Editors Letter. 72&Rising Volume One
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Welcome to the first edition of 72&Rising! This is a magazine dedicated to our water planet. If you were to take a trip into outer space, you might see why Earth is often labeled the blue planet. We are a rock in space, 72% of whose surface is covered by water; water that is rising. Water sustains everything alive on Earth, whether it is to live in, gather food and water from, for transport or a myriad of other reasons, it is vital to our day-to-day survival. Our magazine is designed for all those with a passion for our oceans and freshwater ecosystems, for those who have a thirst for knowledge and an inquisitive nature. Created specifically to satisfy an appetite for more information about our aquatic realm, our content ranges from wildlife and the environment, destinations and adventure, conservation and science to photography, news and many other gems. This first free issue is dedicated to one of my own passions, sharks! Our Wildlife & Environment contributors provide an insight into the Sharpnose Shark of North and South America, allowing us to understand their behavior, movement patterns and the threats and conservation issues surrounding this lesser known shark species. Still in the Wildlife & Environment department, our regular article on the Top Five Critters features in this issue the Julian Rocks Marine Park in Byron Bay, Australia. From massive whales to small cuttlefish, we investigate what makes the JRMP such a unique location for these animals. Our Gallery features photographer John Natoli as he showcases some of his favorite shark images. Alex Mustard provides us with some tips on how to photograph the classic anemonefish, one of the most frustrating subjects for a photographer, and in our regular Readers Photos section, we present some of our readers prized aquatic related images.
Editor: Our Science pages feature the work of Charlie Huuveneers, a shark Rowena Mynott biologist in South Australia. Dr Susan Theiss provides an in-depth
article about her work on shark vision and our resident marine
Copy Editor: biologist answers your watery related questions. Sebastian Mynott Creative Director: Steve Sanshwe Publishing Director: Simon James
Ever wanted to know more about shark nets? Well, I take a look at the Australian beach meshing program and highlight some of the issues in order to let you make up your own mind about this highly debated topic. Also in the Conservation arena, Seanna Cronin discusses the Discovery Channels Shark Week series and Marcel Mariozi talks to Paul Hamilton about the new Guinness record holding aquarium in Dubai.
Photographers: As you can see it’s a jam-packed issue. We hope you enjoy sitting John Natoli back, relaxing and flicking through the pages. Alex Mustard
Rowena Mynott
Contributing Writers: Editor Rebecca Davis Rowena Mynott Andy Murch John Natoli Sebastian Mynott Marcelo Mariozi Seanna Cronin Jeff Shaw Researchers: Dr. Charlie Huuveners Dr. Susan Theiss
mmeanrtes o c s ’ r e d Our croenatribuptiinognsus on andal to kee roviding vitack with p ant to tr what you w value y reavdi.ewWse. For laena se p r youespondence at corr contact uesdia.com wntm info@ha
contents 72&Rising Volume One
Featured Artis Portfolio John Natol t i
y r e GALLERY l l a g ADMIT ONE
ANI
Migr MAL a plac tions a EVEN n e th is ed d anim TS al a i t ion . . . . . . . . . . . . . . . . . . ANI ctiv ities M Top A taki L 10 c ng L I ritte N E r U s P to sp FOC 9 ot th Shar US O is m NA pnos onth e Sh . . . . . . SPE ark. . . . . . . . . . . . . . . . . . . 11 CIE
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ALSO FEATUR
ING Photography Ti ps . . . . . . . . . . . . . . . . . . . . . . . . Readers Photog . . 3 raphy. . . . . . . . . . . . . . . . . . . . . . . 7
wildlif environm e & ent
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A GREAT WHITE ADVENTURE PG.20
FOCUS ON A SPECIES
n o i t a n i t s de dventure &a
sharpnose shark PG.13
17 O VISIT T S E C PLA ck Cave. . . . . . . . . . . . . . . . . . . . Fish Ro 20 EPORT TRIP R ture. . . . . . . . . . . . . . ven hite Ad W t a e r G
n o i t a v r e s n co issues S 24 ISSUE am . . . 1 r N g o O r I P 3 VAT eshing
ER n Beach M CONS ia s u tral
33 A 47 e Th eek . . . . . . . . . . . . . . . . . . . . . . . . . W . . . . . . . . . . . . . . . . . . . . l k l r a Sha eM ined . . . . . . . . . . . . . . . s In Th Shark inning Expla F Shark
E S IN TH K R A H S LL PG.33 MA
“The seek mistake not c ing to d we mak e estr a oy eithe de ring stupi stroy th if we ina sharks o r in is th dity. em is on dverte r in at we I nt e wi f I ha of cos ly a animnd prote ll come ve one homic t ignoals beforct these o apprecpe it w r i e to wiance, stu we manaonderful ate ge, t pe th pidi hr em ou ty an t alt d gre ough - Pe e oget ter B her.� d, ench ley. Auth or of
SCIENC
E Focus o n a rese archer Austral Shark E ia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cology in Ask A M South arine B iologist. . . . . . . . . . . . . . . . . . . . . Guide to Shark v ision. . . . . . . . . . . . . . . . . . . . . . 40 43 45
FUN PAGES Fish Bites R ecipe . . 48 Media Revi ews. . . . . 49 Competitio ns . . . . . . 50
scie
nce
PHOTOGRAPHY PORTFOLIO:
JOHN NATOLI I was a late starter in the sport of scuba diving being certified as a Padi Open Water Diver at the age of 46. In no time, I became addicted to the sport and quickly advanced my certification to PADI Rescue Diver. On obtaining my certification I commenced diving every Friday and have continued doing so ever since - clocking up no less than 100 dives every year. Then came the digital camera and I thought “Why not? Capturing the images of my experiences would extend the thrill of diving into my home and allow me to share these moments with my family and friends.� When photographing, I use a rule of thumb that generally works well for me - on days where the visibility is under 10m I will always use a 105mm macro lens and spend most of my time scouting for little critters. It is amazing what life you will find when you slow your dive down and take the time to spot the little wonders of the ocean - nudibranchs, crabs, little eyes of an octopus hiding in their holes, blue ring octopus, mantis shrimp, a variety of gobies and blennies and much, much more. And then, when the visibility picks up over 20 metres, particularly when the Grey Nurse or Leopard sharks are about, out comes either the wide angle 18 - 70mm zoom lens or a fish-eye lens - either a 10.5mm fixed lens or a Tokina 10 - 17mm zoom lens.
72: WILDLIFE AND ENVIRONMENT
Underwater photography is now an ever-consuming passion. In fact, I feel almost naked if I venture into the water without my housed camera - always on the lookout for the elusive award winning shot, which may one day grace the cover of National Geographic.
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SEE MORE PHOTOS www.natoliunderwater.com All photos Š John Natoli
001 Anemonefish over purple tentacles. Try using a different viewpoint to create a more original take on the anemonefish photo. Nikon D100 SLR. Subal housing. Nikon 60mm. 1/180th at f22. 2 x Subtronic Alpha strobes.
72: WILDLIFE AND ENVIRONMENT
A GUIDE TO SHOOTING NEMO By Alex Mustard
It is often the most exotic subjects that make us first want to take a camera underwater: sharks, manta rays, dolphins. But much of the time, by the nature of diving we end up pointing our cameras at more everyday subjects. If you do the majority of your diving on coral reefs then this often means anemonefish.
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I’d confidently predict that around the world divers take more pictures of anemonefish than anything else. Technically, getting a photo of an anemonefish is pretty straightforward with either a digital compact or SLR. But despite there being lots of decent photos out there, truly outstanding ones are few and far between. The main photographic problem with anemonefish is one that they share with young children. Namely, they never stay still long enough to allow us to compose, focus and expose that special shot. I regularly wait patiently in front of anemones, watching those pesky little fish buzzing around, with the ideal image in my head, struggling to transfer it to the camera. The best anemonefish photos require perseverance.
It’s the pretty ones we’re after. Many anemones are drably coloured, others have dull sausage-shaped tentacles - we don’t want these. Avoid ones covered in specs of sediment, as this always shows up in your pictures. We want the super-models of the anemone world with tentacles in interesting shapes and colours, accompanied by skirts in even brighter hues. The striking red skirts of the anemone photo here is a great example. Pose any fish against this punch of poster
But we’re getting ahead of ourselves. Before we dedicate precious dive time to waiting for that perfect pose, there are other factors to consider. The key to great anemonefish shots is not the fish, but the background. So when we’re down on the reef, it is not so much a case of finding Nemo, but finding the right anemone.
002 Anemonefish under breaking waves. The red skirt of the anemone contributes significantly to the impact of this photo. Nikon D700 SLR. Subal housing. Nikon16mm fisheye with a 1.5x Kenko teleconverter. 1/125th at f10. 2 x Subtronic Alpha strobes.
colour and the result is certain to be eye catching. The good news is that whatever colour you can find, the anemone will come with attendant anemonefish.
photographic time in the lighter coloured individuals, or at least to fish where the lighter coloured face continues behind the eye. It will pay off in the pictures.
Another factor to look out for is fluorescence. Some anemone’s fluoresce red and are usually well known to dive guides who point them out in briefings. Examples are the one near the stern of the USAT Liberty wreck in Bali or the well-known one at 10m at Small Crack, in Sha’ab Mahmoud in the Red Sea. On film this fluorescence always seems to photograph a disappointing brown, but digital cameras capture it much more effectively.
So we have got the right anemone and fish, how do we get the image? First, resist pursuing the fish around the anemone with your lens. Your pictures won’t be in focus and your head will spin. The one guarantee with anemonefish is that they are not going anywhere. Instead watch the fish for 30 seconds or so. Most anemonefish swim quite regular circuits round their anemone and seem to have favourite spots where they like to look out from. Find a photogenic feature on this route, such as a fold in the skirts, take a test shot to be sure of exposure and then wait for the fish to appear. Then fire. Keep shooting until you have bagged the perfect pose. Take plenty of frames because it is also easy to be slightly off with the focus or to clip a fin.
Worldwide there are 28 species of anemonefish and few photographers have completed the set. I am still over 10 short. Even within each species there are differences, which are important for photographs. With anemonefish the definition of the eyes is the crucial feature and in some species, such the Red Sea anemonefish, this is very variable. In all portraits good eye contact with the subject is an essential element. With anemonefish, if their body colour is too dark then their eye, and therefore eye contact, tends to get lost in this background. So look to invest your
That is exactly what I did with the wide angle picture here. I visited these same anemones on three dives during this particular day. Selecting the wide lens for the final dive, when I expected them to begin to close and reveal more of their red skirt, which I thought would look best against some blue
water. Anemones often show more skirt in the afternoon, as they close up after a day of catching the rays. Looking at the times on the files, I spent about 15 minutes with this anemone and shot nearly 40 frames. I have many similar shots, but I like this one because the wave breaking overhead adds that something special. Technically the shots are straightforward to produce. For close ups and macro images shoot with only strobes for lighting, using a small aperture and the fastest shutter speed possible with flash. This will produce clear, sharp images, without any blur from
003 Anemone fish portrait. This anemonefish lived in a dull anemone so I got the camera low and framed it against open water.
72: WILDLIFE AND ENVIRONMENT
Nikon D2X SLR. Subal housing. Nikon105mm macro lens. 1/50th at f14. 2 x Subtronic Alpha strobes.
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subject movement, particularly tentacles waving in the current. For wide-angle images you must balance your strobe lighting with the ambient light, so that the foreground (anemone) is lit with the strobes and the background (reef and water) is illuminated with the ambient light. I have heard many people say don’t enter an anemonefish photo in a competition, you will never win. This isn’t true, first public votes often favour these cute, familiar subjects. But also note that we judges always comment that many entrants send in photos of their best dives, rather than simply their best photos. Common subjects give photographers the chance to show what they can do, rather than how lucky they have been with an encounter. You can capture a great photo of an anemonefish with any camera. If you can come up with something eye-catching and original, you might just have a winner on your hands.
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READERS PHOTOGRAPHY
72: WILDLIFE AND ENVIRONMENT
Fabrice Jaine (top) South African seascape shot in Mosselbaai. This morning I was going out at sea and was mesmerized by this scene of a cloudy sky and divided sea. I was lucky to have these seagulls in the shot, moving as if they were trying to avoid crossing the border and getting onto the dark side. It reminded of the South African Apartheid and all the discrimination that still exists today. Shot at ISO 100, 1/400, f/4.0, 17 mm
Fabrice Jaine (left) Golden sunset photographed at low tide on North Stradbroke Island, Australia. While taking a walk on the island I live on, my eyes were attracted by that scene of a boat resting on an exposed sandflat at low tide, with a wonderful golden sunset in the background. I tried to compose the image so that all the elements would lead the eye to the sun setting behind a mystical cloud mass. Shot at ISO 100, 1/250, f/10.0
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photos Š Fabrice Jaine
Fabrice Jaine (left) Sunrise scene photographed in Byron Bay, Australia. For this shot I was aiming to get on the site for an early sunrise session but ended up arriving late. Instead, I was lucky to observe this scene of a sailboat cruising peacefully, with the sun making its way up high in the sky through a thick layer of stormy clouds. Shot at ISO 100, 1/250, f/9.0
GET YOUR PHOTOS PUBLISHED email: info@hawntmedia.com
With the title ‘Photos’ in the subject line. Please submit your photos as original sized jpegs and also include your name, your location and a title for each photo.There is a maximum of 3 submissions per person per issue. Don’t forget to accompany each photo with a 50-word description or story. Unfortunately we are unable to return the images, so make sure you retain a copy. Your submission of photos to ‘Readers Photos’ grants 72&Rising the right to publish them at any time in the magazine or website with proper accreditation. info@hawntmedia.com
Carlie Edwards (below) (From Left) Butterfly fish taken at Sacred Rock, Isle of Pines, New Caledonia. Surgeonfish taken at Savu Savu, Fiji. Hawkfish taken at Champagne Bay, Vanuatu. Olympus compact
photos © Carlie Edwards
CALENDAR:
APRIL - JULY Whale sharks at Ningaloo
ANIMAL
EVENTS
Ningaloo Reef, Australia. Ningaloo Reef is located within the Ningaloo Marine Park off the west coast of Australia. The reef is the largest fringing coral reef in Australia and the only reef of its size to be found so close to a continental land mass. It is so near in fact that at its closest point it is just 100 meters offshore. As a result of its relative remoteness from major population centers and lower profile compared to the Great Barrier Reef, Ningaloo Reef has had relatively little damage from tourism. Beautiful corals still abound as well as a plethora of marine life including, at the right time of year, a large congregation of whale sharks.
72: WILDLIFE AND ENVIRONMENT
This seasonal aggregation is linked to the increase in coral spawn that occurs here each year around March to April. The whale shark is the largest fish in the sea growing up to 18m long. Despite their enormous size and their name they are nothing to be feared, in fact their name is a little deceiving. Whale sharks are not whales at all, and yet neither do they present an image of sharks in the traditional sense. They do not have teeth but prefer instead to filter feed on plankton. These amazing animals visit Ningaloo Reef each year between April and July. Whale sharks may live up to 150 years; however, the ones seen at Ningaloo are on the smaller side and it has been suggested that they may be juveniles or young adults gathering here. No matter whether they are large or small, swimming beside a whale shark is a once in a lifetime experience.
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APRIL - SEPTEMBER Coral Spawning
MAY - SEPTEMBER Giant Cuttlefish Spawning
JUNE - JULY Sardine Run and Humpback Migration
Hawaii, U.S.A.
South Australia
The wild coast, South Africa.
The Giant Australian Cuttlefish are the largest species of cuttlefish in the world. Reaching almost one meter in length and weighing up to 10 kilograms, these chameleons of the ocean spend much of their time resting and hiding from predators. The big exception to this rule is during breeding season when thousands of giant cuttlefish gather together to spawn. Their preferred breeding grounds are the rocky shores that line the area of South Australia around Whyalla. The females will deposit their eggs on the undersides of rocky ledges in the bay. Performing his main role in life and one that he will only be able to do once, the male fertilizes the eggs, which finally hatch out a couple of months later. Sadly both the male and the female will not live to see the next years season as, with a life span of only two years, they die not long after The coral spawning in Hawaii at this time of breeding is complete. the year is a remarkable event as it is the only place in the world where the spawning can be viewed in daylight hours. As the corals start their reproduction, other marine creatures such as sea starts, urchins and marine worms are stimulated to initiate their own spawning. Of course the increased particles in the water are food for some, and filter-feeding fish are drawn in to feed on the sperm and eggs, which in turn draws in larger marine predators.
Granted, compared to giant cuttlefish and whale sharks, sardines don’t seem all that exciting. However in the cool waters off South Africa, these sardines congregate in such a volume that some have said they resemble the great wildebeest migrations of the Serengeti. In terms of the size, the shoals of fish can often reach more than seven kilometers long, and can be 30 meters deep. For as yet unexplained reasons these little silvery fish, schooling together in large bait balls, migrate east to the warmer waters of the Indian Ocean. Its not only the amazing sight of so many fish en-masse that people flock to see, it is the predators that follow them that make the trip all the more exciting. With so many tasty treats in the water the temptation for larger pelagic creatures to follow is just too much. Seen from the air sharks carve distinct paths through the shoals as they feed and send the small fish scattering for cover. The surface of the water boils with the activity below as sharks, dolphins, larger game fish, and many marine birds such as penguins and seagulls have their fill. The sardine run also coincides with the annual migrations of humpback whales along the coast of South Africa who get in on the action, feeding as they pass.
With waving tentacles and sometimes tree like structures, corals were once thought to be plants. Consisting of individual polyps measuring a few millimeters in diameter, these varied and colorful structures are actually a colony of animals. Although some corals are able to reproduce asexually, reproduction for the majority occurs through spawning. Complex cues guide these corals to initiate spawning through a combination of lunar events, sunset times and in some cases chemical signals. Corals that are part of a reef system can be part of synchronized spawning, an event where multiple species release their genes into the water at the same time. Often causing the water to turn a cloudy white, this synchrony is thought to aid in coral speciation where new species can evolve.
animal lineup Julian Rocks: part one Julian Rocks is located within the Julian Rocks Marine Park off the coast of Byron Bay, New South Wales, Australia. The local indigenous peoples, the Bundjalung people, tell the story of a jealous husband standing on the cliff watching his wife canoe out to sea with her lover. Becoming frustrated he threw a spear, which landed in the canoe breaking it in two halves. Each end sticking out of the water has formed the rocks that make up the Julian Rocks today.
72: WILDLIFE AND ENVIRONMENT
The rock itself is part of the local volcanic system formed from an eruption 23 million years ago. Located at the most easterly point of Australia, the warm waters from the north and cooler waters from the south mix around the rocky outcrop to form an eclectic visual sensation of over 600 species of tropical and temperate fish. It is not only home to an abundance of marine life, but is also a nesting ground for many marine birds such as gulls, terns and cormorants. Water temperatures, currents and food resources fluctuate with the seasons and with these changes come seasonal visitors. In our animal line-up this issue we look at the top five critters to find at the Julian Rocks Marine Park over the next couple of months.
Manta Ray (Manta birostris) The largest and most impressive species of ray, mantas have been know to display curiosity around humans, swimming close to divers and snorkelers. This makes for an impressive experience with an animal that can measure up to seven and a half metres across and weigh up to 2300 kilograms. They feed on plankton filtered from the seawater passing through their gills as they glide along. They are known to frequent cleaning stations where small fish such as wrasse, remora and angelfish swim in the manta’s gills and over its skin to feed, in the process cleaning it of parasites and dead tissue. Manta rays are known to live in excess of 20 years. They have low fecundity, giving birth to a single pup, possibly two pups on occasion. Different populations show differences in movement habits and site fidelity. Like many elasmobranchs, manta rays are highly vulnerable to fisheries given their life history and population structure. The IUCN Red List categorizes them as near threatened.
Common Lionfish (Pterois volitans) Their long poisonous spines, giving the appearance of a mane, support the spectacular fins of the lionfish. It is one of the most venomous fish on the ocean floor. Though they are not aggressive toward humans, envenomation from a lionfish sting is normally excruciatingly painful. They are voracious predators, feeding on a diverse diet of reef fishes, but their spines are used mainly for defense. They comprise five genera of the Scorpaenidae family. Commonly adults measure 30 cm to 35 cm in length. They are native to the Indo-Pacific oceanic region. There have been recent introductions into the warmer regions of the Atlantic Ocean and Mediterranean, Caribbean and Red Seas where, because of their aggressive predatory nature and strong defense to predation, they have the potential to cause significant changes to the ecology of these regions.
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Cuttlefish (Sepia apama) Cuttlefish are among the most intelligent of the invertebrates. They have a remarkable ability to rapidly alter their skin colour. They use this for camouflage and counter-shading but also for communication with other cuttlefish. With a name that means ‘head-footed’, this endearing little creatures can grow to 90cm and in some cases such as the Australian Giant Cuttlefish, almost as large as a man. They have ten tentacles that they also use for communication and for prey capture. Their preferred diet is crabs and fish. Their eyes are among the most developed in the animal kingdom with several features similar to a humans eye although they are thought to have evolved independently from those of the vertebrates.
Zebra Shark (Stegostoma fasciatum) Absent over the winter months, the Zebra Shark is a common sighting around the Julian Rocks area at this time of year. Also referred to as a “Leopard Shark” they reach an average size of around two and a half to three metres. Zebra Sharks are usually solitary animals, but can be found in large aggregations resting on sandy bottoms or near coral reefs in coastal waters. Easily identifiable by its spotty leopard-like colouration, this shark possesses a long crescent shaped tail and large rounded head. These docile sharks are harmless to humans, feeding mostly on crustaceans, molluscs and small fishes. They are capable of ram ventilation enabling them to lie motionless on the ocean floor whilst using their mouth to pump water across their gills to breathe. Zebra sharks are oviparous (egg layers), producing three to four egg capsules per month. The eggs are oval shaped, about 17centimetres in length and are very well camouflaged to resemble a piece of seaweed. They have a fibrous material attached that anchors the egg to a reef or rocky outcrop. After around six months, the pup hatches, measuring approximately 25-35cm in length, beginning its life already completely independent of its mother. In most parts of the world, these sharks are classed as vulnerable to extinction by the IUCN. Their population numbers are being depleted by commercial fisheries, degradation of their reef habitat by human development and destructive fishing practices such as dynamiting or poisoning. However in Australia, population numbers are greater as only low levels of by-catch from commercial fishing have an impact on them.
The cuttlebone, which can sometimes be found washed up on the shore, is an internal structure composed of aragonite and provide the cuttlefish with buoyancy.
Humpback Whale (Megaptera novaeangliae) Visiting the calm waters around Julian Rocks, the humpback whale at this time of year is completing its northerly migration. The migration takes place each year as the humpbacks head to warmer waters to give birth and mate. Humpback calves are born with very little blubber and would not survive the cooler southern ocean waters, so the first couple of months of the calves’ lives are spent basking in the warm coastal Australian waters. Part of the baleen whale family, humpbacks possess brush like fibers instead of teeth and feed on a diet of krill. The majority of krill can be found in Antarctica, the starting point for their migration. Having gorged on krill before leaving, they will not eat for their entire journey, an impressive feat especially for a mum feeding a newborn calf. As they make their northern migration past Julian Rocks, they will often show the aerial acrobatics they are most famous for as they propel their up to 40 tonne, 15m long bodies into the air. Lucky divers and snorkelers can hear their haunting song underwater, and might on occasion be lucky enough to be offered a glimpse as they pass. Hunted once from 200,000 animals on the east coast of Australia down to just 100, this population of humpbacks was in danger of becoming extinct. Now due to protection, their numbers are steadily increasing and starting once again to reach healthy proportions.
SHARPNOSE SHARKS
72: WILDLIFE AND ENVIRONMENT
By Andy Murch
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length in metres of the maximum size of the Atlantic sharpnose shark.
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The family Carcharhinidae contains a diverse selection of species from tiger sharks to hammerheads. Many are large, powerful animals that play a vital role in the check and balance of life in the oceans, but there are less celebrated (yet equally important) carcharhinids such as the diminutive sharpnose sharks which live along virtually every continental coastline warm enough to support them. These omnipresent predators can be found from the Eastern Atlantic to Northern Australia and where they occur, they tend to abound.
There are currently seven described species of sharpnose sharks in the genus Rhizoprionodon. However, there is some conjecture among taxonomists regarding the correct number because the Atlantic sharpnose R.terraenovae and the Caribbean sharpnose R.porosus are practically indistinguishable from each other. Vertebral counts officially differentiate the two but some taxonomists feel that vertebral variation is like the differences between eye colors in humans; genetically significant but not worthy of separate species status. For the last eleven years Dr Eric Hoffmayer from the Gulf Coast Research Lab in Ocean Springs, Mississippi has been conducting an abundance and distribution study on the inshore sharks of the northern Gulf of Mexico. Dr Hoffmayer’s longline and gillnet surveys are concentrated around the barrier islands of the Mississippi Sound where shark for shark, Atlantic sharpnoses outnumber all other species combined by nine to one. Dr Hoffmayer is perplexed by the influx of thousands of almost exclusively male sharpnose sharks into the Mississippi Sound each summer because as Dr Hoffmayer believes that this is why male Atlantic habitats go, the sound has very little to offer. sharpnose sharks enter inshore waters with large As well as extremely low salinity which tests the oil rich livers, but by the end of the summer their sharpnoses’ ability to osmoregulate, the Mississippi livers have shrivelled to a third of their original size. Sound is plagued by areas of very low oxygen (dead Unable to consume enough food to compensate zones) which are far from ideal for a ram ventilator for their elevated metabolisms, the sharpnoses are forced to use up their internal energy stores. Even like the Atlantic sharpnose to be foraging in. their muscles lose a significant amount of their mass During the oppressive summer months, the water which leaves the sharks looking visibly emaciated. in the sound also becomes extremely warm which Local fishermen call these withered little sharks adversely raises the shark’s metabolism to the point ‘wormies’. where it has trouble maintaining a calorific uptake high enough to keep up with its increased energy Sharks generally use a combination of lift created by their forward momentum and buoyancy provided by expenditure. their oil rich livers to counteract their natural tendency to sink. Interestingly, Atlantic sharpnose sharks must be capable of adjusting their swimming technique so that they can negotiate their liquid world without their natural internal buoyancy aid.
What the long term effect would be of
completely removing a once abundant
predator like the sharpnose from the ecosystem is unclear but there will inevitably be serious repercussions both up and down the food chain.
It is a common strategy among some shark species to give birth in coastal lagoons where there is protection from larger sharks and an abundant supply of food that the newborns can feed on until they are big enough to venture further afield. Female Atlantic sharpnose sharks also head towards shore in the summer but they generally give birth long before reaching the relative safety of the shallows. Dr Hoffmayer has a couple of different theories on why this may be. Possibly, the gravid females need to conserve more of their energy to nurture their unborn young and therefore they may simply not have enough stamina to complete a long shoreward migration.
Alternatively, female sharpnoses may be more stenohaline than males i.e. they may not be able to tolerate the low salinity that occurs in the sound. Sharks osmoregulate by excreting excess salt through their rectal glands as their environment becomes less salty. If they fail to do this they effectively drown through osmosis; the process by which fresh water continuously tries to infiltrate saltier environments. By excreting salt, the osmotic gradient between the shark and its surroundings is minimised and the
The sound has a reasonably good supply of all these foods but so does the cooler, metabolically more comfortable, deeper reaches of the gulf.
sharks do not become water logged.
safety. Sharpnose sharks are a favourite prey of many other requiem sharks and although bull sharks, blacktips and various other large sharks also venture into shallow water, compared to the shark eat shark world of the greater gulf, the murky Mississippi Sound is a relatively safe place to hide. When inshore temperatures plummet in the late fall, the male sharpnoses are forced out into deeper water where seasonal temperature shifts are less dramatic.
So, considering all the environmental hurdles that the male sharks have to overcome just to stay inshore and the lack of female company, why do so many male sharpnose sharks gather in the Mississippi Sound each summer? Dr Hoffmayer believes that it all comes down to
72: WILDLIFE AND ENVIRONMENT
Juvenile sharpnose sharks have very efficient rectal glands and are well adapted to life in brackish water. In fact, they are able to tolerate salinity as low as 16 parts per thousand. Adult males can only handle a salt content above 22ppt so as sharpnose sharks mature they tend to avoid water where their offspring are hiding. As sharks are cannibalistic by nature, this is a great strategy to protect the young sharpnoses In the Gulf of Mexico, Atlantic sharpnose shark from being preyed on by their parents. numbers remain high. This is partly because there If further studies show that female sharpnose sharks is no directed sharpnose shark fishery and partly are restricted to an even saltier environment e.g. because Atlantic sharpnose sharks reach maturity 30ppt, then that would explain why they pup in after only two to three years which among sharks is deeper water, forcing their young to run the gauntlet rather quick. into the shallows. On the west coast of North America the sharpnose The sharpnose’s appearance in the sound does not story is somewhat different. The Pacific sharpnose appear to be specifically diet related. Stomach content shark R.longurio is an important food fish and the analysis has revealed that smaller sharpnose sharks focus of a large artisanal fishing effort. Everyday, consume a lot of shrimp and squid whereas larger scores of panga based long-line fishermen ply the animals prefer bony fishes especially menhaden. coastal waters of the Sea of Cortez in search of
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sharks. As in the Atlantic, sharpnose sharks are the most commonly caught inshore species but small hammerheads and smoothhound sharks are also taken in fairly large numbers.
Iemanya Oceanica is a grass roots non-profit organization based in La Paz that is working with local shark fishermen around Baja. Iemanya is entrenched in a multifaceted shark conservation campaign that includes education and direct assistance to shark Each boat lowers two or three kilometers of braided fishermen that are ready to look for alternative or monofilament line bristling with 500 to 1000 baited sources of revenue. hooks. Catches may range from a few small sharks per set in the summer months to a hundred kilos or Rather than dictating to fishermen how they should more on a successful day during the winter. make a living, Iemanya’s representatives ask each fishing village to collectively come up with an alternative business plan that will allow them to stop shark fishing. If the plan is practical and sustainable then Iemanya provides as much guidance and financial assistance as possible to help the fishermen change tack.
In the Gulf of Mexico, Atlantic sharpnose shark numbers
remain high. This is partly because there is no directed sharpnose shark fishery and partly because Atlantic sharpnose sharks reach
Time will tell whether the remaining Pacific sharpnose shark population will succumb to the web of long lines and gill nets that crisscross the shallow bays of the Sea of Cortez. Unlike their larger cousins, sharpnoses are physiologically well equipped to bounce back from over fishing because they mature relatively quickly and they can have up to twelve pups each season. Even if their numbers plummet further, if they are left in peace for a few years there is a good chance that they will eventually recover.
maturity after only two to three years which among sharks is rather quick. Little is known about the health of Pacific sharpnose stocks but scientists and fishermen agree that they are probably declining. At present there are still enough sharks to support a modest fishery but this may change if quotas are not implemented soon. One of the big problems is that the gestation period of Pacific sharpnoses may last as long as eleven months so the fishermen consistently catch gravid females before they have had the chance to spawn the next generation. One veteran shark fisherman from MulegĂŠ, who recently returned with seven small sharpnoses after setting 1400 hooks, commented that on his best day twenty years earlier he had landed 1700kg of sharks in the same time frame with inferior fishing gear. A decline of that magnitude does not bode well for the future of the Pacific species. What the long term effect would be of completely removing a once abundant predator like the sharpnose from the ecosystem is unclear but there will inevitably be serious repercussions both up and down the food chain.
To find out more about Iemanya Oceanica and other environmental groups working on the front line of shark conservation, please visit www.elasmodiver.com/protectingsharks
WHATS NAME? IN A
By Andy Murch
72: WILDLIFE AND ENVIRONMENT
500
Estimated number of grey nurse sharks left on the east coast of Australia
1984
The NSW grey nurse sharks were the first sharks in the world to be given protection status in 1984.
2009
In 2009 scientists successfully bred wobbegong sharks in an artificial uterus that is designed to be used to help repopulate grey nurse shark numbers. 17
When it comes to naming things, Australians like to keep it simple. There’s the redback spider, the blue tongued lizard and my personal favorite; the yellow belly black snake. While they may not be the most imaginative monikers, they get the point across.
A twenty minute boat ride from Southwest Rocks (obviously named by an Aussie) there is a craggy pinnacle crawling with marine life that has the most unassuming yet succinct name of all; Fish Rock.
the gutters are completely empty but more often than not, a dozen or more snaggle-toothed sharks can be found levitating in place or slowly milling around like submarines waiting for orders. Sometimes the valleys are jammed with sharks, which leads me to believe that the original estimate of there being less than 500 grey nurse sharks remaining on the east coast, was a little off the mark. Don’t get me wrong, they’re undoubtedly endangered but it wouldn’t surprise me if there are sometimes 100 or more at Fish Rock alone.
It is indeed a rock covered with fish, but the name Fish Rock really doesn’t do it justice. For starters, it is a very big rock. In fact, its a topographic anomaly that soars one hundred meters or more off the sea floor, terminating in a guano covered outcrop of windswept stone, reminiscent of a drowned snow capped mountain. Although the sharks appear to be permanent fixtures, the composition The mostly submerged monolith of the grey nurse aggregation is supports a riotous community of constantly changing. It is hard to invertebrates that act as a living keep track of individual sharks but smorgasbord for tens of thousands of occasionally an obvious newcomer resident fish. At the top of the food will show up. In the summer of 2007 chain, scores of enormous wobbegong the first recorded albino grey nurse sharks sprawl on every available shark put in a brief cameo appearance horizontal surface. While deeper at Fish Rock. I was lucky enough to down, grey nurse sharks meander be there at the time but the ghostly along the shady gullies. apparition was very shy and did not stick around long for the paparazzi. When diving at Fish Rock, it is easy to forget that grey nurse sharks are Albinism in sharks is not a new officially endangered. Occasionally phenomenon but it is rare to see
albino sharks reach adulthood because juveniles that contrast strongly with their surroundings make very easy targets. Along with the grey nurse sharks, there are at least three species of wobbegong sharks living year round at Fish Rock. Spotted wobbegongs grow the largest but banded wobbegongs tend to control the best real estate. The ideal spot for a wobbegong to lay in wait for a meal is an unobstructed flat ledge under an overhang where small fish congregate (ironically seeking protection from large predators). Fish Rock has many such perches and on a good day they’re all occupied by large wobbegongs. Banded wobbegongs (once known as ornate wobbegongs) are a photographer’s dream. Their hides are covered in an intricate pattern of golden hued blotches, fringed by contrasting broken black lines on a mottled white background. Their complex coloration is designed to help them become one with the reef but against the purple sponge and coral encrusted backdrop of Fish Rock, they stand out in vivid detail.
The mostly submerged monolith supports a riotous community of invertebrates that act as a living smorgasbord for tens of thousands of resident fish
72: WILDLIFE AND ENVIRONMENT
A few years ago, a shark researcher named Charlie Huveneers started looking more closely at ornate wobbegongs. He noticed that some ornate wobbegongs (which can grow to almost three meters in length) were reaching maturity while still very small. That didn’t make much sense, so the good doctor took a series of measurements and scrutinized the tiniest details of each shark’s ornate patterning.
To make things interesting, the tunnel leading to the main cave is invariably blocked by resting wobbegongs which divers must squeeze past in order to progress through the cave system.
The deeper of the two entrances is a narrow triangular fissure about two meters wide. To find it, divers must first drop into a shark gutter and muscle their way past beefy grey nurse sharks that often hang motionless in the doorway like After months of laborious lab work he bouncers outside a nightclub. Then, was able to confirm that the original depending on the surge, it is either a ‘ornate wobbegong’ (Orectolobus quick kick or a mad scramble through ornatus) that local shark fishermen the first tunnel until they reach the had been indiscriminately catching, midnight tranquility of the inner was actually comprised of two subtly chamber. distinct species. Both have since been classified as near threatened Claustrophobics beware; the lower by the International Union for the tunnel can feel extremely oppressive. Conservation of Nature (IUCN). Beyond the first bend there is very little ambient light but once He renamed the smaller of the two artificially illuminated, the walls the ‘dwarf ornate wobbegong’ and in explode with color and life. Hundreds true Aussie fashion, came up with the of crayfish scurry away into deep self explanatory ‘banded wobbegong’ recesses and dazzling schools of (Orectolobus halei) for its larger silver-sided bullseyes swim in unison cousin. Incidentally, wobbegong is an perilously close to the mouths of Australian aboriginal word meaning expectant wobbegongs. shaggy beard. Venturing onwards and upwards, the cave eventually opens back up Fish Rock is by no means the only to the light revealing more grey place along the northern New South nurse sharks silhouetted against the Wales coastline where you can entrance. dive with grey nurse sharks and wobbegongs. What sets it apart is its After diving at many celebrated spots location. It is a mere two kilometers around the planet, I am convinced from the edge of the continental shelf that a trip through the shark cave at which puts it directly in the path of Fish Rock is an experience worthy of schools of migrating pelagic fish. every diver’s bucket list. Few people would disagree that Fish It also has a unique geological feature. Rock should be off limits to fishing, There is a rift running through the but it has not yet been designated as entire upper section that forms a fully fledged marine protected area. a large cavern wide enough for Fishermen are no longer allowed to experienced divers to swim through. anchor on its coral covered slopes but they are still permitted to motor back and forth, trailing hooks that indiscimanently capture fish and sharks alike.
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Hopefully the rule makers will eventually come to appreciate Fish Rock’s importance as a habitat for endangered grey nurse sharks and afford it full protection. When foul weather or strong swells make Fish Rock undiveable, there are many other sites around Southwest Rocks that are worthy of a quick dip. Green Island (brilliantly concise) is a protected site that has a respectable reef of its own. In fact, it comes complete with all the shark species found at Fish Rock plus a whole slough of shallow water rays and plenty of crevices harbouring tiny blind sharks. Anywhere else, Green Island would be considered a first rate dive site but next to the magnificence of Fish Rock it is lost in obscurity. When the seas really kick up, Southwest Rocks has plenty to offer back on land. Picturesque Hathead Lighthouse, a sprawling 19th century colonial prison and a number of long pristine beaches are just a few places to while away a windy afternoon. For more athletic visitors, there is some decent rock climbing right on the sea cliffs and the surfing is as good here as anywhere else along the coast. But it’s ‘the rock’ that draws people back year after year. Jon Cragg the owner of Fish Rock Dive Centre sums it up nicely. He has dived Fish Rock more than 2000 times. When I asked him where else he likes diving, he shrugged and said “After diving Fish Rock, why would I want to dive anywhere else?” He has a point.
By John Natoli
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number of degrees GWS maintain their brain temperature above the temperature of surrounding seawater
20,000
number of kilometres some GWS have been know to migrate in less than one year
900
number of metres GWS are known to dive to
Jason, alias ‘Underwater Irish’ as he came to be known on the ‘Princess II’, celebrates his birthday 70 kilometres out to sea off the coast of South Australia. The location is North Neptune Island and at the age of 28 Jason is now fulfilling a boyhood dream. At the impressionable age of 15 Jason had a sketch of a great white shark, one that he drew himself, tattooed to the side of his calf muscle and vowed that one day he would see the ‘real deal’ in the flesh.
day 1 It is early morning, June 16th, 2009 around 7.30am, as the Rodney Fox Shark Expedition team heads out to sea on the Princess II with Jason and 11 other passengers all anxious in anticipation of whether their expectations of sighting a great white shark are to be realised. The voyage from Port Lincoln to North Neptune Island will take approx five hours as we make our way in very mild conditions with slight seas and wind speeds no greater than 15 knots. Rodney Fox tries to fit in five to six trips a year and we are lucky enough on this trip to enjoy the company of Rodney himself. Travelling at a speed of eight knots we have the occasional sighting of dolphins, which keeps some of the passengers amused whilst others sit around chatting with Rodney and the rest are eagerly making last minute checks and adjustments to camera and video gear – of course, I am one of the latter. As we near Neptune Island, the anticipation grows. When will we sight our first shark? How long could it take? Will we be lucky enough to see any at all? How big do you think the sharks will be? Lots of questions, all in search of answers.
Within seven minutes of the chum first seeping into the blue waters of the Southern Ocean, Jason’s boyhood dream becomes reality, as the first great white shark appears astern. The excitement explodes when a second shark appears moments later chasing two young fur seals across the water. Little did we know, from this moment on, we are to enjoy non-stop shark activity for the entire three days. In no time, the first four passengers immerse themselves into the surface cage. A shark wrangler stands on the duckboard, just behind the cage, with a great chunk of tuna tied to a rope and lures the sharks towards the cage. The very first sighting of a great white shark heading straight towards you with its mouth wide open is a sight one can never forget. Someone asked me ‘Is it exhilarating or terrifying?’ Exhilarating it is, unbelievably so. My first stint in the surface cage is nearly an hour long but it feels like only five minutes. All afternoon, we are in and out of the surface cage swapping positions and taking turns. It didn’t matter if you are in the cage watching the sharks underwater or standing on the back of the boat waiting for the shark’s ‘head and teeth’ to breach the surface in a sudden lunge to steal the tuna bait, the activity continues to be non-stop, thrilling and breathtaking.
We arrive at a time when lunch is normally served on the boat, but nobody is interested in eating. The skipper, Robbie, positions the boat in a sheltered little bay known as Main Bay, just off North Neptune West Island. From In total, we sight five different sharks on the first day, here we can see the New Zealand fur seals, some lying ranging in size from three and a half metres to a large on the rocks and others swimming about. This is great female suggested to be five metres in length. white shark territory. Robbie signals to drop anchor and so Andrew, a young deck hand, and Jezza, who is also the cook on the boat, get straight to it.
72: WILDLIFE AND ENVIRONMENT
Immediately the anchor is set, Robbie, Jezza and Andrew waste no time in getting around to the stern to untie the two shark cages, getting them into position and then start chumming the water to attract the first sharks. Whilst this is all happening Jennifer, best known as ‘Tinker’ Taylor, gets out the video camera to start recording a trip video for the passengers.
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day 2 Time to get some action in the submersible cage, the only place in the world where this can be done. Of the 12 passengers, only four of us are certified divers and we are all very keen to be sent 20m down to the bottom of the ocean to capture the behaviour of the great white shark at depth. Not being lured by a slab of tuna, there are no gaping mouths swimming straight for us. Here we find the sharks to be calm and inquisitive showing as much interest in us as we are in them. Three or four sharks constantly circling us occasionally giving the cage a little nudge almost as if they are trying to determine whether we are alive or inanimate. And then, coming in from the blue water column, arrives ‘Big Muma’, a six-metre monster female that has a girth the size of the average family car. She is massive and looks more like a submarine. Every shark we have seen up until this moment now pales into insignificance. Like most people I had seen the movie Jaws, but in my opinion i always thought that the movie was far-fetched. It seemed the shark that was portrayed in the movie was far too big to be realistic, I now know better. ‘Big Muma’ puts reality back into perspective. She simply takes my breath away. On the surface, ‘Big Muma’ makes a regular appearance throughout day two. The sight of her large dorsal and caudal fins slicing the water sends a shiver down my spine. Rodney Fox remarks the shark is one of the three biggest great white sharks he has seen in his 42-year history of shark expeditions. That makes us feel special. As I hit the pillow that night and close my eyes, all I can see is the vision of great white sharks imbedded in my mind. Rodney Fox explains that this happens to many people after a day of constant focus on this superb animal.
day 3 the action continues all day. ‘Big Muma’ still hangs around and ‘Jonny’, a five-metre male, makes an appearance. In total we sight 13 different great white sharks on this trip. Finally, it’s 4.00pm and time to head back to Port Lincoln. We are all a little sad for having to leave the sharks back at North Neptune Islands and what has been an awesome three days, but at the same time we are ecstatic to be taking home the memories of an adventure that will never be forgotten. The crew consisting of Jennifer, Robbie, Jezza and Andrew have been marvellous and have very much added to making our trip an awesome experience. The trip video, filmed and edited by Jennifer ‘Tinker’ Taylor will take pride of place in my DVD collection, which reminds me, I’d better make another copy of it, as it will be well worn in no time. The opportunity to enjoy the trip with Rodney Fox on the boat and share the many experiences he is able to recount has also been very memorable and a major highlight for all of us on board. You don’t have to be a diver to enjoy this trip. The Rodney Fox Shark Expedition experience is one to be enjoyed by all young or old, above and below the water, diver or non-diver. For all of us on board, this was an all-time ultimate thrill and one that also witnessed ‘Underwater Irish’ realise a boyhood dream.
by jeff shaw
oceanic
“The concept for Oceanic Defense started as a training module for my scuba students. I wanted to stress responsibility to our aquatic environment and teach students how to properly act as stewards of the sea. As time went on I realized that the general public could benefit from these lessons too and Oceanic Defense was born. Today, I am humbled and honored to work with a select and talented group of professionals and private volunteer citizens as well as our advisory board that guides our organization.” - Jeff Shaw Executive Director, Oceanic Defense. Oceanic Defense is a worldwide nonprofit organization with members in over 60 countries, spanning 6 continents with 1 mission -- healthy aquatic ecosystems free from human abuse and neglect. Oceanic Defense ‘educates and activates’ our membership by giving them the tools they need to respect and protect our global oceans by acting responsibly as consumers and by making smart decisions in our daily lives. Because, whether we are buying groceries, commuting to work, planning a vacation or advocating within our own communities, each action we take or decision we make can either help or hurt our oceans. Our goal is to empower people to be part of the solution rather than part of the problem; working together, as ‘the Aquatic Army’ to protect our blue planet.
RISING: SCIENCE & CONSERVATION
we educate and activate by:
LEARN MORE www.oceanicdefense.org
To learn more about Oceanic Defense and how YOU can advocate within your own community to protect our oceans: become a member of our Aquatic Army. 23
Educating the public on subjects Instruct individuals for the purpose useful to the individual and of improving or developing beneficial to the community their capabilities to protect our as it relates to our relationship natural resources allowing them with the ocean, including our to advocate within their own award-winning outreach series, communities by providing program “Shark Conservation & YOU” and such as the ‘Shark-Free Marinas’ developing programs such as Ambassador’ opportunities. “Dolphin Defense & YOU” “Effective conservation of our natural resources and our marine wildlife must start with each of us individually. Respect and understanding remain the keys to preserving both the oceans themselves and the life they support; and that, combined with action, is what makes Oceanic Defense and the Aquatic Army a force for positive change.” – Samantha Whitcraft, Conservation Biologist, Oceanic Defense. Today, Oceanic Defense champions many causes including domestic and international shark conservation, cetacean issues, ocean pollution and consumer responsibility. The organization also supports and promotes other like-minded organizations conducting charitable activities as it relates to oceanic education and preservation.
the australian beach meshing program. By Rowena Mynott
“
The mistake we make either in seeking to destroy sharks or in not caring if we inadvertently destroy them is one of cosmic stupidity. If I have one hope it is that we will come to appreciate and protect these wonderful animals before we manage, through ignorance, stupidity and greed, to wipe them out altogether.
“
Peter Benchley. Author of JAWS
F
or anyone traveling to a country that is known for its large marine predators, sharks must surely be on the mind when entering the water. Shark ‘attacks’ make for a dramatic news story and it is often these stories, perhaps accompanied by the JAWS theme tune, that play through swimmers heads when they find themselves alone in deeper water. This same fear of what is lurking in our waters, is one of the contributing factors that initiated a positive vote for beach meshing, also known as shark nets, along beaches in some countries visited by pelagic shark species, and what keeps the nets in place today. But in an ironic twist may of these same countries also now sustain thriving shark diving businesses. As governments lay traps to reduce the number of large sharks around their shores, dive operators are encouraging positive interactions with these sharks and providing education by enabling an up close encounter. Most people have a strong opinion either way on the beach meshing debate, but do we really know enough about it to make up our own minds – you might be surprised!
sharks and why they are important:
The earth is approximately 4.5 billion years old. Covered by 72% water, the adage that we know more about the moon than we do about what is in our oceans is old but true. There is little doubt that sharks are one of the greatest marine predators on the earth. Inhabiting the planet for over 400 million years (Ma), the original species looked a little different to the ones that we share the globe with today. They still possessed similar features to their modern counterparts (e.g. paired fins, replaceable teeth) but were in many respects very different. ‘Modern day’ sharks first evolved from their ancestors around 150Ma whilst species that we might be more familiar with in our oceans today, those like the great white and hammerhead evolved even more recently 16Ma - 50Ma. It is even possible the most famous extant shark, the great white, evolved from the most famous of extinct sharks, Megaladon, a 15 meter leviathan with teeth about three times the size of a present day great whites’ tooth.
Ocean Surface
With over 400 species of sharks inhabiting all the waters of the earth, from the polar seas to tropical and temperate oceans, even venturing into freshwater, sharks are a diverse and adaptable class. Members of the Chondrichthyan family of fishes that contain sharks and rays, sharks are perfectly suited to their role as apex predators of our oceans. As an apex predator, they resemble a CEO of the ocean, responsible for multiple tasks in order to keep ocean business running smoothly. They are responsible for the clean up of rotting carcasses; responsible for maintaining fish stock health through the removal of sick or injured fish and perhaps most importantly, responsible for keeping populations of each species in its place and not allowing any one to become greater than can be supported by the surrounding ecosystem. A lobster fishery in Australia for example is now threatened due to the demise of shark populations in the area. With a decrease in shark numbers, there is nothing to keep octopus numbers in check and of course, the favorite food of the octopus is lobster. You can figure out the rest.
Surface Buoys
Gaps in between the nets
Figure 1: Nets.
6 metres
Gap to substrate
what is a shark net and what does it do?
RISING: SCIENCE & CONSERVATION
Shark nets were introduced to beaches to try and decrease the incidences of shark bites on beach goers. Beach meshing programs can be found in several countries around the world, including Australia, New Zealand, Hong Kong and South Africa. The target sharks for these areas are mostly larger adult pelagic sharks, those that might be considered ‘maneaters’ such as the great white, bull shark, tiger shark and the oceanic white-tip. As each beach meshing program varies slightly in how they operate, this article will focus primarily on the Australian beach meshing program. Introduced to Australian beaches in 1937 by the Department of Primary Industries (DPI), the first beach meshing installations were only on the coastline of New South Wales (NSW). Queensland (QLD) followed suit 30 years later implementing the program along its beaches. Being the most populated areas, these are currently the only two states in Australia to have a beach meshing program running. Despite this fact, although occasionally occurring in these two states, the larger shark species, such as the great white are more prevalent in the waters off the states to the south and west. The nets (Figure 1), which hang from buoys on the surface of the water set adjacent to the shoreline, are 186 meters long in QLD, 150m long in NSW, and six meters deep. As the nets 25
DPI
Surface Buoys
12mm braided rope
186 metres
10 metres of 10mm chain Anchor
are set in water of about 12m depth, the six meter height of the net sits approximately mid water allowing substantial room above and below. The nets are set differently in NSW and QLD. Having once been bottom set nets in QLD, it was shown that this method netted too many ray species and the nets are now set from the surface of the water. In NSW, the nets were once surface set, however due to a high incidence of reptile and mammal by-catch it was decided to drop the nets to bottom set nets. Drumlines are another more modern method of shark control. These are becoming more popular due to the possibility of reduced bycatch. Drumlines are in place along the beaches of QLD and can either be used instead of nets or in association with them. Figure 2 shows an example of a drumline set. These are quite simply baited hooks hanging from surface buoys weighed down by a weighted anchor. The QLD DPI states that the drumlines are set to target actively feeding sharks.
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There’s a curious paradox inherent in our reckless assault on sharks. As the bizzarre overreaction to “jaws” demonstrated, while we may fear sharks and profess to hate them, we are also thrilled by them.”
Ocean Surface
“
Peter Benchley. Author of JAWS
Torpedo Floats
the issues with beach meshing
Whilst there is no doubt that many beach goers feel a little more secure in the knowledge that shark nets are in place, the feeling of security comes at a price. All data regarding the beach meshing program is released by the DPI to the public, including numbers of by-catch, species catch and release plus the number of human injuries and fatalities on meshed and unmeshed beaches pre and post installation of these programs. With a little research, we are able to identify the issues associated with the implementation of beach meshing. Despite this information being available to the public, most of these facts do not filter down through the media, or they become skewed in their translation and interpretation. To be able to make an informed decision regarding the necessity and the future of the beach meshing program, a little self-education is necessary as beach goer attitudes are the reason the nets are still in place.
DPI&F
Marker Buoy
3 metres of 12mm float rope
2 metres of chain with a 14’0/19’0 baited hook.
12mm plaited rope 4 times depth of water Not less than 2 metres to the sea bed 10 metres of anchor chain
Anchor
Figure 2: Drumline.
/ Human Protection. Lets look at the theory that the nets create an impenetrable barrier to protect swimmers from sharks. The DPI states on their website that the nets are in place to… “..reduce the numbers of sharks and thereby reduce the risk of shark attacks. The shark mesh nets do not act as a complete barrier to sharks reaching beaches as they are not permanently set in the water, do not cover the whole length of the beach, and do not extend from the water surface to the seabed. In fact, approximately 40% of shark entanglements occur on the beach side of the nets, because sharks are able to swim over and around the nets.” We hear little in the media of sharks becoming entangled on the beach side of the nets and yet the figure of 40% is only the proportion of sharks we see caught in the nets. It is possible that more than 40% of sharks are gaining access to these beaches and back out to sea again. Presenting these figures isn’t meant to alarm, but to show that if swimming in the ocean, even at a meshed beach, the chances of unknowingly swimming with sharks is fairly high. It is also stated in media that there have been no deaths since the nets have been introduced, compared to a large figure pre beach meshing. Once again, we can consult the NSW DPI website for the data. Figure 3 below shows as an example the number of fatalities and injuries pre and post beach meshing for NSW. The information in this table shows an interesting set of data and raises a couple of questions.
Dates
Number of Years
Number of Fatalities
Number of Injuries
Number of Uninjured
Total Number of Incidents
1791-1936 Pre beach meshing
145
48
33
2
83
1937-2009 Post beach meshing
72
22
81
36
139
Figure 3: simplified table using data taken from DPI www.dpi.qld.gov.au
1) As we can see, the rate of incidents per year has more than tripled from pre beach meshing. Some scientists have hypothesized that an increased presence of sharks closer to our beaches could be due to overfishing. Declining fish stocks in our oceans mean sharks migrate closer in to shore to find food. Increased population size and popularity of water activities are also important factors in these figures. 2) Human fatalities have indeed decreased post beach meshing. We can expect that advances in medical technology and medical response time should increase the survival rate of victims. Twentieth century medical technology is light years ahead of that experienced in the eighteenth century, so victims in the post beach meshing era should have an elevated chance of survival.
“
One of the ironies of the program is that one of the main target species, the great white shark, is listed as vulnerable under the Environment, Protection and Biodiversity Conservation Act 1999 and is protected in Australian waters due to their dwindling numbers.
“
RISING: SCIENCE & CONSERVATION
Even when taking into consideration the increases in population as well as the increases in medical technology when looking at these figures, it seems that the nets have a
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very limited effectiveness.
/ Sharks. Sharks targeted for the beach meshing program are over two metres in size according to the QLD DPI. This aims to eliminate the possibility of smaller sharks becoming unnecessarily entangled in the sets. It is believed that some species of shark such as the great white are actually born at two metres. With a late reproductive maturity, a high probability of pre reproductive mortality makes their populations vulnerable to rapid decline. Data from the QLD DPI shows that out of 7,619 sharks caught between 1999 and 2006, 51% were less than two metres in length – the non-target group. One of the ironies of the program is that one of the main target species, the great white shark, is listed as vulnerable under the Environment, Protection and Biodiversity Conservation Act 1999 and is protected in Australian waters due to their dwindling numbers. Up until recently any ‘dangerous’ shark caught in nets in NSW had to be shot rather than be released. Thankfully the NSW DPI has now ruled that any shark caught needs to be released if it is in good enough condition. In QLD it is possible that policy is still to shoot any sharks caught by the program. This in itself causes a problem as a shark caught on a line for 2 days can thrash around enough to cause substantial damage to its own health, causing fatalities from injuries or stress. This thrashing can also attract other sharks to the area. Newspapers around the world carried headlines in 2009 of a great white that had started to feed on another great white caught on a drumline in QLD – another hazard. On meshed QLD beaches there are usually one to three nets and up to six drumlines. The main issue concerning drumlines is that they contain baited hooks. We know that sharks possess an incredible sense of smell and are able to detect one drop of blood in 100 litres of water. It begs the question, by putting baited hooks near beaches are we not attracting
sharks into the area that may not have been there initially? We may be contributing to the problem and not the solution.
By-Catch.
Along with target and non-target shark species caught, there is a huge problem with by-catch caught in the nets and on drumlines. Everything from whales, dolphins, turtles, birds and dugongs to fish and other shark species can fall victim to the program. FIGURES! The QLD DPI is credibly trying to improve the effectiveness of the nets and drumlines to reduce by-catch. Pingers have been installed on nets to try to deter whales and dolphins, however numbers of these animals still become entangled. Plastic hook guards have been introduced to drumlines to prevent turtles and dolphins becoming victims. Despite there being a reduction in bycatch, these animals are still being caught. Encouragingly the NSW DPI also took steps to minimize the impact of the program on larger marine mammals. NSW now removes their nets between May 1st and August 31st during the humpback whale migration. QLD nets remain in place seeing 5 humpback whales (some of them calves) tangled in the nets during one month in 2009. Investigations by the Fisheries Scientific Committee determined that the beach meshing program adversely affects two or more threatened species and could cause other species that are not yet
conclusions threatened to become so. They have therefore listed the beach meshing program as a key threatening process to our marine life. What are the conclusions from these facts? We have to look at the viability of the nets. Are they providing the service that was required of them initially, are they outdated and when is it decided that enough by-catch is enough? The nets constitute a large financial loss to QLD and NSW governments as each year QLD pays $1.8 million and NSW $750,000 towards the upkeep of the nets. It is not only the financial loss that is a problem; there is the loss of marine fauna and the flow-on effect these losses have on marine ecosystem functions. Data contained in the DPI information is far too extensive to show in one article, however with a little analysis we are able to calculate the effectiveness of the beach meshing program. In NSW for the years 1950-2008, the total catch of target sharks as well as bycatch was 16,323 specimens. The percentage of target sharks caught during this time and therefore the effectiveness of the nets is 23% with the remaining 77% composing by-catch. It seems a simple conclusion. In 2004 a tag and release program for harmless shark species was established to help understand their behavior upon release. There is interesting on-going work by the NSW DPI on Sydney beaches through the catch and release of target species, however it would also be beneficial to perform tag and release for target sharks caught in nets rather than solely tagging netted non target species. This would provide a clearer understanding of their behavior and perhaps enable a more sustainable solution to be implemented. This article is not meant to paint a rosy picture of sharks. We have to be realistic and sharks remain the apex predator in the ocean, still posing a risk to anyone who is a water user. A negative interaction
“
“I couldn’t write ‘JAWS’ today. The extensive new knowledge of sharks would make it impossible for me to create, in good conscience, a villain of the magnitude and malignity of the original.” Peter Benchley. Author of JAWS
“
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with a shark is never something that one would wish for. However this risk can be minimized with a little education. The number of shark bites each year around the world are so few that we are still more at risk from car crashes, smoking, going to the toilet using vending machines and plenty more simple every day tasks that, even knowing the risks, don’t stop us from undertaking. The change in attitude after some shark education can be no better portrayed than that of Peter Benchley, the author of the movie ‘Jaws’. After penning his detrimental story on sharks that has been one of the greatest contributors to their demise, Mr. Benchley became an advocate for sharks in the latter years of his career. Before his death in 2006 and after spending many years studying these creatures, he summed up his feelings about sharks: “I couldn’t write ‘JAWS’ today. The extensive new knowledge of sharks would make it impossible for me to create, in good conscience, a villain of the magnitude and malignity of the original.” On a final and more positive note, there is one other country that used to have a beach meshing program – Hawaii. Running from 1959 to 1995, the program ended when the public put pressure on the government to remove the nets citing there were no measurable effects on shark incidents. The government listened to the people and now Hawaiian people happily share their oceans with some of the greatest marine predators on earth. Role model? - reword!
common misconceptions
/ Shark Education – Simple advice to stay safe.
Shark nets form an impenetrable barrier between the ocean and the beach. The nets
• Do not swim if you are bleeding. • When spear fishing make sure that caught fish are
are 150m wide and six meters deep sitting in 12m of water, allowing animals to pass over, under and either side.
Beach meshing is designed to keep swimmers safe. The NSW/QLD Department of
sharks are most likely to be feeding.
•
Fisheries states that the purpose of the shark nets is to reduce the numbers of ‘dangerous’ sharks in our waters.
•
The nets catch only dangerous sharks. Only
•
6% of the nets catch is of the beach meshing programs target sharks. This means that the program is only 6% effective and that the remaining 94% of catch is bycatch, including threatened and endangered species.
Numbers of sharks in the wild are so great that the ones caught by the nets wont affect survival rates. Shark numbers are dwindling in the
wild. The shark nets have been listed as a key threatening process for some of these shark species. Due to declining numbers great white sharks, one of the programs target sharks, are protected in Australian waters.
All sharks are predatory and target humans as food. All sharks with the exception of one or two eat fish and therefore will not be attracted by mammals such as humans. Most bites are through misidentification or an inquisitive bite. The problem comes as a shark’s inquisitive bite is often big enough to cause damage to a human. Knowing when to swim, what not to do in the water and how to react when you see a shark is key to avoiding a shark bite.
RISING: SCIENCE & CONSERVATION
• Do not swim at dusk through to dawn, as this is when
Since the nets have been introduced the number of shark ‘attack’ fatalities have decreased. Fatalities from shark bites have decreased
since the introduction of the beach meshing program. However advances in medical technology and emergency response has progressed so dramatically in the last century that the chances of surviving a shark incident is greatly increased compared to the 1900’s (pre shark meshing). This indicates the data is misleading.
If the shark nets were removed, shark ‘attacks’ would increase. The NSW beach meshing report states that 40% of sharks caught in the nets were on the beach side, which shows that humans had been swimming alongside sharks without any problems.
The only good shark is a dead shark.
Sharks are vital for our ecosystem. They keep our oceans clean and keep our fish stocks healthy by removing sick or weak animals. They keep populations of certain animals in check to keep a constant equilibrium in the oceans. 29
• •
• •
either removed from the water quickly or are attached to a very long line away from your body. If you notice a shark, watch its body posture. If it arches its back and puts its pectoral fins down it is not happy. Move away from the area slowly and exit the water keeping your eyes on the shark. Do not wear jewelry or swimmers with shiny decoration – this can look like fish scales. Do not harass a shark. Even the most docile sharks such as the bottom dwelling wobbegong can deliver a nasty bite in defense. Don’t swim where there are fishermen or birds diving into the water. This means there are fish around and most likely sharks too. Do not swim in murky water. Splashing will often attract sharks such as bull sharks that inhabit the murky waters of canals and river mouths. Due to the lack of visibility the only option for the shark is an exploratory bite. Be careful of swimming with a dog. A dogs erratic swimming movements can resemble a flailing fish attracting sharks. Swim with a friend or with a group of friends.
/ Remember
• When we enter the ocean or rivers, we are entering • •
sharks territory. They are well equipped to live there. We are not. We need to respect that. The number of shark bites each year is miniscule compared to the number of people that enter the water. Sharks are not fearsome creatures. If you respect them and follow the simple advice it is possible to have some beautiful interactions.
CALL TO ACTION:
For further information regarding the information quoted in this article on the Australian beach-meshing program, please visit: New South Wales Department of Primary Industries:
www.dpi.nsw.gov.au
QLD Department of Employment, Economic Development and Innovation (formally known as Queensland Department of Primary Industries):
www.dpi.qld.gov.au
If you would like some more information on sharks, shark safety, ecology and behavior, Symbiont Ecology Group, an ecological research and education group, have available a Shark Awareness Presentation for primary, high school and community groups on this topic. Contact details can be found at
www.symbiontecology.com
SYMBIONT ECOLOGY GROUP
We are a specialist independent environmental research, consultancy and education company providing scientific advice and consultancy services to industry, government and conservation groups. We specialise in marine, coastal, estuarine and aquatic research and management; assessment and mitigation of environmental impacts; education and training about environmental issues and their management.
We believe that, through rigorous science and engaging education programs, we as a society can achieve a balance, a symbiosis, with nature. Achieving this vision requires no more radical a notion than to approach old problems from a new perspective. Our services include: Strategic Environmental Assessment Review of Environmental Factors Environmental Impact Assessments for Marine and Aquatic Ecosystems Species Impact Statements Active Adaptive Environmental Management and Impact Mitigation Ecosystem Health and Regeneration Flora and Fauna Ecological Survey and Monitoring Marine and Aquatic Biomonitoring Biodiversity Assessment & Modeling Invasive and Pest Species Adaptive Management Sustainability Assessment and Eco-Efficiency Optimisation Environmental Education and Training Programs For more information on our services, please visit our website:
www.symbiontecology.com or contact us at symbiont@symbiontecology.com
SHARK WEEK By Seanna Cronin
Shark Week, Discovery Channel’s annual summer block of shark-themed programming, has been praised and criticized by shark supporters and conservationists. The series, now in its 22nd year, was one of the first to feature an in-depth series about sharks and attracted large audiences thanks to explosive footage from shows such as Air Jaws. It has also given marine biologists such as Dr Samuel Gruber and Aussie Richard Fitzpatrick an international platform on which to explain shark behavior. But the series has also continued to promote negative shark stereotypes. The majority of promotional materials feature a great white shark powering mouth-open towards the camera. Media kits sent to Australian media outlets promoting this past year’s Shark Week featured a hologram of a great white shark lunging towards the viewer, with the works prey and pray alternating as the hologram is turned.
9,000,000
Number of viewers of the 2008 Shark Week
Nightmare-inducing reenactments of shark attacks are a regular feature, and inaccurate descriptions such as ‘man eater’ and ‘monster’ are still thrown around.
60%
A newcomer to shark week, New Zealand’s extreme fisherman Matt Watson was recruited by the Discovery Channel to film a segment for 2009’s Shark Week, which aired in Australia in December.
Of survey respondents who view documentaries as their primary source of information about sharks.
Watson rose to fame after posting film clips from his New Zealand fishing series The Ultimate Fishing Show on the internet. photo supplied and © The Fishing Show
Labeled the Fish Hunter, his extreme fishing antics caught the attention of US talk shows and the Discovery Channel, which offered him his own pay TV series - Man Vs Fish. Watson carried out a series of intelligence tests with a mako shark for Shark Week and had a close encounter with a blue shark during the same shoot. “That was one of those times I thought ‘oh shit, I’m not invincible and these are sharks’,” says Watson.
RISING: SCIENCE & CONSERVATION
He also spent time in north Queensland tagging tiger sharks.
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“I don’t believe for a moment that a shark or any fish has a beef with a human,” he says.“I think a lot of the reputation comes from fisherman seeing them attack other large fish or turtles and we as people have this ability to project ourselves into these scenarios.” Watson says making watchable television, which does well enough in the ratings to be more than a one-off, with a conservation message is a tough balancing act.He admits he has questioned the way some of his Shark Week footage was edited. “In a way I agree with a lot of the detractors,” he says.
“They’ve got a remote and they can just change the channel,” he says. “I like to think that if I’m able to do the sensational stuff to get people’s attention, then I can get the information across.” That’s not to say we won’t see a serious documentary from the fisherman at some point in the future. “In the long term I want to get the message across that the ocean needs looking after,” he says. “But at this stage in my career, if I was to go out there and
“People want to see danger. There’s an appetite for danger out there on television, and I think that at least by doing what people think is crazy, if I can hold their attention long enough and communicate that these fish are awesome and need to be conserved and looked after, that’s better than preaching.” “Particularly the shoots that involved sharks, I said a lot of make a show where I just talk about conservation people stuff about their anatomy and why (that was cut out). aren’t going to listen to me. I’ve got to grab their attention in another way. “Many of the parts that were left out could have explained the behaviour a bit more.” “Hopefully my profile will get to a point where I can get people to listen to the boring stuff. They don’t know me He takes a pragmatic approach, reasoning a fair and well enough yet. If I’m not about to get eaten by something balanced shark series is useless if no one watches it. they won’t listen.” “People are quick to point the finger at Discovery or Watson might be selling himself short. Filmmaking pioneer whoever; it’s driven by what people want to watch,” he Sir David Attenborough is one example of someone who says. draws scores of viewers without putting himself in harm’s “People want to see danger. There’s an appetite for danger way or dumbing down his content. out there on television, and I think that at least by doing But in a media world dominated by ratings share and what people think is crazy, if I can hold their attention long bottom lines, Watson may have a point. Unless we can enough and communicate that these fish are awesome and bankroll another Blue Planet series, we might have to need to be conserved and looked after, that’s better than strike a few compromises and grit our teeth through yet preaching.” another blood-filled shark attack reenactment that gets the If you want to get your message across to Generation Y, conservation message out there. then sensationalism cannot be avoided, he says.
photo supplied and © the Discovery Channel
CALL TO ACTION To encourage the producers of Shark Week to include more positive and accurate information about sharks, leave your comment at http://extweb.discovery.com/viewerrelations.
RISING: SCIENCE & CONSERVATION
*SHARSINTHEMAL
SHARKS IN THE MALL
750
Thickness in millimetres of the 32.88m x 8.3m acrylic viewing panel
990,000
Number of litres that panel must hold back
33,000
estimated number of marine animals in the aquarim
30
By Marcelo Mariozi & Rowena Mynott Number of litres available
33
per animal in the aquarium
LL*
On the footsteps of the world’s tallest building, the Buri Khalifa, inside Dubais biggest and trendiest mall is a new initiative by Dubaibased real-estate company, Emaar.
Worth at least one hundred million dollars, this Guinness Record holding aquarium contains the largest single acrylic panel in the world. Measuring 32 meters wide this panel provides an amazing view of the ten millionlitre tank and its 33,000 inhabitants. The tank itself is suspended hovering over the shoppers and mall facilities beneath. Aquariums and animal captivity can be a sensitive issue and can represent a paradigm of nature for some people. How far should an aquarium go in presenting wild animals to the public with commercial intent? What animals should be allowed in captivity? How long should these animals be in captivity and who regulates the conditions? Dubai Aquarium is no different to any other in respect to these questions and with so many other establishments making what are sometimes considered controversial decisions, we decided to try and find some answers.
Marcelo Mariozi took some time out to speak to Paul Hamilton, an experienced and dedicated marine biologist who specializes in big aquariums, about this aquarium and to answer some of these questions.
Hi Paul, thanks for the interview, What about the total number of What kind of programs do you you have an amazing facility fishes in the aquarium? When develop to bring those people, here, what kind of programs you say 33 thousand it sounds especially the non-divers, close are you developing with these like too many for one tank? to these animals? sharks? PH: That’s because it includes a PH: There are all levels of proximity
PH: The sharks are here obviously lot of small fish, we have sergeant we can provide, the highest level for visual benefit primarily, but we also have some breeding programs going on so they can be offered to international aquariums. We are hoping to supply sand tiger sharks in the future because they can no longer be fished from the ocean and so there is a high emphasis on captive breeding now and we are gearing up to do this work.
That’s great. Do you have any idea of when you are going to have the first “baby shark” born? PH: We are looking into two types
of reproduction with them. First there is natural reproduction, at only seven years old our sharks can be considered teenagers in human years. They are just becoming mature and only start to explore the possibility of reproduction. We are seeing some natural mating behavior but they never really completed the copulation so we hope for this natural reproduction in the near future as they become more experienced, and the females start cycling their ovaries. We’re also looking into artificial insemination; we have so many males and females here together that we have a high potential for sperm collection and insemination of the females.
RISING: SCIENCE & CONSERVATION
And those sharks getting bigger, does it represent a problem for the aquarium? PH: No, the sand tiger sharks will
grow to about three and a half meters, some might reach four meters long, but we have created a fairly realistic habitat here for them. They have access to a cave and even having a 10 million litre ocean area you see that probably 70% of the time the sharks utilize a very small confined space, which means they like the close company of their own species. At any given time you will find most of the sharks are actually in that cave, they go out and swim for about an hour then they go back, its very similar to their behavior in the natural environment as well.
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majors, cleaner wrasse, and a lot of other species that don’t really jump out at you in the beginning. This number is based on the count we started with in the aquarium, there will be some natural predation but that is very minor, and if we have some issues in the future we will just move animals around to other facilities, we are facing that now with the jack population, as it is growing to an extent we have to take some out and send them overseas.
Some people tend to think of the aquariums as a paradigm, that they take the same animals we want to save and keep them in captivity for exhibition and sometimes for profit purposes. How do you balance this? PH: I’d say 95% of the aquariums
worldwide are for profit...it’s their business, they sell tickets and make profits, I personally feel they still do some good for the environment. You have to enter the human psyche to understand it; we don’t tend to care about anything we are not exposed to. SCUBA divers tend to be the ones who would comment on captive animals because they have seen that animal in the wild and they have appreciated that beauty for “free”. But the general public doesn’t see it that way, they haven’t seen these animals in the wild, this is their first exposure to it. This is especially true for sharks; to expect people to appreciate them without ever coming across one is unrealistic. The general perspective of a shark is “JAWS” and aquariums can change that perspective by bringing people close to the animal, especially those people that have never had access to it, they feel differently after they see the animal for themselves. A lot of the public expects the sharks to go on a rampage when they see them and suddenly they realize they are at peace with their environment.
is when we take someone who has never dived before, we train him or her to dive and we get them within half a meter of a shark. We also take school groups in the tunnel, with all the sharks over their heads and we give a shark conservation talk. So there are all levels, from the main window to glass bottom boats, the tunnel, caged snorkeling, and actually SCUBA diving in the tank. The general public who are in the mall looking for a handbag, they didn’t really intend to see us, they walk by and end up being attracted by the aquarium because it is a very captivating thing to see. That appreciation was pushed upon them by having this facility in the middle of a shopping mall
On the ethical part of it, who regulates that? How do you control what you can and what you can’t do, or how far can you go? What kind of animals you can exhibit? PH: Our local regulations authority
(ministry) is the first one, they regulate every animal that we get or that we send out. And the ethics are controlled by international NGOs like WAZA - World Association of Zoos and Aquariums - they publish standards and when you adhere to them you come under an umbrella of what is considered state-of-theart as far as ethics go. To have a membership with WAZA, we and the administrators of the aquarium, Oceanis Australia, must meet all the WAZA standards. I think that it’s the best effort around the world.
The sharks are here obviously for visual benefit primarily, but we also have some breeding programs going on so they can be offered to international aquariums
I’d say 95% of the aquariums worldwide are for profit...it’s their business, they sell tickets and make profits, I personally feel they still do some good for the environment. You have to enter the human psyche to understand it; we don’t tend to care about anything we are not exposed to. During this first year of operation, That is amazing. Any last words what would you consider the to our readers? best and the worst moments in PH: Yes, standing back and having a the aquarium? look at one of the initial questions as PH: The worst moment happened to whether aquariums are good or bad when we were trying to start this facility, whilst all the construction was still going on around us. That was very difficult. When the world’s largest mall is being built around you and the world’s tallest building is being built just outside as part of the same complex, it is very hard to shut them out. To open an aquarium it takes at least six to eight months of operation before you go public, there is a lot of work on the biological, engineering, staff training sides and so on. We had to be up and running long before other contracts were complete. Especially going through summer in Dubai with 50 degrees Celsius outside and we were trying to maintain a constant environment in here. But we have gotten through it, our mortality rate was much lower than what we had anticipated since the project started which resulted in many cancellations of fish supplies. The best moment was when we did a shark feed around early 2009, and I was on the bottom of the tank hand feeding the sand tiger sharks, I looked out the window and I would estimate six thousand people watching a shark feeding. This is the kind of crowd you’d expect on a rock concert! Every level of the mall (there are 3 levels facing the main window) was packed with people trying to see the sharks, and that was fairly impressive I haven’t come across that in any aquarium situation ever before, it was stunning to have so many people appreciating an aquarium in one moment.
for the environmental efforts going on around the world. My personal view on it, I mean what helps me sleep at night with the whole situation, is that I am certain we reach a lot of people that the biggest conservation organizations around the world are not reaching. We are exposing people to the marine environment that do not look at the billboards, read the magazines or watch conservation efforts on TV. These people come from all over the globe, most from urban areas where conservation organizations struggle to penetrate, and when we reach these people we are holding our end of the bargain as environmental awareness goes. We had one and a half million paying customers on our first years, we estimate more than 25 million people saw our main window for free. This article and interview would not be possible with the participation of Emirates Diving Association, Al Boom Diving the official operator of the Dubai Aquarium, Oceanis Australia and Dubai Mall.
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When one tugs at a single thing in nature, one finds it attached to the rest of the world. - John Muir
by Rebecca Davis
FAST FACTS Many countries are now required by law to land the entire shark carcass to reduce the number of fins obtained.
37
DNA testing of shark fins in Asia showed that the products had been sourced Shark fishing is a way worldwide. Of of earning a living for particular concern Contrary to popular many people in third were the scalloped In 2000, an Act of myth sharks do suffer world countries. A hammerhead Congress banned from tumours. There more sustainable populations from the shark finning at sea has been no scientific solution needs to western Atlantic who in the United States evidence to show that be enforced rather made up 21% of the of America. Sharks Shark fin has very the consumption of than a complete shark fins sold, and must now arrive as little flavour and its shark cartilage will ban to enable these whose populations an entire carcass to use is purely to show protect an individual communities to still are listed by the IUCN reduce the number of status. from cancer. survive. as endangered. fins taken on board.
of us have heard the What Is Shark Most term at some stage or have at heard of shark fin soup. Finning? least Here we aim to give a better understanding of this controversial, yet poorly understood practice.
Shark finning is the process of removing the fins from various shark species for commercial purposes. In some cultures the consumption of shark fin is a high status symbol and is used as a key ingredient in shark fin soup. This is often consumed during weddings, business deals and other important events. Sharks posses natural healing properties and it is believed in many cultures that the consumption of shark cartilage will heal various diseases such as cancer and promote longevity in the consumer.
Sharks are commercially fished using a variety of methods with the most common being longline fishing. This practice uses monofilament lines laid out in the ocean stretching from one kilometre to a hundred kilometres. Along this line are hundreds The use of shark fin has been a tradition in many south east Asian or thousands of baited hooks. The lines are set adrift for 24 to 48 cultures throughout history and the demand for it is creating a hours before being pulled in to retrieve the catch. lucrative market on an international scale. Generally the sharks are landed upon the deck of a fishing boat. The valuable fins (including tail, pectoral, dorsal and also smaller fins) are removed using handheld knives. The fins are of much higher value than the meat, so the remainder of the sharks body is discarded back into the ocean, often whilst the animal is still alive, where it sinks and either drowns, starves or is prey for marine Shark finning is considered a threat carnivores. The fins are usually dried, the dermal denticles (tiny scales) removed, the skin is bleached for aesthetic purposes, often to shark populations because of its using hydrogen peroxide, and sold for large amounts of money.
What’s Involved?
“
unsustainable nature, devastating effects on vulnerable shark populations and
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increasing presence in the global fishing industry
There are around 21 species of shark that are ‘preferred’ for their fins. This factor alone causes concern for the conservation of certain species, as around half of these 21 species are already classed as Vulnerable to Extinction or as Endangered Species. Some notable target species include the Whale Shark, Hammerhead, Oceanic Whitetip, Lemon Shark and Sand Tiger (also known Grey Nurse or Ragged Tooth).
products in the world. The What’s It food worldwide production of shark fin the year 1997 alone was worth Worth? during US$90.4 million to the industry. More Shark fin is one of the most expensive
recently, the market has soared – however data on production volumes and market values are difficult to determine due to the controversial nature of the industry. It has been suggested that between 26 - 73 million sharks are traded annually worldwide. On a smaller scale, one kilo of dried shark fin can fetch US$65 per kilo and in some restaurants a bowl of shark fin soup can sell for up to US$400. The shark fin industry is most prominent in Asian countries where it is often considered a treasured food. It is however, also present in other areas such as North and South America, Oceania (New Zealand, Australia, Fiji and Solomon Islands) and Africa. Although the practice of finning is illegal in some countries, it may still occur undetected or commercial entities may simply choose to import the product.
So What’s Wrong With This Picture? Aside from the inhumane methods of obtaining these fins, shark finning is considered a threat to shark populations because of its unsustainable nature, devastating effects on vulnerable shark populations and increasing presence in the global fishing industry. Recent increases in fishing efforts targeting sharks produce higher yields and the expansion of areas fished have all put greater pressure on wild shark populations. The effect of overexploitation is further amplified because sharks often have slow reproductive rates, due to late sexual maturity, and few offspring. Their populations exhibit long recovery times in response to overfishing. Increasingly, international conservation organizations are trying to implement protocols and guidelines to curb shark finning and create a more sustainable approach to this sector of the fishing industry. Unfortunately, these protocols are difficult to enforce. • In 1999, the United Nations Food and Agriculture Organization (FAO) introduced the International Plan of Action for the Conservation and Management of Sharks (IPOA-Sharks). This is a voluntary set of guidelines that nations can follow to ensure the conservation and management of sharks and their long-term sustainable use. • in 2004, the International Union for Conservation of Nature and Natural Resources adopted a recommendation urging all states to ban shark finning and to require shark fins to be landed attached to their bodies. • Also in 2004, the United Nations General Assembly included a provision that discourages shark finning, and calls for implementation of the FAO International Plan of Action on sharks. On a smaller scale, many consumers are unaware of how their shark fin soup was obtained. Increased public education about shark conservation and the process of shark finning may reduce consumer demand for fins. Shark fins as well as shark meat (sold under the name flake) have been found to carry high levels of mercury, which can act as a neurotoxin, meaning human consumption carries a risk of mercury poisoning. In countries where consumption is high, public health warnings may help to decrease shark fin soup popularity. What began as a cultural tradition has fast become a multimillion-dollar industry and, consequently, a global conservation issue. Through global management, responsible fishing practices and public education it may be possible to achieve a balance that satisfies the consumer, the fishing industry and the environment.
CALL TO ACTION:
To sign a petition to stop shark finning please visit: www.saveoursharks.com.au
SHARK ECOLOGY IN SOUTH AUSTRALIA
BY CHARLIE HUVENEERS
17
length in centimetres of the smallest species of shark, the dwarf lanternshark, Etmopterus perryi.
15
length in metres of the largest species of shark, Rhincodon typus, or whale shark.
Since I have become a scientist working on shark biology and ecology, I often meet people telling me how much their dream was to become a marine biologist and to work on the ocean. I also often hear from parents asking me about what their children should do to successfully startt a career in science. The best advice I could give these people is to have initiatives, perseverance, and to stand-out from the crowd.
I first started being interested in marine biology and more specifically in sharks when I was 11 years old and had to prepare a presentation on an animal. I chose to do this presentation on sharks from which my interest kept growing.
RISING: SCIENCE & CONSERVATION
Following my last year of high school, I undertook an exchange year in Australia through the Rotary International during which I learned English and started to learn about sharks and potential opportunities. However, since I am originally from Belgium, it was logistically easier and cheaper to organise an undergraduate degree in England rather than in Australia. I was quickly accepted within Southampton University to undertake a degree in Oceanography with Marine Biology with Honours. Throughout my undergraduate degree, I maximised opportunities to volunteer and help out diverse research projects including work on basking shark in England, white sharks in South Africa, lemon sharks in the Bahamas, and pelagic sharks in the Gulf of Mexico, USA. Thanks to these volunteering experiences and high grades achieved during my undergraduate and honours, I obtained a scholarship within Macquarie University in Sydney to undertake a PhD investigating the impacts of fishing in wobbegong sharks in New South Wales. Three and a half years later I submitted my PhD and graduated a few months later. During my PhD, I was able to redescribe a new species of wobbegongs and learn about their reproductive system, diet, age, growth, and movements. These provided me with knowledge in various areas of shark biology and ecology, opening the door to many work opportunities. My first official job after my PhD was a short-term contract within the South Australian Research and Development Institute (SARDI) in Adelaide as shark ecologist to undertake a review of pelagic sharks occurring in the Great Australian Bight. However, after four months in Adelaide, I was offered another position back in Sydney in which I was going to be running the Australian Acoustic Tagging and Monitoring System (AATAMS). This project aimed to deploy several hundred acoustic receivers around the entire Australian coastline and tag various marine organisms including reef fishes, tuna, rays, and sharks. I worked for AATAMS for two years during which I had the opportunity to undertake fieldwork in some amazing remote areas of Australia and tagged many very different marine species. Once again, a great opportunity opened up with the advertisement of a new shark ecologist position and lecturer in South Australia within SARDI and Flinders University. I was successfully chosen for this position and I have now been back in Adelaide for nearly a year. As part of this new position, I have created the Southern Shark Ecologist Group (SSEG) and initiated various projects on chondrichthyes (sharks, rays, and chimaeras) with students and other collaborators. These include projects to:
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I maximised opportunities to volunteer and help out diverse research projects including work on basking shark in England, white sharks in South Africa, lemon sharks in the Bahamas, and pelagic sharks in the Gulf of Mexico, USA.
fatty acids, their signatures, which are passed to the tissues of the predator, can be compared to determine diet composition of these predators. This study will be the first time fatty acid signature analysis is investigated and validated in sharks, and will enable scientists to assess the diet of threatened and protected species such as white sharks and mako Assess the post-release survival rate and sharks from which stomach contents are physiological stress of stingarees following difficult to obtain. This is a PhD project of trawling capture. Bycatch levels of prawn Crystal Beckmann; trawling are often high and while many species are discarded by fishers, survival Determine the movements and migratory rate is mostly unknown. This project aims patterns of mako sharks. Mako sharks to increase our understanding of how are currently being tracked to improve stingarees react to capture during prawn our knowledge of their movement trawling operations. This is an honours patterns, dive behaviour and temperature project of Matt Heard. preferences. State-of-the-art technology combining pop-up tags and satellite Test the use of fatty acid analysis to ‘Splash’ tags are being used, providing quantify the diets of elasmobranchs. information which will help determine Previously dietary information of sharks links between shark movement patterns, was obtained from stomach contents and oceanographic and physical features. from dead or sacrificed animals. However, Ultimately, this project will help determine stomach contents only provide information the role of these top predators in the about the last meal. This study will develop pelagic ecosystems of Southern Australia. a new non-lethal method to assess the diet This is a PhD project of Paul Rogers; of sharks and rays. This method uses the chemical components of food (including Quantify the impacts of fishing on whaler fatty acids) which are stored within the sharks (bronze and dusky whalers). We tissues of prey and predator. As different are beginning a project using various prey types have different proportions of methods including satellite and acoustic Investigate the osmoregulation of Port Jackson embryos to assess their survival rate and physiological impacts following increased salinity levels (e.g., resulting from the outflow of a desalinisation plan). This being taken up as an honors project by Calie Heaven.
tagging as well as biological sampling (diet, reproduction, and age and growth) in collaboration with commercial fishers to quantify the resilience of whaler sharks to the current fishing pressure. In collaboration with Paul Rogers; Model the fine-scale swimming behaviour of white sharks in response to the berleying undertaken by cage-diving operators. During cage-diving activities, operators commonly use berley (mixture of minced fish and blood) to attract sharks close to the boat for viewing. Recent years have seen a marked increase in the number of days that cage-diving operators are on site from about 120 days to over 300 per year. The impact of this increase in berleying activity on the behaviour of white sharks at the Neptune Islands is unknown and requires further investigation to ensure the appropriate management arrangements are established to minimise the impacts of the cage-diving industry. At present there is very little information on how white sharks behave in the vicinity of pinniped colonies and specifically how they behave during periods when cage-dive operators are on site and berleying. Our project uses continuous tags and acoustic telemetry that enables fine-scale modeling of the swimming behaviour of the tagged sharks through continuous recording of positions and depths within one meter accuracy.
ASK A MARINE BIOLOGIST LIFE’S MYSTERIES ANSWERED
Which countries have banned shark finning? Erin Garden, Canada
RISING: SCIENCE & CONSERVATION
Shark finning is a destructive practice where sharks fins are removed, tragically often whilst the animal is still alive. The fins are sold for products such as shark fin soup or for traditional medicines. The remaining shark carcass is discarded back into the water as it has little commercial value. Shark finning is a billion dollar industry and because demand is so high, illegal operations are often prevalent. Longline fishing which is the preferred method of catch for these operations, are one of the most significant causes of shark decline worldwide. It is estimated that up to 70 million sharks are killed annually with one pound of dried shark fin fetching US$300.
I find it amazing how marine life How deep is the ocean? predicts events in the ocean way Carlie Edwards, Australia before they actually happen – like the tsunami. How do they do this? This question is a tricky one to answer
The Boxing Day tsunami was triggered by a magnitude 9 earthquake. The waves that followed killed 150,000 people and yet in each area of devastation very few animal carcasses were found. Most of the strange behavior reported from this time was from terrestrial animals, unless you are diving of course you probably wouldn’t have noticed any unusual marine behavior. Some of the behaviors included elephants running away trumpeting before the wave hit, flamingos leaving their breeding areas for higher ground, zoo animals taking cover and dogs not wanting to leave Today, a greater awareness about shark their homes. Strangely enough very little study finning is causing many nations to re-examine has been conducted into this phenomenon, so their fishing policies. Worldwide 17 countries we know very little about it. have now banned shark finning along their We do know that many animals have the ability seacoast. These are Switzerland, Austria, to sense changes to their physical environment Bolivia, Paraguay, Andorra, Lichtenstein, which are too subtle or beyond a human’s Luxembourg, Sudan, Rwanda, Hungary, Czech sensory ability. For instance, many species of Republic, Botswana, Central African Republic, birds and fish have much better eyesight than Mongolia, Tajikistan, Uzbekistan, and Nepal. we have; they are able to see into the ultraviolet The United States recently banned finning by spectrum and so can visually detect patterns all U.S registered vessels. Along with many or traces of other animals better than we can. other countries, including Australia and much Others, such as marine turtles have sensory of the EU, the US has implemented a ruling that abilities to detect changes in the earth’s shark fins cannot be brought to shore without magnetic field. They use this to navigate the the entire shark carcass thereby reducing the vast distances they travel around the world in number of shark fins for sale and the number search of food, mate and, for female turtles, to of sharks being killed. In January 2009, the navigate back to the same beach every year US House of Representatives passed the to lay their eggs. Sharks have very sensitive Shark Conservation Act of 2009 in order to ampullae of lorenzini, the electroreceptor’s close loopholes in the US finning ban. In late located along their snout, which are so 2009 the UK government closed all loopholes sensitive they will react to the electrical field regarding shark finning making it illegal for produced by muscle contractions of animals in the surrounding area. these operations to continue in its waters.
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because of course the depth of the ocean
Gaye Hawnt, UK varies depending on where you are in the
world. We are able to give an average depth over our oceans, which is about 4.3km (2.65 miles). The deepest part of the ocean is located beneath the western Pacific Ocean in the Marianas Trench. The trench is about 2,550km (1,580 miles) long and at its deepest point, known as Challenger Deep, is approximately 11 km (6.85 miles) below the oceans surface. Ocean depth is actually related to geological processes, in particular global plate tectonics. As the eight major, and several minor, plates move around the earth, our landscape and oceanscapes continually change. Most activity, creative and destructive, is found at boundaries where these plates meet. Constructive boundaries, which are the result of plates colliding, cause oceanic ridges and rises, creating island arcs. Destructive boundaries, which are the result of plates separating, such as subduction zones form deeper ocean trenches such as the Marianas Trench. Other intraplate features such as hot spots form islands like the ones we see in Hawaii today. Of course there are other features too that affect the depth of our oceans such as the formation of coral reefs, lagoons and mangroves. These are often the result of other processes like erosion, sedimentation and the settling of biological organisms such as reefforming corals.
What kind of species live in the deep ocean?
Do fish have eyelids?
It wasn’t until relatively recently that we even knew creatures lived in our deep oceans. Until the 1960’s it was assumed that nothing could survive in such harsh environments that are found at great depths. Today we know better and have managed to explore further than ever before but there are still many deep ocean creatures that we know very little about and surely some that have yet to be discovered.
eyelids. The reason that we as humans have eyelids is to stop our eyes drying out and to keep them moist. As fish live in water, there is no need for an extra body part to do this for them. They do however have a clear protective membrane over the eyes and some fish have the ability to roll their eyes back into the sockets.
Simon Holloway, UK Carlie Edwards, Australia It may sound a little fishy but fish don’t have
Deep ocean fish have special adaptations that allow them to survive in the harsh conditions and due to this their appearance can often look quite intimidating. Low light conditions create enlarged eyes and bioluminescence, and at the greatest depths evolution has sometimes foregone optical sensors altogether. A scarcity of food means that deep-sea critters have to be inventive. Many have evolved fishing lures on their body that light up and move to imitate a worm or small fish, luring larger fish in which then become lunch. Others have developed vampire like teeth, some too big to even fit in the animals’ mouth causing them to hang out ferociously. The gulper eel even has a hinged skull allowing it to rotate upwards to swallow large prey; in fact this critter can swallow creatures much larger than itself. The worlds deepest fish, from the family of brotulids, was found in the Puerto Rican Trench at 8,372m.
Chondrichthyans (sharks and rays), which are also fish, are slightly different. These animals possess a nictitating membrane that is similar but slightly different to a human eyelid. The nictitating membrane moves horizontally over the eye and is present in many sharks and rays to protect the eyeball from damage from prey. If you are ever close enough to see a shark feeding, you will notice how at the last minute the membrane, which is white in colour, covers the eyeball.
QUESTIONS? email: info@hawntmedia.com
Do you have questions about our oceans, rivers, wetlands, wildlife, coastal geology or other water related topic? We would love to hear from you Send us your aquatic questions to: info@hawntmedia.com with the title ‘Q&A’ in the subject line
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RISING: SCIENCE & CONSERVATION
From freshwater rivers to bustling coral reefs and down in the darkness of the ocean’s depths, sharks are found in nearly every aquatic environment on earth. With such vast differences present between these habitats, one might wonder how sharks are adapted to perceive their particular environment in order to survive in it. For most people, vision is considered to be the most important sensory system. Visual perception plays a major role in several day to day activities, such as choosing what to eat, getting safely from one point to another, deciding who to ask out on a date and picking your best friend out from the crowd. While we might not give these events much thought, Some of these senses are similar to those found in humans, such as taste, touch, vision, olfaction (smell) and audition (hearing), but sharks also have two extra sensory systems, electroreception and the mechanosensory
lateral line, which are exclusive to aquatic animals. Electroreception is the ability to detect weak electric fields, which all marine organisms emit, and the lateral line system is used to detect water movements. Some species of shark have also been known to geonavigate over long distances, possibly through the detection of the earth’s magnetic fields, but the mechanism for this is poorly understood. All of these sensory systems are beneficial for different aspects of a shark’s biology, and the reliance on a particular sensory system, or systems, may vary between species depending on their specific ecological needs. Originally, sharks were considered to have quite poor vision but in the last 50 years, several studies have shown that shark vision is actually much more advanced than traditionally thought. The basic structure of all vertebrate eyes is similar; however, vertebrate animals span a wide diversity of physical environments. Therefore, the visual system is often modified to best suit a particular habitat and hence several adaptations have evolved to deal with life underwater. For example, the cornea (the transparent portion at the front of the eye) is the major refractive
sharks depend on vision for basic survival strategies such as prey detection, predator avoidance, mating and communication.
component of the terrestrial vertebrate eye. However, the refractive index of the cornea is nearly identical to that of seawater, which renders the cornea essentially useless underwater. In order to compensate for this and focus light on to the retina, aquatic vertebrates, including sharks, have evolved a spherical, or near-spherical, lens with an elevated refractive index compared to the lenses of terrestrial vertebrates. To fully understand some of the visual specialisations found in sharks, a brief introduction to the visual process is needed. Light enters the eye through the cornea and pupil and passes through all optical components before reaching the retina, which lines the back of the eye. Photons of light are absorbed by photoreceptor
cells in the retina and converted into a biochemical signal that passes through the rest of the retina to the ganglion cells. The axons of the ganglion cells form the optic nerve, which transmits the visual signals to the brain where an image is perceived. An important structure located behind the retina in sharks is the tapetum lucidum, which is also found in many other, mainly nocturnal, vertebrate animals. The tapetum functions like a mirror to reflect any light that has not been absorbed back onto the photoreceptor cells. This helps to maximise light capture and increase visual sensitivity in low light conditions. A larger eye will also allow for enhanced visual sensitivity as more wavelengths of light can reach the retina. This would be beneficial to species relying on vision as a primary sensory system, or species living in habitats with minimal light penetration. In fact, using relative eye size as an indicator for the importance of vision in sharks has just been investigated, and the sharks with the largest eyes are pelagic species, such as the blue shark, and benthic or bentho-pelagic species found at deeper depths.
RISING: SCIENCE & CONSERVATION
As the light detecting cells in the retina, the photoreceptors of sharks have been of great interest, particularly in recent years. Like other vertebrates, sharks have two types of photoreceptors, rods and cones, which differ in morphology and physiology. Rod cells are used during dim light conditions (e.g. at night) and provide good contrast vision. Cone cells, on the other hand, operate under bright light conditions (i.e. during the day) and are responsible for colour vision. A major misconception, however, is that the mere presence of cones means that an animal has colour vision, and this is, in fact, incorrect. Both rods and cones contain visual pigments, which are the compounds responsible for the absorption of light. There are several different types of visual pigments and each one is tuned to absorb only a small portion of the wavelengths of light in the visible spectrum. Therefore, for an animal to have colour vision, it must have at least two types of cones, each with a visual pigment absorbing in different regions of the light spectrum. This facilitates a comparison of the wavelengths of light in the two different areas of the spectrum, and hence allows for discrimination between colours. To put this in perspective, humans have three different cone types, a blue, green and red cone, whereas most other mammals have only two cone types. This is the reason you might have heard that dogs are ‘colour blind’ or only see in black in white. Dogs most certainly can see in colour, but they are not able to discriminate as many colours as humans. Similarly, human red-green colour blindness is the lack of the green cone type, which also prevents those affected from distinguishing certain colours. While multiple cones types in fish, reptiles, birds and mammals are common, rod cells are normally present as only a single type.
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photo by Scott Cutmore
Determining how many cone types are present in sharks fills an important gap in the evolution of colour vision in vertebrates. The presence of cones in sharks was first
documented over 100 years ago, and every species examined since, save a handful of deep-sea sharks, have been found to have cones. However, essentially nothing is known about the cone visual pigments in sharks. In contrast, rod visual pigments are fairly well understood and appear matched well to the wavelengths of light available in a particular environment. For example, longer (‘red’) wavelengths of light are filtered out quickly in the ocean with depth, and thus rod visual pigments in deep-sea sharks are shifted to absorb the shorter (‘blue’)
a shark’s eye is 10 times more sensitive to light than human’s wavelengths of light that dominate in deeper waters. One of the problems with studying shark cone visual pigments is that sharks have fewer cones in relation to rods and, therefore, cones are much harder to find within the retina. The proportion of rods and cones is related to habitat and behaviour, such that diurnal species, or those species living in brightly lit environments, have a higher proportion of cones than nocturnal species and species occupying dimly lit habitats. The deep-sea piked dogfish, for example, has 50 times as many rods than cones whereas great white sharks have only four times as many rods. Behavioural experiments from the 1960’s and 1970’s sought to prove the existence of colour vision in sharks by training them to associate with different coloured targets. The experiments proved inconclusive, however, as it could not be determined whether the sharks were responding to a change in colour brightness or hue. In recent years, a new technique has been used to assess visual pigments in a variety of marine creatures, including sharks, and this has proven to be a very successful and accurate method for analysing visual pigment absorbance. Studies are still underway on sharks, but it’s been shown very recently that some species of the closely related rays, the giant and eastern shovelnose rays and the blue-spotted maskray, have three different cone types. This means they have colour vision comparable to humans, which is a very exciting finding! While the jury is still out on whether or not sharks see in colour, there can be no doubt that the visual systems of these fascinating creatures are adapted remarkably well to their particular lifestyles and habitat preferences. There is still a wealth of information waiting to be uncovered on the visual system of sharks, and in a time where understanding the biology and ecology of sharks is critical to their survival, sensory neurobiological studies offers another method for predicting such bio-ecological factors as predatory strategy, habitat preference and behaviours.
Dr. Susan Theiss Centre for Marine Studies The University of Queensland, St Lucia Brisbane, Qld 4072
Email: s.theiss@uq.edu.au Phone: +617 3365 9758
FISH BITES: SUSTAINABLE RECIPES FROM THE SEA Sesame Crusted Yellowfin Tuna on Cucumber Salad Yellowfin Tuna (Thunnus albacares) have shorter lifespans and more rapid growth than other species of tuna. These qualities help the species to withstand high fishing pressures. They are found throughout the world’s tropical and sub-tropical oceans. Though depleted compared to historical levels, most fisheries managers consider Yellowfin Tuna populations to be healthy. Choose pole and troll-caught fisheries over purse-seine and long-line fisheries to avoid the impacts related to bycatch of the latter two fisheries. Wakame (Undaria pinnatifida) is a seaweed that is a staple of Japanese and Korean food. It has a delicate flavour with slightly slippery texture and is known to have excellent health benefits. However, according to the Global Invasive Species Database (www.issg. org), it is also among the top 100 of the world’s most invasive species. Its native range includes the seas around Japan, China and the Koreas. It was accidentally introduced to Australia, New Zealand, Tasmania, and the Mediterranean Sea. It was deliberately introduced into the North Atlantic, to Brittany for commercial exploitation, and was then recorded in natural communities in France, Britain, Spain and Argentina. The impacts of Undaria pinnatifida are not well understood and are likely to vary considerably depending on the location. Undaria can change the structure of ecosystems, especially in areas where native seaweeds are absent. It has a microscopic phase in its life cycle, which makes eradication difficult. Management efforts are therefore aimed at slowing its spread. Advice given by the New Zealand government to reduce the spread of Undaria are: •
Applying antifouling paint to your boat’s hull regularly;
•
Regularly cleaning hulls in a facility with collection and land-based disposal of fouling material, thus preventing fouling from returning to the sea;
•
Cleaning fishing, aquaculture and diving gear thoroughly and away from the sea before using it in a new locality;
•
Preventing the build-up of fouling on buoys by allowing them to dry out occasionally;
•
Supporting the Undaria management initiatives in your area.
This Japanese-inspired dish is served rare, so be sure to use fresh, good quality steaks.
BY SEBASTIAN MYNOTT
Method
Ingredients
1. Soak the wakame in a bowl of warm water for about • 15 minutes or until fully opened. • 2. Combine the soy sauce, mirin, sake and sesame oil • and divide equally into two small bowls. Add the rice wine vinegar into one of the bowls and reserve as a • salad dressing. • 3. Halve the cucumber lengthways, scoop out the centre • with a tablespoon and discard. Slice the cucumber very thinly using a sharp knife or mandolin. Using • a vegetable peeler, peel the skin off the daikon and discard. Rinse the peeler in clean water and peel • several long strips of the daikon. Peel the ginger and slice into thin strips. Drain the wakame thoroughly and • combine with the cucumber, daikon and ginger. • 4. Stir in a very small amount of wasabi paste (or add it to taste) to the second bowl and use the mixture to • coat the tuna steaks. Spread the sesame seeds on a • plate and lay the tuna steaks over them to coat both • sides.
4 Yellowfin Tuna steaks 10g dried wakame ½ cucumber ½ daikon radish 2.5cm fresh root ginger 5 tbsp sesame seeds 3 tbsp soy sauce 3 tbsp mirin (Japanese sweet wine) 3 tbsp sesame oil 2 tbsp rice wine vinegar 2 tbsp sake 2 tbsp rice oil wasabi paste
5. Heat the rice oil in a frying pan over high heat and sear the tuna steaks in the pan for about 30 seconds on each side or cook to your taste. 6. Add the dressing to the salad and assemble it in a small pile on each plate. Lean the tuna steak against the salad, spoon a little of the pan juices over the tuna and serve!
Principles for choosing sustainable seafood 1. Choose locally caught, fresh seafood (avoid imported seafood); 2. Choose fast-growing species (avoid long-lived, slow growing or deep sea species); 3. Avoid sharks and rays (many are overfished and are important for maintaining healthy ecosystems); 4. Refer to a locally produced sustainable seafood guide (the WWF (www.panda.org) has a list of sustainable seafood guides worldwide on their website).
FILM REVIEWS
THE END OF THE LINE (2007) DIRECTED BY: MAURICE DEVEREAUX
The Tragedy of the Commons is a landmark paper by Garrett Hardin published in 1968 in the journal Science (Vol. 162, pp. 1243-1248). In it, Hardin describes the logical inevitability of tragic overexploitation of unregulated common resources. Hardin uses the example of a common pasture, open to all. Herdsmen graze their cattle on the pasture and, being rational people, each herdsman concludes that the benefit of increasing the number of animals in his (or her) herd is greater than the cost each of them will bear as individuals. With the benefit of our perspective we can clearly see how the tragedy will unfold as, with limited capacity, cattle overrun the pasture and it is rendered useless to all. Released in May 2010, the documentary film The End of the Line (www. endoftheline.com) shows us how this same tragedy has been unfolding in our oceans. The world’s oceans are our planet’s greatest and least regulated commons. What brought about this tragedy is not just the advent of large-scale commercial fisheries and not simply the illegal, unregulated and unreported fishing. Fisheries managers themselves are not without rebuke; by setting biologically unrealistic catch quotas fish species have little or no opportunity to recover. But all of this ultimately comes from our own massive demand for seafood globally. The film deftly rides the line between effectively delivering its message without appearing to be too anti-fishing or anti-seafood. Filmgoers are empowered to accept a sense of responsibility towards our oceans and to take action by demanding sustainably caught seafood.
SHARK WATER (2006) DIRECTED BY: ROB STEWART
Released in late 2007, the documentary film Sharkwater (www.sharkwater. com) won 31 international awards for its portrayal of the threats faced by global shark populations. Years of systematic overfishing fueled by popular misconceptions of sharks as mindless killing machines have led to dramatic declines in nearly all species worldwide. Canadian director Rob Stewart mixes guerilla journalism with evocative nature documentary styles to deliver a compelling piece of work. He highlights the importance of sharks in contributing to the health and stability of marine food webs, exposes the shark fishing industry, its lack of regulation, and, in telling the story, he also becomes a part of the story.
FUN PAGES
Unlike the issue of overfishing, the overexploitation of sharks has largely been occurring for decades under the radar for most people. As mentioned in the film, many of the large global conservation organisations have only recently mounted campaigns for shark conservation. Graphic and often at times grim the film is important as it gives us a glimpse into a world rarely encountered by the average person. Though well crafted, the film is not so much enjoyable to watch as it is necessary.
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COMPETITIONS
72&RISING
JOURNALISM Are you studying journalism or are you a journalist who is passionate about the environment? Each issue we will be running a competition to uncover talented photojournalists. We are looking for articles with images that cover any aquatic related topic, from conservation issues and wildlife articles to interviews with scientists about their work and cultural stories. The best article for each edition will be published in 72&Rising along with full credit to the author. You will also receive a free one-year subscription to 72&Rising. Ideally your articles should be between 500-1500 words and have images to accompany the text, though exceptional articles without photos will also be considered. Third party images will not be considered.
COVER ART Think you can do a better job at design than our graphic artists? Give it a go! Each issue we will run a competition to find some of the best artists around the world. We are looking for original works that convey an aquatic conservation theme and display the number 72 somewhere in the image. Send us your drawings, paintings, and images (we welcome the use of Photoshop or other creative tools) in an approximately A3 format at 300DPI along with a short (up to 250 word) bio about yourself and your artwork. Winners will have their artwork displayed on the cover of 72&Rising, your bio and description of your artwork will appear in the magazine and on the 72&Rising website. You will also receive a free one-year subscription to 72&Rising. It’s great exposure for yourself and your work.
THE RULES
email entires to: info@hawntmedia.com with ‘Competition’ in the subject line Your submission of work in these competitions grants 72&Rising the right to publish them at any time in the magazine or on the website with proper accreditation 1. All contributions, including all text, images and artwork must be the contributor’s own work. 2. Contributions cannot be returned so please make sure that you retain a copy. 3. Copyright remains with the artist/author
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