had knocked this one back, you could have just about kissed goodbye to any Marine Aquaculture in NSW. We would have been better to go to Victoria, Tassie, SA or even WA where the governments are more encouraging to mussel aquaculture.” However, Chris now sees a good future for the industry and the local community. “We could be producing some 100 to 150 tonnes (p.a.) depending on the number of lines we put in and will be looking to employ local people on the farms. Marine Technology is offered at the (Eden) High School, yet there are few places for them in the local fishing industry. We estimate we could have ten full time jobs out on the leases and another seven on shore.” Visual Amenity Report Even now, Mike can’t see why there was so much opposition to

A find crop of large juicy mussels. Photo courtesy of Mike Bamford.

12 Austasia Aquaculture | August/September 2005

the mussel farming. “We treasure the Bay more than anyone else because we have all our investment in it. We need high water quality to ensure our mussels are the best quality. With our Shellfish Quality Assurance Program (SQAP) we are continually monitoring the Bay for pollution. We were only the second place in NSW to be registered by the SQAP to harvest shellfish straight out of the water (i.e. no depuration for 36 hours in UV-treated seawater). We regard the Bay as special; it’s our livelihood. We have worked with other users to keep it clean. For example, now the fishing industry people don’t dump out their bilges or throw their wastes into the Bay.” A Visual Amenity Report was requested as part of the Stage 2 development, examining the impacts of the rafts, the long line buoys and the navigational buoys. Mike’s lease area is close to the Eden wharf and is overlooked by a few houses. The report was undertaken by landscape architect Terry O’Hanlon (O’Hanlon Design P/L), who had completed a similar report for the Sydney rock oyster farms in NSW. The method for this study was based on assessing both the scenic quality of the visual catchment and the visual impact of the proposed new lease areas within the overall local character. It was comprised of two assessment components: • assessment of scenic quality, and • assessment of visual impact. Whilst assessment of scenic quality involved evaluation of such parameters as landscape, waterway and foreshore character, viewer characteristics and aesthetic value, that of visual impact was concerned with the degree of harmony (and intrusion of) the mussel lease area with (and into) the perceived surrounding landscape. The result of these two assessments is a ranking of scenic quality and impact into High, Medium or Low. The report concluded that the critical characteristics were the distance and locality of the activity. Terry said that impacts can be high if people are very close to an activity. “With the Eden study, it was recognised that Eden is a

FARM PROFILE

The Rikara Star steams past the ends of the long lines. Photo courtesy of Mike Bamford.

The Rikara Star next to a line of rafts. Photo courtesy of Mike Bamford.

working port so there is an expectation of different uses of the waterways. If the area was purely recreational, then the proposed mussel culture would have different (higher) impacts.” Generally the report found that the visual impacts were negligible or low at both sites; however, at night-time the flashing corner marker buoys could be an issue. With respect to mitigating measures, the consultants wrote that the most significant mitigation measure is the careful management of the leases. “Maintaining appropriate numbers of buoys to suit the shellfish load, allow the buoys to remain partially submerged, reducing bobbing and reduces breaks to the water edge line. This must be balanced against the suitability and construction of buoys for submersion. Current commercially available buoy types appear to require relatively high flotation levels. “Colour can also be used to reduce visibility. This, however, depends on sea conditions, cloud cover and viewing elevation. One colour will not meet all the possible conditions. The current use of predominantly black buoys suits

views from elevated locations on overcast or windy days. This seems to work reasonably well.” “It is often a perception issue,” Terry explains. “If the buoys and lines are set out in regular lines, people perceive the site as being well managed, clean and tidy.” New Longlines When the Environment Impact Study was completed in 1996, designs for the longlines were suggested. The technology for the longlines was based

on that used for the pearling industry in northern Australia. The lines face east into the sea and have been aligned 33m apart to allow plenty of room for the Rikara Star to manoeuvre and even turn around. “We use 4 tonne concrete wedge blocks to hold the ends of the lines in place,” Mike says. “The only improvement we would make now would be to install bigger eyelets in the 8” hawsers rather than using shackles.” The main lines are 160m long, 32mm polypropylene suspended between 7 and 15 buoys (depending on the stock of mussels being held). The 200L plastic buoys are attached to the long line by one end so the line itself is below the water. Mike says black mussel buoys from Tasmania are used as well as blue plastic drums. “They blend in with the water and can’t be easily seen unless it is calm and you are close by.” By moving to the longlines, Mike adds that the farm also has the capacity to move to other higher value mollusc species, such as the Akoya pearl (Pinctada imbricata). “The site has plenty of primary production so there is lots of food for the shellfish. “When we set up our first lines, we found we lost mussels due to waves surges, so we learnt to set up loose lines. This also reduced the wear on shackles at the anchor ends.” And he’s developed a preference for 12, 14 or 18mm polypropylene ropes for the droppers. “These don’t foul as much. They can be between 5.5 and 6m long,

Austasia Aquaculture | August/September 2005 13

FARM PROFILE

A hook holds up the longline so the dropper ropes can be united and the mussels harvested. Photo courtesy of Mike Bamford.

and can hold up to 70kg of mussels. We have around 11,500 ropes, some of which we first started with in 1976. A special knot is used to tie the droppers onto the long lines so they are easy to remove at harvest. The Rikara Star pulls along side the long line which is 1-2m below the surface. A grappling hook on a lazy wheel pulls the line in to be held it in place. Droppers are selectively untied and pulled by hand on board. The mussels can be easily stripped off the droppers which are stored for later clean, drying and then reuse. A plastic shovel is used to break up the large clumps of mussels before they are binned in 30L plastic crates. Once the harvest is completed the boat returns to the wharf where a freshwater hose is attached to the barrel declumping machine. Considerable experimentation led to the current configuration of teeth size, number and placement inside the 3m-long barrel. “We’re happy now with it. We found that the teeth only needed to be as long as the mussels. In about 10 minutes we can declump around 2 boxes (80kg) of mussels and can process around a tonne per day.” The area is usually covered by a canvas deck cover to both keep it cool and reduce sun exposure (OH&S) for the workers. “All of this is described in our Code of Practice which we had to develop for the NSW Food Authority (ex. Safe Food).”

The mussels are collected in a bin for hand sorting. Then ice is thrown on top of a rubber mat on the sorting table (to keep it cool), the mussels spread out and up to three sorters set to picking out the good mussels. Thick knives or small tomahawks are used to clean the mussel shells of any sponges or other fouling organisms. The product is weighed into 6kg portions in net bags and placed in mesh socks for a rewatering period allowing the mussels time to recover from the stress of the harvest and declumping. Afterwards, foam boxes of mussels are packed with ice before transfer to

14 Austasia Aquaculture | August/September 2005

South Coast Freighters for refrigerated transport to Sydney and elsewhere. As long as the mussels are kept at 3-7°C Mike says they have a shelf life of up to 5 days. Wharf sales are becoming popular with tourists and locals alike who particularly enjoy observing the mussel declumping and sorting process. Plastic bags of 1, 2 or 3kg of mussels are sold there. Even if the trip home is short, Mike says some ice is packed into the plastic bags and the buyers advised to keep their purchase cool. “It’s is a must-do.” Waste shells and fouling materials are collected and binned for later disposal at sea. However, Adam says fishermen often drop by to get a free bag of berley. “The fish love it and catches are usually good with it.” Transport and Marketing Although the main harvest season runs from Christmas to Easter, product can be supplied for much of the year. The mussels spawn out in the cold water months (August, September and October), a little later than Tasmanian or Victorian mussels due to Eden’s slightly warmer waters. “Our best year was in 1999/2000 when we did 72 tonnes,” Adam recalls. “We reckon we grow the fastest mussels in the world. We catch the spat on one of our rafts and after three months thin them by taking out every second

The rafts can hold many mussel drop ropes. Photo courtesy of Mike Bamford.

FARM PROFILE

rope. These are transferred to the long lines where they just go bang. In the spring with an increase in water temperatures of over 16°C they grow very fast. In less than 10 months they can reach 7 to 8cm.” The majority of the Bamford’s harvest is sold within the region, south west to Lakes Entrance, west to Canberra and the snowfields of Victoria and southern NSW, and north up to coast to Bega. “We get $6/kg farm gate plus we have to add the cost of the box and freight,” Mike says. “A number of customers we have been supplying for years.” For many years Mike and another grower (Andrew Harvey at Jervis Bay) shared the Sydney Fish Market. “Over 15 years ago we developed the high quality restaurant mussel – two dozen to the kilo (8cm long, approx 42g). Now many other growers have improved their products to take some of the market share. For example, Spring Bay Seafoods (Triabunna, Tasmania) are doing around 15 tonnes a week, and a few other growers are getting bigger. So there are a lot more mus-

sels at the SFM. Still the prices are okay. We were also finalists in the aquaculture section of the SFM Awards in 1999, 2001 and 2003.” Mike is also happy with the improved services offered by the Sydney Fish Market. “They have really changed their profile and now offer as a contact to solicit customers. This can be either through the SFM’s website (www.sydneyfishmarket.com.au) or on the auction floor. They also handle direct sales to a number of the retail outlets. It’s a contact service that only costs a percentage of the total price and they send us one cheque for a number of sales. We send the mussels with ice in SFM crates and they arrive in the evening. The SFM re-ices the product, takes care of security overnight and during the day, allow the buyers to pick up their designated boxes next day and get the payments and all that. It works out that we get around $6/kg delivered.” He’s now very confident of a successful mussel farming industry at Eden. “Someone is going to make a lot of money out there. With the new area we

could easily do up to 100 tonnes. There would even be plenty of smaller mussels to set up a secondary industry based on pickled meats. “But it won’t be me. Poor health is making me spend less time on the farm. I’m looking to get out and Adam doesn’t want to run the business even though he’s a good mussel grower. He likes the farming side, the boats and all that outdoor stuff but not the business side of things. We’re looking for a buyer now.” By Dos O’Sullivan For more information on mussel farming contact Mike Bamford, Eden Mussels, 35 Cocora St, Eden 2551, Tel: 02 6496-1116, fax: 02 6496-3412. OR Chris Boynton, NSW Mussel Growers Association, Tel/fax: 02 6495-6988. For information on the Visual Impact Assessment contact Terry O’Hanlon, O’Hanlon Design, Tel: 02 9816-5883, Email: qoh@qoh.net.au For government information see www.fisheries.nsw.gov.au/aquaculture/ whatsnew

Austasia Aquaculture | August/September 2005 15

FARM PROFILE

Marine Harvest, barramundi farming the Bathurst Island way

86m circumference plastic circle with an external preditor net (white), jump net (black), steel net or splash zone (intertidal zone) and walkway system. Photo courtesy of David Silva.

One of only two marine-based sea-cage operations for barramundi, Marine Harvest is well on track to becoming the largest producer of barramundi in Australia. Barra Base is Marine Harvestâ&#x20AC;&#x2122;s barramundi (Lates calcarifer) facility located at Port Hurd in the Tiwi Islands, 60 nautical miles north of Darwin in the Northern Territory. Established as an initiative between the Tiwi people and Marine Harvest, the environment has proven to be exceptional for the large

scale culture of Australiaâ&#x20AC;&#x2122;s premier sport and table fish. The facility, the first of its kind undertaken in the Northern Territory, currently consists of one Canadiandesigned Wave Master facility incorporating twelve 24m x 24m x 9m deep cages plus seven 86m (inside circum-

16 Austasia Aquaculture | August/September 2005

ference) and four 48m plastic cages (the local description for the Polar Cirkel-type cages). The establishment of a suitable mooring system will see the addition of a further five 86m and two 48m Polar Cirkel in 2005, allowing the Marine Harvest Barramundi Seafarm to produce a dependable export

FARM PROFILE

quality supply of large 3kg to 4kg barramundi on a year round basis. The first intake of just 3,0000 juvenile fish (avg 75mm, avg 5.9g) was undertaken in May 2001. Despite setbacks caused by several cyclones, numerous attacks from crocodiles and just a few sharks, Barra Base will harvest 1,100 tonnes of 3kg product plus 100 tonnes of plates (300-400g) in the 2005 calendar year – more than that produced by the commercial fishery in the 2004 season. This places the farm at the forefront of barramundi production. Growing Environment Marine Harvest’s facility is situated in a moderately deep bay on the northwest end of Bathurst Island. The mouth of Port Hurd faces the west and is protected by extensive offshore sandbars preventing any significant wave action from penetrating far into the system. Since the farm’s inception in 2001 four tropical cyclones – including Cyclone Ingrid (March 2005) – have passed through the area causing only slight damage to the farm. The facility is shore-based with cages just a short two minute boat drive from the jetty. During the dry (winter months) season prevailing winds are easterly, whilst westerly winds dominate the wet (summer months) or monsoon season. Generally water temperatures range from a low of 25°C in July through to a high of 32°C in November. Historically this allows growth for nine months of the year, the months from July through

Proud silver sponso r of Prawn and Barramundi Conference

Austasia Aquaculture | August/September 2005 17

FARM PROFILE

to September see little increase in fish biomass. Tidal movement varies: as little as 2cm movement during the neap tides but up to 760cm in the spring tides. Associated with the bigger tides are strong tidal currents, equal to 3 to 4 knots or 170cm/sec. During the spring tides dissolved oxygen measures 80 to 90% saturation (5 to 6 ppm); however neap tides produce oxygen readings as low as 25% (1.5 ppm). During periods of low tidal flow, liquid oxygen is introduced to the nursery pens to ensure maximum survival of juvenile fish and the larger fish are not fed. During spring tides the water is also very turbid with visibility less than 1520cm. But neap tide days can see visibility of 5 to 6 meters so all diving operations revolve around the neap cycle.

The bar grader used to sort fish. The larger fish travel down the top side whilst the smaller fish go under the bar. Workers are Neville Johnson (left) and Allen Stevens. Purpose built barge the Bushmanused for fed and mooring work on the farm which was named after a local Tiwi traditional owner. Ty Bannister is the skipper. Aerial view of the farm facing west to Cape Helvetious. Photo shows the Wave Master system with two plastic cages along side into which fish are being graded. The nursery cage system and the main grow out can be seen at the top of photo. Aerial view of the Marine Harvest shore based accomodation facing west. Photographs courtesy of David Silva.

New Cage Technologies March 2004 saw an exciting new phase in the farmâ&#x20AC;&#x2122;s development with the construction of the first plastic cages to be used in NTâ&#x20AC;&#x2122;s aquaculture industry. Working closely with Tasmanian company Plastic Fabrications, seven 86 meter circumference (built using rings of 400mm diameter heavy walled HDPE

Cumminscorp Limited believes to have developed the most advanced portable Recirculating Aquaculture System (RAS) in the world. The systems incorporate revolutionary new techniques and technologies to deliver the most efficient, cost effective, environmentally sound and climatically controlled portable fish farms. RAS will provide farmers with an economical and environmentally friendly alternative form of high yielding seafood production.

1300 367 172 www.cumminscorp.com.au

18 Austasia Aquaculture | August/September 2005

FARM PROFILE

pipe) and four 48 meter (280mm diameter heavy walled HDPE pipe) cages have been put into production. Two 110mm wide walkways are made from fibreglass mesh panels and, due to the intense sun, handrails are finished in white instead of the more traditional black. To provide added integrity all stanchions are strengthened above standard requirements to compensate for the extremely large tidal variations encountered in the area. All the plastic cages at Barra Base are now fitted with One Steel Marine Mesh nets, as farm history showed fibre nets were not suited for growing fish in this particular area. The original metal nets supplied for the Wave Master system were 25mm bar x 2.6mm thickness wire. However, due to problems associated with corrosion, predation and net integrity, all of the new nets are 32mm bar or x 3.2mm wire thickness. Nets are hung on the square from the inside collar of the plastic cages with a 5mm head wire and a 7.3mm wire passed through the top knuckle and two tonne straps spaced at 70cm intervals. The nets are attached to the straps with 3.25 tonne tested shackles. Net integrity is assured by overlapping each section of net and by adding two wire spirals/seam. To prevent corrosion, sixteen anodes are added to each cage system. This equates to one anode per panel and seems to provide adequate in corrosion prevention. The benefits of installing the Marine Mesh at the farm include: • elimination of fish losses from direct kills from predation and lack of water flow during net bagging, as well as loss of escapees through predator created holes; • creation of a safer working environment, and • a significant decrease in labour costs due to the elimination of net changes. Due to its weight (4-5 tonnes) Marine Mesh is self-weighting eliminating the need to add weights allowing each net to hold its shape even in the strongest tides. Finally, the decrease in biofouling associated with the steel mesh means fish stocks are healthier, decreasing the growout periods from 21 to 18 months for a three kilogram fish.

Stock management All fingerling supplied to the farm are spawned by the NT Government’s Darwin Aquaculture Centre facility at Channel Island. All fish are treated for Vibrio sp. and histological examinations are performed on 100 randomly selected fish before they leave the hatchery. At present batches of 100,000 plus fingerlings (weight range 10.0 to 53.58g, length 95 to 189mm) are transported to the farm via a converted milk tanker aboard the local barge service that operates in the area. On the farm all the fish are fed Skretting’s Nova ME grower pellet in 4mm, 6mm, 9mm and 11mm size increments. The fish in the nursery are fed twice daily whilst grow out fish are fed just the once per day. Auger style Sterner Feeders compliment hand feeding at the nursery stage whilst larger fish are fed using a water canon (in-house design). This is located either on a workboat or lifted onto the walkways. The 700kg capacity feed hopper is filled from 500kg bags. The fish are fed for a minimum of 40 minutes per cage per day. Grading of the juvenile fish occurs at 200g and then later at 12 to 13 months (average weight 1,800g), with stocking densities of 38kg/m3 being the upper limit for optimum growth. However work carried out at Barra Base indicates that growth of barramundi is not severely hampered when stocking densities are 50kg/m3, though this in not recommended as there can be losses from increased stress and disease.

Key Performance Indicators (KPIs) To allow inter-farm comparisons, each AAM farm profile details a number of key performance indicators for different aquaculture systems. Except for the comments under ‘Key Management Decisions’ which are prepared by Dos, the information has been supplied by the farmer: • Key Management Decisions include: – Use of self weighting metal mesh nets to overcome predation and net bagging problems – Use of different cage sizes to allow more management options for fish transfers – Production of two different sized of fish for the market – Interaction with local stakeholders (Tiwi People) to ensure production methods are acceptable – Plans for significant expansion, particularly with respect to the processing plant. • Culture System utilised: floating sea cages with steel mesh nets. • Growth rate (from stocking to market): <18 months (10g to 3,000g,) • Survival rate: not released • Av. stocking density: 38kg/m3 • Annual harvest: 1,300 tonnes (predicted for 2005) • Production rate: still increasing • Water use: not applicable for cage operation • Power use: not applicable for cage operation • FCR: 1.3:1 (number of kg of food to produce 1kg stock) • Sale price: $8.50/kg (3 kg fish) farm gate

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AQUATIC HEALTH PROFESSIONALS • Disease diagnosis & management – all species • Sole agent for AQUI-S NZ, Syndel Ltd & Aquafauna Bio-Marine Inc. • APVMA registered anaesthetics & spawning products • Feed additive – Beta Glucans • Hatchery diets & Brine shrimp Dr Stephen B. Pyecroft BVSc (Hons)

Dr Darryl A. Hudson BAppSc PhD

29 Lincoln Street Wilston, Brisbane QLD, Australia 4051 Phone: 07 3830 5039 Mobile: 0409 727 853 Fax: 07 3352 6689 Website: www.adsi.com.au Email: dhudson@hypermax.net.au Austasia Aquaculture | August/September 2005 19

FARM PROFILE

tures of the fish is checked every 4 hours to ensure it stays below 4°C. The ice slurry is regularly drained and bins are topped up with fresh crushed ice. Tuesdays are the harvest days so the fish arrive in Darwin on Wednesdays for packing (for refrigerated transport) and a Friday sale, primarily at the Melbourne and Sydney fish markets. Up until June this year, only 3kg whole fish were sold but since then one kilo whole fish have also been marketed. Future plans include smoked product as well as cryovac portions.

Harvested barra being iced down once they are in the fish bins on the Tiwi Trader.The employees (from left) are Peter Bader, Ben Walsh and Nick Westley. The photo also shows the harvest cage and the de-water machine which prevents warm cage water from entering the ice slurry.

Fish are kept at the farm for 18 to 21 months before harvest. Typically, cumulative FCR’s at harvest is 1.1-1.5; recently it has been averaging 1.3. All fish transfers are undertaken during neap tides. The plastic cages are moved together ensuring fish transfer distances are as short as possible. Crowd nets are used and aeration is added at 6l/sec with up to 5 Point-Four air bars. Fish under 2kg are transferred between cages with a Silkstream (8” intake) fish pump for fish; fish over 2kg use a Tansvec (10’ intake). The fish are counted with an Aquasmart counter (accuracy is rated at approx. 95% +/- 1.5%).

A 35m barge the Tiwi Trader is used for the harvesting of the market size fish. The initial crowding with seine nets is undertake in the same manner as with fish transfers. Harvesting of 3kg+ fish is undertaken with the Transvec fish pump straight into an ice slurry at a rate of 130-140 per 500L bin and then iced down to less than 4°C within 2 hours to ensure a maximum shelf life of 21 days. The Tiwi Trader takes around 12 to 15 hours (depending on weather and tides) to transfer the harvested fish to the processing plant in Darwin. During this time the internal flesh tempera-

The Future 2005 will be a huge year for Marine Harvest’s NT team. Plans to add another five 86 meter and two 48 meter cages to the farm will see the farm’s output increase to 3,000 tones by 2006, making it the largest single producer of farmed Barramundi in Australia and confirm its place as an industry leader. The Wavemaster system is being phased out of production in preference to the plastic cages due to corrosion issues in these tropical conditions. Work is currently being undertaken at several new sites on the Tiwi Islands and in the Bynoe Harbour region to determine their suitability for offshore barramundi cultivation. At present four sites are being tested for tidal surge and bottom conditions and, if successful, it is hoped that Marine Harvest will be granted licenses to start these farms toward the end of 2005. The addition of an extra farm on the Tiwi Islands will be a financial windfall for the Tiwi people allowing them to consolidate their financial independence as well as providing employment to local residents. Finally Marine Harvest, in conjunction with several partners, has begun constructing the Territory’s first purpose-built fish processing facility, underlining the company’s commitment to the marine industry in the Top End. By Peter Bader For more information contact Peter Bader, Marine Harvest, PO Box 41583, Casuarina NT 0811. Tel: 08 8978-3987, Fax: 08 8978-3793, Email: tripletail03@yahoo.com.au

20 Austasia Aquaculture | August/September 2005

FARM PROFILE

NSW Native Fish Hatchery – fingerlings by the millions

Using breeding techniques initiated during the late John Lake’s research into the biology of inland fish species in the 1960s – and completed by Stuart Rowland in the late 1970s – the NSW Fisheries Centre at Narrandera has researched and developed most of the techniques used in commercial warmwater aquaculture today. Primarily a research station vital to improving the recovery of native fish populations in inland rivers, such as carp control, fish ladders, fish population monitoring and the recovery of a number of threatened species, the Centre has a visitors display and operates a hatchery breeding native angling species for stocking freshwater impoundments and re-stocking the endangered trout cod in selected habitat. John Lake’s contribution has been recognized in the name of the visitors display area: the John Lake Centre. In aquaculture circles the Centre is best known for Stuart Rowland’s work on breeding techniques for the com-

mercial native fish species Murray cod (Maccullochella peelii peelii), silver perch (Bidyanus bidyanus), golden perch (Macquaria ambigua) and, to a lesser extent, eel-tailed catfish (Tandanus tandanus). The first three species, along with the tropical barramundi, make up the bulk of the warmwater fish produced in Australia. When Stuart moved up to Grafton in 1982/83 to work on another endangered species, the eastern cod (Maccullochella ikei), Stephen Thurstan was appointed Hatchery Manager. Since commencing the breeding program the Narrandera Fisheries Centre has directly enhanced the state’s fish stocks in the order of 29,818,476 fish (figures to 2004). The benefits from this program can be seen in sustainable angling stocks in many of NSW’s water impoundments. Of this total 712,020 have been the endangered trout cod (Maccullochella macquariensis). 2,965,928 Murray cod, 18,886,630 golden perch, 7,224,630 silver perch and 29,832 cat-

Main pic: Murray cod larvae waiting to stocked out in fertilized plankton ponds. Above: Steve is holding the large fine meshed shrimp net used to clear clam and fairy shrimp from the ponds should the hydrated lime treatment fail. Two people can manage this operation.

Austasia Aquaculture | August/September 2005 21

FARM PROFILE

fish have also been produced. Catfish breeding ceased in 1977/78. The warmwater fish breeding area of the Centre consists of 25 broodstock ponds, 11 plankton production ponds and one of the most extensive undercover hatchery facilities for warmwater finfish in Australia. The hatchery is supplied from bore water and the ponds are filled from the nearby Murrumbidgee River. Murray cod and silver and golden perch are produced for recreational stocking. Average production is two million fish a year. Back in the late 1980’s production was peaking at around 600,000. Four new plankton ponds were added and production climbed to 1.2 million tails in the 90/91 season.

Steve with black drum used as a hide in the cod ponds when the breeding drums aren’t being used in the broodstock ponds.

A sample of the shrimp that cause so much concern at the NFC.

Clam and fairy shrimp In 1988/89 clam and fairy shrimp invaded the ponds with the incoming water from the Murrumbidgee. Once established, the shrimp become the physically dominant algal filter feeders. Within a week of filling a pond the shrimp are larger than the fish larvae stocked. The fairy shrimp reach 50mm and the clam shrimp 8mm. They then create a massive biomass that suppresses production of the beneficial rotifers, copepods and daphnia. The clam shrimp also generate turbidity that reduces phytoplankton production, which in turn leads to lower diurnal DO levels. Fish survival growth and final biomass was reduced by an aver-

age of 80% in ponds with shrimp. Within a few years all the rearing ponds were infected with large numbers of resting stage cysts, either blown in or deposited by adults. Control measures that did not impact fish productivity were not available from the limited amount of literature available. A drain and refill program was tested that would hatch the shrimp cysts in the dry pond and flush them out before they had time to lay down another batch of cysts. This had limited success as the shrimp have a very efficient breeding process, as would be expected of an animal that evolved in a region with a harsh and unreliable climate like inland Aus-

tralia. The cysts have a tough shell and are buried in the pond sediment. Only about a third of them hatch at the initial flooding so the remainder are ready for the next opportunity to propagate. “Even cleaning out a pond didn’t work,” says Steve. “The cysts are very small. We’d scrape out one pond and get only one good plankton bloom as the remaining shrimp would lay down enough eggs to stuff up the next filling. Cysts were blown into clean ponds from dry ponds. It only takes a couple of hundred and you’re back where you started from.” He points out that these shrimp are pests in rearing ponds around the US where they have had lit-

FIBREGLASS AQUACULTURE TANKS * Fish transporters * Larval Rearing * Spawning * Parabolic * Brine Shrimp * Settling and Storage For further information and a brochure, contact:

SUPERIOR FIBREGLASS GPO Box 7841, Cairns QLD 4870 Phone: (07) 4035 1884 Mobile: 0409 794 326 Fax: (07) 4035 5755 22 Austasia Aquaculture | August/September 2005

The egg screens are attached to this hexagonal Murray Cod spawning drum frame, which in turn is inserted into the nesting drums submerged in the breeding ponds.

FARM PROFILE

Mark Stimson and Peter Fraser checking samples taken from the fry rearing ponds under the microscope

Plankton production is crucial to the success of a breeding season. These plankton nets are in continual use.

tle success in controlling them. One research paper suggested that carp eat the small shrimp so this too was given a go. But it had no impact on shrimp numbers and the carp did their own share of damage to the pond bottoms and banks as they rummaged for food. It wasn’t until 19997/98 with the introduction of a liming and seine-netting regime that the adverse impact of the shrimp was reversed. By introducing hydrated lime (calcium hydroxide) into a full pond the pH is raised sufficiently to kill off the nauplii of the shrimp. If the pH fails to reach lethal levels a fine meshed net is used to harvest as many as they can, using paddlewheel aerators to push them against the net. In 2005 low doses of copper sulphate were also effective in controlling shrimp nauplii at low pH’s. The normal routine is to flood a fertilized pond. The flooding triggers a hatch of the shrimp eggs. After three days the phytoplankton bloom is driving pH levels to high nines and low 10s. It doesn’t take much calcium hydroxide to jump the pH up over 11. The shrimp nauplii can handle pHs of 10 but not the sudden jump to >11. It kills off a lot of plankton at the same time, but there is no toxic chemical residue, only an addition of calcium, hydrogen and oxygen to the pond.

Within a week or two the pH begins to come down and normal plankton blooms recommence. Although the control measures are effective, Steve feels if they didn’t have clam and fairy shrimp on the station they would be breeding three million native warmwater fish a year.

Trout cod The breeding techniques for trout cod are similar to those used on Murray cod before in-pond nesting boxes were adopted as the preferred method of collecting eggs for incubation. The broodstock are inspected when the water temperature reaches 16°C. After it has been established that the female’s eggs are mature, the females are injected with 1,600 i.u.; the males less. The injected fish are held at 20°C during ovulation, which takes 51.5 hours. The males and females are stripped by hand. Fertilized eggs are then poured onto screens and incubated at 20°C for 8-10 days. After 9 days the larvae have exhausted their yoke sacks and are ready to feed. For 3-10 days they are fed atremia before being stocked in freshly flooded plankton ponds. After 6-8 weeks they are harvested ready to be released. Steve has found that hatch rates are better with the trout cod than with the Murray cod when using the hormone induced method. An 800g female can be mature, but the egg count is too low to be economical. So broodstock need ideally to be well over

Austasia Aquaculture | August/September 2005 23

FARM PROFILE

Mark and Stephen syphoning decapsulated atremia cysts.

A shot of the main floor of the hatchery at Narrandera.

a kilo. A 1.5kg female will have 5,000 eggs, a 5kg female about 30,000 eggs. When it comes to trout cod, the emphasis is on re-establishing them including such issues as habitat restoration, environmental flows and fish ladders. “They weren’t identified as a separate species until the mid seventies,” Steve explains. “By then they’d almost disappeared from the river systems where they used to occur, except for a good population below Yarrawonga (weir). There was no scientific, let alone anecdotal, evidence on why they’d disappeared. “A number of factors are likely to have played a part. The most likely

cause for their decline, as for most of the natives, are the significant changes (deterioration) to the river habitats. Cold water pollution, de-snagging, siltation, changed flow regimes, less floods, introduced species, introduced diseases, and angling pressure could have all played a major role. It’s most likely that they haven’t done well with the cold water pollution from the big dams and the changing of flows. There’s some part of their biology that hasn’t adapted as well to the changes as the other native fish. Until we work that out and have good self supporting populations the species is still endangered,” he adds.

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Conditioning perch females For a number of years the Narrandera hatchery has been conditioning golden perch in 5,000L tanks, advancing breeding times by up to four weeks. In the confined space of the tanks the fish become quite tame and can be hand fed yabbies and pieces of carp. Steve says it’s also handy to have broodstock on hand rather than have to drain a whole brood pond and have to inject every fish in pond because they were so stressed they’re likely to resorb their eggs. In the tanks, the fish can be anaesthetized, the eggs inspected, and if not ready, they can be returned to the tank without them knowing much about what had happened to them. Silver perch respond in the same way to conditioning in tanks. However, where spent golden perch can be returned to the tank, spent silvers tend to be aggressive and losses became unsustainable. Steve has got around this by putting the spent silvers out into a pond until late summer before they are brought in for over wintering and conditioning in tanks. Although there’s been some experimentation with adjusting daylight hours by covering the tanks, it’s been found that just gradually warming the water has been enough to build up the gonads ahead of seasonal conditions.

FARM PROFILE

of copper sulphate per 3ML has been used as a control measure. With the lime treatment for clam and fairy shrimp the carbonate hardness levels are high, in the vicinity of 200ppm to 300ppm. This can promote filamentous algae in ponds.

These egg laden screens are taken from the frames set inside the egg collection drums. They are incubated in the 500L tanks.

The hatchery is restricted by the fry ponds’ capacity to produce plankton in the colder conditions and a month is as far forward as Steve has been confident to advance the spawning date without compromising survival numbers. He also points out that fish from the tanks are better conditioned and produce better eggs than the fish in the ponds with access to natural live food. Survival is enhanced by feeding artemia to the larvae while plankton production is developed to sustainable levels. Held at 100,000 to 200,000 larvae to a 1,000L tank, this may take a week or two. Swim bladder inflation is a critical phase where the tanks need to be clean of any oil film and appropriately lit.

they spawn over six to seven weeks so you’ve got eggs at all different stages but you finish up with a helluva lot more than you would with the hormone induced breeding.” Double spawnings also occur. “Broodstock ponds with three pair of fish are producing six spawnings. We always replace the drums now. The second spawnings are almost as good as the first. This has been a big bonus to our production.” One of the biggest problems in the rearing ponds is filamentous algae, particularly in a cool season. Aquatic Blue (a shading dye) and, more recently, 1kg

Silvers Stocking of silvers in impoundments has had mixed results. Windermere and Glenbawn and many others have produced very good angling, but Steve hasn’t heard of anyone catching one at Blowering Dam, where 500,000 have been released over the years. Steve doesn’t know why these differences occur. He feels it could be redfin predation, lack of macrophytes or anglers aren’t fishing for them specifically. The Narrandera Fisheries Centre is one of NSW Fisheries success stories. It has provided angling for the recreational community, a base for saving an endangered species and developed breeding technology for the warmwater aquaculture industry. Most importantly to the wider community, it continues to do vital research to help better manage the rivers for fish and helps educate the public with the John Lake Centre on important issues concerning our inland rivers. By John Mosig Stephen Thurstan can be contacted by phone on (02) 6959 9036, or by email on thurstas@fisheries.nsw.gov.au

Murray cod The NFC pioneered hormoneinduced breeding of Murray cod. But with the rise in the price of hormones and development of in-pond egg collection from breeding boxes it has changed to collecting naturally spawned eggs. Hatch rates went up from 40% to 50% for the hormone induced eggs to an average of 90% with natural spawning; some batches going as high as 99%. “It has turned out to be cheaper, low-tech and more efficient,” Steve says. “The problem with it is that

Austasia Aquaculture | August/September 2005 25

FARM PROFILE

Rice and yabbies – the perfect companions Carl Reinehr’s lifetime with yabbies began with Tim Dawes and the Victorian Yabby Company in 1984 at Carrum Downs in Melbourne’s south east. The focus was on intensive methods in those days. Twenty years on and experience has dicated a complete turnaround in the way he produces a crop. His latest operation grows is low-input, extensive aquaculture based on using the water twice – firstly for yabbie and then on an agricultural crop. Carl and wife Penny moved to a 320ha rice block with a 600ML water right in 1998. Pumping direct from the Murray River they are also able to collect off allocation water – usually available early spring direct from the river – adding as much as a further 150ML. The farm is 10 minutes north of Moama/Echuca, itself just two hours by car from Melbourne. The method Disillusionment with methods founded on grain-based diets took Carl

to the US to investigate farming methods for the 20,000 tonne a year crawfish (red swamp crayfish - Procambarus clarkii) crop. He found them growing in a rich rain of detritus from rice stubble. Here that’s not possible – the yabby’s growing cycle coincides with that of rice – but Carl’s implemented an antipodean solution: he irrigates a crop of rice to feed yabbies before moving the water onto other summer crops as and when they need it. One of the problems he saw in the old methods was the outlay. “I couldn’t justify throwing pellets into a pond to grow yabbies,” he says. “The cost of starting a rice crop is $800/ha including seeding, spraying and fertilizing. That will give us about 16t/ha of feed a year. Once the rice is established the only costs are watering and harvesting, and we’re watering anyway as part of the normal farming practices.” The farm works on a 4:1 ratio: four hectares of agriculture to 1 ha of aquaculture. The agricultural crops vary

A typical yabby pond showing the harvesting laneway cut intro it. This pond is coming up for its first full summer of production.

with market demands but the most rewarding to date have been maize and pasture. With the ground being slightly acid, under normal circumstances it would require application 2.5t/ha of agriculture ground limestone (AGL) every 3-5 years. However the integrated operation renders that unnecessary because the soft Murray water is hardened up with AGL – by pouring it into the bubbler distributing the water – for the yabby ponds each year. Yabbies need the extra calcium. The farm Farm development is still work in progress but this summer Carl and Penny will have the 20ha of rice sewed last year plus a further 10ha that’ll be put down to rice in the spring. Once the first stage of development is complete there will be 20ha going in every spring, with 20ha already in production and another 20ha in fallow. Each rice/yabby pond is around 3ha, rectangular and can hold a water depth of 500mm, enough to keep the rice growing and shedding leaf. Six hectare ponds were trialled but water exchange became problematical. At 3ha the ponds hold 15ML of water and Carl can exchange 20% of that – 3-4 ponds at a time – in a working day. Each one will probably have its volume exchanged 6-7 times over the summer. That’s 100ML for each pond. Carl keeps an eye on the behaviour and growth of the yabbies as an indicator of how often the ponds need a flush of water through them. As the pond water tends to clear, a water exchange has the added benefit of making the water around the rice turbid, camouflaging the yabbies. Oxygen In a system that’s not only growing yabbies but also producing detritus, water exchange ensures maintenance of dissolved oxygen (DO) levels at reason-

26 Austasia Aquaculture | August/September 2005

FARM PROFILE

A yabby pond at the end of its life cycle. Note the gaps in the crop and the intrusion of cumbungi. This intrusion is managed during the fallowing period.

able levels. As it grows the rice does release oxygen into the water through the roots but it’s not a lot. And the yabbies can climb up the rice stems to breathe oxygen from the air should levels in the ponds run too low. Conditions are also ideal for daphnia production and the yabbies, particularly the juveniles, can feed at all levels of the water column by climbing the stems. While it sounds all ‘beer and skittles’ Carl notes that you have to know what you’re doing. “If there’s too much organic matter in the ponds, and it’s breaking down quicker than the yabbies can eat it, they’ll go quite dark,” he says. “If the water clears up they’ll also go dark. “We use the water in the winter storage dam first but always keep it at least a third full. It’s stocked with yabbies. Whilst these can be used use to top up a pond if we feel numbers are down, the main benefit is that they keep the water turbid and we can use it to colour the ponds if we need to. “The three dimensional nature of the ponds allows the yabbies to seek the environment they want,” he adds. “If they want warm water they can come to the surface. If they want cooler water, they can go down to the bottom of the pond.” Predator control. Another now-unnecessary outlay is predator netting. The water is too deep for wading birds and the rice too thick

Looking over the rice paddies that will produce their yabby crop this season. Carl feels that if yields can be sustained economics levels, it will revolutionize how yabbies are produced in Australia.

for diving birds. Coupled with the water turbidity, these factors reduce losses from birds to near zero. Not that bird numbers are too high at the moment due to the drought. But that’s a temporary thing: Carl reckons that a good flood and the subsequent boost to fish breeding will soon see the birds flock back. Fish can be a problem. Mosquito fish

(Gambusia sp.) are prolific in the Murray Darling system and are present in some numbers when the ponds are first flooded. But populations tend to drop off as the yabby crop builds. It’s not clear if the yabbies prey on them (as some suggest) but given that numbers tend to grow again as the yabbies drop off at the end of a crop cycle, the theory may hold water.

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Austasia Aquaculture | August/September 2005 27

FARM PROFILE

Inlets are netted to minimise carp introductions with the short production cycle keeping their numbers to a manageable level. Production cycle The production cycle starts with a dry, laser-levelled pond in September which is fertilized with superphosphate and flooded once ground temperatures reach 17°C. Carl likes to get the rice in by the first week in October. It is sown at the rate of 130kg/ha and four days later sprayed for blood worms. Water levels are raised to promote plant growth. Come the second week in December, the paddy is drained down until the ground is dry enough to get a tractor onto it. Harvesting laneways are put with a slasher and the pond re-flooded (if the ground gets dry enough, the laneways will also be ploughed up, boosting water turbidity). Drying the ponds and removing the water’s ‘thermal blanket’ stresses the rice right at the time that it is setting seed. That, with any luck, makes the rice sterile, diverting its energy away from reproduction and back to growth (of more yabby fodder). When the ponds are refilled, nitrogen is applied to boost growth even further. If it’s not cold enough at time of draining to stress the plants sufficiently

to make them sterile, Carl will hope for a cold snap later on, sometime around 100 days after sowing. If it is not cold enough then so be it. The extra spread of nitrogen can also decrease seed volume by promoting vegetative growth at critical stages, the reverse of what you’d do if you were growing for seed rice. Once the ponds are reflooded and the rice capable of handling a water depth of 300mm, yabbies are stocked (usually by late December). Whilst seedstock selection is indiscriminate, Carl does aim to put at least 100kg/ha of mixed stock into a new pond. Yabbies come from other ponds: the undersized animals and berried females from a commercial harvest. “If we put in yabbies by Christmas at 30g to 40g we’ll have at least one breeding out of them and be harvesting the original seedstock by Easter at 50g to 60g,” he continues. “We tend not to harvest over winter and start again when the ponds start moving in the spring. We stock with nothing over 50g and can pull yabbies out that are over 200g. The lifetime of each pond depends on environmental factors and ranges from 18 months to 2 years. Once the yabbies start stunting and the rice is no longer producing enough food, the pond is closed down and the cycle started again after a spell between

28 Austasia Aquaculture | August/September 2005

Netting is placed over the pond inlets to minimize the intrusion ofaquatic predators.

crops. Carl says the yabbies do extremely well on fresh country. Back to basics Carl reckons his ‘back to basics’ model is one ideally suited to yabbies. “In the USA and China they’ve been successfully growing crawfish for some time. Yet we’ve basically ignored their management system with a species that is fairly closely related. Our research bodies have wasted large amounts of dollars on non-production research rather than on modifications of existing production models,” he contends. “It all comes back to simulating flood plain conditions. They’re a boom or bust animal and thrive on floods and dry spells. If you get the water and food conditions right it’s amazing how quickly they’ll grow. I believe our problem in the past has been that we’ve been too technical, too busy trying to out advanced aquaculture such as triploidy. We should be getting back to basics.” The ponds are either harvested and drained down before they go into their second winter or, if they’re going well, will stand over that winter and be harvested in the spring. Being literally no more than rice bays, they can be used to grow an agriculture crop during the fallow season.

FARM PROFILE

summer crop of maize or sorghum. The next rice crop won’t be put down to until the following spring. Fallowing breaks the cycle of any water borne pathogens and allows any aquatic predators – such as fish that may have slipped through the defences and tortoises that have taken up residence – to be cleaned out and the soil structure regenerated and aerated. And it is also a cumbungi (bullrush) control measure. Cumbungi are tough perennial plants that thrive in slowgrowing, nutrient rich irrigation channels and ponds, especially after three summers under water.

Feral pigs come into the fallowing rice paddies digging for dormant yabbies in the substrata.

That fallow can range from 18 to 24 months. If the pond is drained at the end of spring it will be fallowed over summer and used to grow a winter crop of wheat or barley before being brought back to rice in the second spring. If it’s drained in the autumn it will be fallowed over winter and used to grow a

Yields and economics Being still on the learning curve and suffering from the drought, Carl has still twice achieved yields of 2.5t/ha over a 12 month period from July to June. At the bottom end of the scale the worst yield they have had was 800kg/ha. These figures don’t include the short harvests at the opening or closing of a pond’s life cycle. With the farm back onto full water allocation, he’s hoping now to some regular seasons.

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The true beauty of this method though is the low cost. “The ponds are nothing but rice bays, and can be used as irrigation bays should we ever decide to go out of yabbies,” he says. “Therefore they have really cost us anything that we wouldn’t be spending anyway. The headlands may be more substantial – to carry a vehicle – but they’re only 5% more expensive than a check bank. All the water moving equipment and other farm gear we would have anyway. “The only extra layout is the yabby traps. Even the boat is the family river runabout.” Labour is negligible. Apart from normal crop observation the biggest input is labour at harvest time: a one man operation. No on farm purging is necessary as the yabbies are sold locally to a distributor. Carl estimates that it costs between $3,000 and $4,000/ha to run a yabby pond through the cycle. So even at $10/kg, the 800kg crop would be in front. However Carl sets his minimum acceptable production target at 1t/ha and is quietly confident that 2t/ha is consistently achievable under good

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FARM PROFILE

Rice is a perennial and will grow as long as conditions are right. Here Carl is inspecting the condition of the crop in mid winter.

management. “If we can do that, I think we’ve got something. There’s no point producing yabbies just for the sake of it. You’ve got to look at the economics of it all. A 20t crop would give a gross of $200,000 with production costs commensurate with normal farm outlays. To get the true picture you’ve then got to take account of the yields and costs of other (agricultural) crops produced on the farm plus the water use.” Marketing Yabby production, being either a feast or a famine, has always created a

marketing problem for yabby growers. Carl sees his job as a yabby producer but recognizes the need for a strong marketing presence in the industry. With this in mind he has joined forces with Greg Williams of Central Victorian Yabbies to set up Perricoota Yabbies. The company aims to take advantage of the vacuum left in the Victorian markets since the collapse of that state’s yabby industry under government regulatory and cost recovery levies. Having a professional marketing organization at his doorstep will enable Carl to concentrate on production in the knowledge that he’ll be able to sell them.

The future Based on his experience on this and his other previous yabby operations, Carl’s now of the opinion that this is the way of the future. “At this point of time my opinion is that yabbies can only develop as part of an integrated irrigation farm, where farm assets of water, land, machinery and labour are spread over many farming enterprises,” he says. “And this comes with a cost as irrigated farms are not cheap and need to be run accordingly. This is not an industry for aquaculture dreamers and hobbyist expecting to get rich on the back of yabbies.” The industry is, however, not restricted to registered rice growers. Wild rice is not a legislated crop and can be substituted for cultivated rice. With stable production, the markets can be developed with confidence; something that hasn’t been possible based on a farm dam harvest vulnerable to seasonal conditions. With everything to gain, and little to lose, the work being done on this southern NSW irrigation block could revolutionise the way yabbies are produced in this country. Carl feels the economics of production are right. Everything except the traps are part of the farm’s capital outlay. The labour input is minimal. If yields can be sustained at the levels Carl and Penny have achieved at “Saint Fort,” yabby production could yet become a major aquaculture sector with substantial export potential. By John Mosig

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30 Austasia Aquaculture | August/September 2005

Carl and Penny Reinehr can be contacted by phone on (03) 5483 8232, or by email on remelle@mcmedia.net.au

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FARM PROFILE

Saltas forges ahead With Tasmania’s Atlantic salmon industry predicted to produce 17,000 tonnes in 2005/06, Saltas’ role as a producer of top quality salmon smolt is becoming even more significant.

The OH&S concerns of the farm has led to the construction of a new walkway and stairs in the ongrowing area. Behind Dr Harry King are the sheds which allow for some of the photoperiod manipulation of the ongrowing stock.

Tasmania is well known for its production of top quality Atlantic salmon (Salmo salar). This has made Saltas (Salmon Enterprises of Tasmania) an essential company for this remarkable industry. Saltas is responsible for the production of approximately sixty percent of all Tasmanian Atlantic salmon smolt. Saltas originated as a joint venture between the Tasmanian government and the state’s Atlantic salmon farming industry in 1985 under the Salt-water Salmonid Act. At the time the government took a 51% shareholding

(reduced to 25% in 2001 /2002) and industry the remaining 49%. Smolts produced by the company are distributed between the shareholders (excluding the government) according to the percentage of shares held, with the sales cost set to just meet production costs. Saltas uses two sites in Tasmania’s Central Highlands. The original site established in the 1980s is near the small village of Wayatinah approximately one hundred and twenty kilometres north west of Hobart. When it became necessary in the early 1990s to

32 Austasia Aquaculture | August/September 2005

establish a second, that was set up in Florentine Valley just seven kilometres away. Both have been built to a very similar design although the Florentine site does boast a few improvements. Each is divided in two – hatchery and growout – with those sections operated very differently from one other. Whilst the ongrowing section is flow-through, the hatchery runs on a large scale recirculating system. “Both sites have concrete raceway systems designed for temporary broodstock holding during the spawning sea-

FARM PROFILE

son,” Harry King explains. “These have capacity to hold roughly two thousand 6kg fish. Each of the ten raceways on each site is twelve metres long, two metres wide and about one metre deep. We also have recirculating incubation systems for eggs and alevins on each site.” Using both upwellers and Californian trough systems, the company has capacity for approximately sixteen million green ova (usually around 5.56.0mm in diameter) or eight million alevins. “In the hatcheries we have recirculating tank systems which are used for the rearing of fry (0.2g to 5.0g) and some out-of-season smolt (5.0g to >100g) production. There are twelve tanks in each of the hatcheries. These tanks are five metres in diameter and have a volume of approximately twenty five cubic metres. These tank systems can hold either two million fry or two hundred and fifty thousand smolts.” The ongrowing (flow-through) area rears parr (5g to >100g) and smolts. It can hold up to two million parr or 1.2 million smolts. At Wayatinah the latest addition of

The walkway enables easy access to the middle of the tanks for mortality removal. The channel at the side allows for water to leave or enter the tank and also for fish movement between tanks with minimal handling.

the fully land-based broodstock growout system incorporates five large concrete tanks each 180 cubic metres in volume. This development was installed to increase the biosecurity of the hatchery so the brood fish no longer have to be taken off-site to grow before returning for stripping season. Harry says that this will also allow the

hatchery to initiate its intended selective breeding program. The system currently runs on a flow-through system but has been designed to permit later conversion to a recirculating system. There are also hopes of another broodstock growout facility to be developed at the Florentine site.

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Responsibilities will include: • Day-to-day husbandry of ova & fish (e.g., feeding, grading etc) • Operation of plant & equipment (e.g. pumps) • Monitoring & control of water quality (e.g., D.O., pH, ORP, NH4+) • Monitoring & reporting of stock performance

Resumes should be forward in confidence to: The Operations Manager, SALTAS, PO Box 1, Wayatinah, Tasmania 7140 E-Mail: admin@saltas.com.au

Austasia Aquaculture | August/September 2005 33

FARM PROFILE

Dr Harry King shows the upwellers (left) and tray systems (behind) in the incubation rooms. There are two rooms which are kept at different temperatures to ensure the eggs are ready at different times to supply farms all year round.

34 Austasia Aquaculture | August/September 2005

Water Quality With a maximum water demand of 800L/sec on each site, a constant supply of clean, cool water is paramount. Yet, as both farm sites are located in forested areas, there is often a significant amount of debris in the rivers. So each has intake screens (100mm bar gap) which exclude sticks and branches (especially during periods of high rainfall) that are checked and cleared daily to ensure constant water flow. The water is then passed through large drum screens (5mm mesh) providing the primary water filtration as it removes the larger particles (small twigs and leaves) from the water. Since initial development of the Wayatinah site, increased water demand and rising water temperatures have necessitated the development of a secondary water intake for summer months. Wayatinah lagoon, part of the

FARM PROFILE

Derwent catchment, is that secondary source tapped by submersible pumps capable of moving 200L/sec. After primary filtration the water can either be pumped into the hatchery area – where it undergoes substantial treatment – or sent to the ongrowing section; there it can be oxygenated using a BOC-designed ‘U tube’ system operating on a side-stream. As the hatchery water is used in both the egg incubation rooms and in the growing tanks it is essential that the water be maintained at a very high standard. Therefore substantial pretreatment is needed for these recirculating systems. “The Wayatinah site uses a strainer before the water reaches the filters and Florentine uses a wedge wire,” explains Harry. “The water then passes through the sand filters, which filter the water to about 10 to 15 µm. After that the water is ozonated to a redox level of 700mV for one hour. Then the water is passed through a carbon filter for ozone removal and once a redox reading of 300mV has been maintained for an hour the water is ready to be used.” Water is treated in 40m3 batches and used to periodically top-up the recirculating system holding sumps. Water already within the hatchery recirculation systems first goes through settling channels to facilitate rapid removal of suspended solids. Smaller solids (> 10-15 µm) are removed by mechanical filtration through the sand filters and then the pH is buffered by passing through cylinders which contain fluidised beds of Magnesium Hydride pellets. The extent of the pH buffering is adjusted manually on the basis of twice-daily pH readings. The

The new concrete broodstock holding system can hold sufficient broodstock to produce sufficient smolts for the industry.

Austasia Aquaculture | August/September 2005 35

FARM PROFILE

water is also passed through biological filtration and a side-stream is treated with ozone to eliminate dissolved organic waste and enhance the conversion of nitrite to nitrate. Oxygen can also be added to this side-stream to maintain DO levels at low stocking densities. A second side-steam is chilled to facilitate temperature control. Then the water is recirculated through the hatchery via UV treatment

units which ensure the destruction of any residual ozone. At higher stocking densities, the water can also undergo additional oxygenation using a pressurised column. “Each hatchery exchanges about ten percent of the total system volume per day,” Harry says. “This amounts to approximately 40m3 of water. Solid waste is removed from the effluent water and transferred into a septic tank.

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36 Austasia Aquaculture | August/September 2005

The water then goes to the settlement pond and then back in to the river.” With most of the farm computer monitored, an extensive alarm system is in place. This has made it possible for any problems after hours to be brought to the attention of a staff member who is then able to respond before any mortalities occur. Hatchery Production As Tasmania’s Atlantic salmon growers harvest year-round, smolt is needed from early April to late October. To meet this demand Saltas produce outof-season smolt, marine pre-smolt, presmolt and spring smolt. Accordingly, approximately one third of the on growing tanks are in sheds to allow for the use of photo-manipulation protocols. The production cycle starts in May with the stripping of broodstock. “Usually we use about 1,500 first year females (three years old and 5-6kg) and another four to five hundred repeat spawners (about 10kg each),” says Harry. “We also use about four to six hundred males but, as there is a reduced demand for mixed-sex fish,

FARM PROFILE

three to four hundred of these are sexmanipulated fish.” The stripping season generally starts in May but can vary a little from season to season. During stripping the females are anaesthetised and hand stripped by trained staff in the area known as the ‘stripping slab’ (next to the raceways where the broodstock are held and conditioned). Eggs are rinsed and mixed with milt in a factorial mating design, increasing the potential genetic diversity and perhaps the fertility rate as well. Fertilised eggs are left to harden before transfer from the stripping slab to egg incubation rooms. Fish that have been stripped are allowed to recover and are either kept on for the next stripping or released into land-locked lakes for the recreational fishery. The Inland Fisheries Commission organises the location and assists with the release of old broodstock. This year Saltas released over five thousand surplus broodstock. Incubation rooms are held at either 4 or 8°C to stagger the hatching times of the eggs. “The eggs are held in upwellers where they are incubated until they reach the eyed stage,” Harry

The concrete raceways are primarily used for broodstock holding during stripping times. The wire is used to crowd the broodstock to allow easier handling.

explains. “Then we shock the eggs gently by transferring them between a couple of containers. This can be enough to kill off the damaged or weak eggs so that they can be removed. After this the eggs are laid out either in the trough systems or in the upwellers which can be packed and modified for the hatching process. In the trays they are laid out on an artificial substrate, which

mimics the natural gravel that alevins would find in their natural environment. So when they hatch they hide amongst the substrate until they use up their yolk sack. At this stage they swim up to the surface for the first feeding.” In the 8°C incubation room, this stage is reached at about August; it takes another three months in the 4°C room. Fry are then transferred to the ongrow-

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Austasia Aquaculture | August/September 2005 37

FARM PROFILE

On the far right is the hatchery’s effluent tank which contains the solid effluent. The white tower is a liquid oxygen tower which is essential for the whole farm.

ing hatchery tanks and introduced to the Skretting Australia‘s Nutra ST range of ‘start feeds’. Although fed by an automatic feeding system, staff are required to do additional hand feeds to ensure that the fish are all being fed. Mortalities are removed on a daily basis. The fish remain in the hatchery until the 4°C fish reach the first feeding stage in

November. Then, at about three to five grams, they are transferred for ongrowing. Ongrowing Production On transfer to the ongrowing area the fish are placed in flow-through tanks supplied. Such tanks vary in size from the 44m3 tanks at Wayatinah to

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AQUACULTURE TANKS 38 Austasia Aquaculture | August/September 2005

the larger 66m3 ones at Florentine Valley. While the latter are larger, Wayatinah site has a more tanks (Wayatinah has 47 compared to Florentine with 32) so that the holding capacity at both is about the same. A number of these tanks at both locations are sited in large sheds to allow for photoperiod manipulation of out of season smolt. During ongrowing the fish are weight-checked fortnightly. When they start to become crowded in the tanks thinning occurs to ensure continuance of good growth rates and conditions. With a maximum stocking density of 45 fish/m3 the fish may be thinned a few times before they leave the farm. Automatic feeders that are checked and refilled daily dispense a commercial ration produced by Skretting. Further hand feeding does occur to check on the fish appetite. “We can feed up to fifty kilograms a day to the fish at maximum capacity,” says Harry. “The farm has a biological FCR of approximately 1:1.1, but economically it would be closer to 1:1.3 or 1.4 due to mortalities and culls.” Once the fish have reached the smolt stage, arrangements are made with the sea farms for delivery of the fish. The fish are transported in specially equipped trucks where dissolved oxygen levels and water temperatures are continuously monitored. The six 3m3 tanks on each truck can hold up to 1,500kg of fish. Fish Health Given the use of the natural water supply, most areas of the farm do see some of the endemic protozoa. “This doesn’t cause us many problems,” Harry says “since the part of the farm where the fish are particularly delicate is in the hatchery where the water is fully treated to remove any bugs in the water supply. However, we immersion vaccinate the fish during the summer prior to seawater transfer. The vaccination protects them against Vibrio in the sea.” Yersiniosis is the primary concern. “We can also have a problem with Yersinia ruckeri in the ongrowing areas. It is endemic to the area and there isn’t

FARM PROFILE

The walkway access to the broodstock tanks uses bouyant material which allows the walkway to slope and provides easier and safer access to tanks with a low volume.

yet a vaccine to protect fish against it. Staff are trained to look for any symptoms and if a case does occur the tank is medicated following bacteriological confirmation of the infection. We do have high hopes for that a vaccine will become commercially available soon to help eliminate this area of concern in future.” “The only other potential problem is with environmental gill disease, largely a secondary bacterial attack on the gills. The staff are aware of how the condition presents and we are able to respond rapidly with salt baths and Chloramine T.” Although there are no immediate plans for Saltas to expand production the company is uniquely placed, by virtue of its comprehensive suite of facilities and corporate structure, to

play a pivotal role in the industry’s fledgling selective breeding programme. In this regard, the significance of the support that the company has received over the years from its shareholders and in particular its key founding shareholder – the Tasmanian State Government – cannot be overstated. A strong emphasis on risk reduction and the maintenance of a strong R & D culture has seen the company develop as one of the world’s most sophisticated producers of Atlantic salmon smolts. By Andrina Fay with Dos O’Sullivan For more information contact Harry King, SALTAS, 289 Wayatinah Road, Wayatinah, Tasmania 7140. Phone: 03 6289-3280, Fax: 03 6289-3290, Email: harry_king@saltas.com.au

• Key Management Decisions for SALTAS include: – Development of a second site to increase production and spread risk – Second water intake for hatchery to ensure sufficient good quality water – Keeping broodstock on site to enhance biosecurity – Release of old broodfish for the recreational fishery – Use of recirculation technology with ozone disinfection for environmental and health management during early rearing – Maintenance of a strong R & D culture • Culture System utilised: freshwater recirculation hatchery and freshwater flow-through grow-out. • Growth rate (from fertilisation to sale): 11-18 months (egg to >100g) • Survival rate: 90% from hatch to sale size (however, 15-25% typically culled during production) • Av. stocking density: ca. 30-40 kg/m3 (range is <0.5 kg to >100kg in recirc. systems) • Annual production: approx. 3,200,000 smolts (approx. 350 tonnes) • Production rate: >700,000 per 1,000m3 (growout system volume) per year • Water use: Not Available • Power use: Not Available • Productivity: 150-200,000 smolts per Effective Fulltime Unit (240 days, 48wk x 40hr)

Austasia Aquaculture | August/September 2005 39

FARM PROFILE

Aussie bass and sea mullet from SE Qld hatchery

The water supply dam covers six acres and only requires two inches of rain to flood. This gives the hatchery access to large volumes of good quality water all year round.

A family-run business, the Sunland Fish Hatchery in southern Queensland has been advancing the culture of both the Australian Bass and the Sea Mullet. Using simple but effective culture methods, good quality 50mm fingerlings are sold for stocking farm dams and major water impoundments. The Sunland Fish Hatchery is located at Boreen Point – a coastal community near Noosa, some 150km north of Brisbane. This family business has been run by Gwen Gilson since the early 1980s; son Richard joined her in 1994. Originally Gwen and her husband John farmed gladioli on their property. A keen fisherman, Gwen's husband came home one day with fifty silver perch (Bidyanus bidyanus) to put in their 2ha water supply dam. “I wasn't

really impressed with these little fish,” Gwen recalls. “They looked somewhat like sardines and I can remember thinking that these fish weren't even fit to put on toast. Anyway we put them in the dam and forgot about them.” Fortunately the story didn’t end there. “It was about eighteen months later when my son Richard was given a fishing rod for Christmas. We went down to the dam to try it out. I didn't think for one minute we would catch anything

The fish are being stocked in to the Somerset Dam in Qld. Fish are moved using the transporter to reduce stress and mortalities.

40 Austasia Aquaculture | August/September 2005

but on the first cast we caught a fish. Not only that but it was a 1.5 kilogram silver perch that almost pulled my son in! From then we were hooked (excuse the pun) and we regularly went fishing in the dam. We had so much fun that we wanted to keep the dam stocked. Our only problem was that at that time there were no hatcheries in Queensland. All the silver perch stocks came from New South Wales. Since we had enjoyed the experience of fishing from our own stocked dam we realised that other people would too. This led us to start with aquaculture.” Although the couple decided to start with marron (Cherax tenuimanus) from Western Australia it wasn’t long before they progressed to finfish, namely silver perch. With luck they found that other people were very helpful with starting up their operation. “Jerry Cook and Len Green were both involved at that time with breeding finfish but more as a hobby,” says Gwen. “They helped us though with the basics and the first hints of what to do. The property we were on was perfect for growing gladioli. It had good soil and drainage but wasn't really that good for fish-

FARM PROFILE

These production ponds are located on the hatchery site. The dirt road that divides the ponds allows for transport vehicle access to all areas of the farm.

ponds. So we sold some of our land and bought some property further down the road. Everyone thought we had gone mad by selling good land and buying land that was all water and clay based. It was land no one wanted but it was perfect for growing fish.” Species Since that time the Sunland Fish Hatchery has continued to grow and develop. While still a small operation it has expanded to include some brackishwater fish. The main species that are bred on the farm at the moment are yellowbelly (Macquaria ambigua), silver perch and the Australian bass (Macquaria novemaculeata). There is also a limited stock of Mary River cod (Maccullochella peelii mariensis). One of the most exciting new additions to the hatchery has been

the sea mullet (Mugil cephalus). The farm’s primary focus is on the quality of the fish produced. “I think it's very important that you can always deliver what you promise. We really make it our aim to produce top quality fish which has meant that we have stayed a fairly small company. This way we are involved in every step of the process and we can monitor the fish and ponds directly.” The breeding of the Australian bass has been one of the biggest success stories for Gwen and Richard. Until their breakthroughs there had been no breeding of that fish in Queensland. The species is native to the Noosa River and had been placed in the endangered species list. It was only by chance that Gwen was given one as a pet. Catching her over the years Gwen realised she always had eggs

in winter – the opposite to yellowbelly and silver perch. Deciding to try and spawn them she phoned the Government Fish Hatchery at Port Stephens. After many failures the hatchery was suddenly full of fertile eggs which hatched extremely well in very large numbers. “Then I rang the Port Stephens Hatchery and informed them of the result,” Gwen remembers. “Steve Battaglene from the Hatchery was curious about the results and John Bourke from the Deception Bay Fisheries Research Station (Qld) was sent to verify the results. That’s how Sunland Fish Hatchery was recorded as the first hatchery in Queensland to breed the Australian Bass. “The people from the research station were really helpful and gave me a crash course on the feeding of saltwater fish,” she continues. “From there the breeding of the Australian Bass just

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FARM PROFILE

grew. But to think that it had started with a few fry, all of which I named all Henrietta (if one died it wouldn't be as upsetting!). Now there are good populations in all the big dams and impoundments so they shouldn’t be listed as an endangered species any longer.” That hasn't been Gwen's only success story either. Just last year (2004) Gwen and Richard were able to breed approximately one and a half million sea mullet, the first time this has been done in a private hatchery. “We did have problems with Fisheries to start with,” Gwen grimaces. “ I wasn’t allowed to sell them; they defined them as a new and intro-

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duced species. After several weeks I reluctantly had to destroy them because the head of Fisheries QLD would not allow them to be stocked in Wivenhoe Dam. Six weeks afterwards I was informed that Wivenhoe Dam could now be stocked.” Gwen’s found the breeding of the sea mullet most exciting. “When we first started I thought to myself that if I just got fertilised eggs I would be happy. But I managed to get one and a half million fish so I'm really excited about the potential for the future. It was a hard slog to start with. I watched several tanks of fish for over eighteen hours without a break so I could observe exactly what the habits and processes were. I even had to eat without looking at what I was eating so I wouldn't miss anything. But it's all paid off. I've been able to develop a system where I can tell what (fish) will spawn within about eight hours. This means that if one or more pairs aren’t going to work I can change them without wasting too much time waiting for something to happen. “Since we have been working here, and especially since we have been working on breeding the sea mullet, we have been very pleasantly surprised about supportive the professional fishermen have provided been. When we needed some broodstock for our first breeding trials we spoke to some fishermen on the beach and they happily provided us with some. It was really surprising to see what groups were providing the most support for a new aquaculture species.” Operations The farm incorporates two sites just twelve minutes drive away from each other. With a catchment is located in a mountainous region all rainfall runs into the dam. “It only takes two inches of rain for our dam to fill, so we have no problems with water availability,” Gwen explains. “That's why we chose this area for the farm. The ground is good and there is never a shortage of water. I think it's essential for a fish farm to have access to plenty of good quality water otherwise you can run into trouble.” One site contains all the fry growout ponds, the other has the hatchery sheds. Whilst permitted to work four-

42 Austasia Aquaculture | August/September 2005

teen hectares of ponds the farm’s current total of nine working ponds – varying in size from .5 acre to 1 acre – cover just under 5 ha. “We are hoping to expand this year,” Gwen says. “I would like to be able to have two or three more ponds to work with.” The ponds are all shaped to fit along the side of a slight hill. In the base of each pond is a cement raceway to assist in the harvest of the fish. Water is pumped into the ponds through a 200 micron filter and is gravity fed down through the system – it passes through another filter before it leaves. Both intake and the outflow are screened to ensure no stock is transferred between ponds. Water plants in the main water supply dam reduce the water’s nutrient load. “We try to keep the farm as natural as possible,” Gwen says. “We don’t use any chemicals and even the fertiliser we use for the ponds is mostly organic.” Indeed the water quality is of such a high standard that the Gilsons found minimal fluctuations over the years and eventually phased out routine water quality tests. The farm’s location also rules out problems with frost or large drops in temperature. “The water temperature falls to 13°C in winter and rises to 31°C in summer, just right for breeding so many types of fish. The only temperature control we do is in the hatchery where some of the broodstock prefer a cooler temperature to spawn and the babies need a warmer temperature.” Due to good management, low stocking densities kept low and siting in a zone where good breezes aid water circulation, supplemental aeration is also not required. The hatchery is the only part of the farm that uses salt water. This is all trucked in and once the breeding season is finished the left over water is filtered and kept for the new season. About twenty pairs of broodstock are kept for silver perch and yellowbelly. All other broodstock is wild-caught to maintain a high genetic diversity. As bass males can be used for more than the one season, it’s usually only the females that are wild-caught. By using such high quality broodstock the Gilsons are able to pick and chose

FARM PROFILE

The production ponds vary in size from a quarter of an acre to three quarters of an acre. The farm currently has nine working ponds with plans to expand with another, two or three ponds.

which fish to use. This provides a good quality product – fast growing and with different blood lines. The spawning season takes place between October and March. As her broodstock are conditioned for at least four months prior, Gwen is usually very confident about the results of her spawning. The broodstock are placed in 1,000 litre tanks in the hatchery. “We bought the tanks second hand. They were all fibreglass and needed some repair so we fixed them up and set them up as a simple recirculating system.” Each tank has its own simple filter where the water is run through prawn mesh and oyster shell and before its return to the tank. The fry spend 30-36 hours in the hatchery. The females are hormone induced to release their eggs. “This is the only time I believe in interfering with the fish,” Gwen continues. “I'll also interfere with some of the aggressive fish to stop the fighting. If I don't then I could end up with half dead fish and that isn't any help to the farm.” Once the eggs hatch (usually 36 hours) they are placed out into fertilised ponds which all contain a good volume of natural plankton. “The best fertiliser we use is supplied by our horses. By feeding the horses a good diet, especially lucerne, they produce a good fertiliser.” The ponds are usually stocked only lightly – thirty five thousand to an acre – to ensure good survival rates (generally 95-100%). Once in the ponds Gwen

has found that the less the fish are handled and interfered with the better the end product. So during the time the fish are in the ponds there is no grading, weight checks or even artificial feeding. “By letting them eat a natural diet, it makes for a very robust fish. We can send them out to dams knowing that they can survive and there won't be high mortality rates from transfer,” says Gwen. These fish are used to foraging in ponds for food and have no problems with disease making them a popular choice for dam stocking. The fish are kept in the ponds until they are about 50mm – usually this takes two months although cooler water temperatures can stretch it to three. “The ponds are managed so that when they have reached this size the feed is almost gone. The water then gets filtered back to the dam and the pond is dried out and left to dry before being filled and re-stocked.” The harvested fish are scooped by net out of the raceway and placed in a transport truck for return to the hatchery site. There the fish are purged for up to two days to ensure that they travel well and arrive at their destinations in good condition. The maximum time the fish stay in the shed is about a week with all sold to farmers for dam stocking or consigned in bulk for impoundment stocking. For a small farm with an annual harvest of just seven hundred thousand fish, the Sunland Fish Hatchery has made significant impact on the

Queensland Aquaculture Industry. Expansions are on the way to accommodate the exciting new production of sea mullet which Gwen predicts may end up as popular as the silver perch and Australian bass for stocking. By Andrina Fay with Dos O’Sullivan For more information contact Gwen Gilson, Sunland Fish Hatchery, Gilson Rd, Boreen Point, Qld 4565. Tel (07) 5485 3144, fax: (07) 5485 3266. email: sunland@microed.com.au

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Austasia Aquaculture | August/September 2005 43

FARM PROFILE

Tathra Oysters win more Sydney Royal Show awards Check lists are used so the judges can determine the oysters with the best characteristics. Photos courtesy of Royal Easter Show Fine Foods Awards.

Grown in probably the most pristine of any of the estuaries in NSW, Tathra Oysters have a fine reputation that’s growing as fast as its list of awards. The October-November 2000 issue of Austasia Aquaculture Magazine (Vol 14 Issue 5) featured Tathra Oysters. The story told how their culture racks were in Nelson Lake which was totally surrounded by the Mimosa Rocks National Park. The term ‘God’s country for oysters’ was used due to the special conditions in the Lake. The result are top quality Sydney rock oysters (Saccostrea glomerata). Owners Gary Rodely and Peter Holdsworth take great pride in the quality of their Sydney rocks believing that it has much to do with Nelson Lake’s unique and almost pristine growing conditions. “The Lake is connected to the sea by a series of winding channels bordered with dense mangrove forests,” explains Gary. “As the

mouth is always open, there is plenty of food for our oysters. Salinity levels are fairly constant except in very wet conditions, whilst the water temperature ranges from 12°C up to 23°C. Our main growing area is an elongated oval shape, about 1km long and 0.5km wide.” Gary also says that as the only oyster farm in the Lake, stocking densities and culture techniques can be adjusted to suit the environment. “We can move our oysters around without worrying about the activities of other farmers. We are introducing more plastic trays from Tooltech and moving away from sticks for growout. This infrastructure build-up will take a couple of years, but we can watch how things are going in the Lake.”

44 Austasia Aquaculture | August/September 2005

Award Winning Oysters All this helps to make Tathra Oysters probably the most prolific award winners in the country. “We have picked up awards since we first entered them in 1992 – our first from the Oyster Farmers Association and more recently from the Sydney Royal Fine Foods Show.” Each year since 2001 the Sydney Royal Easter Show hosts the Fine Food Show. The objective is to recognise and reward outstanding excellence in food production. Categories include wine, cheese and dairy, aquaculture, pasta, coffee, bread, cakes and pies, olive oil, deli meats and regional products. Each year dozens of Australian highest quality aquaculture producers come together to showcase an exciting and diverse

FARM PROFILE

ing it an enviable record at this prestigious event: • 2001 1 Silver and 2 Bronze, Show Champion • 2002 3 Gold, Show Champion • 2003 3 Gold, Show Champion • 2004 3 Gold, Show Champion • 2005 2 Gold, 1 Silver However Gary’s humble about such successes. “We would like to say that we are smart and have great farming techniques but really it’s our protected waterway that does it. We don’t have the big threats of urbanisation which other farmers suffer from.”

Local Graham Riches tucks into a feed of tasty Tathra Oysters. Photo by Nicole Riches.

range of produce and to vie for a coveted Sydney Royal Gold Medal, the entries to be judged by Australian and International invited food experts. Judging is held in two stages to reflect the seasons of the aquaculture produce. Farmed black tiger, kuruma and banana prawns (Penaeus monodon, Marsupenaeus japonicus, Fenneropenaeus meguisenis) and Sydney Rock Oysters are judged in February, while Pacific (Crassostrea gigas) and Angasi Oysters (Ostrea angasi) are judged later in the year when they are at their best. With oysters, the criteria include: • Flavour (taste sweetness, after taste, richness, firmness and dryness) • Visual appearance (colour, shape and fullness before and after opening) • Condition (texture and mouth feel) All of the oyster entries are submitted unshucked (unopened) so they can be assessed both as a shucked and an unshucked product. Awards are either Bronze, Silver or Gold (see box insert for Sydney Rock Oysters) although judges needn’t make any awards if no entries make the grade. They can award ‘Champion of the Show’ to entries that are of a vast superior level. In 2005 Tathra Oysters again picked up gold medals, as well as a silver, giv-

Retail Outlet A 50m2 brick building behind Gary’s house acts as a packing, storage, opening and retail outlet for Tathra Oysters. Award certificates cover almost the whole ceiling and walls of the retail shop which moves over 80% of the farm’s sales. People flock there between 9 am and 5 pm seven days a week. The remainder of the harvest is sent to selected restaurants in Sydney. “Our clients include Fish at the Rocks and the Quay,” Gary continues. “We have a few more in the pipeline as we expand.

The oysters are packed in polystyrene boxes and sent in refrigerated trucks to keep temperatures down (below 25°C).” Executive Chef at the Quay Restaurant, Peter Gilmore, has had Tathra Oysters listed on his menu for a couple of seasons, usually from December to May. “It is such a unique and special oyster with a nice and clean taste,” he explains. “People know it and it sells well. It has a clarity of flavour, salt brine and comes from a pristine environment. Gary has great quality control only selling when his premium quality oysters are available. “We heard about them from their wins at the Easter Show. I prefer to buy direct from producers and I know he hand sorts them and they have a large plump meat. They’re usually a standard size but occasionally I can get some larger ones which we would put in as a special. However the prices are higher and only the most discriminating oyster eaters are attracted to them.” Peter serves them au naturale on ice. “Sometimes I will also offer an ice cold Chardonnay Vinegar Granita. Spooned on top of the oysters this strikes a perfect acid balance to the oysters. Some

Austasia Aquaculture | August/September 2005 45

FARM PROFILE

can sit down and open 16 oysters a minute. The knives are made by Amon Industrial from New Zealand (www.oysterknife.co.nz, Tel: +649 406-7123). I wouldn’t go back to the ordinary knives. I used these pneumatic knives for a couple of years and they’re great.”

Entree from Royal Easter show presentation lunch including award winning pasta, prawns, olive oil and Tathra oysters. Photo courtesy of Royal Easter Show Fine Foods Awards.

people ask for a slice of lemon as well. Thathra Oysters’ retail clients come from near and far. “Some come in every week, others we see only once a year,” Gary says. “Word of mouth advertising ensures we have a pretty steady trade.” The range includes: • Premium (55+g) selling at $14/dozen • Bistro/standard (35g – 45g) at $9/dozen • Cocktails (25g – 30g) at $7/dozen All are shucked with the meats

turned. Placed on polystyrene trays with a piece of lemon and parsley, plastic wrapping is used to keep them fresh whilst in the large refrigerated cabinet. “We need to cater to a lot of different people, so we also have 120ml jars of shucked oysters – between 18 and 24 oysters in each jar – selling for $9 each.” The premises are kept very clean even in the oysters opening area where Gary uses a pneumatic (compressed air operated) oyster knife to open the oysters. “I

Quality Assurance Program Gary notes that the NSW Food Authority has been working with the Oyster Farms Association and the Oyster Section of the NSW Farmers Federation on a shellfish quality assurance program (QAP). This is designed to ensure that all shellfish harvested from NSW waters were safe to eat. Every growing area is monitored, including Nelson Lake with the program funded partly on a ‘user-pays’ system. The budget is $14,243 per year which is now funded largely by the NSW Government. “It is a bit rough that we are in the most pristine estuary in NSW, yet potentially we will have to pay the biggest bill,” Gary contends. “Due to the low nutrient input in our area, we have lower stocking densities than in other estuaries. This in turn means we require more area to farm successfully, so we pay more both ways as fees are based on area.” However, now that the QAP is operating and Nelson Lake has the highest

Results 2005 Fine Food Oyster Competition Class: 2 Sydney Rock Oysters, Unshucked, Unwashed Award

Cat # Exhibitor

Exhibit

Gold Gold Gold Gold Gold Silver Bronze Bronze Bronze Bronze Bronze Bronze Bronze Bronze

21 25 29 32 33 20 24 26 27 28 30 31 22 23

Sydney Rock Oysters Sydney Rock Oyster Sydney Rock Oyster Sydney Rock Oysters Sydney Rock Oysters Sydney Rock Oyster Premium Sydney Rock Oysters Sydney Rock Oysters Premium Sydney Rock Oysters Sydney Rock Oysters Sydney Rock Oysters Sydney Rock Oysters Sydney Rock Oysters Sydney Rock Oysters

Bed Rock Oysters Greenwell Point NSW 2540 Tathra Oysters Tathra NSW 2550 Tathra Oysters Tathra NSW 2550 Shoalhaven Oyster Service Greenwell Point NSW 2540 Bay Rock Oysters Pty Ltd Batemans Bay NSW 2536 Tathra Oysters Tathra NSW 2550 V C Diemar Pty Ltd Nelson Bay NSW 2315 Merimbula Gourmet Oysters Pambula NSW 2549 V C Diemar Pty Ltd Nelson Bay NSW 2315 Merimbula Gourmet Oysters Pambula NSW 2549 Holiday Coast Oysters Port Macquarie NSW 2444 Merimbula Gourmet Oysters Pambula NSW 2549 Holiday Coast Oysters Port Macquarie NSW 2444 Merimbula Gourmet Oysters Pambula NSW 2549

(Source: http://www.eastershow.com.au/FineFoodswebsite/FineFoodResultsDisplay)

46 Austasia Aquaculture | August/September 2005

FARM PROFILE

NSW Primary Industries Minister Ian Macdonald and Fine Food Chairperson Lyndey Milan present Gary Rodely of Tathra Oysters with the Championship ribbon. Gary was latter presented with the Award of Outstanding excellence which was the first time it had been presented in the award’s history. Photo courtesy of Royal Easter Show Fine Foods Awards.

classification, there is no requirement to use a depuration tank. Instead a rainfall of 85ml triggers sampling of both water quality and the oysters. If pollution indicators are found then harvesting is stopped until the further testing reveals that the pollution has cleared. “It is very easy for us as we don’t have a lot of other farmers to inform about rain events,” Gary continues. “We simply shut down our harvesting and just go off and play golf until the samples show the all-clear.” Innovative systems As first mentioned in AAM 14.5, Gary and Peter are continuing to find innovative ways to increase their turnover, including: • Focus on single seed oysters (the spat are collected on piles of vinyl slats and are able to catch over 10,000 seed per metre) • Collection of sufficient spat for sales to other farmers • The use of 3,000 tumblers (cylinders which move with the tides and wave action) to rotate the single seed as they grow to 25mm before stocking in the trays. • The use of trays to allow the oysters to spread out to give their particular rounded-shape with a large oyster meat. As these oysters are easier to open and sit well on a plate, they are

preferred by the restaurants. • Use of mesh netting over the trays to reduce bird predation, mostly by pairs of pied oyster catchers. • To combat winter mortality (unexplains mass mortalities of oysters in the cooler months) they try to get the oysters in and out quickly through an emphasis on smaller oysters (less than 40g). • Trials with subtidal raft culture, including the use of dry out times to reduce mud worm problems. Gary is very excited about the future prospects for Tathra Oysters. “We are going to increase our production whilst maintaining our quality and continue to

• Key Management Decisions for Tathra Oysters include: – Selection of a pristine site – Focus on quality of product, also retail/direct sales – Use of alternative technologies to • Culture System utilised: intertidal racks and trays with unattached oysters • Growth rate (from stocking to market): <28 months (5g to 40g) • Survival rate: 95% from first stocking of single seed spat to sale size • Sale price: $7-14 / dozen (retail shop)

grow the reputation of Tathra Oysters.” By Dos O’Sullivan For more information contact Gary Rodely or Peter Holdsworth, Tathra Oysters, 1 Reservoir Street, Tathra, NSW 2550, Tel/fax: 02 6494-1453. For more information on the Fine Foods Show call 02 9704-1299 or email dcaruso@rasnsw.com.au, website www.sydney.royalshow. com/find-food.html

Phone Steve Amon on 64 9 406 7123 Fax: 64 9 406 7125 Email: sales@oysterknife.co.nz www.oysterknife.co.nz

Austasia Aquaculture | August/September 2005 47

F E AT U R E

Feeding yabbies

A new book on commercial yabby farming by industry stalwart Rob McCormack has been released. A veteran of twenty years in the industry, Rob’s gathered together all the available information and latest research into this latest offering. His advice, start small with a pilot scale venture and don’t give up the day job until you’re into production! In this excerpt, he examines the feeding of yabbies on a commercial farm. Feeding yabbies is critical to your success. Feeding is in two forms. Firstly you have a base food source of hay in the pond constantly that you will top up on a monthly basis. Secondly, you have supplemental food that you add on a daily basis. The base food source is the hay placed in the pond. After one month add an additional bale. Just break it up and sprinkle on surface of pond. It will blow around the pond with the wind. Hay by itself has little nutritional value. However, after 3 – 4 weeks in the pond decomposition occurs, this allows every blade of grass to be coated in a layer of algae, bacteria and micro-

organisms that are consumed with the hay (detritus material) and it is this that gives a high protein value to decomposing hay. Decomposing hay in a pond will create a mass of microorganisms, some of these will be consumed directly by the yabbies but many will create a food source for larger organisms to eat and then proliferate, these then become a food source for the yabbies. Yabbies are a predator and will actively hunt and eat anything they catch. They will spend a large proportion of their time actively hunting live food organisms and prefer a meat based diet, but eat vegetables as well. Weeds

48 Austasia Aquaculture | August/September 2005

and algae are also consumed by yabbies. Supplementary food consists of three different feeds. It is essential you vary the yabbies diet. Yabbies quickly become bored with the same food day after day. For 100% consumption of food and remarkable growth vary the diet daily. Growth is the critical factor. If you feed the same food day after day feed consumption and growth rates reduce. 1. Commercial crayfish pellets, specifically formulated pellets designed for crayfish approximately $800 per tonne. 2. Cracked lupins, just a green pea available at most produce stores approximately $400 per tonne.

F E AT U R E

3. Different brand or flavour of commercial yabby pellet. Some commercial pellet manufacturers now produce yabby pellets in two distinct flavours. We, however, usually use two different manufacturers. As a last resort if not available locally you can use layer pellets, standard chook food approximately $350 per tonne. Yabbies only eat about 10% of the layer pellets but the left-over does feed the pond over the short term. We use layer pellets only as an absolute emergency, maybe one bag per year total. Feeding regime is simple; feed six days per week without fail. Once started feeding you cannot stop. Additional feed will promote growth and your pond will support a higher size and density than without food. If you stop feeding then yabbies will cannibalise themselves down to the number the pond can support. Feed requirements are minimal for a 50mtr x 40mtr pond stocked with 2,000 15 gram animals (1/m2). First and second month 200 grams per day. Eg: Monday 4 handfuls commercial yabby pellets 1. Tuesday 4 commercial yabby pellets 2. Wednesday 4 handfuls lupins Thursday 4 handfuls commercial yabby pellets 1. Friday 4 handfuls commercial yabby pellets 2. Saturday 4 handfuls lupins One day per week no feed. For us it’s Sunday. A day at the beach for us, a day of scavenging and pond clean up for the yabbies. Also, yabbies grow better and faster with a day without food. They don’t get lazy. Feeding is generally by hand and bucket, just grab a handful and throw it in. Approximately 50 gram per man sized hand. I would recommend you feed by hand not by bike and blower etc if a small farmer. If you are a large farm with lots of ponds it is unrealistic to waste your time walking around each pond everyday feeding and bikes and blowers are the only option. But do

Note: Chook pellets are held in contempt by most crayfish farmers as yabbies only eat 10% of them and the balance ends up on the pond floor. We use them occasionally to feed the pond itself and by feeding these micro-organisms the yabbies can in turn feed on them. As an alternative food used sparingly only once per week, no problems, though yabby pellets are better value for your dollar. I would recommend you use yabby pellets, not chook pellets.

take the time to observe each pond as best as you can when you feed and do take the time once per week to have a leisurely stroll around your ponds to check them out individually. By walking around your pond and observing you can notice problems before they become disasters. Month 3 – 4 double feed 400 gram / day Month 5 – 6 feed 800 – 1000 gram / day Monitoring your pond by daily (weekly) walking around it and closely observing the pond is a major priority. Visual observation will detect problems

before they become disasters. I am sure that many yabby growers will consider these feed rates to be so small as to be infinitesimal. We have trialled feed rates ten times those suggested without any major increase in growth, only 10%, but for a higher feed and labour bill. Remember your main food source is the initial hay and the additional bale each month as well as the natural food produced in the pond. The additional pellet food is a small supplement only. We recommend a feed rate of 0.5% to 1% of biomass/day for six out of seven days. Many yabby farmers feed their stock at a rate of 3% – 5% biomass per day. (Biomass is the total weight of yabbies in the pond). For example if you have 2,000 x 100 gram yabbies = 200kgs. Less 10% mortality = 180kgs of yabbies in the pond. Official recommended feed rate 3% per day (3% of 180kgs) = 5.4kgs. Yet I am advising you to feed only a maximum of 900 gram (0.9kg) per day. This equates to 0.5% of biomass. That’s half of one percent. Keep in mind that natural food production is the main source of food for your crop and artifi-

Austasia Aquaculture | August/September 2005 49

F E AT U R E

cial food is a supplement only. This whole feeding regime depends on only stocking yabbies at one or two per square metre. If you increase the biomass to say 3/m2 then you will need to increase your feed rate to 2% of biomass and if up to 4/m2 then increase up to 4% biomass. The natural food created by the pond is being fully utilised by the 2/m2 and if you increase that number you need to supply a full diet for the extras. Working out the biomass of yabbies in the pond is a very difficult problem. Sample trapping is the usual way. Drop 4 – 6 traps in the pond.

Weigh the yabbies caught and average the weight. Then average weight by estimated number of yabbies in the pond equals biomass. Unfortunately traps catch the largest first, so average is high and estimating survival in pond is hard for inexperienced farmers. It all depends on the level of predator protection you can offer. Experienced farmers with netting and fencing will loose 10%. Inexperienced farmers can lose 75 – 100%. I would recommend to all farmers when estimating biomass to work on an average of 30% mortality of initial stock over full period of production cycle. If for example a six month cycle then allow 10% mortality every two months. It’s pretty rough but does seem to be quite accurate. Keep records of the amount stocked and the number harvested and you will over time work out your mortality rates for your ponds on your farm. Another way to estimate or check your estimations of a pond population is to do a sample/population check. 1. Trap harvest the pond one day and keep your catch. At the end of the days trapping mark all the yabbies you captured and return them to the pond. Just use paper towels to dry the back/carapace of the yabby and then mark it with a texta. We have quick dry Mark Masta texta that works well. I have hard other people use liquid paper or paint. Once all your yabbies are marked, release them back into the pond they came from. 2. The next day you can start trapping again but best to wait another day or two if you can to ensure the marked and released yabbies are unstressed. Trap all day and keep the catch. The more animals you capture the more accurate the results. At the end of the days trapping sort the catch into marked and unmarked yabbies. 3. The formula is quite simple. For example if you trapped and marked 500 yabbies the first day and returned them to the pond and on the second trapping you captured 750 of which only 100 were the marked ones. The number of marked yabbies in the recapture sample

50 Austasia Aquaculture | August/September 2005

Note: Just a note on the storage of feed. Pellets need to be kept cool, dry and vermin free. Keep the bags out of the sun. They have vitamins and minerals in them that will deteriorate with time. It is better to use pellets within six months of purchase. Never use pellets that have mould growing on it, as many moulds can be toxic to your yabbies and also a health threat to you so take care. Never inhale any pellet dust.

(100) ÷ the total number of yabbies in the recapture sample (750) = 0.1333. So 100/750 = 0.1333. This is the proportion marked. 4. To work out the Total Pond Population you need to divide the total number marked originally (500) by The Proportion Marked in recapture (0.133). So 500/0.133 = 3750 yabbies in the pond. These sample population checks are a good exercise to see if your estimates are on target. This is especially important as you near the end of the production cycle as your feed amounts are becoming large enough to impact on the pond if not consumed. Remember if you throw too much food into the pond and there are not enough yabbies in the pond to eat that food, it will sit on the bottom and rot and pollute your water. As your water quality deteriorates those yabbies in the ponds go off their food, so they eat less and this increases the problem. We have had slightly better results with increased feed rates (double those I have recommended 1% of biomass) but for new farmers I do recommend caution. A good rule is underfeed – do not overfeed and pollute your water. Overfeeding will pollute your water, raise your costs and lower or destroy your production and profit. Start with my recommended feeding rate of 0.5% per day. If you have a good crop and good production – keep records. Next crop increase feed rate and see if extra food costs is worthwhile. Good record keeping over the years will show where the profit lies. Records are what you need to start an accurate prediction of what is going to occur with your crop.

F E AT U R E

If you have good fast growing stock and good predator protection you should have few problems and be able to accurately predict growth rates and with large juveniles and growing them under ideal conditions at low densities for fast growth. I cannot stress enough the damage that controlled pond breeding will do to your growth rates of the yabbies in your ponds. Regardless of the size they reach in the five months of grow out you must harvest if a mixed sex pond otherwise the juveniles produced by uncontrolled breeding will halt or at least seriously reduce growth rates. The following are estimates on growth and food conversion ratios for commercial ponds. The example given is very straight forward with a 10% increase in weight per week and a 2% mortality of stock per week. This is incredibly simplified and all sorts of variables can improve or reduce these estimates, you will have to tune these to your farm. Food conversion ratios for yabbies are great as the hay is a base food source and you only need a small amount of supplemental food. I must warn you that this is only valid if stocked at 2/m2 maximum and if you grow them quickly before in pond breeding impacts dramatically on food availability per individual. For good results stock with 15 to 20 gram animals as they may have spent the better part of a year getting to that size in high density ponds. Once these animals are released in a low density new pond the growth rates are phenomenal on a small supplemental pellet feeding. Survival is entirely dependent on your level of protection and the size at initial stocking. The smaller the size at stocking the higher the mortality rate. At 15 gram plus you will still have mortality over the five months, at the very least this will be 10% and if you do not have netting, up to 95%. Feeding yabbies in ponds is a difficult task to do with accuracy, the majority of time you are just guessing as to the number in the pond on any given day. Only at the end of the production cycle will you be able to see how accurate you were. By Rob McCormack. Copies of â&#x20AC;&#x2DC;The Commercial Yabby Farmerâ&#x20AC;&#x2122; by Robert McCormack (RBM Aquaculture, 2005) are available from RBM Aquaculture, PO Box 3, Karuah NSW 2324. Phone 02 4997 5160; Email rob@rbmaqua.com.au.

Food conversion ratio for semi intensive yabby farming Large 2500m2 pond stock at 2/m2 at 15 gram, grown for 21 weeks Feed at 0.005 biomass per day for 6 days per week Growth increase of 10% per week and mortality of 2% per week Week

Weight

Qty

Biomass

Feed @ 0.005

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

15 16.5 18.15 19.95 21.96 24.15 26.57 29.23 32.15 35.36 38.9 42.79 47 51.78 56.96 62.85 68.92 75.81 83.39 91.73 100.91

5000 4900 4802 4706 4612 4519 4429 4340 4253 4168 4085 4003 3923 3845 3768 3692 3618 3546 3475 3406 3338

75000 80850 87156 93864 101276 109148 117684 126858 136733 147380 158906 171288 184381 199094 214625 231303 249352 268822 289780 312432 336837 Total

375 404 435 469 506 545 588 634 683 736 794 856 921 995 1073 1156 1246 1344 1448 1562 1684 18454

Therefore, 3338 yabbies @ 100.91 grams = 336.837kgs in pond At 0.005% feed / day = total 18.45kgs x 6 days/week = 110.724kgs of pellet FCR

= TOTAL FEED : WEIGHT GAIN = 110.724 : 336.837 = 75.00 = 110.724 : 261.837 = 0.42 :1 Therefore for every tonne of yabbies produced you need 420kgs of pellets. Austasia Aquaculture | August/September 2005 51

TECHNOLOGY

High Density Continuous Rotifer Culture Systems Aquasonic are now the Australia and New Zealand agents for a highly innovative British company named Varicon Aqua Solutions. Varicon was formed by a small group of hatchery and industry specialists to manufacture and supply a range of “state of the art” solutions for aquaculture producers. The primary focus is the provision of a range of live feed systems, utilising the BioFenceTM (continuous algae culture system) and the Varicon Aqua HDRS (High Density Rotifer System). These systems utilise patented and proprietary solutions which facilitate uninterrupted and economical production of hatchery feeds for long periods. The HDRS system is fully process controlled which takes the stress out of rotifer production; increasing reliability and consistency whilst leaving hatchery operatives more time to focus upon other areas of production. The time and space saving characteristics of the sys-

tems offer significant cost advantages when compared with conventional batch production methods. The production platforms are available in a range of sizes and can be configured to meet site specific requirements and are ideal for research institutes to large commercial hatchery applications. The Varicon Aqua continuous rotifer culture system has been designed to function optimally by using algae pastes as the primary feed substrate. Aquasonic are also the agents for Pacific Trading Co, who supply high quality fresh chlorella products and these will directly support the HDRS systems. A combination of algae and artificial diets can be employed, but higher percentages of concentrated algae are proven to provide best results thus far. The Varicon HDRS is designed to be a flow through system, which is controlled via timer and flow meter controlled sole-

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noid and harvested rotifers are collected at a receiver tank where they can be sieved and enriched as required. The systems are designed to operate up to a level of 50% turnover per day. In, for example a 500L tank system this equates to a maximum water flow rate of 250L per day but the recommendation is for it to be operated at 33%. Thus for a 500L system operating at an optimal rotifer density of 3000 rotifers per ml, production would be approximately 500 million rotifers harvested per day. Just think about the space, time and effort involved in producing 500 million rotifers per day using traditional methods and then realise that the Varicon system takes up a foot print of only about 1m x 1.5m and requires only about 15-20 minutes a day to look after. Very little power is required (utilising on site blowers in most cases). Compact design means space savings. High yields, scaleable design, low maintenance, predictable, reliable, simple and easy to operate. These are some of the reasons why this new culture technology has so much potential to improve the economics and productivity of hatcheries throughout the world. For more details please contact Aquasonic Pty Ltd, www.aquasonic.com.au. sales@aquasonic.com.au, ph 02 65864933 or fax 02 65684944.

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52 Austasia Aquaculture | August/September 2005

www.proaqua.net.au

TECHNOLOGY

Barclay Oysters outstanding success with Aquapurse Graham Barclay Oysters, the largest intertidal oyster growing company in Australasia, is situated in the very picturesque joint coastal town of ForsterTuncurry in New South Wales. It’s magnificent and beautiful estuary and the adjoining Wallis Lake are extremely popular area for fishing and pleasure boats. At the same time its expansive waters have been the home for a great number of years for many intertidal oysters farmers, growing the sweet tasting indigenous Sydney Rock oyster ( Saccostrea glomerate) – a gastronomical delight. (The Pacific oyster – Crassostrea gigas is not allowed by law in this area). As can be imagined, fast moving and increasing number of seacraft can interfere very much with oyster farm infrastructure. Constantly coping with this has been a real problem for Barclay Oysters owner Graham Barclay. Over a period of time he has made many efforts to establish effective wave barriers – with a mixed amount of success. That was until almost twelve months ago when, because of its design, sturdy construction and capacity, he decided to experiment with the Ploma Aquapurse®, setting up over a thousand of them on longlines to act as a wave barrier and farm his oysters at the same time. As they say “the test of the pudding is

in the eating”. Not only have the Aquapurse® been highly successful in their wave barrier function but they have been extremely successful in their farming purpose. Barclay says that the oysters in the units have grown at least a third faster than any other oysters in the area and at the same time have developed a better and more consistent shape. Also, by using soft mesh spat bags in the Aquapurse®, he has enormously reduced spat loss and at the same time has found the units resist predator attacks by the large fish population. The bags are absolutely ideal for the hatchery stock. “The experiment has been an out-

standing success” Barclay says, “so much so that I am already constructing further infrastructure in other areas of the farms to use the Aquapurse® in a similar way”. Barclay attaches the 16mm mesh Aquapurse® with suspension hooks to plastic coated longlines – six across. When servicing the lines, a light aluminium plank is used to rest on the timber cross beams and any required work is then easily carried out. Reg Breakwell, Marketing and Export Manager for Tooltech Pty Ltd, who manufacture the plastic Aquapurse® units, agreed that the initiative used by Barclay Oysters has been well rewarded. He said that the Aquapurse® System is now being used in many countries.and added that the unit provides the oyster grower with what is known as “The Essential Three” – i.e. perfects the shape of the oyster; produces consistency of size, and provides space to expand. Breakwell added that perhaps its protective’ ability should be added as a fourth quality. For further information contact Reg Breakwell, Tooltech Pty Ltd PO Box 197, Richlands Qld 4077 Telephone: 07 3271 1755 Email: mailbox@tooltech.net.au

Austasia Aquaculture | August/September 2005 53

TECHNOLOGY

Datacall The remote Transmitter Unit with a difference, that uses your mobile telephone and the Internet to remotely monitor or control virtually any parameter Hobart based company Technolab Marketing Pty Ltd together with Datacall Telemetry Pty Ltd, the manufacturers of Datacall, are packaging the Datacall unit for aquaculture applications. Technolabâ&#x20AC;&#x2122;s experience in monitoring dissolved oxygen, pH, conductivity, temperature etc. leads them to believe that Datacall with OxyGuard and other probes is a winning technology for remote water quality monitoring, and control. Datacall interfaces to equipment in a similar manner to traditional remote terminal units, which have digital and analog inputs along with digital output controls. However, Datacall MK1and Mk2 are unique in that they can both use Short Messaging (SMS) for signalling. The MK2 also uses the new 1xRTT packet switching protocol, which has the ability to send data at high speed (up to 153kbps). Messages can automatically sent to the datacall web site, which is an optional service being made available to Datacall users, where all messages and events are stored for analysis or data logging purposes. The concept behind the development of the Datacall is based on the convenience of transferring data and initiating control functions via the CDMA mobile telephone The chart below has been supplied with the compliments of the Tassal Group and illustrates a Datacall multichannel computer plot of twodissolved oxygen and a single temperature probe.

Fig No 1 above, shows a schematic diagram of a typical off shore fish cage installation where two OxyGuard dissolved oxygen and one temperature probe, are deployed to monitor, log and plot the output data to a computer screen connected via the internet.

The picture above shows a Datacall installation located at the Tassal Groups Roberts Point Atlantic Salmon farm, South of Hobart where Tassal are using a Datacall l to remotely monitor and log dissolved oxygen and temperature in fish cages.

network, rather than the added expense of developing and maintaining individual custom made radio links. By using their mobile telephone or the Internet PC connection, farm staff can communicate with the Datacall from anywhere providing that they are

calling from within a mobile telephone network. Data can be recalled or commands issued either manually or automatically to monitor a variable parameter or to turn on or off electrical equipment. High and low alarm settings can be programmed to autodial scheduled staff when parameters move outside selected limits. Alternatively Datacall has output relays for use with automatic control systems such as aeration for switching on or off aeration, water pumps and lighting systems etc.

The picture below shows three OxyGuard digital readouts used by the Tassal installation for viewing the output of the local oxygen and temperature probes.

The Datacall logging software provides options to log raw numerical data, which can be transferred in total or in part to an Excel, spread sheet for further data reduction.

For further information contact John Powell Technolab Marketing Pty Ltd PO Box 334 KingstonTas Telephone 03 6229 7437 Fax 03 6229 2748 Email:sales@technolab.comau

54 Austasia Aquaculture | August/September 2005

TECHNOLOGY

Twenty one years and still flowing strongly

Student constructed aquaponics system at CQU.

Just over twenty years ago the Biology Department of what is now Central Queensland University made a bold decision to begin a two year training program in aquaculture to cater for the developing tropical aquaculture industry in Queensland. While the bureaucracy insisted on calling it an Associate Diploma of Aquatic Resource Management, the students (and staff) quickly adopted the acronym ADARM. The acronym stuck even though the aquatic courses are now embedded as a specialisation within a Bachelor of Science degree. Students can still exit after two years of study and receive an advanced diploma. From the outset, the courses focussed on practical skills and industry practice. Each year internal students construct and manage their own aquaculture systems as a group project.

External students attending residential schools maintain and monitor the systems during mid-term vacations. Students get to take one species (usually silver perch) through an entire life cycle from spawning to grow-out. The system provides hands on experience in water quality management and other practical aspects of aquaculture. Students are also encouraged to do an Industrial Placement course based within the industry to broaden their skill base. “From my own experiences I have found that many university graduates are finding it hard to get jobs ... However, there are some exceptions, ... the prawn industry saw the worth of the Central Queensland Uni’s aquatic resource management degree taking many of the graduates, showing that it was not always necessary to undertake

an aquaculture specific qualification.” (Dos OSullivan, 2001, pg. 11) With changing industry demand the CQU program has changed with less emphasis on basic field biology and construction techniques and more emphasis on the aquatic sciences that underpin modern aquaculture. As well as Culture Techniques and Aquaculture, students study courses such as Aquatic Systems, Aquatic Physiology, Coastal Marine Resources, Water Quality Management, Botany of Aquatic Environments, Microbiology, Biological Experimentation and Marine Environmental Impact Assessment. Internal and external students have access to a wide range of electives in biology as well as courses in Environmental Science, Environmental Management Systems and Environmental Law and others.

Austasia Aquaculture | August/September 2005 55

RESEARCH

Kiwi ingenuity and Iraqi skill hatches eels for the first time In early July, NZ fish breeder Paul Decker organised a time – a week in advance – with a TV crew for some fish eggs to spawn. “The producer asked if they could come on the next Thursday and I suggested between 10am and midday,” he recalls. “I explained that it would give them time to set up their cameras before the action at 11am. And it proceeded like clockwork. “Right on time the female was ready to strip, the males came on and the eggs were fertilised straight away. “I’ve bred hundreds of different species and even goldfish and the carps aren’t that perfect. I stood there and thought to myself: ‘Gee, we have really cracked this’. It’s literally on-demand. So if you want to sleep in, you can do it a little later.” Spectacular, yes. But the surprises don’t end there. This wasn’t just one of the myriad aquaculture or ornamental species with known breeding techniques. This was Anguilla australis, the short-finned eel. No-one has seen spawning of this species in the wild, let alone in captivity. Scientists don’t even know where it occurs. And Paul’s team has gone the next step too. They’ve hatched the eggs, filling their tanks with thousands upon thousands of babies. Not just once but four times in a couple of weeks. No-one has seen that quantity of hatchlings of any eel species … ever. How does one come to such a breakthrough? Five years of trial and effort, inspiration, experience and a bucketload of Paul’s own scarce cash – $400,00 at last count – supplemented in the last couple of years by $200,000 from the publicly-funded Foundation for Research, Science and Technology. Risk capital with a capital “R”. But the passion, commitment and expertise of the highest order has won through. With eel aquaculture long-established

and worth well over a billion dollars worldwide, Paul’s team is writing a new chapter in its celebrated story. The motivation As a boy of ten in his native Queensland, Paul was already breeding Siamese fighting fish and zebra danios for sale to local aquariums. Mum was OK with that. But she was not so sanguine with his other hobby … breeding carpet snakes and fattening them up for sale to pineapple farmers. “If any ever escaped my Mother would have an axe over them,” he recalls. “She hated them. It’s an Adam and Eve thing. Kids have it drilled into them that serpents are bad.” New Zealand doesn’t have any snakes. Instead it’s the poor eels that get dragged up the river banks to get the living daylights bashed out of them. “Human psyche seems to demand that we kill the buggers because they wriggle,” Paul suggests. Yet he likes eels. And watching such savagery always makes him wince.

56 Austasia Aquaculture | August/September 2005

Nevertheless the scientist in him recognises that the reason eel numbers are on the decline is not this haphazard slaughter. Nor is it commercial fishing. Environmental degradation is the real cause. “The streams are being turned into muddy culverts, killing off the feed species,” he explains. “If it wasn’t for the fact that eels are opportunistic scavengers they’d be extinct already.” Furthermore, Paul recognises that the best way to conserve a species is to give it commercial value. However, as a practising aquaculturalist he knows that success can only come if the biology – as well as the potential return – meets certain criteria. “There are parameters you must have. Fecundity is one. Look at the marron for instance. It gives one baby per gram of animal. That’s not enough … you can’t sustain an industry on a ‘test-tube baby’. Eels each produce 1.52 million eggs. And once the hatchlings reach the glass eel stage they are very resilient. Food conversion is also good when fed the right tucker.

The research team: (from left) Paul Decker, Dr. Tagried Kurwie, Adrian Paarman, David Cooper and Kim Pierce.

RESEARCH

“The big advantage is that there’s already this huge industry growing adults from glass eels (which are currently collected from the wild). Our job is complete when we can produce industrial quantities of glass eels in the hatchery. We don’t have to invent the whole wheel.” The beginnings Paul couldn’t have set himself a more difficult challenge. “It’s jigsaw puzzle. Since no-one knows where or how they spawn, we had to begin with some educated guesses.” It certainly helped that most of Paul’s small team at Mahurangi Technical Institute (MTI) had been fish breeders for a lifetime. “We could work out the obvious. For starters they’re externally fertilised. Since they are going to lay eggs we needed to strip – dry strip rather than wet strip. Then came the decisions on how to fertilise the eggs – so we started with a suite of normal procedures and worked from there.” The questions kept coming. Do the eggs float? Do they sink? Do they do both at different stages of the incubation cycle? What sort of water flow is needed? “Eels are complicated, that’s for sure,” Paul says. “We have certainly flushed away a lot of eggs over the years.” Even conditioning the broodstock was a fair task. Thankfully Paul could call on the expertise of Dr Tagried Kurwie, a Iraqi fisheries scientist whose family had fled the clutches of Saddam Hussein. She in turn found good counsel in Otago University’s eel researcher, Dr Mark Lokman. An inspired choice as lead scientist Tagried has stayed with the program despite moving to London where her husband is now employed. She spends 5-6 months each year in New Zealand. Tagried’s background is in fish nutrition so she soon had the broodstock short-fin eels in tip-top condition. These eels are caught by commercial fishers as they return to sea for migration to breeding grounds – thought to be in the vicinity of Tonga – during a season that begins in late February and lasts much of autumn.

Dr Tagried Kurwie

Soon the team could get the adults fat really quick on a few favoured recipes. “Eels don’t like dry food or eating off the surface,” Paul says. “They much prefer a jelly substance that they can take big chunks of and swallow hard – to go back for another mouthful straight away. “They’ve definitely got the ‘last meal’ syndrome; great for aquaculture. A hungry, aggressive feeder with millions of eggs. Wow!” But it proved not that easy to ensure high quality. It’s well known that eels are resilient, but tough doesn’t necessarily equate to high quality. There were some diseases the breeders needed to get on top of – nematodes mainly – but

perfecting environmental conditions was perhaps the biggest challenge. Take temperature, for example. “In the ocean the temperature doesn’t change very much,” Paul explains. “We used to use a standard thermostat on our heating units. But they have a 10% tolerance so at a setting of 21°C they kick in at 20.1°C and kick out at 21.9°. “So we had to move to digital control.” Getting handling protocols right was another challenge. “A skittish animal is hard to keep for any farmer. Just ask the deer farmer who was badly gored here last week. And one of the biggest killer of marron is pre-moult stress. We’ve found eels to be quiet and sedate, the ‘Jersey cows’ of aquaculture. There’s

Austasia Aquaculture | August/September 2005 57

RESEARCH

Eel eggs straight after fertilisation.

a way of tickling them on the tummy that they really like. “To begin with one of our big concerns was choosing the best type of anaesthetic as they’d have to be sedated frequently for weighing, measuring and

injecting (with hormones). “This year we didn’t need to anaesthetise at all. We’ve learnt to handle them so that they respond nicely – we’re aiming to produce organic babies! The more natural process is, the

Dissection of a female eel showing the eggs.

58 Austasia Aquaculture | August/September 2005

more commercial it will be.” Manipulating light regimes has also proven crucial, as has control of salinity and the selection of type and quantity of ovulation-inducing hormones. Perhaps though the crucial ingredient is what Paul calls “fish fingers”. “When you’ve got the aptitude for it and the right background, prolonged observation gives you a sort of sixth sense as to what is going on with your fish. If you don’t pick your time right you might come along ten minutes late and the female’s let go in the tank. Or if she’s not ready to go and you force her the eggs are immature. “In other words we get savvy to the personalities and reactions of each eel.” He reckons you simply can’t do this if you don’t respect your fish. “Good farmers of any type respect their animals and their land/water. A good dairy farmer has a relationship with his cows. I’ve been all over the world looking at fish farms and it’s no different. Ask an

RESEARCH

old farmer on a Chinese farm to show you some goldfish. He’ll dip a small net into a tank of water and show you the most beautiful goldfish you’ve seen. “You can see by the look on his face and the way he treats them that he respects his fish and he’s rewarded with a great product.” And Paul’s eels? “You certainly fall in love with the buggers.” In return, provided with the right conditions and inducements, Tagried can spawn these fish on-demand. What’s more, the team is quietly confident that they’ll soon have the knowledge to spawn them out of season too. Multiple spawnings are also possible. “We now know that the eels don’t give all of their eggs in one go,” Paul explains. “They do it in batches, probably half a million a batch. “The question was could we succeed with hatching from that next batch? The answer is yes. We’ve now done it.” The hatching Another crucial member of Paul’s team has been Adrian Paarman. According to the team’s Project Manager, David Cooper, Adrian is one of those handy souls who can “make anything out of anything for nothing”. “He’s been building gadgets – especially incubators – for years. This home-made Kiwi ingenuity has been a key ingredient, allowing Tagried to continue to refine her methods.” That continual refinement took her and the team to the point last year of being able to reliably produce viable embryos to within an hour of hatching. “But then micro-scavengers were attacking them and fungal infections were getting in,” says David. It seemed that if these infections could be minimised, success would come. And so it proved. With an improved incubator system in place for the 2005 season, the first sign came with the discovery of an empty eggshell in water being examined under a microscope. Then the floodgates opened with tens of thousands hatching over four spawning events. The hatchlings were taken through to day 10, marking the end of the

research project for this year. What’s next? Now that the MTI team can hatch thousands of eels on demand, the next stage of experimentation can begin. “Taking them through from hatchlings will be a challenge but at least we will be able to work with as many fish we need to test all the variables,” says Paul. “We’ll be able to have quite a number of pilot processes going on at once to see which is best. And if we need more babies, we’ll simply produce them en masse.” One way to speed up the process though is to share knowledge with others of relevant experience. Paul is no fan of the ‘silo’ approach. “Aquaculture is an industry that seems to attract all these entrepreneurs who try to hide their breakthroughs. I tell them that if the business is so small that you can’t talk to anyone, then you’re in the wrong business. “We cracked the (industrial-scale) eel hatching code first but it’ll be a bit like the four-minute mile; took ages to break but then everyone could do it.” He expects Australian scientists will be not far behind. “The short-fin is right along the east coast. What we really need to do is work together, not waste time reinventing the wheel.” So he’ll be talking to any and all interested parties over the coming months to see what arrangements can be put in place to close out the final steps in high quality, large quantity glass eel production. That includes investors. As David puts it: “We’re looking to take it through to full commercialisation. There’s been quite a bit of interest already.” But how such a partnership would be structured is yet to be determined. Already the team is full of plans for new hatchery equipment and processes. Nothing like a historic breakthrough to fire the missionary zeal!

For more information contact Paul Decker and David Cooper at the Mahurangi Technical Institute; Tel: +64 9 425 8493; Email: paul@mti.net.nz and david@mti.net.nz.

Hatching out.

One hour after hatching

One day old

Three days old

Four days old.

Austasia Aquaculture | August/September 2005 59

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FISHENEWS

ABALONE BASKETS LOST Around 190 of 250 1.5m by 1.2m abalone baskets were lost from the Elliston area recently, and most have been found on beaches up to 100 kilometres away following storms. The baskets had been attached to a pontoon in a conditioning process and broke away when ropes failed. The company responsible, Australian Bight Abalone, hired four people and chartered an aircraft and a boat to search for the equipment. Additionally a $10 reward has been offered for each basket recovered. Primary Industries and Resources SA (PIRSA) has indicated the company has satisfied its obligations in the matter. However the conservation group Friends of Elliston has seized on the issue as indicating the group's hesitation on the project is correct. A spokesman has said he believes there are still many more baskets to be retrieved, and they present a navigational hazard, with fears they may also be a problem because of possible interaction with sea lions. There's also the issue of the appropriateness of the site in terms of its exposure to rough sea conditions. In later news, the State Environment and Heritage Department is investigating the deaths of a number of sea lions off the Eyre Peninsula. Aquaculture farm staff observed the animals and have suggested a significant rock fall caused their deaths. However there have been suggestions the problem could have been caused by the missing baskets. A government spokesman advises the cause of death will be investigated and appropriate action taken if an unnatural circumstance proves to the cause. State Democrats leader Sandra Kanck, following on a visit to the area, has called on PIRSA to review its approval of the existing 20ha site and in the meantime to halt consideration of the proposed 40ha extension. Source: Christopher Salter in the Adelaide Advertiser (17/6/2005); Stan Gorton in the Port Lincoln Times (16/6/2005 & 21/6/2005); AAP Newswire (21/6/2005).

DESTINY QUEEN â&#x20AC;&#x201C; PROS AND CONS Destiny Abalone chief executive officer Lesley Wahqvist advises the ship now has 1.5 million abalone on board, and with the entire stock possibly harvested twice a year, an annual harvest of 280 to 300 tonnes is likely. The process for growing the animals at sea is now perfected. Ten-millimetre abalone take just over two years to grow to the 80-millimetre harvest size â&#x20AC;&#x201C; 20 months less than in a land-based system. Meanwhile Transport SA won't release details from the recent 'Destiny Queen' inspection. However Transport Minister Pat Conlon has stated the Government wants to avoid lots Austasia Aquaculture | August/September 2005 61

FISHENEWS

of floating factories setting up. The Government is taking legal advice on new laws addressing foreign crews. Mr Conlon asserts the vessel plainly is exploiting a gap between state and Federal laws and he will be asking the Commonwealth to attempt to fix it. Members of the ship's crew, under an Australian captain, have been described as happy with their circumstances and to have good morale. An Australian Maritime Union representative and an International Transport Worker's Union representative were recently denied access to the 'Destiny Queen' on the basis of security. Their major concern is that the ship operates in Australian waters with Chinese and Ukrainian workers, not Australians. Source: Stan Gorton in the Port Lincoln Times (9/6/2005)

INITIAL APPROVAL FOR ELLISTON ABALONE FARM Primary Industries and Resources SA (PIRSA) has given initial approval for 120 hectares of additional marine abalone farms off Elliston and Ceduna. However it's necessary for the Development Assessment Commission (DAC) to review the development prior to the issue of licences for the use of floating pontoons. It's possible PIRSA may also place additional conditions on the licences. Community groups have raised issues such as the interaction between sea lions and the development, especially since the farm is 1.5 kilometres from a major sea lion colony. There's also a suggestion that the applicants have already a 20-hectare lease approved under the old Fisheries Act, and the farming techniques should be proven on that lease before approval to use the additional area is given. Opponents also suggest the Environmental Protection Authority (EPA) should play a large role in the approval process, making recommendations on ecological impacts as well as on pollution. PIRSA aquaculture division's Ian Nightingale has responded to this by stating both the EPA and the Department of Environment and Heritage can submit applications as part of the development approval process through the DAC. Source: Port Lincoln Times (14/6/2005).

COUNCIL EXPLANATION ON ABALONE FARM Exhibiting its position on a proposed marine-based abalone farm at Waldegrave Islands, the Elliston District Council has issued a statement. In an outcome from a meeting in May, the Council stated that because further government assessment was required, the council supported the development in principle because it supported any business within the district that was soundly based. A soundly-based development, advised the council, was one having good management practices, good planning and environmental management criteria and providing an overall positive outcome. Source: Stan Gorton in the Port Lincoln Times (2/6/2005).

'SHOW US,' SAY INSPECTORS The 'Destiny Queen' will, following three weeks of negotiations with the Adelaide and Hong Kong-based ship owners and operators - the Destiny Abalone Group - be boarded by SA government inspectors. The ship, moored in SA waters and operating as an abalone farm, will be investigated to 62 Austasia Aquaculture | August/September 2005

determine crew competency and safety equipment compliance. These are the only areas under which the inspectors have jurisdiction. Source: The Australian (6/6/2005).

HIDDEN AGENDA, SAYS SITE OWNER Tony Brindle is the owner of the site at Pindimar proposed to be developed as an abalone farm. He claims nearby residents opposed to the development are ignoring the facts and have a hidden agenda. He points out the project has been scrutinised by government departments and approved by the local council. Mr Brindle states a protest held at Pindimar in May was a distortion, noting that in fact sea grasses would not be disturbed, pipes going into the Port would be buried and noise would be minimal. He claims protestors were on the wrong site to convey the impression the farm would be closer to homes. They also claimed dolphins would be affected, which, he says, is ridiculous. Mr Brindle states, " I just wish they'd be honest and say they don't like it instead of making up excuses." It's hoped work on the farm, which will employ six people and produce 30 tonnes of abalone annually, will commence in August Source: Port Stephens Examiner (19/5/2005).

ABALONE FARMS IN POSSIBLE MARINE PARKS NOT ON â&#x20AC;&#x201C; BUT APPLICATIONS PROGRESS While West Coast residents unhappy at the prospect of abalone farms at Elliston and Ceduna query why such ventures are approved in what could become marine parks, it appears the areas may not be considered for marine park status for three to four years - and aquaculture could be side by side with the parks if they appear. Greg Leaman, the director of Natural and Cultural Heritage of the Department for Environment and Heritage, advises the community would be consulted to assist in forming the new series of marine protected areas. Marine parks are scheduled to be established in Spencer, St Vincent and the West Coast by 2010. In the next few weeks it's expected Government officials will sign off on the licences for the abalone ventures, and the next step will be possible additional approval by State planners at the Development Assessment Commission. Community groups opposed to the developments cite a range of reasons under which they object to the ventures, while claiming they aren't against aquaculture, simply its environmental sustainability. Source: Port Lincoln Times (17/5/2005); Stan Gorton in the West Coast Sentinel (19/5/2005).

BARRAMUNDI FUNDS FOR KARUMBA FISH HATCHERY The Federal Government has provided $103,290 to the Gulf Barramundi Restocking Association to allow capital works and equipment purchases for the Karumba fish hatchery. The funds were provided under the Regional Partnerships Program. The outcome from the improvements will be more fish stocks leading to more jobs in the area. Source: North Queensland Register (30/6/2005).

FISHENEWS

YEPPOON PROPERTY FOR SALE There's a new 450 square home on land zoned for aquaculture listed for sale at Yeppoon. The property is currently carrying 2000 barramundi and has a shed and bore. Details from O'Reilly's Real Estate. Source: Morning Bulletin (9/7/2005).

MAJOR AWARD FOR BARRAMUNDI FARM The Ingham barramundi farm operated by Geoff Orpin and Cynthia Taylor of Barramundi Blue Aquaculture has won a major environmental award sponsored by the Queensland Environmental Protection Agency. The operation was a finalist in six out of the eight categories in the Queensland Seafood Industry Awards held recently in Brisbane. The business will now become a finalist in the Australian National Seafoods Awards in Sydney in September. Source: Townsville Bulletin (21/6/2005).

AUSTRALIS AQUACULTURE CONTINUES TO GROW Australis Aquaculture exports barramundi fingerlings to the USA and grows them out to distribute in major cities. The company remains one of the year's best-performing new listings - its shares have traded three times higher than their issue price of $0.25 last August. They closed at $0.68 on 17/6/2005. The business has achieved its long-term aim of producing commercial quantities of fish at the plant near New York, though the plant isn't quite yet at break-even point. It's expected to get there in the first six months of the coming financial year. The company's sales in March were $50,000 and reached $114,000 in April - it was necessary to take on additional staff. There are forward orders well into next year. Recently some $3.7 million has been raised to expand plant capacity by as much as 50 per cent. Building is expected to commence in September. The original plant will go into full production in July. To date there's no indication of when a profit will be made or when a dividend will be paid. "It's a major growth industry," says managing director Stewart Graham, "To expect a dividend you're in the wrong place. You're here for capital growth." Source: Australian Financial Review (18/6/2005).

BARRAMUNDI STOCKING INTO LAKE TINAROO The Tablelands Fish Stocking Society has released another 2000 tagged young barramundi into Lake Tinaroo, continuing a successful program. While the fish are currently bought in from Cairns, the group has established a hatchery at Atherton intended eventually to be the source of the fish they release. Survival rates after release are at around 60 per cent. Source: Atherton Tablelander (17/5/2005).

television program in which the SIFTS technology used won an award. With the advent of cold weather in the area, the project must be divested of its fish. Source: Avon Valley Advocate (25/5/2005).

MARKETING A MESSAGE FOR MELBOURNE'S CHEFS AND DISTRIBUTORS Food South Australia and the South Australian Marine Finfish Farmers Association has hosted Melbourne chefs and seafood distributors on a two-day visit to the Eyre Peninsula during which they experienced the region's seafood. While the emphasis was on Hiramasa Kingfish and Suzuki Mulloway, there were also opportunities to see yabbies, oysters, abalone, mussels and tuna. The meeting also provided for farmers to learn the needs of distributors and chefs in terms of fish cuts, sizes and packaging. In the next six months there'll be large quantities of Hiramasa Kingfish and Suzuki Mulloway ready to market. Source: Stock Journal (30/6/2005).

PROMOTING SA AND AUSTRALASIAN AQUACULTURE 2006 Ian Nightingale, aquaculture executive with Primary Industries and Resources South Australia (PIRSA), and the National Aquaculture Council's executive officer Simon Bennison attended to World Aquaculture Conference in Bali in May. They highlighted the achievements of SA's aquaculture industry, also promoting Australian Aquaculture 2006 which is to be held in Adelaide in August next year. The event will focus on innovation in all aspects of the industry with emphasis on marketing, partnerships, research and production. Source: Stock Journal (30/6/2005).

LOOK AFTER SALMON AND OYSTERS Speaking at the Aquafin Cooperative Research Centre for the Sustainable Aquaculture of Finfish 2005 conference in Hobart, Simon Bennison, CEO of the National Aquaculture Council, observed that the Australian atlantic salmon industry needed to become clever in its marketing to promote the domestic product. He added that it was important the salmon and oyster industries have long term viability and could consolidate markets in Australia, also becoming internationally competitive. Mt Bennison said making sure Australia has marketing strategies which clearly differentiate Australian aquaculture product from the rest of aquaculture products internationally, allows the Australian product to demand a price premium. Source: Hobart Mercury (7/7/2005).

SPRINGFIELD AQUACULTURE FISH ON HOLD Around a tonne of barramundi from the research project at Springfield Aquaculture are being kept in the TAFE tanks at Challenger College in Fremantle following a 1.2 tonne harvest. They'll be gradually distributed to restaurants in the area. The project, at Northam, was recently featured on a

M U R R AY C O D SIFTS TRIALS FOR MURRAY COD PROJECT Primary Industries Research Victoria (PIRVic) is using the latest prototype of the television-award-winning Semi Intensive Floating Tank System (SIFTS) developed by McRobert

Austasia Aquaculture | August/September 2005 63

FISHENEWS

Aquaculture Systems and others to grow Murray Cod. The project is using SIFTS and other cage systems on farms at Mildura in the project 'Multiple use of water in agriculture landscapes'. The intent is to find ways to add value to irrigation water by first using it for fish production before applying it in horticultural cropping. Work has shown that the SIFT system can increase aquaculture yields from five tonnes per hectare to 25 tonnes.

CANIA DAM RELEASES The Cania Dam Fish Stocking Association has received $10,771 in funding for this financial year under the State Impoundment Permit Scheme (SIPS). In the past six months the Association has released 20,283 silver perch, 50,000 golden perch and 30,000 Australian bass at a cost of $15,000. The most recent release was of silver perch purchased from the Sunland Fish Hatcheries.

Source: Sunraysia Daily (25/5/2005); Jenny D'Anger in the Fremantle Rooster (27/5/2005).

Source: Central & North Burnett Times (9/6/2005).

MUSSELS HYPERSALINE WATER THREAT There are concerns the 180 megalitres per day return of concentrated sea water into Cockburn Sound could threaten the $10 million blue mussel industry. The returned water will come from the Kwinana desalination plant. The mussel industry is valued at $3 million annually. However the Water Corporation advises that, while it has not performed a specific study on the impact of the (concentrated) sea water on the mussel farming industry, studies around the world suggest it will not be an issue. Advice is the water emerging from the desalinator discharge pipe will be only slightly more concentrated than sea water, and it will be mixed with the Sound's water. Source: Suzannah James in the West Australian (2/6/2005).

O R N A M E N TA L S MANBANA AQUACULTURE CENTRE Ms Jacynta Fong won a scholarship to a five-day export market development course and is now using the knowledge she gained from the training to investigate ways to enter the Asian export market. Manbana is examining the possibility of exporting ornamentals such as clown fish and tropical seahorses. Singapore and Bali are two immediate choices, followed by Hong Kong and Japan - however the fish are difficult to freight. The company has recently sold 250 clownfish to a Melbourne outlet. Ms Fong advises the workshop gave her a big insight into export industry operations, and she doesn't know how people export without taking the course. Source: Mike Doyle in the Broome Advertiser (9/6/2005).

O T H E R F R E S H W AT E R F I S H MELBOURNE TO TRIAL GLADSTONE MULLET The Victorian Department of Primary Industry is to trial 20,000 mullet bred in Gladstone's fish hatchery, to determine their ability to clean up waste water ponds. Hatchery manager Dr Ken Cowden says there's great potential for the use of mullet in sewage treatment. The hatchery, which is a cooperative venture involving the Central Queensland Ports Authority and the Gladstone Water Board, has recently obtained a very large breeding tank and can easily deal with the growing demand for fish. Source: Gladstone Observer (9/7/2005).

64 Austasia Aquaculture | August/September 2005

STURGEON GO TO THE US Mark Zaslavsky has imported live Beluga sturgeon into the US in an attempt to establish a Beluga caviar business based on aquaculture of the fish, which is threatened because of the demands on wildstock elsewhere. Real Beluga caviar - as opposed to the range of imitations on the market - commands as much as $200 an ounce. Mr Zaslavsky hopes to produce 10 tonnes annually from the 200,000 fish he plans to keep on a farm in Florida. Source: Jeremy Kaplan in Time Australia (6/6/2005).

OTHER MARINE FISH STRIPED TRUMPETER A GOOD OMEGA-3 BET Scientists have found that the striped trumpeter has potential as an aquaculture species. The trumpeter is already sought after, perceived as one of the best eating fish in Australia and esteemed as shashimi in Japan. Investigations have now shown that cultured trumpeter raised for 2 to 4 years on a specific diet have greater levels of oils, including Omega-3 oils, than samples of wildstock trumpeter. The levels recorded are the highest known to the researchers, of any cultured fish. The scientists have recommended further studies to ascertain culture processes leading to an optimum oil content and type. Aquafin Cooperative Research Centre chief executive Peter Montague, addressing a Hobart conference on the sustainable aquaculture of finfish, described the trumpeter as a well-regarded species that would fill a need as farmed salmon become increasingly subject to world price competition. However currently an obstacle to starting farm production is rearing enough healthy fingerlings to the stage when they can be placed into sea cages. Source: A paper produced by P.D. Nichols, M. Brock, G.A. Dunstan, M.P. Bransden, R.M. Goldsmid and S.C. Battaglene, reproduced in Food Australia (July 2005); Charles Waterhouse in the Hobart Mercury (6/7/2005).

PUBLIC THANKS TO BUG FARM SUPPORTERS The bug farm proposed for Moreton Bay was given the goahead by the NSW Government early in July. The $40 million project could create employment for 200 people after six years. Michael Dalton, managing director of Australian Bay Lobsters, has publicly thanked those who supported the project, which will be the first commercial-scale lobster production facility in the world. In 2004 the proposal met fierce opposition by locals expressing concerns about some aspects of the venture, including an increased risk of flooding. It was

FISHENEWS

subsequently classified as a state significant development which removed approval from the Tweed Shire Council. There are 110 conditions attached to the approval. Kingscliff Chamber of Commerce president Des Ireland is mooting the development as having great potential for tourism promotion in the area. However, Clinton Beisler, Convenor of the Oxley Cove Community Group, claims suggestions of wide-spread support for the venture are incorrect. He asserts he's getting many phone calls from locals appalled by the decision. In a letter to the editor of the Daily News he lists a number of issues which he says remain unchanged, including problems relating to flooding, agricultural land damage, odours, no environmental impact examination, and discharge into the Tweed. Mr Beisler points out the NSW Department of Planning has failed to respond to more than 200 letters of objection from Oxley Cove residents. He also challenges Mr Dalton's claim of input and support from the Tweed Shire Council, and notes that Mr Dalton didn't include a range of groups which would be most directly affected by the development in his list of those supporting the venture. Mr Beisler observes that those groups will continue to oppose the development. Source: Daily News (2/7/2005, 4/7/2005 & 6/7/2005); Clinton Beisler, Convenor, Oxley Grove Community Group in a letter to the editor of the Daily News (8/7/2005).

QUESTIONS ASKED â&#x20AC;&#x201C; CLAIMS OF 'PRO-INDUSTRY' ATTITUDE Kris Hanna, a Greens member of the SA State Parliament, has again raised the issue of the location of the growout cages being operated by the Stehr Group in Boston Bay. The cages are established on the site of a former Government research lease - the lease was legitimately transferred under the Aquaculture Act. However the Greens have asserted they'll continue to monitor aquaculture regulators and what they allege is a pro-industry attitude and a lack of environmental oversight. PIRSA advice is that the cages are being operated legally and the activity does not contravene the Lower Eyre Peninsula Aquaculture Policy. Farmer Hagen Stehr advises that environmentalists with questions about the location of the site are invited to visit it. He has also invited Mr Hanna. Mr Stehr explains his company has the highest environmental standard - ISO 14001 - and leads the industry in research and development. Source: Port Lincoln Times (30/6/2005 & 7/7/2005).

ASSESSMENT EXTENSION FOR TUNA FARM Environment Minister Judy Edwards has pleased the community group Vive La Recherche by extending the environmental assessment for the proposed M.G. Kailis tuna farm from four to eight weeks. She has also directed the company to prepare a monitoring and management program for the two-year trial of the 150-tonne farm, which is in the Remark islands area of the Recherche Archipelago. However, the Vive La Recherche Group has expressed disappointment the project was not granted the highest level of assessment, which would have satisfied the wishes of the Esperance community. The farm has been placed at the second level of assessment. Source: Kalgoorlie Miner (8/7/2005).

FISH ESCAPES AND NAVIGATIONAL HAZARDS-NEW CONTROLS The State Cabinet has been examining new regulations developed to address regular complaints about fish escapes from marine farm containments, and there'll also be consideration of processes to deal with the issue of marine farm structures as navigational hazards. The new regulations on controls for fish escapes were drafted by Primary Industries and Resources South Australia (PIRSA). The size limits on kingfish taken by recreational anglers have been dropped to help resolve the problem, however the issue of mulloway escapes another concern - has not yet been addressed. The SA Marine Finfish Growers Association has been meeting with PIRSA to discuss matters such as net repairs and inspection diving frequency. A code of conduct is also being prepared covering the logging of dives and research into net materials. Regulations on how companies mark their structures with lights and other identifiers are being reviewed by Transport SA officials. Source: Stan Gorton in the Port Lincoln Times (7/6/2005); Eyre Peninsula Tribune (16/6/2005).

RESEARCH INTO LOBSTER FARMING Live Queensland tropical rock lobster wholesales into Hong Kong and mainland China for between $35 and $45 a kilo, returning $20 to $30 a kilo to the fishers. The catch is capped at 700 tonnes annually from a limited area in the wild. Wild harvesting is complicated since for reasons unknown the lobsters can't be captured in pots - divers collect them. Queensland's Department of Primary Industries and Fisheries aquaculture stock enhancement facility is working towards a technique to breed and grow out the creature. The project, headed by Dr Clive Jones, is now in its fourth year, funded by the Fisheries Research and Development Corporation. The greatest problem to date has been growing the lobsters through their many stages while preventing them from succumbing to bacteriological infection - a hygiene and water quality issue. Assumptions are that another five or six year's research will be required before the problems are resolved. The painted crayfish is favoured because it grows out far more rapidly than the western or southern crayfish. Source: Ian Morgan in the Queensland Farmer (June 2005).

SAAM GETS $17,000 GRANT-AND HAS A 'KICK-ARSE PRODUCT'! South Australian Aquaculture Management (SAAM) has won a $17,000 grant and been commended for its approach to building exports. The grant has come as part of the Export Market Development Grants, aimed at supporting companies to continue their overseas successes. Companies can apply for the grant annually, though it's tied to a company spending at least $15,000 on product promotion overseas, after which half of each dollar spent can be claimed. In associated news SAAM's kingfish has been described as a 'kick-arse product' by Americans. SAAM has been sending kingfish to San Francisco, Napper Valley and Miami, working in conjunction with the national Food Industry Strategy under which top chefs in such areas have been targeted. Recently there was an Australian Seafood Extravangaza in the Austasia Aquaculture | August/September 2005 65

FISHENEWS

Napa Valley which attracted a huge number and range of interested parties and the media. SAAM kingfish is regarded as a high end product which is extremely versatile. Source: Whyalla News (26/5/2005).

'FAIR GO' ARGUMENT NOT APPRECIATED Writing as a guest columnist in the Kalgoorlie Miner, Elaine Siemer, Convenor of the 'Vive la Recherche' group, has expressed concerns at a recent request by the president of the WA Aquaculture Council for a 'fair go for the tuna farm'. She points out that while opponents of the project agree with president Dan Machin's opinion "It was important the level of review was thoroughly considered and debated by all parties", there's argument with the statement 'the project should be given a fair go'. Ms Siemer states, "We are of the opinion it is this community which should be given 'a fair go' by a decision from the Minister for the Environment to assess the project at the level of an Environmental Review and Management Plan. This would provide members of the local community with an adequate period of time in which to formulate and communicate their ideas on the possible environmental impacts of the proposal." The Environmental Protection Authority has decided to assess the proposal at the level of a Public Environmental Review - and this has been appealed by 10 parties, showing a community desire to pursue debate at a higher level. Thus, states Ms Siemer, a higher level of debate is necessary. MS Siemer also indicated reservations that the executive director of WA's peak aquaculture body aligned his organisation with implementation of a project which had, she asserted, a dubious right to be considered the practice of aquaculture - and which pre-empts the implementation of a management plan for the Recherche Archipelago. Source: Elaine Siemer in the Kalgoorlie Miner (1/6/2005).

MUD CRAB FARM IN DARWIN Two Aboriginal communities, Kulaluk and Minmarama near the heart of Darwin, have signed agreements to establish a mud crab farm. The Federal Government will provide $350,000 for the venture under a shared responsibility scheme. The communities will help run the farm and allow access on request for people to learn from the project. The Gwalwa Daraniki Association, in partnership with NT Fisheries and Tropical Aquaculture Australia, hopes within five years to be producing 100 tonnes of mud crabs each year. Source: Ashleigh Wilson in the Weekend Australian (21/5/2005).

TREPANG FARMING IN THE NT Tasmanian Seafoods, a company which has been diving commercially for trepang since the early 1990s, has completed a hatchery trial at the Darwin Aquaculture Centre and is poised to move into commercial farming of the species. Juveniles have been produced and there are now moves to cultivate a bigger group of fish. Options for land purchases for farming are now being considered. Currently the company harvests around 30 tonnes each year for export to China, with a value of $4 million. Farming the species could build that figure to $20 million. Source: Paul Dyer in the Northern Territory News (30/5/2005)).

66 Austasia Aquaculture | August/September 2005

TUNA SALE NEGOTIATIONS Over the next weeks tuna companies will progress negotiations with buyers in Japan to pin down the price for this year's bulk tuna contracts. Fresh tuna prices have improved over last year's but only negotiations will determine the frozen product value. Prices depend on market conditions, with supplies coming from various parts of the world. Tuna industry spokesman Brian Jeffries advises he anticipates the Mediterranean catch will be significantly lower than last year's. The Mexican season is about to commence. Source: Stan Gorton in the Port Lincoln Times (26/5/2005).

ROW OVER ESCAPED FISH IN MACQUARIE HARBOUR West Coast Mayor Darryl Gerrity claims 10,000 to 30,000 trout and Atlantic salmon, each weighing between 5 and 10 kilos, escaped from a harbour fish farm in May and are being targeted by fishers from all over Tasmania. The fishers are netting the escapees, leaving frames and guts on boat ramps, some walking away with between 100 and 200 fish each. Councillor Gerrity asserts escapes from farms occur constantly, and Primary Industries Minister Steve Kons and the marine farming division should examine the issue and do something about cleaning the problem up, since it's not a good look when tourists visit. A Tasmanian Government spokesman has suggested that, if the Council has concerns about debris left by fishers, they should consider applying for funding for signage encouraging anglers not leave a mess. Source: Burnie Advocate (17/5/2005); Charles Waterhouse in the Hobart Mercury (17/5/2005).

'BE REASONABLE' ASKS AQUACULTURE COUNCIL Dan Machin, executive director of the Aquaculture Council of WA, has said project developer MG Kailis has gone out of its way to make sure all questions about the project to farm southern bluefin tuna in the Recherche Archipelago can be addressed. He has urged the Esperance community not to appeal the level at which the Environment Protection Authority will scrutinise the venture. He believes the project should be given a 'fair go', and interested parties should pursue accurate debate. Environmental groups are demanding the project be assessed at the highest level of scrutiny. MG Kailis has scaled down its proposal and must submit a scoping study leading to a public review. Currently a Community Reference Group is being established, with MG Kailis supporting the second highest level of assessment. However a petition opposing a trial of feedlotting in the archipelago and signed by 1611 people will soon be presented to State Parliament. Ten appeals for a higher level of assessment were received by the end of the appeals period. MG Kailis proposes two trial seasons, from December to July, over five years, using four to six circular pens each 40 metres in diameter and 20 metres deep. They would placed in about 40 metres of water off Remark Island Source: Megan Sadler in the Kalgoorlie Miner (17/5/2005); Victoria Young in the Esperance Express (17/5/2005); the Esperance Express (17/5/2005)

FISHENEWS

OYSTERS CENTRAL COAST OYSTER FARMS TO BE QUARANTINED From December, Central Coast oyster farms are to be quarantined for an indefinite period while the Department of Primary Industries investigates the problem of the QX virus. The study, to determine whether the pest exists in the area, is being funded by the State Government as part of a $2.8 million package to help oyster farmers. The quarantine process allows oysters to be brought into the area to be grown, but oysters in the area may not be moved out. It's expected the study will be completed by late 2006. There are around 48 oyster farmers in the area. Much of the money will be used to pay for the costs of removing dead stocks and infrastructure over the next three years while QX-resistant oysters are being grown out - the seed stock was supplied earlier this year using government funds as more assistance to growers. However it's been suggested it may cost as much as $6 million for the cleanup. Source: Central Coast Express (29/6/2005); Andrew Tillet in the Hornsby Advocate (30/6/2005).

CHANGES PREDICTED TO INCREASE OYSTER PRICES Loss of government funding for water quality monitoring combined with the loss of Hawkesbury River oyster production is predicted to increase the cost of oysters to the consumer. NSW oyster farmers will receive only $400,000 in State funding for water quality testing in this financial year less than half of the amount made available last year. Farmers will be required to make up the difference. It's been calculated costs for tests will represent around 12 per cent of farmer's income in meeting industry safety regulations. There are suggestions this may force industry leaders out. It's expected the cost increase will appear to consumers in September this year. Farmers are preparing to approach local councils in a bid to gain some support in exchange for the water monitoring and databases. There's also a possibility an independent review will illustrate the benefit of water quality testing to councils and help secure funding. There are claims that the 12 per cent of income cost to NSW farmers places them at a disadvantage compared with operators in Tasmania and South Australia, where costs are 2 per cent of income. Source: Karisa Whelan in the Milton Ulladulla Times (29/6/2005).

AKOYA PEARL OYSTERS IN THE TWEED Following an 18-month trial, Robert and Lee Eyre are hoping over the next 12 months to turn their Birds Bay Pearl Farm into a booming aquaculture and tourism business. The farm, set at Terranora Lakes, is thought to be the only pearl tourism site on Australia's east coast. The Eyres have received nearly $50,000 under the Sustainable Regions Program to help establish the project. The couple have a development application in with the council. Plans are to grow about 10,000 pearls annually. Source: Tanya Kirkbride in the Gold Coast Bulletin (8/7/2005).

OYSTER FARMERS WORRIED OVER 'DORMANT' QX At a recent meeting in Merimbula arranged for oyster farmers by the NSW Department of Primary Industries (DPI), a number of discussions were pursued. DPI staff offered information on nursery operations, breeding, new initiatives and export opportunities. The Select Oyster Company's Ray Tynan talked about industry issues. Farmer Dominic Boyton canvassed nursery operations. Fisheries Research and Development Corporation work on the commercial production of Sydney Rock oysters was also explained. However, of great concern to local farmers is the knowledge that the QX disease organism is known to be lying dormant in Merimbula and other estuaries, and it's not known what may stimulate it to become active. There's much activity in preparing applications for funding to support further research into the disease. The State Government is now undergoing increasing pressure to deal with a huge departure of farmers from the industry, with the New South Wales Farmers' Association supporting calls for the NSW Treasury to deliver on commitments made by the Government. Growers are concerned that the Government hasn't implemented the next stage of the QX recovery package, established to assist farmers whose crops were completely destroyed by the disease. A major issue is that it seems the Government is stalling on delivering the assistance package's cleanup component. This is vital to farmer's ability to rebuild the industry. Currently farmers are forced to simply leave the industry, leaving behind infrastructure. There's also the issue of the cost-sharing process associated with funding water quality monitoring. However NSW Premier Bob Carr recently stated growers will receive $2.8 million in further assistance, including a clean-up package to help remove dead and infested stock and infrastructure. Source: Bethany Dortmans in the News Weekly (8/6/2005); Port Macquarie News (15/6/2005); AAP Newswire (23/6/2005).

POINTS ON PACIFIC OYSTERS Ms Sabine Ditman, senior lecturer at Flinders University, recently spoke during a series of informal science talks presented by the Great Australian Bight Marine Park and the Flinders University Lincoln Marine Science Centre. Discussing the threat to vital mud flats from development and invasive species, Ms Ditman noted that while Pacific oysters were an invasive threat in some parts of the world such as Germany, on Australia's West Coast where there are many Pacific oyster farms the lack of freshwater rivers and estuaries they required for breeding meant that they hadn't gone feral. Her comments were supported by Oyster Growers Association president Michael Willas, who added research work had shown that the genetics of Australian oysters had changed very little since their introduction in 1947. Mr Whillas observed that oysters had been farmed in Coffin Bay since 1967 without going wild. Another issue was that while Pacific oysters had been a problem in New South Wales, the local industry believed they could tolerate salinities as high as 36 parts per million. Source: Port Lincoln Times (7/6/2005).

Austasia Aquaculture | August/September 2005 67

FISHENEWS

ENVIRONMENTAL FLOW REDUCTION A THREAT Greens MP Ian Cohen advises that under level three water restrictions imposed by the State Government, environmental flows to the Hawkesbury will be cut by 50 per cent - a daily release change from 50 to 25 megalitres. He predicts this will cause permanent damage to the river, which is already in very poor condition. Oyster farmer's operations will be prejudiced by the restriction. Minister for the Environment Bob Debus responds that reducing the flow balances the need to preserve drinking water supplies against maintaining flows for river health. He states the Sydney Catchment Authority will bank the water saved and it may be released for environmental purposes when the drought breaks. Source: Emily Toxward in the Penrith City Star (7/6/2005).

OYSTER FARMERS ANGRY, TALKING ABOUT THE PROBLEM The Oyster Farmers Association is to demand answers from the Department of Primary Industries in June following delays in planning to clean up the Hawkesbury River, which is required prior to setting out of Government-supplied replacement QX-resistant oyster stocks. Some 23 oyster farmers in the region are fearful of more job losses as the QX parasite remains unchecked in the area. Farmers have offered to help the Government clean up the area, and the Association submitted its own plan for a clean-up on May 12. Growers met at a Department of Primary Industry event in Port Macquarie on 29 June to discuss the outbreaks and other industry issues. Experts were available to highlight industry research, and there was a plethora of information on breeding, nursery oper-

ations and new initiatives. Mark Bulley, chairman of the NSW Farmers Hastings River Oyster branch, observed that information on the QX outbreak was especially important to growers. However a major concern for local growers was water quality, with growers considering themselves guardians of water quality. He noted, "We pick up changes well before anyone else." And the debate over the cost of monitoring water quality continues on, with predictions of as many as a third of NSW oyster farmers quitting the business if the government doesn't continue its part-funding of the monitoring costs – which provide benefits to other areas of the community. Source: Shoba Rao in the Daily Telegraph (31/5/2005); Port Macquarie News (1/6/2005); Jan Shorrock in the Daily Examiner (3/6/2005).

DAIRY AND OYSTER FARMERS WORK TOGETHER Dairy farmers, oyster growers in the Crookhaven River, and the Southern Rivers Catchment Management Authority (SRCMA) are involved in a joint project to control the problems created by cattle which can access the river banks. The cattle create pollution by defecating at the water's edge, and cause erosion. Under the scheme, which also involves Landcare and Greencorps volunteer efforts, cattle are being fenced away from large sections of the waterway. The work is providing real benefits for the environment as well as to oyster growers. Mangroves are already regenerating and will eventually help keep the waterway clean. Source: Glenn Ellard in the South Coast Weekly (16/5/2005).

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68 Austasia Aquaculture | August/September 2005

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