Aquaculture Magazine October-November 2021 Vol. 47 No. 5 by Aquaculture Magazine

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OCTOBER - NOVEMBER 2021

INDEX

Aquaculture Magazine Volume 47 Number 5 October - November 2021

EDITOR´S COMMENTS

INDUSTRY NEWS

on the

cover

24 ARTICLE

Designing environmentally efficient aquafeeds through the use of multicriteria decision support tools.

30 ARTICLE

12 FISH AND SHRIMP FARMING PRODUCTIVITY

Exploring the Multimodal Role of Yucca schidigera Extract in Protection against Chronic Ammonia Exposure Targeting: Growth, Metabolic, Stress and Inflammatory Responses in Nile Tilapia (Oreochromis niloticus L.)

18 ARTICLE

Estimation of Phosphorus and Nitrogen Waste in Rainbow Trout (Oncorhynchus mykiss, Walbaum, 1792) Diets Including Different Inorganic Phosphorus Sources

Antiparasitic and Antibacterial Functionality of Essential Oils: An Alternative Approach for Sustainable Aquaculture.

Animal Protein Sources as a Substitute for Fishmeal in Aquaculture Diets: A Systematic Review and Meta-Analysis.

36 ARTICLE

Market aspects and external economic effects of aquaculture.

40 ARTICLE

Resource use in Whiteleg shrimp Litopenaeus Vannamei farming in Ecuador.

52 ARTICLE

Application of hybrid electrocoagulation–filtration methods in the pretreatment of marine aquaculture wastewater.

58 ARTICLE

Fish packing perfected with robotics.

Volume 47 Number 5 October - November 2021

Editor and Publisher Salvador Meza info@dpinternationalinc.com Editorial Contributor Marco Linné Unzueta Editorial Assistant Marcela Gracia editorial@dpinternationalinc.com Editorial Design Francisco Cibrián Designer Perla Neri design@design-publications.com Sales & Marketing Coordinator Juan Carlos Elizalde crm@dpinternationalinc.com Marketing & Corporate Sales Claudia Marín sse@dpinternationalinc.com Business Operations Manager Adriana Zayas administracion@design-publications.com

60 ARTICLE

Net resilience in the times of COVID.

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COLUMNS

REALISTIC AQUACULTURE SOLUTIONS Recirculating Aquaculture Systems. The Good, the Bad and the Ugly. By: By: Yedod Snir *

TECHNICAL GURU

THE FISHMONGER

DIGITAL AND SOCIAL MARKETING BYTES

Ozone contact, waste not, want not… By Amy Stone

Are you leadign?

Tips for Improving Website Searchability. By: Sarah Cornelisse*

OCTOBER - NOVEMBER 2021

THE GOOD, THE BAD AND THE UGLY EHP update.

By Stephen G. Newman Ph.D. * President and CEO, AquaInTech Inc.

The Potential of Marine Aquaculture

1.4 million square kilometers have been detected with the potential for developing marine aquaculture farms worldwide, with an estimated potential production of 15 billion tons annually: 100 times the current worldwide consumption of seafood. Even though marine aquaculture is potentially one of the most significant protein sources for future human consumption, its present-day production is concentrated in just three countries: Norway, Chile, and China, which still have great growth potential but are not the countries with the highest biological growth potential for a variety of species. Today, the potential of marine aquaculture is restrained more by social, economic, and governability factors than by biological factors or by usage conflict. This communication problem between science, politics,

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and local socioeconomic conditions is the most common factor for limiting the growth of marine aquaculture in the world. Even though the growth potential of marine aquaculture is acknowledged, the establishment of new farms is not standard. There are still restrictive regulations that difficult its growth. There are high costs for physically establishing the farms at sea. There is a lack of capital for investment, plus limitations in the transference of knowledge to develop cultivations. Thus, it is expected that the areas where marine aquaculture will have more growth are not the areas where it is currently taking place. The countries where the most significant growth potential for mariculture has been detected, given by the particular biological conditions of their seas, are the following (in order

of importance with a production of between 8 and 24 million tons per year): · Argentina · Australia · Indonesia · Mexico · India 11.4 million square kilometers have been detected with the potential for developing marine aquaculture farms worldwide, with an estimated potential production of 15 billion tons annually: 100 times the current worldwide consumption of fish and seafood. The potential for a fast expansion of marine aquaculture is evident. Still, it takes knowledge and the political will of the countries with the best conditions to trigger this production, to smooth out all the obstacles currently restraining this economic activity full of great expectations.

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INDUSTRY RESEARCHNEWS REPORT

Released the First-Ever Canadian Code of Practice for the Care and Handling of Farmed Salmonids The National Farm Animal Care Council (NFACC) and the Canadian Aquaculture Industry Alliance (CAIA) has announced the release of the firstever Code of Practice for the Care and Handling of Farmed Salmonids. “We are pleased to have a Code of Practice that will further support the sustainability of the Canadian aquaculture sector,” said Dr. Barry Milligan, a veterinarian who has held senior roles in both salmonid production and fish health, and who also serves as the Chair of the Code Development Committee. “Our industry’s participation in the Code development process demonstrates our producer’s commitment to animal health and welfare and dedication to responsible fish husbandry.” A summary report from the Code Development Committee is also available at www.nfacc.ca/codesof-practice/ farmed-salmonids. The report summarizes the feedback received on the draft Code, both from the public comment period and from a 2019 top-of-mind survey, noting how the Code Committee considered this feedback in finalizing the Code. Committee members thank everyone who contributed their feedback, which led to several improvements in the final Code. While not all concerns were able to be addressed, the Code Development Committee worked hard to balance producer achievability, available research, and stakeholder viewpoints in the Code’s development. “I commend the aquaculture sector for initiating the development of this Code. A significant milestone has been achieved in releasing Canada’s first Code of Practice for the Care and Handling of Farmed Salmonids,” said Leigh Gaffney, who represents World Animal Protection Canada on the Code Committee. “This Code reflects the hard but very important conversations we had on how to bring meaningful improvements to the welfare of farmed salmonids in Canada.” “We are very proud to be releasing the first Code of Practice for farmed 6 »

salmonids in Canada,” noted also Arlen Taylor, Code Development Committee member and owner of a secondgeneration family business that operates five rainbow trout hatcheries in Ontario. “This Code is a valuable resource for large and small farms alike. It will allow us all to improve our practices while continuing to innovate for the future betterment of animal care.” Canada’s Codes of Practice are nationally developed guidelines for the care and handling of farm animals. They serve as the foundation for ensuring that farm animals are cared for using sound management and welfare practices that promote animal health and well-being. Codes are used as educational tools, reference materials for regulations, and the foundation for industry animal care assessment programs. NFACC’s development process is a unique consensus-based, multi-stakeholder approach that ensures credibility and transparency through scientific rigour, stakeholder collaboration, and consistency. The development of the Farmed Salmonids Code was led by a 14-person Code committee that includes participants from across Canada including producers, animal welfare and enforcement representatives, researchers, veterinarians, and government representatives. Aiding in their work was a five-person Scientific Committee that included animal science and veterinary expertise

in fish ecology, behaviour, health, and welfare. A public comment period was held from November 2, 2020 to January 7, 2021 to allow the public and all stakeholders to provide input. Canada’s Codes of Practice was born to be a powerful tool for meeting rising consumer, marketplace and societal expectations relative to farmed animal welfare. Codes support responsible animal care practices and keep everyone involved in farmed animal care and handling on the same page. The Farmed Salmonids Code is the thirteenth Code of Practice developed through NFACC’s Code development process. More information on the Codes of Practice and NFACC’s Code development process can be found in www.nfacc.ca. Funded in part by the Government of Canada under the Canadian Agricultural Partnership’s AgriAssurance Program, a federal, provincial, territorial initiative.

The organisms NFACC is a collaborative partnership of diverse stakeholders created in 2005 to share information and work together on farm animal care and welfare. It is the national lead for farm animal care issues in Canada. The Canadian Aquaculture Industry Alliance (CAIA) is the national association that speaks for Canada’s seafood farmers, representing their interests in Ottawa to regulators, policy makers and political leaders. OCTOBER - NOVEMBER 2021

Regal Springs Tilapia Is World’s First Tilapia Producer to Use Traceability Integrating Directly with Best Aquaculture Practices (BAP) Certification Systems This innovation is enabled by the Wholechain traceability system and has been designed in collaboration with Best Aquaculture Practices (BAP) with the goal of enabling real time data monitoring for this certification. The Switzerland-based company, a world leader in premium tilapia, grows tilapia in floating pens in lakes. Its farms and processing facilities located in Mexico, Honduras and Indonesia are all BAP certified. Regal Springs partnered with the Global Seafood Alliance (GSA), which owns the BAP program, and Wholechain to launch the traceability integration, bringing unprecedented transparency and verification to sustainability claims in farmed tilapia. Regal Springs’ traceability is further enhanced due to Wholechain’s integration with the Mastercard Provenance Solution, a global blockchain-based solution which enables verifiable records of all traceability events. The purpose of the traceability system is to bring more visibility to the origins of Regal Springs’ tilapia and to the standards to which the company’s farms and processing plants are held. BAP-certified farms and processing plants are audited annually by a thirdparty auditor and held to high standards for environmental responsibility, social accountability, food safety, and animal health and welfare. Regal Springs, GSA and Wholechain initiated this collaboration with the Full Circle Market private label brand of tilapia available at grocery stores across the United States with QR codes that consumers scan to learn about their quality standards as well as their social responsibility and sustainability practices. “As a vertically integrated producer, traceability is in our DNA and we are excited about this collaboration,” said Edward Kiger, managing director of Regal Springs Trading. “We commend Regal Springs, Wholechain and Mastercard for colOCTOBER - NOVEMBER 2021

laborating with us on a project that will lead to more visibility in the seafood supply chain, which our retail and foodservice partners as well as consumers are asking for,” said GSA COO Brian Perkins. “This has the potential to be a game changer on the traceability front.” “The convergence of technology enablers such as blockchain with the complexities of modern supply chains creates opportunities for traceability, building trust and streamlining operations for parties,” said Deborah Barta, senior VP of provenance and strategy for Mastercard. “In partnership with Regal Springs, GSA and Wholechain, the industry-agnostic Mastercard Provenance Solution supports ESG certifications, enabling the verification of sustainability claims in farmed tilapia with end-to-end visibility.” Feed Forward, a food impact agency based in New York City, is a key partner to Wholechain in connecting these products to neighborhood grocers and our communities. As an added benefit to the sales of these products in grocers like Lincoln Markets, a percentage will go back to Feed Forward’s More Than A Meal program. More Than A Meal supports local communities impacted by food insecurity through a simple tech-backed platform that matches individuals and families with meals and groceries in their neighborhoods. Lincoln Market supermarkets based in New York City will be the first in the state of New York to carry the tilapia, in

addition to the whole Full Circle Market product line of fully traceable sustainable seafood, starting in late November. “We always focus on quality for our customers. Knowing that this product is of the highest quality and is backed by endto-end visibility for us and our consumers, while simultaneously giving back to our community via the More Than A Meal program, is a homerunk and we can’t wait to get started,” said Khalil A., store manager for Lincoln Market. “This initiative is a prime example of the impact that we have set out to do as an organization. Our communities are receiving quality products, traceability information and education about the product, while also supporting their neighbors in need. Like the name on the package states, it truly is full circle,” said Liz Peralta Foxwell, co-founder and VP of impact for Feed Forward. Best Aquaculture Practices is a thirdparty certification program developed by the Global Seafood Alliance, an international, nonprofit trade association, dedicated to advancing environmentally and socially responsible seafood practices through education, advocacy and third-party assurances. Regal Springs, for their part, is the largest vertically integrated white fish farming producer in the world. The company operates Responsible Aquaculture and Processing in Indonesia, Honduras and Mexico and is famous for producing Premium all-natural Tilapia. »

INDUSTRY RESEARCHNEWS REPORT

New European Strategy for Sustainable Aquaculture and Fisheries in the Mediterranean and the Black Sea The European General Fisheries Commission for the Mediterranean (GFCM) has adopted its new 2030 Strategy for the Mediterranean and Black Sea at the end of the 44th annual session, some weeks ago. An agreement was also reached on an ambitious package of measures translating strategy into concrete actions. “The new GFCM 2030 Strategy provides the framework and the necessary tools to ensure a sustainable, just and inclusive future for our fleets and our local communities, while protecting the ecosystems. We understand that we must act quickly and decisively. This is why, under the leadership of the European Union, the GFCM has already started to implement the strategy with the adoption of an ambitious package of measures at the annual session. The EU remains committed to the implementation of the new strategy. This is why we will also increase our financial contribution through the GFCM Grant”, said Virginijus Sinkevičius, European Commissioner for the Environment, Oceans and Fisheries. For aquaculture, the strategy sets the framework for long-term governance and responsible investment. It also promotes new technology and best practices through the GFCM’s regional knowledge-sharing hubs and aquaculture demonstration centres. In parallel to the adoption of the new strategy, the implementation process was launched immediately. 35 GFCM recommendations and resolutions translating the objectives and targets of the strategy into concrete actions were adopted at the meeting, with 33 of those tabled by the EU. The recommendations include important measures to improve fisheries management and control in the Adriatic and Black Seas, better protect sensitive species and habitats, and consolidate the monitoring and control framework, including combatting illegal, unreported and un8 »

regulated (IUU) activities in both the Mediterranean and the Black Sea. The new strategy builds on recent achievements, with its five targets, it takes an integrated approach to the complex challenges in the region and the “green transition’’. It addresses issues such as the condition of the marine environment and preserving biodiversity in order to provide maximum sustainably yields (MSY). The strategy will also help to consolidate GFCM member’s ability to take strong action against IUU fishing and create a level playing field around both sea basins. Furthermore, the strategy continues to support local communities and their livelihoods along the value chain, with special focus on smallscale fisheries. There will also be coordinated measures to ensure decent working conditions, support young people and properly recognise the role of women in the fisheries and aquaculture sector, as well as promote the participatory decision-making process. In addition, the European Union and the MS were granted a Compliance Award, recognising their commitment to observing and implementing all GFCM decisions and data submission requirements (Category 1 – Full compliance).

The GFCM 2030 Strategy was prepared through a series of highlevel events and technical meetings in 2020 and 2021. It was politically endorsed on 9 July 2021 and formally adopted with a GFCM Resolution at the 44th annual session. In line with the UN Agenda 2030, the strategy covers a ten-year period until 2030. A mid-term review of its objectives and outcomes will assess the progress of its implementation. The GFCM 2030 Strategy is articulated around five targets. Each target is composed of expected outputs and strategic actions, including an action plan comprised of a set of detailed actions. This action plan will be regularly updated. The implementation of measures from this plan is already underway, through the decisions adopted at the 44th GFCM annual session. The European Union presented 35 proposals for recommendations and resolutions, 33 of which were adopted. For the remaining two proposals, the regional partners requested more time to assess at technical level, with a view to adopting them at the next annual session in 2022. The European Union will support the implementation of the strategy with an increased financial grant. OCTOBER - NOVEMBER 2021

The Sheikh Khalifa Marine Research Centre delivers 600,000 Fish Fingerlings to Aquaculture Companies in United Arab Emirate The Sheikh Khalifa Marine Research Centre has delivered 600,000 fish fingerlings to a number of aquaculture companies in the United Arab Emirate (UAE), including Emirates National Fish Farming Company, as part of the country’s efforts to develop the sector as a means to support the nation’s food security plans. The shipment is the first following the full renovation process the centre had undertaken to enhance its hatchery, with the initial batch comprising European seabream, of which a number will be raised in the aquaculture companies’ cages. Fish Farm LLC -the company in charge of the management, operation, and maintenance of Sheikh Khalifa Marine Research Centre- is working to enhance operations to reach full operational capacity in one month, in time to support the upcoming fish farming season. The company has set a comprehensive plan to produce more than 7 million fish fingerlings of various species, including seabream, hammour, seabass and cobia, among others. Maryam bint Mohammed Almheiri, Minister of Climate Change and the Environment, said: “The development of fisheries and aquaculture is a top priority for the UAE. It is a key component in our plans to enhance our food security and increase our annual food production. The Sheikh Khalifa Marine Research Centre’s hatchery is an important instrument in achieving these objectives; the facility boasts an enormous capacity to produce nearly 30 million fish fingerlings per year in two stages. This demonstrates the hatchery’s great ability to supply aquaculture farms around the country with top-quality fingerlings in preparation for their breeding and entry to the market within a short period.” “We are delighted to be delivering the first shipment of fingerlings from the complete renovated and developed hatchery to a number of aquaculture companies in the UAE , including Emirates National Fish Farming Company”, OCTOBER - NOVEMBER 2021

he added. “Work is ongoing to develop the hatchery and employ advanced technologies to enhance its productivity in the future, and increasingly grow our production capacity, while adhering to the highest sustainability standards. Preserving our resources from waste and protecting our marine environment are a non-negotiable commitment for us.” In April 2021, Almheiri signed an agreement with Fish Farms LLC, represented by its CEO Bader bin Mubarak, to operate and maintain the Sheikh Khalifa Marine Research Centre’s hatchery in Umm Al-Quwain in accordance with the highest international standards. The MoU aims to boost the hatchery’s productivity and upgrade the quality of the fish fingerlings it produces to be supplied to aquaculture farms around the country -a central component of the UAE’s food security system. The United Arab Emirates established Sheikh Khalifa Marine Research Center, which will house 14 specialized laboratories divided in 5 clusters (Generator Room, Pump Station, Plant room, Broodstock, Hatchery, Offices, Weaning, Nursery and Surrounding Area), to be operated in partnership with interested regional and international partners. The UAE welcomes regional and international businesses, entrepreneurs and research institutions to partner to conduct cutting edge research at the research center. The Research Center was build in Umm AL-Quwain by the Ministry of Public Works of the UAE. The objective of the Marine Hatchery Complex is to produce 10 million juveniles per year of a variety of local and non-indigenous fish species to allow the

indigenous sustainable development of Aquaculture. The country is one of the pioneers in aquaculture among the countries of the Gulf Cooperation Council (the GCC, founded in 1981 with Saudi Arabia, Kuwait, Bahrain, Qatar and the Sultanate of Oman). The UAE is endowed with many natural lagoons, bays and creeks, most of which are encircled by mangrove swamps providing ideal spawning and nursery grounds for a wide variety of fish and shrimp species.

INDUSTRY RESEARCHNEWS REPORT

Rimini will host the conference of the European Aquaculture Society 2022

The Palazzo dei Congressi di Rimini (Palacongressi), in Italy, will host the Aquaculture Europe 2022, the conference of the European Aquaculture Society 2022 (AE2022) from September 27 to 30. The 2021 edition took place recently on the island of Madeira with more than 1400 participants from 57 countries. “Over the three days of the congress, explained Fabio De Santis, Event & Conference Director of Italian Exhibition Group (IEG), more than 1500 professionals, breeders, researchers, consultants, students and industrialists from the world of aquaculture from all over Europe are expected”. The Food and Agriculture Organization of the United Nations (FAO) will also participate, thanks to Alessandro Lovatelli, its regional responsible for fisheries and aquaculture, as conference chair. 10 »

How aquaculture is facing these all its challenges, and the solutions put in place to develop a sustainable, responsible and productive and climate neutral European aquaculture sector for key marine and freshwater fish, shellfish and algal species are the main themes for AE2022 event in Rimini. The issues of compatibility and mutual synergy between the users of marine, brackish and freshwater resources and their relationship with the quality of those ecosystems are central in promoting the sustainable development of the Blue economy and aquaculture, and will also be topics of this conference. Other matters of interest will be climate change, depletion of natural resources, loss of biodiversity, food security and safety, environmental pollution and waste represent important sustainability challenges

for further expansion of European aquaculture and the ambition of the European Green Deal and the Farm to Fork Strategy. The organizers consider that it will be necessary for the sector to address these externalities, but also focus on the way in which they chose, use and re-use resources, as move towards a circular Blue economy. The AE2022 parallel sessions will cover the full scope of European aquaculture and will comprise submitted oral and ePoster presentations. AE2022 will also feature an international trade exhibition, industry forum, student sessions and activities, satellite workshops and updates on European Union research.

2021 in Madeira On the other hand, Aquaculture Europe 2021 (AE2021) was held recently on the island of Madeira, OCTOBER - NOVEMBER 2021

in Portugal. Aquaculture has a clear place in securing food production in Europe and the theme of the event, ‘Oceans of Opportunities’ underlined the significant potential for development and investment if given the political and social licence to expand and develop, accompanied by public awareness and acceptance of its role. AE2021 was attended by more than 1400 participants from 57 countries. The trade show allowed 80 companies to present their products and services to the sector and included a special pavilion of Portuguese companies presented by the Ministry of the Sea, Ricardo Serrão Santos. 943 abstracts were submitted for conference presentations and 560 of these were presented orally in the 39 conference sessions. A further 383 ePosters were presented online and on several viewing stations in the conference area. 248 students were registered and had a dedicated workshop and special events and excursions during the week. Special sessions and workshops were also organised during AE2021, including ‘Mediterranean aquaculture integrated development’, the final workshop of the EU Horizon 2020 MedAID Project, with the collaboration of PerformFish, the EU Blue Invest Day -a forum for innovation and investment for aquaculture within the EU Green Deal- and workshops organised by the EAS Thematic Group on Percid Fish Culture, the Mediterranean Aquaculture Product Environmental Footprint Stakeholders event and the HiSea demonstration of high-resolution water quality data services. It should be noted that the opening plenary was delivered (by

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video) by Shakuntala Thilsted, Value Chains & Nutrition Research Leader of WorldFish, from Malaysia. Her ranging overview of the ‘Diversification of aquatic food systems: Oceans of Opportunity for nourishing nations’ framed the importance of aquaculture for nutrition, health and livelihoods throughout the world, with key messages for stakeholders in general and especially policy makers and legislators. Shakuntala was awarded the 2021 World Food Prize for her ground-breaking research, critical insights, and landmark innovations

in developing holistic, nutritionsensitive approaches to aquatic food systems, including aquaculture and capture fisheries and more recently the 2021 Arrell Global Food Innovation Award from the University of Guelph’s Arrell Food Institute (AFI) award program.

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By: Zizy I. Elbialy, Abdallah S. Salah, Ahmed Elsheshtawy, Merna Rizk, Muyassar H. Abualreesh, Mohamed M. Abdel-Daim, Shimaa M. R. Salem, Ahmad El Askary and Doaa H. Assar. ABSTRACT. Despite trials for its control, ammonia remains one of the most environmental toxicant for aquatic species. In this study, we explored the modulatory effect and potential mechanism by which Yucca schidigera extract (YSE) can ameliorate ammonia intoxication-induced adverse effects on tilapia health and metabolism. YSE supplementation succeeded in improving water quality, markedly alleviated chronic ammonia-induced adverse impacts on fish growth while reducing the feed conversion ratio (FCR) via improvements in food intake, elevation of hepatic insulin-like growth factor (ILGF-1) and suppression of myostatin (MSTN) expression levels with the restoration of lipid reserves and the activation of lipogenic potential in adipose tissue as demonstrated by changes in the circulating metabolite levels. This suggests that YSE supplementation exerted an ameliorative role against chronic ammonia-induced oxidative stress and toxic effects due to its free radical-scavenging potential, potent antioxidant activities and anti-inflammatory effects.

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he intensification of aquaculture causes water pollution, which is consistently related to increased levels of ammonia, and represents about 70% of nitrogenous fish wastes. Decomposed un-eaten feed in water favors ammonia formation, and thus subjects fish to stress risk. Ammonia induces oxidative stress via the overproduction of ROS (reactive oxygen species), which deteriorates important biomolecules, such as DNA, proteins and lipids, and initiates a cascade of events that causes impairment of cellular functions Yucca schidigera is a medicinal herb which represents an important future ecofriendly supplement in livestock production. Numerous studies documented that Yucca schidigera extract (YSE) has the ability to regulate energy metabolism and hormonal activity in animals. Nile tilapia (Oreochromis niloticus L.) is an important cultured aquaculture species throughout the world that could be used as a suitable model for studying nutrition and metabolism not only because of its rapid growth and high resistance to diseases and toxic stress, but also due to the availability of its whole genomic information. The present investigation aimed to declare YSE modulatory effect (s) against chronic ammonia intoxication in Nile Tilapia (Oreochromis niloticus).

Experimental Design, fish diet and water quality A total of 120 healthy male monosex Nile tilapia (Oreochromis niloticus) were collected from a private farm, acclimated for two weeks, and then divided into four groups. The first group kept as a normal control group, the second group supplied with YSE in water at a dose of 8 mg/L water every two days, the third group exposed to ammonia from the beginning of the experiment for four weeks, and the fourth group was supplied with YSE and exposed to ammonia for four weeks. OCTOBER - NOVEMBER 2021

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Different water parameters were measured on a daily basis throughout the experiment’s duration, including dissolved oxygen (DO), ammonia, water temperature, and pH, in all experimental groups.

Blood Sampling, evaluation of Lipid Peroxidation and Antioxidant Enzymes After four weeks, blood samples were collected from fish in a random order from the caudal vein and divided into two parts. for biochemical measurements of transaminases (ALT and AST), LDH, amylase, lipase, TC, TG, HDL-C, total proteins, albumin, BUN. A piece of liver was subjected to biochemical determination of malondialdehyde (MDA) content, and glutathione peroxidase (GPx). Superoxide dismutase (SOD) was evaluated and reduced glutathione (GSH). Histopathology Study, total RNA Extraction, cDNA Synthesis and Quantitative PCR Assay Sections from liver, spleen, brain and gills were dehydrated using ascending concentrations of ethanol (70–100%), cleared in xylene, and embedded in paraffin wax, cut on a microtome, stained with hematoxylin and eosin (H&E) and examined with a light microscope To evaluate gene expression levels, liver, adipose, muscle and brain tissues (3 fish/replicate) were collected. Gene expression analysis was performed in the mic-PCR Real-time PCR system (Bio-molecular systems) using the SensiFast SYBR No-Rox kit (Bioline) using Nile tilapia genespecific primers with 16s rRNA as the housekeeping gene. Results YSE supplementation significantly reduced (p < 0.05) pH, TAN and UIA levels compared to the fish group exposed to high ammonia levels. Moreover, compared to the control group, fish exposed only to high ammonia level showed significantly low14 »

ered FBW (final body weight), BWG (body weight gain), and SGR (specific growth rate), and higher FCR (feed conversion ratio). Conversely, supplying YSE to ammonia-intoxicated fish successfully enhanced FBW, BWG, and SGR and significantly lowered FCR in comparison to the fish group exposed only to high ammonia levels. YSE administration to ammoniaintoxicated fish restored the values of the stress leukogram to normal reference levels compared to the second fish group, which was intoxicated by high ammonia levels, where no changes occurred. YSE resulted in an effective improvement according to the measurement of ammonia- altered hepatorenal injury markers. The findings of ammonia-intoxicated fish additionally supplied with YSE were opposed to the findings for the ammonia-intoxicated group, in which there was an inhibition of hepatic MDA content and an enhancement of SOD, GPx enzyme activities and GSH levels. Ammonia intoxication induced marked degenerative and necrotic changes within the hepatopancreas (P) with a moderate degree

of hepatic vacuolation. However, YSE treatment markedly improved pathological changes in the hepatopancreas that were induced by high ammonia levels. On the other hand, YSE treatment to ammonia-intoxicated fish had improved the MMC However, the administration of YSE to ammoniaintoxicated fish resulted in tiny foci of malacia with a marked decrease in gliosis. Additionally, an elevated ammonia level induced severe loss of secondary lamellae with marked infiltration of inflammatory cells, while YSE treatment resulted in a marked decrease in the adhesion between the secondary lamellae. The second fish group, which was intoxicated by ammonia, had reduced levels of both brain NPY and hepatic IGF1. The fish group supplied with YSE and intoxicated with ammonia (3rd group) exhibited higher expression levels of brain NPY, and hepatic IGF1, with a decreased expression of liver MSTN compared with the chronically intoxicated ammonia group. Compared to the control group, the ammonia- intoxicated group exOCTOBER - NOVEMBER 2021

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hibited reduced expression levels of glycolytic gene PK and adipose tissue lipogenesis encoding of the FAS gene, as well as elevated gluconeogenesis genes G6pase and PEPCK and enhanced adipose tissue lipolysis regulating the LPL gene the groups supplied with YSE, either with ammonia intoxication or without, experienced down regulation of the hepatic IL1B, TNFα and HSP70 gene expression levels compared to the ammonia- intoxicatedonly fish group after two and four weeks

Discussion High ammonia level was harmful to Nile tilapia through the induction of oxidative stress via an elevated hepatic MDA content with depletion in the measured level of hepatic antioxidant defense markers. Digestive enzyme activities are good indicators of digestive capacity and precisely reflected the nutritional status of fish, and they are also highly sensitive to ROS. We found that the growth-suppressing effects of chronic ammonia exposure may have resulted from the downregulation of brain NPY and hepatic ILGF-1 and the elevation of myostatin (MYSN) expression levels, in addition to the depletion of lipid reserves through the enhancement of adipose tissue lipolysis and the diminution of the adipo-lipogenic potential. fish intoxicated with ammonia compared with control group revealed reduced NPYa expression with elevated serum glucose levels and enhanced gluconeogenesis and lipolytic activity of LPL, suggesting that chronic ammonia stress could indirectly inhibit food intake through the hyperglycemic and lipolytic effects. More specifically, we demonstrated here for the first time that YSE supplementation counteracted the suppressive effects of high ammonia levels on Nile tilapia growth at the molecular level through enhancement of brain NPYa, hepatic ILGF1 and inhibition of hepatic MSTN expression levels. 16 »

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compared to the control fish group. During chronic stress, cortisol influences the liver physiology of fish by modulating the carbohydrate- and lipid-related metabolism. Our data reinforced the hypothesis that the absence of a concomitant increase in hepatic glycolysis and the stimulation of gluconeogenesis in the liver may contribute to the establishment of elevated blood glucose levels.

The hemato-biochemical indices reflect hepatic, renal and immune functions, as well as lipid and protein metabolism, in the blood of the organisms. Therefore, the general physiological and health condition of fish reared under stressful conditions or specifically supplied with modulatory agent can be well characterized. In this work, we challenged fish with ammonia level whose leukogram picture was indicative of stress. Interestingly, YSE supplementation for ammonia-intoxicated fish succeeded in producing a decline in the hepatic expression levels of TNF-α and IL-1Ɓ and a stress alteration in HSP70. OCTOBER - NOVEMBER 2021

In the current work, ammonia intoxication was observed to lower the serum total proteins and albumin concentrations compared to the control fish group, which indicates the severe impairment of the tilapia immune system. However, high ammonia-stressed tilapia supplied with YSE demonstrated enhanced TP and albumin concentrations, reflecting the impact of YSE in regulating the nutrient metabolism of tilapia reared under either optimal or stressful conditions. In this study, we found that ammonia-intoxicated fish showed a reduced adipose tissue FAS expression level and enhanced LPL expression level

Conclusions Our results provided a novel perspective on the multiple interacting mechanisms through which YSE may exert its protective role against chronic ammonia toxicity. These results affirmed the growth-enhancing effects of YSE via the sustained enhancement of food intake, the elevation of IGF-1, the suppression of hepatic and brain MTSN expression levels, and the restoration of carbohydrate and lipid reserves, mediated through alterations in the levels of circulating metabolites. Our results indicated that Yucca schidigera extract alleviated the adverse impacts induced by ammonia intoxication through its ability to scavenge free radicals, potent antioxidant activities and anti-inflammatory properties. The results of this study suggested that YSE supplementation was clearly beneficial for both health and growth in Nile tilapia, and that YSE could be used as a functional water supplement in aquaculture.

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This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled “Exploring the Multimodal Role of Yucca schidigera Extract in Protection against Chronic Ammonia Exposure Targeting: Growth, Metabolic, Stress and Inflammatory Responses in Nile Tilapia (Oreochromis niloticus L.)” developed by: Zizy I. Elbialy, Abdallah S. Salah, Ahmed Elsheshtawy, Merna Rizk, Muyassar H. Abualreesh, Mohamed M. Abdel-Daim, Shimaa M. R. Salem, Ahmad El Askary and Doaa H. Assar. The original article was published on July, 2021, through the Animals Journal of MDPI under the use of a creative commons open access license. The full version can be accessed freely online through this link https://www.mdpi. com/2076-2615/11/7/2072.

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Estimation of Phosphorus and Nitrogen Waste in Rainbow Trout (Oncorhynchus mykiss, Walbaum, 1792) Diets Including Different Inorganic Phosphorus Sources

Environmental management of intensive aquaculture is essential for the

achievement of sustainable aquaculture in the coming years. With this By: María Consolación Milián-Sorribes, Ana Tomás-Vidal, David S. Peñaranda, Laura Carpintero, Juan S. Mesa, Javier Dupuy, Andrés Donadeu, Judit Macías-Vidal and Silvia Martínez-Llorens.

aim, a decrease in phosphorus (P) and nitrogenous (N) discharge from aquaculture effluents would reduce water eutrophication, and therefore, its environmental impact. The main strategy to achieve this reduction is through the optimization of diet formulation.

espite the fact that fish can absorb minerals from water through their gills, fish require an additional source of P in their diet, since P is usually a limiting mineral in most natural waters, and its absorption rate from water is low. P in fishmeal, mainly in the form of hydroxyapatite or bone phosphate as well as inorganic supplements, is relatively available to rainbow trout (Oncorhynchus mykiss). In contrast, approximately two-thirds of the P in plant sources is bound to phytate, being only partially available to fish, presumably due to low levels of intestinal phytase, the selection of the inorganic P source is an important issue, and it will be based on its solubility and digestibility, which may be affected by the calcium level in the diet, as well as changes in pH under gastrointestinal conditions. In general, monobasic phosphates from monovalent cations are more digestible and soluble, followed closely by monocalcium phosphate (MCP) and, beyond this, by tricalcium phosphates or bone apatite. This is generally applicable to marine and freshwater fish with a stomach, such as rainbow trout. A low absorption and retention of nutrients will mean a higher dis18 »

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charge into water, affecting the sustainability of the production. Aquaculture effluents with high levels of P and N contribute to the pollution of the aquatic ecosystem through the eutrophication of natural fresh water. Consequently, aquaculture faces a dilemma: feed must meet P levels, but at the same time, feeding practices must comply with environmental guidelines to minimize the P load in the aquatic environment. The mixture of chemical products ends up directly influencing the degree of bioavailability of the phosphate species in each species, which is defined as the degree to which a nutrient ingested from a particular source is absorbed and remains available for the animal’s metabolism. The aim of the present study was to evaluate in vivo the P availability and excretion level of diets including four different inorganic P sources in rainbow trout and excretion level of diets including four different inorganic P sources in rainbow trout. As a novelty, new formulations of inorganic phosphates were assessed from nutrition and environmental point of view for its inclusion in fish diets.

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Experimental Procedure Around 200 rainbow trout with an average weight of 130 g were moved by an authorized service from the fish farm “El Zarzalejo” located in Zamora (Spain) to the Fish Nutrition Laboratory belonging to ICTA-UPV (Valencia, Spain). Four supplemental inorganic P sources were chosen for determining the apparent P availability and nonfecal P excretion. Before formulating the diets, each ingredient was individu-

ally weighed and analyzed in triplicate, then mixed. To obtain the feces, a Latin square experimental design of 4 treatments × 4 tanks × 4 trials was followed (consisting of four trials or periods, and in each of them, four tanks were fed with one of the feeds, so that the fish in all the tanks were fed with the two experimental feeds) The feeding rate was once per day at 10.00 a.m. from Monday to Satur-

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day, with a starvation day on Sunday. Feeding was carried out at a restricted rate, according to the average weight of the fish and at water temperature, and the ration per tank was calculated according to the biomass of each fish. The same experimental design was followed as that described in the digestibility test. Fish diets, feed ingredients and feces were analyzed based on the Association of Official Analytical Chemists (AOAC) procedures. Due to the critical importance of being able to distinguish between the different phosphates with higher bioavailability in each species, a predictive program has been developed considering the different chemical species that compound each phosOCTOBER - NOVEMBER 2021

phate, by means of different chemical parameters. Each of these chemical species has been assigned a digestibility weighting value based on previous in vivo studies. The combination of the chemical balance with the weightings leads to Predictive Equations for Digestibility Comparison (EPCD) of commercial phosphates. In vivo digestibility estimation requires specialized settings, expensive operating costs and a high number of fish, and it is difficult to perform and achieve the desired experimental working conditions. In this regard, EPCD can help to successfully evaluate the effect of diets on nutrient digestibility providing very reliable information. Prior to analysis, the normal distribution was

checked through a Kolmogorov– Smirnov test, while the homogeneity of variances using a Levene test.

Results and Discussions Both treatments, MAP and SCP-2%, showed higher values than SCP-5% and MCP in terms of P digestibility (92 and 90%, respectively). The MSP and DCP values were in concordance with those obtained for shrimp but considerably lower than the values of 90–98% and 46–71%, respectively, reported for fish. The 73% value for the MCP is higher than the 49% reported for shrimp. These differences in digestibility are mainly due to the different degrees of solubility between phosphates » 21

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Due to the critical importance of being able to distinguish between the different phosphates with higher bioavailability in each species, a predictive program has been developed considering the different chemical species that compound each phosphate.

This difference in solubility is very relevant, since it reflects the ability of P to solubilize at neutral pH, simulating the intestine (absorption of P). This fact is even more important in fish, since they lack a true stomach in which a first stage of solubilization begins prior to digestion. The needs of P in the diet depend on several factors, including the bioavailability of the element, food intake, the requirement for new tissue synthesis and the amount of endogenous loss, among others. These factors being dependent on the life cycle and size, and even environmental factors such as salinity and temperature. It is difficult to explain the differences observed in the present ex22 »

periment regarding N digestibility, because the protein source was the same in all treatments and only the inorganic phosphate source differed between diets. One possible explanation could be the differential buffering capacity (BC) of inorganic phosphates, which could affect the pH, and consequently, modulate digestive enzyme activities, and therefore, raising the protein and mineral content. A high correlation (>0.9) was obtained between the results of the in vivo P digestibility assay and the estimated results using the EPCD index. This index could become a useful tool to formulate practical diets. Nevertheless, it is noteworthy that the only factor not taken into account in the

EPCD index is the variability stemming from the different particle sizes of phosphate; therefore, an inclusion of this factor might be needed for products with a different granulometry or the comparison only of products with similar textural properties. The P excretion into the water system provided similar values independent of the diet, with a maximum at 6 h after feeding, similar to previous studies. he authors indicate that when fish consume excess available P, the excess P is mainly eliminated through the gills and kidneys as non-fecal soluble P. Excretion of soluble non-fecal P also depends primarily on P source. Therefore, differences in P excretion observed in the present study might OCTOBER - NOVEMBER 2021

Considering fecal and soluble P losses, even though data on P retention are not available, it was possible to carry out an approximation of P and N losses in each of the treatments.

Conclusions Considering N and P as the most relevant nutrients for inducing water eutrophication, it would be relevant to minimize these components into the column water. Currently, there are a wide range of commercial inorganic phosphate available; however, the most used in aquafeed are the monoammonium, monocalcium and monosodium phosphates due to their good availability in fish, although the new formulation (SCP-2%) can improve the wastes generated in the aquaculture production, which is crucial to improve the environment. The SCP-2% source (AQphos+) presents a phosphorus digestibility comparable to MAP (without significant difference at a statistical level), but with lower P and N excretion, and thus, it is more environmentally friendly. Therefore, SCP-2% as a phosphorus source is more advantageous from a nutritional, environmental, and industrial point of view (biofilters and recirculation systems in fish farms). be due to the available P contained in the diets. In the rainbow trout intestine, there is a sodium-dependent inorganic P carrier that is closely regulated by dietary P. Intestinal absorption rates of inorganic P decrease as dietary P levels increase, suggesting that the effectiveness of phosphate transport systems in retaining dietary P may decrease when dietary P levels are very high. Soluble P is the most flexible component of effluent P. There is no excretion of soluble P at low levels of dietary P, but soluble P becomes the main route of excretion as the available P concentration increases above hypothetical levels of P requirements for the species. OCTOBER - NOVEMBER 2021

Analyzing the overall data on daily excretion rate, the results corroborate that fish fed MAP feed had significantly higher N excretion, probably due to the ammonium content of MAP, as has been reported in previous studies. This excess excretion must be considered when sizing biofilters in fish recirculation systems, or in the case of open systems, since it will mean a greater release of ammoniacal N into the natural environment, which will lead to greater eutrophication of the water. in addition to optimizing dietary P, the use of diets with an optimal level of digestible N will become another key to sustainable aquaculture.

Global Feed have sponsored this article

This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled “Estimation of phosphorus and nitrogen wastes in rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) diets that include different sources of inorganic phosphorus” developed by: María Consolación Milián-Sorribes, AnaTomás-Vidal, David S. Peñaranda, Laura Carpintero, Juan S. Mesa, Javier Dupuy, Andrés Donadeu, Judit Macías-Vidal y Silvia Martínez-Llorens. The original version was published in June 2021 through Animals, under the use of a creative commons open access license.

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Antiparasitic and Antibacterial Functionality of Essential Oils: An Alternative Approach for Sustainable Aquaculture

By: Mahmoud A. O. Dawood, Mohammed F. El Basuini, Amr I. Zaineldin, Sevdan Yilmaz, Md. Tawheed Hasan, Ehsan Ahmadifar, Amel M. El Asely, Hany M. R. Abdel-Latif, Mahmoud Alagawany, Nermeen M. Abu-Elala, Hien Van Doan y Hani Sewilam.

Due to the increase of consumer demand, aquaculture technique

has been shifted from extensive to super intensive. Intensification of aquaculture needs a higher amount of artificial feed supply, water treatment and reuse, and high stocking density resulting in aquatic environmental degradation.

ounting of stress and quality deterioration of living environment increases the activity and virulence of infectious and opportunistic microbial pathogens. To eliminate diseases and parasitic attacks in the aquaculture industry, different synthetic antibiotics, chemical drugs, vaccines, and chemotherapeutics are being used at high rates from year after year. Using of these chemical substances cause mass killing of beneficial aquatic bacteria, produce multi-drugs resistant pathogens, and leaving residues in fish which can be transmitted to human. Essential oils (EOs) are the secondary metabolites of medicinal plants and possess bioactive properties to be used as a phytotherapeutic 24 »

agent for sustainable aquaculture. Terpens, terpenoids, phenylpropenes, and isothiocyanates are the key chemical groups identified in EOs. EOs mainly penetrate and act upon the membrane and cytoplasm of bacteria to inhibit their action mechanisms by altering cell morphology and organelles deformities. Although natural EOs have enough potential for sustainable aquaculture, EOs have high volatility and can be decomposed by exposure to heat, humidity, light, and oxygen to lose effectiveness. The use of nano encapsulated EOs becomes a promising trend in the field of EOs applications, especially in the aquaculture sectors, protecting the volatilization, low stability, low solubility in water, and associated problems of using EOs

The focus of this article is to identify EOs antimicrobial and antiparasitic properties that can be used for sustainable aquaculture practices. Moreover, EOs effects for aquaculture species growth, immunomodulation, and infection resistances were also postulated. In addition, research gaps and tentative future research activities are also mentioned to effectively use EOs in sustainable fish culture.

EOs as Growth, Immunity, and Disease Resistance Enhancer Modulation of the intestinal microbiome by EOs can be considered one of the possible reasons for the modulation of immune-related genes. Significantly, phenolic compounds like thymol and carvacrol modulate innate immunity through OCTOBER - NOVEMBER 2021

in cultured freshwater fish. When L. Origanoides and L. Sidoides EOs were applied as 100 mg/L for 5 min, they showed 100% efficacy. Cichlidogyrus is the parasite genus that occurs naturally in cichlid fish and has the most species among gill parasites, with its 131 different species known. Lippia sidoides EO had 100% efficacy against Cichlidogyrus spp. and Scutogyrus longicornis when applied as 160 mg/L for 1 min 58 s while Mentha piperita EO had 100% efficacy when applied as 320 mg/L for 8 min 11 s. Dawestrema spp. Application of M. piperita EO as 160 and 320 mg/L for 30 min showed 100% efficacy on D. cycloancistrium and D. cycloancistrioides parasites. Gyrodactylus spp. causes economic losses in many cultured fish species. Only O. americanum EO as 50 mg/L for 1 h had the most effective anthelmintic action (98% efficacy) against Gyrodactylus spp.

two possible ways i) direct action on host tissue ii) influence on the intestinal microbial community. A 60-day experiment was conducted with dietary supplementation with bitter lemon (Citrus limon), and sweet orange peels (C. sinensis). In both cases, EOs elevated innate immune parameters (NBT, WBCs, lysozyme, and myeloperoxidase activity) and decreased serum/blood glucose, cholesterol, and triglycerides. C. limon and C. sinensis EOs administrated tilapia demonstrated resistance against Streptococcus iniae and Edwardsiella tarda, respectively.

Essential Oils as Antiparasitic Agents Acanthocephalas Neoechinorhynchus buttnerae Acanthocephalas NeoechinoOCTOBER - NOVEMBER 2021

Trepomonadea Hexamita inflata Hexamita inflate is a flagellated anaerobic protozoan and free-living in fresh and seawater. Moon, et al. reported that L. angustifolia and L. rhynchus buttnerae is an acantho- intermedia EOs as 1 and 0.5% for 30 cephalan parasite causing signifi- min exhibited 100% efficacy on H. cant economic losses in Colossoma inflate. macropomum fish in the region of Amazon. It was reported that Men- Clinostomidae Euclinostomum tha piperita, Lippia alba, and Zingiber heterostomum officinale and Piper hispidinervum, Piper Euclinostomum heterostomum is parahispidum, Piper marginatum, and Piper sitic trematodes and very common callosum essential oils showed 100% in Europe, Asia, and Africa. It inanthelmintic effect on N. buttnerae. fects muscular tissues and kidneys of freshwater fish. Verbesina alternifolia and Mentha piperita EOs could Monogeneans Anacanthorus spathulatus, No- act on E. Heterostomum in high doses tozothecium janauachensis, and and for a long time. Mymarothecium boegeri cause significant infections in species be- Oligohymenophorea longing to the Serrasalmidae family Ichthyophthirius multifiliis as C. macropomum fish being. Among Ichthyophthirius multifiliis is the most the EOs, the most effective one was famous virulent ciliated protozoan ectoparasite that invades the skin, Lippia sidoides. Dactylogyrus spp is one of the fins, and gills of fish. de Castro most common parasitic pathogens Nizio, et al. indicated that Varronia » 25

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curassavica EO showed 100% efficacy against I. multifiliis trophont and tomont when applied as 10 mg/L and 50 mg/L for one h, respectively. EOs applications were also found to be effective on I. multifiliis.

Essential Oils as Antibacterial Agents: An In Vitro Perspective

Aeromonas spp. It is known that many different Aeromonas species cause disease in fish. The antimicrobial effects of Origanum onites, O. vulgare, and Thymbra spicata EOs on 18 different A. salmonicida isolates, and it was reported that EOs of these herbs formed 10 to 30 mm zone depending on the disc diffusion test, and they had moderate inhibitory depending on MIC values. Cinnamomum cassia EO was reported to have a very high inhibitory effect on A. salmonicida subsp. with a 56 mm zone diameter. T. vulgaris EO had the highest zone diameter on Aeromonas sobria and Aeromonas veronii with 31.5 mm and 36 mm, respectively. Cymbopogon nardus and Syzygium aromaticum EOs had a strong inhibitory effect on Aeromonas hydrophila and Aeromonas spp. It was found that C. cassia, Cin- namomum aromaticum, Cymbopogon citratus, and Origanum vulgare EOs were effective against Aeromonas spp., Aeromonas salmonicida subsp. Salmonicida, A. hydrophila, and A. veronii bv. Sobria Among Piper aduncum, Piper callosum, Piper hispidinervum, Piper hispidum, and Piper marginatum EOs on 11 different A. hydrophila isolates, only P. marginatum had a strong inhibitory effect on three different A. hydrophila isolates It was reported that Eucalyptus globulus, Lavendula angustifolia, Origanum vulgare, and Melaleuca alternifolia nanoemulsions were more effective on A. hydrophila than their EOs, and among four different herbs, O. vulgare essential oil was found as the most effective 26 »

Vibrio spp., Listonella anguillarum, and Photobacterium damselae Historically, vibrionaceae family members are the most severe infectious diseases in marine fish species. The antimicrobial effects of O. vulgare, M. alternifolia, C. citratus, C. verum, and T. vulgaris EOs on Vibrio campbellii, Vibrio harveyi, Vibrio vulnificus, and Vibrio parahaemolyticus have been researched, and it was reported that generally moderate and weak inhibitory effects of these EOs on Vibrio spp. It was reported that E. globulus, L. angustifolia, O. vulgare, and M. alter-

nifolia nanoemulsions were more effective on Photobacterium damselae than their EOs, and among these herbs, O. vulgare EO and nano-emulsion were found as the most effective. Pseudomonas fluorescens Pseudomonas fluorescens is a harmful pathogen in a variety of farmed fish. It was reported that Ocimum basilicum EO exhibited a potent inhibitory with 9 μL/mL MIC value on P. fluorescens, C. Nardus and S. aromaticum EOs showed marked activity on Pseudomonas spp. and P. Aeruginosa.

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Citrobacter spp. Citrobacter spp. is an opportunistic fish pathogen affecting farmed fish species. It was determined that C. freundii showed susceptibility towards the Argania spinosa EO with a zone diameter of 15 mm. Raoultella ornithinolytica Raoultella ornithinolytica was isolated from kidneys and skin lesions of naturally diseased silver catfish (Rhamdia quelen), and Ocimum gratissimum EO showed a moderate inhibitory effect on this pathogen. Nocardia seriolae Nocardia seriolae is the causative agent of nocardiosis in cultured fish species. The most effective herb species were C. zeylanicum and T. vulgaris. Flavobacterium spp. Flavobacterium species are widespread in soil habitats and fresh and marine waters and cause economic losses in cultured fish. T. vulgaris EO exhibited a potent inhibitory with 320 μg/ mL MIC value on F. psychrophilum. Staphylococcus aureus Staphylococcus aureus is an important Gram-positive opportunistic pathogen for aquaculture species. Gulec, et al. reported that O. acutidens EO formed a zone diameter of 28 mm on S. aureus, Z. officinale, N. Sativa, T. Vulgaris, S. Aromaticum and E. Sativa EOs had no inhibitory effects on S. aureus. Streptococcus spp., Lactococcus spp., and Vagococcus salmoninarum Streptococcaceae family species are important Gram-positive pathogens for cultured fish. Among L. alba, L. sidoides, M. piperita, O. gratissimum, and Z. officinale EOs, strong inhibitory effects of L. sidoides EO was reported on Streptococcus agalactia. Gholipourkanani, et al. determined that among E. globulus, L. angustifolia, O. vulgare, and M. alterOCTOBER - NOVEMBER 2021

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The efficiency of EOs depends on plant variables, chemical compositions of bioactive compounds, environmental characteristics of plant origin, and parts of plants from which EOs is extracted.

nifolia nano-emulsions and EOs, O. vulgare EO and/or nano-emulsion were found as the most effective on Streptococcus iniae. A remarkable activity of Z. multiflora and R. officinalis EOs were reported, respectively, with 0.06 μL/ mL and 0.5 μL/mL MIC, and 0.12 μL/mL and 0.25 μL/mL MBC for S. iniae. Similarly, R. Officinalis, Z. Multiflora, A. Graveolens, and E. Globulus EOs exhibited potent inhibitory effects on S. iniae, and R. Officinalis showed the highest inhibition with a zone of 45 mm, and MIC value of 3.9 μg/mL, and MBC value of 7.8 μg/mL Zataria multifora, Thymbra spicata, Bunium persicum, Satureja bachtiarica, and Thymus daenensis EOs exhibited potent inhibitory effects. 28 »

t was found that T. vulgaris EO was more effective on Lactococcus piscium (MIC: 320 μg/mL) than Lactococcus lactis (MIC: 1280) and Lactococcus lactis subsp. lactis bv. diacetylactis

Research Gaps and Concluding Remarks The efficiency of EOs depends on plant variables, chemical compositions of bioactive compounds, environmental characteristics of plant origin, and parts of plants from which EOs is extracted. Sometimes plant originated EOs possess a mixture of different compounds, which may produce undesirable side effects on fish and shellfish. Commercial pharmaceutical companies might play significant roles in refining the desirable and undesirable

compounds of EOs to achieve better effects in fish culture. Before applying EOs in aquaculture from any new plants, local and international drug regulating agencies (FDA or EU) permission or guidelines should be needed or followed.

This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled “Antiparasitic and antibacterial functionality of essential oils: an alternative approach to sustainable aquaculture” developed by: Mahmoud A. O. Dawood, Mohammed F. El Basuini, Amr I. Zaineldin, Sevdan Yilmaz, Md. Tawheed Hasan, Ehsan Ahmadifar, Amel M. El Asely, Hany M. R. Abdel-Latif, Mahmoud Alagawany, Nermeen M. Abu-Elala, Hien Van Doan and Hani Sewilam. The original article was published on The original version was published in February 2021 via Pathogens.

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Animal Protein Sources as a Substitute for Fishmeal in Aquaculture Diets: A Systematic Review and Meta-Analysis

Fishmeal prices have been raised even further because of competition

with domestic animals, shortage in world fishmeal supply, and increased demand. Increased fishmeal prices have contributed to the quest for alternatives necessary to replace fishmeal as a global research priority. The use of animal protein sources as a replacement for fishmeal in fish diets has had a positive impact on the feed conversion ratio, variable growth rate, final weight, and survival rate of By: Rendani Luthada-Raswiswi, Samson Mukaratirwa and Gordon O´Brien

y producing fish with minimal environmental impact and maximum benefit for society, aquaculture is predicted to contribute more effectively to economic development, international food safety, nutritional wellbeing, and poverty reduction. Aquaculture production (66 million tons) exceeded global beef production (63 million tons) for the first time in 2012. Increased aquaculture production means that more than half of the fish being consumed by humans worldwide is produced by aquaculture. The quality of the protein ingredient used in feed formulation is generally known to have effects on the nutritional value of fish diets produced. The demand for feed resources, particularly for prime quality protein fishmeal, has increased because of the global supply of fish as aquaculture production increases. For both carnivorous and omnivorous species used in aquaculture, fishmeal has been used as an essential 30 »

different types of fish species of different size groups.

protein source, and many aquaculture formulations/feeds have a higher percentage of fishmeal than feeds of other animal species. Fluctuations in supply, price, and quality of fishmeal present considerable risks because fishmeal is dependable solely on an ingredient by people. Therefore, the identification, development, and utilization of alternatives to fishmeal in diets in aquaculture remain a high priority as a risk reduction strategy. Competitive price, full availability, ease of handling, shipping, storage, and use in feed production are features that a candidate ingredient must possess to be a viable alternative feedstuff to fishmeal in aquaculture feeds. Additionally, it should have high protein content, favorable amino acid profile, high nutrient digestibility, low fiber levels, starch, non-soluble carbohydrates, which are nutritional characteristics. The more expensive fishmeal has been replaced by several sources of plant protein, single-cell protein, and animal protein in part or in full. Due

to higher protein and lipid content, superior essential amino acids, and excellent palatability, animal protein sources have commonly been considered ideal substitute protein sources to replace fishmeal in formulating fish diets. The purpose of this study was to conduct a systematic review of published articles on animal protein sources used in aquaculture and assess the results of recommended diets against the control diet.

Materials and Methods A systematic search of published literature on Google Scholar and EBSCOhost from 1999 to 2019 was carried out using the following terms or phrases: Fishmeal replacements in fish feeds, fishmeal alternatives in fish diets, animal protein sources in aquaculture, insects in fish feeds, terrestrial by-product, and fishery byproducts. Meta-analysis was conducted for final weight, specific growth rate, feed conversion ratio, and survival rate OCTOBER - NOVEMBER 2021

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Results There were 1030 articles obtained from search engines, and additional records were identified through other sources. Eligibility was evaluated for 217 articles, and 18 articles were included in the systematic review and meta-analysis Fish Species Used and Recommended Levels of Animal Protein Sources Results from the review articles showed that animal protein sources replacing fishmeal ranged from insects (Mopane worms (Imbrasia belina), grasshoppers (Zonocerus variegatus), field crickets (Gryllus bimaculatus), blowfly maggot (Chrysomya megacephala), black soldier fly (Hermetia illucens) and superworm (Zophobas morio), terrestrial animal by-products (fermented feather meal, feather meal, poultry by-products, meat and bone meal, and blood meal), and fishery by-products (fish silage, shrimp head meal and krill meal). Furthermore, a variety of fish species such as Oreochromis mossambicus, Clarias gariepinus, Oreochromis niloticus, Sparus aurata, Dicentrarchus labrax, Scophthamus maeotinus, Lutjanus guttatus, Ophiocephalus argus, Red tilapia (O. mossambicus × O. niloticus × Oreochromis aureus), and Acipenser glueldenstaedtii (which were 32 »

not selected but reported because it is important to know when reporting for protein sources used) have been used. Animal protein sources inclusion levels in the diets ranged from 0%, 5%, 10%, 20%, 25%, 30%, 40%, 50%, 60%, 75%, to 100%. Rec-

ommended levels of animal protein sources in feeds were 20% for feather and shrimp head meal for C. gariepinus, 20% of meat and bone meal for Op. argus, 25% of superworm, poultry by-product and grasshopper meal for L. guttatus and C. gariepinus respectiveOCTOBER - NOVEMBER 2021

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ly, 30% of krill meal for A. glueldenstaedtii, 20–50% of fermented feather meal for O. niloticus, 50% of poultry by-products and fish silage for O. niloticus and Red tilapia (O. mossambicus × O. niloticus × O. aureus), respectively, 60% of mopane worm meal for O. mossambicus and 100% of field cricket meal for C. gariepinus.

Values for Final Weight, Specific Growth Rate, Feed Conversion Ratio, and Survival Ratio The specific growth rate ranged from 0.56% to 7.89%. Feed conversion ratios of 1.25, 1.51, and 2.20 were reported for O. mossambicus, C. gariepinus, and C. gariepinus, which were fed insect meal (I. belina, Z. variegatus, and G. bimaculatus), respectively. For terrestrial by-products (fermented feather meal, feather meal, poultry by-products, poultry by-products, and meat and bone meal), feed conversion ratios of 1.73, 1.34, 1.20, 140, and 1.24 were obtained for O. niloticus, C. gariepinus, L. guttatus, O. niloticus, and Op. argus, respectively. Feed conversion ratios of 1.35, 2.50, and 1.10 were obtained in Red tilapia (O. mossambicus × O. niloticus × O. aureus), C. gariepinus, and A. glueldenstaedtii fed fishery-by products (fish silage, shrimp head meal, and krill meal), respectively. Survival rate ranged from 83% to 100%, except for Red tilapia (O. mossambicus × O. niloticus × O. aureus) and C. gariepinus, which were fed fish silage and shrimp head meal, respectively, where the survival rate was not reported. Meta-Analysis For the meta-analysis, data from studies analyzed were grouped into final weight, specific growth rate, feed conversion ratio, and survival rate. Samples analyzed were 1335, 1430, 1450, and 1307 for final weight, specific growth rate, feed conversion ratio, and survival rate, respectively. Results showed the overall effect size of 9015. The level of heterogeneity observed were I2 = 99.70%, I2 34 »

= -17.73%, I2 = -25.79%, and I2 = 101.08% for final weight, specific growth rate, feed conversion ratio, and survival rate, respectively.

Discussion Human health benefits, competitive price, fish safety, efficiency, customer acceptance, minimal contamination, and ecosystem stress are factors in selecting feeds. Growth performance measured by final weight and specific growth rate showed that excess protein could not be used efficiently for growth because of growth energy used for the deamination and excretion of absorbed excess amino acids. After all, each fish species had a specific protein limit. When dietary protein levels increase, the feed conversion ratio decreases. Recommended levels reported for insect meal in this review shows that a total fishmeal replacement has not

been successful. Limitations of using insects include their (i) varying nutritional value, which is dependent on the species, stage of development, and the substrate used to feed the insect, (ii) low concentration of sulfur-containing amino acids, and (iii) absence of eicosapentaenoic and docosahexaenoic. Fermented feather meal, blood meal, poultry by-products, feather meal, meat and bone meal are some of the terrestrial animal by-products used in aquaculture diets. Terrestrial by-products have been reported to have great potential as fishmeal replacement because they are readily available, economical sources of protein and have more complete amino acid profiles than vegetable proteins. The use of feather meal in aquaculture feeds is limited by the fact that fish are unable to digest it. Fishery by-products are products generated from fishery indusOCTOBER - NOVEMBER 2021

tries. Skin and fins, scales, heads and bones, viscera, and muscle trimmings are the main by-products produced in fishery industries with (1–3%), (5%), (9–15%), (12–18%), and (15–20%), respectively Limiting factors of using fishery by-products include the cost of the collection of fish waste, timely processing, and quality control. Furthermore, fish waste varies highly in its physical nature and proximate composition; and some fish waste such as from seafood is only available during the fishing season. Results for final weight, specific growth rate, feed conversion ratio, and survival rate, shows that there is a statistically significant difference among studies. The level of heterogeneity (I2 index) was very high for both the final weight and survival rate with values 99.98 and 101.08, respectively. Final weight, specific growth rate, feed conversion ratio and survival rate of fish in experiment or in farming in general are affected by many factors such as age of fish, fish species, stocking density, feeding level and frequency, protein source, and water quality parameters such as water temperature, dissolved oxygen, and pH. Variety of fish species, size, inclusion levels, recommended levels of protein found were reported, and these are the reasons our meta-analysis indicated heterogeneity in studies. Despite all the heterogeneity observed, these animal protein sources have shown positive effects on feed conversion ratio, spe-

cific growth rate, final weight, and survival of different fish species of different size groups.

Conclusions Despite the limitations in the use of insects, terrestrial by-products, and

fishery by- products as replacement of fishmeal, these animal protein sources have shown positive effects on feed conversion ratio, specific growth rate, final weight, and survival of different fish species of different size groups. However, future studies have recommended to (i) identify a fishmeal replacement that has no limitations, (ii) assessing the suitability of readily available animal meat or by-products as fishmeal replacement.

This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled “Animal Protein Sources as a Substitute for Fishmeal in Aquaculture Diets: A Systematic Review and Meta-Analysis” developed by: Rendani Luthada-Raswiswi, Samson Mukaratirwa and Gordon O´Brien. The original version was published in April 2021 through Applied Sciences. OCTOBER - NOVEMBER 2021

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Market aspects and external economic effects of aquaculture By: Ruth Beatriz Mezzalira Pincinato

his special issue of Aquaculture Economics & Management features five articles based on the 24 contributions presented at the International Association of Aquaculture Economics and Management (IAAEM) sponsored section on economics and marketing at the Aquaculture America conference in Honolulu, Hawaii, February 9–12, 2020. The contributions covered topics on different farmed species groups (e.g., tilapia, catfish, salmon, and oyster), from different producing or market regions (e.g., USA, China, South Africa, Norway, and Brazil), and also with a global scope. The section provided an arena to discuss issues related to risk management, regulations, trade and border rejections, seafood certification, consumers’ preferences, market integration, product differentiation, mariculture tourism, food

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security, effects, and contribution of aquaculture to the regional economy. The papers in this special issue reflect a variety of topics also seen in the section during the conference. One of the papers in this special issue focus on different aspects of aquaculture products demands, considering the consumers’ willingness to pay for different farmed fish products. Two papers investigate aspects in the supply chain, that is, market integration, and product differentiation challenges, and opportunities. The final two papers offer an evaluation of the effects of aquaculture farms on respectively nearby housing property values and the contribution of the overall aquaculture industry to the regional economy. This shows the increasing appreciation of aquaculture’s importance in a wider societal context highlighting user conflicts as well as positive externalities. Thus,

this issue deals with two levels of decisions and their consequences; internal decisions related to aquaculture marketing, and external economic effects of aquaculture.

Profitability decides aquaculture’s fate. Farmers’ decisions with respect to which species group to farm (e.g., oyster or salmon), how to produce (e.g., organic or GMO soybean-based feed), where to produce (e.g., landbased or coastal farm), and which product forms to sell (e.g., whole or fillet) all contribute critically to the industry profitability. In addition, population growth, income growth, and cultural changes such as health awareness are expected to lead to an increase in demand for seafood, giving incentives to the aquaculture industry to increase production. Thus, further development of aquaculture

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depends on its markets and demand growth. More specifically, consumers’ acceptance, preference for specific attributes and willingness to pay for the product to be sold are aspects that the producers must be aware of in order to be able to exploit the best opportunities in the market. Some product attributes may not be directly observable such as food safety, sustainability, country of origin, animal welfare, the sustainability of production, and labor conditions. For instance, consumer concerns with environmental issues may provide incentives to farmers to address the industry negative externalities by their demand and wiliness-to-pay for products certified according to a good environment and social practices. Other attributes are observable by the consumer such as size, product form, flesh color, freshness, appearance, and convenience. In the first paper on this issue, Adhikari et al. show how these aspects influence their preferences, and accordingly can be used to target specific market segments. More specifically, the paper investigates these aspects for five newly developed convenient catfish products. Product attributes such as appearance, color, and glossiness were found to be key for the consumers’ preference for panko-breaded products. In addition, socioeconomic aspects such as education, household income, ethnicity, and fish-eating frequency, influenced significantly consumers wiliness to pay for the different products.

The importance of seafood market analysis. In general, product differentiation highlights the attributes that are unique to the product (e.g., species, geographical origin) to improve consumer’s perceptions and preferences for this product. So, a differentiated product is expected to achieve higher prices in a specific consumer segment. Product differentiation creates a potential for segmentation in the seafood market. This means that OCTOBER - NOVEMBER 2021

understanding the seafood market boundaries and interactions between products and markets is also important to reach the potential of the seafood production opportunities (markets segmentation) and expansion as well as associated with specific markets or trade relationships. Landazuri-Tveteraas et al. investigate the market integration between Atlantic salmon and salmon-trout. Norwegian salmon farmers hold a license that allows them to farm Atlantic salmon or salmon-trout, and such licenses have been very valuable. Even though the majority of the farmers produces salmon and the market seem to be highly integrated, the reason why some of them pro-

duce salmon-trout could be linked to product differentiation as there may be premiums associated with various cost product attributes even in an integrated market. For instance, the authors suggest that some markets (Japan) may have preferred, at least during the 1990s, the redder flesh color that salmon-trout can offer. However, this is no longer the case, for results show that these two “cousins” are close substitutes, with Atlantic salmon determining the price for salmon-trout. This makes it more difficult for salmon-trout to expand its production and segment away from Atlantic salmon and find new markets where salmon-trout specific attributes are preferred. » 37

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Opportunities and challenges Opportunities and challenges go hand-in-hand, particularly in an industry where its product is traded globally, and the production process is frequently susceptible to shocks. Shocks due to environmental conditions, diseases, and trade may affect the consumer markets by segmenting it depending on how globally integrated in the market. For instance, important changes in the salmon market with respect to product form and destination happened after the Chilean producers experienced severe disease outbreaks from 2009 to 2012 resulting in high mortality rates. During the last decades, shrimp farming disease outbreaks and trade

disputes have imposed challenges to the affected producers. However, this meant opportunities for their competitors to increase their shares in this globally integrated market. For Brazilian shrimp producers, the U.S. antidumping tariff imposed in 2003 was a challenge difficult to overcome in this global market, so that their share was lost to other countries. However, Brazilian shrimp producers found an opportunity in the untapped domestic market related to its overexploited fisheries. It is expected that disease outbreaks can be somewhat controlled over time, since factors influencing them, such as inputs (e.g., vaccines) and other managerial factors can be

improved by innovation and technology development. However, shocks in the seafood systems are likely to continue to occur, such as the pandemic related to Covid-19 and climate change. Thus, it is essential to build more resilience in the sector in order to address the challenges and to be able to identify the opportunities. The third paper in this issue, Cojocaru et al., breaks down the opportunities and challenges for Norwegian salmon product differentiation. Based on an interview with salmon farmers they find that product differentiation takes place mostly on the non-directly-observable attributes such as country of origin, branding, and certification. In addition to high prices and constant supply issues, the strong brand of “salmon from Norway” and the certification process have also been cited as a challenge to be overcome for further differentiation within the sector. In general, the Norwegian salmon industry has been able to realize the opportunities for product differentiation in a very limited way, especially compared to other protein industries such as poultry. This is important because not only salmon, but seafood in general, has a relatively lower footprint when compared to the other proteins such as from poultry, and it is expected to be a source of protein for many from a more climate-friendly perspective. Farmers’ decisions, especially with respect to where to produce, impact not only their own profits but also other sectors and the regional economy. The last two papers in this special issue look at the consequences of the individual aquaculture decisions on other sectors, such as residential land use, and the regional economy. These are important topics as the social impact of aquaculture is highly controversial.

Land-Based aquaculture advantages In contrast to most land-based aquaculture, marine aquaculture development requires coastal and offshore 38 »

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areas that are common to other users. Farms located in these areas often meet opposition because they may negatively impact, for example, the fishery industry by altering the ecosystem and/or excluding a potential area for fishing. It can also limit the scenic view of some areas, which affects both the tourism activities and the pricing of housing properties nearby. However, there are some exceptions such as the increasing tourism activities related to aquaculture and food culinary experiences. The fourth paper of this special issue, Sudhakaran et al. contributes to this literature. Using a difference-in-differences approach they estimate the effect of shellfish farm construction on property values in Rhode Island between 2000 and 2013. While construction of shellfish farms seemed to in general increase property value, it has decreased prices for luxurious housing property. OCTOBER - NOVEMBER 2021

While there are benefits to the community and economy in having the aquaculture sector, there are conflicts to be pondered between the different sectors within the region and the overall benefits. Thus, the general public and policymakers may balance their willingness to accept the industry in their region according to how much economic and social benefits the industry adds to the regional economy. One way to assess this contribution is by regional economic assessments, which depend on quality data. In particular, the heterogeneity in aquaculture production makes the evaluation even more difficult, with different species, different production methods, and different regions. Botta et al. analyze this issue for the Florida (US) shellfish aquaculture industry. They provide an overview of economic contributions, challenges, and techniques to overcome these challenges.

Conclusion To sum up, understanding farmer’s decisions, and their consequences for their business, and the external economy is key to ensuring the production of seafood. Studies addressing these aspects, such as the ones in this issue, contribute to the general literature and to more informed decisions, not only made by the individual farm level but also made by the other stakeholders in the aggregate level (e.g., regional economy).

This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled“Market aspects and external economic effects of aquaculture” developed by: Ruth Beatriz Mezzalira Pincinato. The original article was published onThe on Vol. 25-02, pages 127 - 134, year 2021 through Aquaculture Economics & Management.

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Resource use in Whiteleg shrimp Litopenaeus Vannamei farming in Ecuador

Ecuador, India, Indonesia, Thailand, and Vietnam are the main sources of farmed shrimp in the international market. Concern that excesses resource use and environmental degradation caused by food production is jeopardizing the sustainability of the world food system extends to aquaculture production and to shrimp farming. The present study was conducted to obtain data from a sample of

By: por Claude E. Boyd, Robert P. Davis, Arturo González Wilson, Fabrizio Marcillo, Susanna Brian and Aaron A. McNevin

Materials adn methods The office of the World Wildlife Fund in Ecuador, Guayaquil, Ecuador, obtained a list of Ecuadorian shrimp farms from the Under Secretariat of Aquaculture of the Ministry of Agriculture, Livestock, Aquaculture, and Fisheries of Ecuador. An attempt was made to randomly select several farms in each province proportional to their frequencies in the list. 40 »

farms and to use this information to estimate amounts of land, water, energy, wild fish, and other resources used at Ecuadorian shrimp farms.

The farm survey instrument used in Ecuador was a slight modification of the one used in Asia. The modifications were made primarily to gather information about the large pumps used at Ecuadorian shrimp farms. Production and resource use variables were calculated on an individual farm basis to reveal variation among farms in management

and resource use within and among provinces. These variables also were calculated separately as weighted averages for all farms in a province combined and all farms combined. Resource (land, water, and energy) use statistics were compared with an ANOVA and subsequently analyzed for pairwise differences with a post hoc Tukey test when warranted based on the results. OCTOBER - NOVEMBER 2021

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RESULTS Physical features Farms contained 19,241 ha of property of which 17,731 ha were devoted to farms with a total of 14,249 ha of production ponds. The dedicated shrimp farm area consists of production pond area plus embankments, reservoirs, canals, settling basins, parking and staging areas, etc. The ratio of the dedicated farm area to the production pond area was called the land to production water surface area ratio or LWR. The LWR had an average of 1.24 for all farms and a range of 1.18–1.53 by province. The property to production pond ratio was greater (1.35 with a range of 1.26–1.87). The farms were constructed on soils that were predominately clayey, silty clay, sandy clay, loamy, silty, and sandy. The soils generally had a sufficient mixture of particle sizes to allow good compaction of embankments to minimize seepage. It should be noted that the average LWR is much larger when based on the average of individual farms than for the overall province LWR estimates. This resulted from larger farms typically having a lower LWR than did smaller farms. Ponds typically had a water inlet gate at one end and a water outlet gate at the other end. Flow was controlled by dam boards fit with slots in the sidewalls. Of the 101 farms, 87 had reservoirs and 42 had canals. In farms without canals, the main inlet channel served as both an elongated reservoir and canal from 42 »

which ponds were supplied. Fourteen farms pumped water directly into production ponds. Farms discharged water into separate canals or drainage ways. Water supplies for filling and exchanging water in ponds were estuaries or estuarine reaches of streams, and some farms were several kilometers inland. Ninety-eight percent of the pumps were operated with diesel engines and the rest with electric motors. Farms had variable numbers of vehicles and other farm machinery depending upon farm size. Most farms had at least one flatbed truck, one dump truck, one pickup truck, and three or four motor bikes. They also usually had at least one tractor, one backhoe, two or more outboard motors, several small boats, and a larger barge.

Pond management Production was feed-based, and an undetermined number of farms stocked postlarvae (pls) at high density into ponds, which served as nurseries before transferring the larger juvenile shrimp to other ponds at lower density for grow-out to harvest size. All farms applied pelleted shrimp feed containing 28.0–38.5% crude protein. The crude protein content typically was reduced as shrimp grew. Feed was applied daily in amounts adjusted for shrimp size and standing crop of biomass in ponds. Feed was broadcast over pond surfaces from a small boat or by automatic feeders.

The farms used a wide range of pond amendments for water quality improvement, wild fish destruction, and shrimp health. The most applied amendments were liming materials, fertilizers, and molasses. Forty-seven (46.5%) farms applied mechanical aeration in some or all ponds. Electric aerators were used at 12 farms, diesel aerators at 29 farms, and six farms used both. Shrimp ponds were completely drained at harvest so that pond bottoms could dry for sanitary purposes. In 87 farms, sediment was not removed from pond bottoms following draining for harvest. Liming materials usually were applied to moist pond bottoms soon after draining. Two farms reported removing sediment after each crop, five removed sediments annually, five removed sediment at 2- to 3-year intervals, and two conducted the task at 5- to 6-year intervals.

Production Annual yield intensity did not differ (p > .05) among provinces because of the great variation among farms. Weighted average annual pond yield intensities based on total annual production and total production pond area of survey farms by province were slightly different from averages based on individual farm performance. The farm-level FCR averaged 1.32 for all provinces with a range of 1.19 (Manabi) to 1.44 (Guayas). However, OCTOBER - NOVEMBER 2021

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the FCR calculated on total production and feed use by province had an average of 1.48 and range of 1.20–1.54. Adjusting this average FCR for 0.5 t/ ha/year of shrimp biomass from natural productivity results in an FCR of 1.60.

Resource use The energy required for construction and maintenance of farm earthen infrastructure was based on a unit the area of which was that the average production pond (6.59 ha) plus the average ratio of canal and reservoir area to production pond area (0.92 ha). The survey farms were repaired at 1–10-year intervals—the average interval was about 3 years. Based on conversations with a shrimp farm design consultant, the maintenance and repair work over a 30-year period would consume an amount of fuel at least equal to that used for initial farm construction. At an FCR of 1.48 and a national production of 510,000 t shrimp, an estimated 754,800 t of shrimp feed were produced. This suggests a fish meal inclusion rate in Ecuadorian shrimp feed of around 6.62%. Shrimp feeds in general probably contain an average of 5% fish meal from the reduction fishery, because many large feed producers use fish meal made from trimmings from fish processing When the fish meal inclusion rate is 4.44 times or more than the fish oil inclusion rate in a feed, all the fish oil can be accounted as a byproduct of making the meal. Assuming Ecuadorian shrimp feed has an average of 5.6% fish meal and 2.5% fish oil from the reduction fishery, more wild fish use would be accrued than for the fish meal alone. Aquaculture certification programs usually require that the wild fish embodied in harvested shrimp be 1.0 t/t shrimp or less. Based on the estimated fish meal and fish oil inclusion rates in Ecuadorian shrimp feed, farms must have an FCR of 1.54 or less to com44 »

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ply with the standard of 1.0 t wild fish or less per ton of shrimp. Twenty-two (21.8%) of the farms had FCR values above 1.54. Energy and wild fish use did not differ among provinces. There was, however, a wide range among individual farms with respect to the use of these resources. Land embodied in feed exceeded direct land use for production pond water surface area. The support area on farms made up about one-fourth of direct land use. Saline water was used for filling ponds and exchanging water accounted for 88.5% of total water use. Embodied freshwater was mainly in feed and fuels. Embodied energy in pond amendments when spread over the farm sample production was only 3.04 GJ/t shrimp. More than one-half of the energy use was incurred as embodied energy, and 49.4% of the embodied energy resulted from feed.

DISCUSSION Based on production pond area calculated from data provided and national production data from 2020, the average pond yield in Ecuador has increased as follows: 1984, 0.49 t/ha/ year; 1991, 0.88 t/ ha/year; 2006, 1.45 t/ha/year; 2018, 3.18 t/ha/year. The farms in the present survey outperformed the national average for 2018, and there is much potential for greater intensification in the country. Moreover, greater intensification will not increase land, water, and energy use per ton of shrimp and will tend to decrease resource use per ton of shrimp. The

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national farmed-shrimp production of Ecuador could be increased to about 1,000,000 t annually by simply increasing the average national pond yield to that of the farms in the survey without the need of constructing new farms or expanding existing ones. Despite the farms surveyed having higher than average production, some farms produced more shrimp and used resources more efficiently in doing so than did other farms. Variation in efficiency and resource is introduced at the farm level through specific farming practices, such as the use of fertilizers or liming materials, water exchange rate, and feed management. There is much opportunity to improve yield and resource use efficiency even among the surveyed farms. The main technique for increasing production

obviously would be greater use of mechanical aeration. The increase in yield possible with mechanical aeration is dependent on the amount of aeration applied because aerators have the capacity to allow 300–500 by more shrimp per horsepower. Aeration generally does not increase the energy input per ton of shrimp but allows greater shrimp yield in proportion to the amount of aeration applied. Aeration also lessens the necessity for water exchange and could reduce energy use for pumping. This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled “Resource use in whiteleg shrimp Litopenaeus vannamei farming in Ecuador” developed by: Claude E. Boyd, Robert P. Davis, Arturo González Wilson, Fabrizio Marcillo, Susanna Brian and Aaron A. McNevin. The original article was published on May 2021 through the Journal of the World Aquaculture Society, by Wiley Periodicals LLC.

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Designing environmentally efficient aquafeeds through the use of multicriteria decision support tools

By: Ronan Cooney, Alex H. L. Wan, Fearghal O’Donncha and Eoghan Clifford *

Aquaculture is the fastest growing food production system, and the sector accounts for more than half of all fish consumed. Its potential as a sustainable food source has been recognised within the EU Farm to Fork strategy and by the targeting of EU Green Deal research funds. Aquafeed is the primary source of environmental cost in farmed finfish and shrimp life cycle assessments (LCA), and thus, emerging ingredients have a key role to play in increasing its sustainability. 46 »

igh value aquaculture species (e.g., salmon, penaeid shrimp and seabass) are often carnivorous, and as such, require high-protein diets, which traditionally have relied on fish oil and meal. Recent reviews of LCA and circular economy studies in aquaculture have high- lighted a need to develop tools and methods that can enhance its sustainability. The environmental burden associated with feed is not unique to aquaculture and can be found in pigs, poultry and cattle production systems; however, terrestrial farmed animal feeds are perceived as less environmentally challenging than aquafeeds due to the lower protein requirement (i.e. omnivorous/herbivorous vs carnivorous fish species). OCTOBER - NOVEMBER 2021

Feed use in aquaculture not only accounts for the bulk of environmental impact but also 40%e70% of monetary production costs. Thus, significant efforts have been made to source alternative, lower-cost ingredients. Research has focused on the replacement of fish meal with cheaper and potentially less environmentally burdensome ingredients, such as plant by-products, algae (micro and macro), insects, land animal by- products and single-cell proteins (including bacteria and yeast). Alternative protein sources need to meet a number of criteria if they are to be deemed commercially viable. These criteria include (i) nutritionally adequate (e.g. digestible and does not significantly impair fish growth performance or physiological and health status), (ii) palatable to the fish, (iii) scalable to commercial levels, (iv) physically stable, (v) easily handled and stored and (vi) crucially, have lower environmental and life cycle impacts. Given the complex criteria that feeds are required to meet, there is a gap in the tools available for feed formulation that balance economic and environmental efficiencies. This paper pro- poses a multicriteria decision support tool that leverages machine-learning techniques and presents a conceptual framework to interrogate these disparate datasets to identify more efficient feed formulations faster.

Towards sustainable feeds—replacing trial and error approaches Advanced computational and statistical modelling, through machinelearning, have been applied to areas such as medicine, renewable energy and wastewater treatment to optimise the design or operation of various products and processes. Such a step does not preclude the need for in vivo or in vitro experimental validation but enables a more targeted approach to the initial selection of product features. OCTOBER - NOVEMBER 2021

The use of machine-learning capabilities in aquaculture has previously been realised in disease detection, water quality monitoring, on-site management, farm site selection, risk assessment and in feeding regimes. Machine-learning applications in aquaculture feed formulation (and indeed other food sectors reliant on complimentary feed) can provide a bridge between disciplines such as industrial ecology, biology, environmental engineering and nutrition to arrive at precise aquafeeds. In one conceptual example, the use of neural networks could allow for the use of meta-datasets and literature to help design options for a least-cost feed formulation, which is species-specific, using low environmental impact ingredients, while shortening the supply chain and optimising fish growth. The use of machine learning as part of this formulation allows for a bolt-on approach to these established methods and may present new possibilities with regards to automation and process efficiency while aligning with emerging policies. By iterating new product prototypes through ‘virtual’ trial and error experiments that also simulate

fish response, the feed development paradigm can be revolutionised. Emerging trends of explain- able machine learning can further be used to interrogate meaningful connections within feed formulations and associated fish response for enhanced insight.

Data availability The links between aquafeed ingredients, nutritional profile and environmental impact have been included in several major feed ingredient studies and databases. Environmental training data can be sourced from life cycle inventories such as the ECOALIM database. The ECOALIM database was designed as a tool, which could be used by feed manufacturers and LCA practitioners to investigate the environmental impacts of a particular aquafeed formulation. The database is a landmark in the development of open-access information concerning feed formulation, impacts and ingredients. In lieu of experimental data, public and proprietary datasets can be used to develop machine learning models. These systems collate feed data and act as repositories for in» 47

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formation on established, historical and emerging feed ingredients. Life cycle databases such as ecoinvent and Agri-footprint can be integrated with the afore mentioned nutritional datasets. Economic data on feed ingredients could be sourced from online databases, price indexes or through industry partnerships.

Feed to farm Extracting relevant data for each of the ingredients from the nutritional, economic and life cycle datasets can allow for the first step in the development of a broader feed design tool. The next step involves transforming the data into a form amenable for use in specific machine learning algorithms. Data are aligned into a pair of row-aligned matrices termed features or inputs and labels or responses, from which the model learns the complex mapping between these paired

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datasets. This step also considers data preprocessing, such as treatment of data gaps, outliers or uncertain data and various range normalisation steps that might be acted on the data to eliminate spurious variations that can skew the learning algorithm. Some of the actions done as part of this feature selection process can include transformations guided by external models and physics- based approaches that combine multiple datasets into distinct features. Feature engineering is generally considered the most important consideration to ensure a successful machine learning model. The follow-on step to this is to train the model and evaluate its results. A core part of this model training is adjusting model hyperparameters to best represent the data. A number of libraries exist to simplify these hyperparameter optimisation steps, such as the Lale semi-automated machine learning framework. Following this, the model generates a prediction that aims to meet nutritional requirements, optimise costs and reduce environmental impact. Using such computational programming approaches, one can un- cover hidden patterns in complex environmental, economic and nutritional datasets that can be used to generate efficient feed formulations faster. This can improve the efficiency of trial-and-error approaches (which it should be said are backed up by significant expertise) and in turn, generate more optimised feeds that can be tested and embedded into sustainable feed supply chains. This switch from a model-centric to a data-centric approach means that there is no restriction on the type of data that is to be considered and enables nonlinear relationships to be interrogated.

Discussion and conclusion The development of a multicriteria decision support tool is a step to optimise economic costs, maintain 50 »

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the nutritional value and nutrient digestibility while minimising the environmental impacts. Assessing these factors rapidly in a simulated manner can enable feed manufacturers and researchers to disrupt the feed development process, optimise the design of feeds before the trial stage, and target the design of feeds with specific priorities in mind. This tool should be grounded in life cycle thinking. As such, it is necessary to expand the boundaries of the tool and connect it with other previously proposed machine learning-based applications and tools. Such an expansion would allow for the accounting of direct, indirect and induced impacts, which feed production and use, can have on the life cycle of aquaculture products. Efficient feed formulation can only increase the sustainability of aquaculture so far. A finalised or commercial version of the discussed approach could include the use of blockchain to increase traceability and security through the supply chain while meeting consumer or market demands. Blockchain has in recent years become a popular means of ensuring the providence of ingrediOCTOBER - NOVEMBER 2021

ents and products. Its inclusion and use in aquafeeds can help to bolster consumer confidence and perceptions in the face of negative publicity, such as those surrounding supply chains of fish meal. With more food products and production systems using blockchain as a means of increasing traceability, its inclusion into the aquafeed production chain can position aquaculture as a prime example of a resource-efficient and traceable food production system. This combination of efficient feed and advanced traceability of the final farmed product could appeal to environmentally conscious consumers. The adopting of a data-centric rather than model-centric approach introduces a paradigm shift where the large volumes of (training) data available allow a machine learning model to learn the pertinent (nonlinear) relationships and mappings between given inputs and outputs. This approach has enormous advantages in terms of simplifying deployments and allowing models to be applied to a wide variety of feed formulations (since only the data changes). By using a data-centric approach, there are no restrictions

to data that can be considered. The application of machine learning to the questions posed by sustainable feed formulation opens up the field to a technology that has made enormous strides across multiple industries over the past decade. This article outlined and presented the benefits for the interlinking of economic, nutritional and environmental impact datasets to develop an innovative framework for feed formulation design for farmed aquatic animals using machine learning. There are numerous datasets and databases available to develop the structure and tools necessary to implement such a system, the benefits that this avenue of research has to offer can increase the sustainability of aquaculture and strengthen its role in feeding the world.

This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled “Designing environmentally efficient aquafeeds through the use of multicriteria decision support tools” developed by: Ronan Cooney, Alex H.L.Wan, Fearghal O’Donncha and EoghanClifford. The original article was published in May 2021 via Science Direct.

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Application of hybrid electrocoagulation– filtration methods

in the pretreatment of marine aquaculture wastewater By: Jianping Xu, Yishuai Du, Tianlong Qiu, Li Zhou, Ye Li, Fudi Chen and Jianming Sun As an environmentally friendly and healthy aquaculture technique, recirculating aquaculture has attracted increasing attention, and the continuous improvement and development of recirculating aquaculture system (RAS) procedures are now established practices. Generally, in the RAS, the effluent of the aquaculture tank is initially channeled through solid–liquid separation equipment to remove the majority of suspended particulate matter, and subsequently through equipment that provides biological oxidation, oxygenation, disinfection and other processes, in order to achieve recycling. The pre-treatment of aquaculture wastewater by solid– liquid separation equipment greatly reduces the processing load sustained by subsequent water treatment units and it reduces the overall energy consumption of the system.

ne traditional method to enhance the efficiency of sewage filtration, involves adding chemical flocculants such as aluminum (Al) or iron (Fe) salts to the sewage ahead of filtering. Ebeling et al. used chemical flocculants (alum) to improve the filtering capacity of the belt filter system on the tail water of the RAS. Electrocoagulation (EC) is also a common method for enhancing solid–liquid separation of sewage, in which the sacrificial anode releases metal cations with flocculation characteristics under the action of an external electric field, then forms flocculants to absorb pollutants in the water. Compared with traditional chemical flocculation, EC has the advantages of causing less secondary pollution and less sludge output and having more controllability. At present, EC–filtration technology has been successfully applied to surface water purification, industrial wastewater treatment and in other fields. Through the flocculation initiated by EC processes, the small suspended particles in the wastewater coagulate into larger particles, improving filtration accuracy without changing the original filtration equipment and showing that EC– filtration technology has a great potential and application for sewage treatment procedures.

Experimental set up In this experiment, a continuous flow EC–filtration system with a laboratory scale was designed, consisting of three sections: an EC reactor, a mixed flocculator and filtration equipment. The effective volume of the EC reactor was 5 L, in which nine groups of electrodes were arranged in parallel: four groups of anodes were composed of Al plate or Fe plate electrodes, and five groups of cathodes contained titanium (Ti) plate electrodes, The mixed flocculator was arranged vertically and its effective volume 52 »

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was about 1.5 L. The filtration equipment used was a microscreen drum filter whose filter pore size is generally between 50 μm and 75 μm. The wastewater used in the experiment originated from effluents of the aquaculture pond used for the Litopenaeus vannamei RAS.

Experimental design In this experiment, five different anode combinations, three different EC reactor hydraulic retention times (HRTs) (1.5 min, 3.0 min, and 4.5 min) and four filtration pore diameters (75 μm, 63 μm, 54 μm, and 45 μm) were used. The current density of the EC reactor was 19.22 A/m2. The experiment was aimed at measuring the removal effect on the total number of Vibrio, chemical oxygen demand (CODMn), total ammonia nitrogen (TAN), nitrite nitrogen (NO2 -N), nitrate nitrogen (NO3 -N) and total nitrogen (TN) in

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aquaculture wastewater, through the use of an EC–filtration system with different combinations of anodes, different HRTs and variable size of filtration pores. Samples were collected at the water inlet of the sys-

tem to measure the initial water quality index. Based on the change in water quality detected, it was possible to evaluate the treatment capacity of the EC reactor under different test conditions.

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Analysis method The total number of Vibrio was detected immediately using the plate counting method (TCBS plate) after the water sample was collected. For the detection method of CODMn followed. And TAN, NO2 -N, NO3 -N and TN were measured using standard methods. Salinity, pH and conductivity were measured by a multi-parameter water quality analyzer (YSI-556, USA). Reported results are based on mean and standard deviation (mean ± SD). Result and discussion The removal effect of the EC–filtration system on the total number of Vibrio In production, RAS uses ozone and ultraviolet synergistic sterilization to control pathogenic bacteria, which usually requires massive energy consumption. Although ozone has strong 54 »

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bactericidal ability, it will threaten the health of cultured organisms, so the use of ozone in RAS needs to be strictly controlled EC–filtration technology, as a pretreatment method of aquaculture water, can eliminate pathogenic bacteria while removing residual bait and feces; its application in RAS can reduce the work intensity and energy consumption of subsequent ozone and ultraviolet sterilization equipment. These flocculates are eventually removed by physical filtration. Also, without a solid–liquid separation, the removal efficiency increased with the addition of the iron electrode proportion in the combined anode and with the increase of HRT. Removal efficiency for Vibrio by EC–filtration showed different trends with the addition of the Fe electrode proportion in composite anodes. This was determined by the two sterilization procedures characterizing the EC–filtration system. When the electrode, electric field and electro-oxidation played a major role, the removal efficiency for Vibrio increased with the addition of the Fe electrode proportion in composite anodes. When the electric neutralization/flocculation– filtration became predominant, the removal efficiency increased initially and then decreased with the addition of the Fe electrode proportion in combined anodes. This was due to the fact that the flocculants produced by the Al-Fe combined anodes in the EC process were superior to those of the single Al or Fe electrode in terms of structure and strength. A portion of microorganisms in the aquaculture wastewater attaches to the suspended OCTOBER - NOVEMBER 2021

particles, which act as a substrate for microbial growth.

Effects of the EC–filtration system on CODMn removal In the RAS, the increase of CODMn in the water body favors bacterial growth, increasing the oxygen consumption rate and thereby adding costs. As a sewage filtration pretreatment technology, the EC–filtration system can remove CODMn from wastewater by

electro-oxidation and flocculation–filtration, which have a better removal effect on CODMn than traditional physical filtering methods. the effect of different composite anodes and HRTs on CODMn removal in the EC reactor. The removal efficiency increased with the addition of the Fe electrode proportion to composite anodes and with the increase of HRT. It was also due to the lack of solid–liquid separation, so that the EC reactor mainly relied on the effect of electro-oxidation to remove CODMn, and the removal efficiency depended on the amount of oxidizing substances present in the water. Compared to Al, Fe as anode can generate more oxidants during the EC process. The removal efficiency of CODMn through filtration equipment depends on the size of organic particles in the water when the filtration aperture is constant; and the larger the particle size, the higher the removal ef-

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ficiency is. In the EC–filtration system, flocculants can be released into aquaculture wastewater by the EC reactor, which can increase the size of organic particles, thus improving the efficiency of the subsequent physical filtration.

Effects of the EC–filtration system on TAN, NO2 -N, NO3 -N and TN removal EC–filtration technology can remove TAN, NO2 -N and NO3 -N at the same time as removing residual bait and feces. Applying EC as a pretreatment process can not only reduce the load of subsequent biological oxidation equipment (such as moving bed biofilter, fixed film aerobic bioreactor), but also improve the activity of microorganisms, thereby improving the nitrogen removal capacity of RAS and reducing the threat of nitrogen pollutants to cultured organisms. The experiment showed that the removal efficiency of TAN and NO2 -N increased with the increase of HRT and the addition of the Fe electrode proportion to composite anodes, The suspended solids in the aquaculture water contain a certain amount of TN, accounting for 10–40% of total TN, which can be removed by solid–liquid separation. Therefore, in addition to electroreduction, the EC– filtration system can also remove TN from aquaculture wastewater by flocculation–filtration. The TN removal efficiency of the filtration system clearly increased after EC treatment, and the higher the HRT of the EC reactor, the greater its enhancement effect on the subsequent greater than when Fe was used, and the removal efficiency for Vibrio and use of filtration equipment. TN was higher. However, under the same operating conditions, the energy Energy consumption analysis The study found that the electro-ox- consumption of the EC reactor with idation of the EC reactor was stron- the anode combination of 4Fe was ger when Fe was used as anode than 2.59 times greater than that of the EC when Al was used; it also found that reactor with the anode combination the treatment efficiency in terms of of 4Al. By utilizing Al-Fe composite CODMN, TAN and NO2 -N removal anodes, the running energy consumpwas higher. When Al was used as sac- tion of the EC–filtration system was rificial anode, the adsorption/floccu- reduced, while combining the advanlation capacity of the EC reactor was tages of Al and Fe anodes. 56 »

When 3Al + Fe was used as anode, the removal efficiency of the system for Vibrio, CODMn and TN was inferior to that observed when 2Al + 2Fe was used as anode, and the difference was relatively small, less than 5%. However, compared with the 3Al + Fe anode, the energy consumption of the system increased by 19.43% when 2Al + 2Fe was used as sacrificial anode. Therefore, when using the EC–filtration system to treat aquaculture wastewater, and considering the OCTOBER - NOVEMBER 2021

procedure from the perspective of treatment efficiency and energy loss, the optimum anode combination method was 3Al + Fe.

sterilization of Fe as anode during EC was more effective than that of Al anode, which is consistent with results reported.

Conclusions In this experiment, EC–filtration technology was used to pretreat aquaculture wastewater, and the effects of anode combinations, EC reactor HRTs and filter pore sizes on pollutants removal were studied. Furthermore, the experiment proved that the

This is a summarized version developed by the editorial team of Aquaculture Magazine based on the review article titled “Application of hybrid electrocoagulation-filtration methods in the pretreatment of marine aquaculture wastewater” developed by: Jianping Xu, Yishuai Du, Tianlong Qiu, Li Zhou, Ye Li, Fudi Chen and Jianming Sun. The original version was published in 2021 through Water Science & Technology.

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Fish packing

perfected with robotics Marel’s RoboBatcher series is the world’s leading intelligent

robotic solution for fish packing, improving food safety, minimizing giveaway and eliminating human error.

t a time when covid-19 has made it difficult for fish processors to find and depend on labor, adapt to shifting market demands, and maintain line flow, automation has become increasingly significant. For operators, the intelligent automation of the RoboBatcher series translates to minimal giveaway, improved food safety, significantly decreased labor costs, and eliminated risk of human error and dependency that may be detrimental to a production line. Using an exclusive combination of state-of-the-art batching software and innovative robotic technology, the RoboBatcher series packs and styles fish into trays, thermoformer packs, or fixed weight boxes so close to the target that giveaway is minimal. Its exceptional grippers are designed explicitly for gentle product handling, ensuring even the most fragile fish isn’t damaged during packing. The fully automated dispatch process ensures that once a box reaches the set target weight, it is immediately conveyed out for final packing and swiftly replaced by a new box to pack. Depending on your packing needs, the RoboBatcher series comes in three types: RoboBatcher Box, RoboBatcher Thermoformer and RoboBatcher Flex. Marel’s RoboBatcher Box intelligently packs and styles fillets into polystyrene and cardboard boxes.

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Transforming the way fish is packed in boxes With unprecedented accuracy and speed, the RobotBatcher Box automatically styles and packs up to 24 boxes simultaneously, with up to 12 various predefined jobs, into polystyrene and cardboard boxes for retail, catering, and further processors. Icelandic fish processor Vísir installed the RoboBatcher Box in November 2019 and has experienced tremendous results in their fish production. “The system is now such that no human hand touches the product after it enters the robot, and as a consequence, each packed box is much closer to the desired weight,” Ómar Enoksson, Production Manager at Vísir, explains. “The resulting combination of faster production speed and

less handling has had a significant impact on product quality.” The RoboBatcher Thermoformer packs up to 120 fish portions, slices and whole fillets per minute into thermoformers.

Packing slices, portions and whole fillets The fully automatic RoboBatcher Thermoformer packs fish portions, slices and whole fillets into thermoformers at an impressively high speed. The intelligent recipe control software combines the individual weights of incoming products to a fixed batch weight,

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fulfilling orders quickly and efficiently and processing up to 120 pieces per minute. Primex Norway was among the first seafood operators in the world to install a RoboBatcher Thermoformer for whitefish. General Manager Martin Rasmussen said of the positive changes in their production line, “we can control and monitor the giveaway much better. We can also utilize the fish differently because it makes more uniform packing possible, compared to manually.” To learn more about the RoboBatcher Thermoformer, visit our whitefish and salmon product pages. The RoboBatcher Flex is a highly flexible system that swiftly and accurately packs fish fillets into trays according to fixed-weight and catch-weight targets.

Adaptability is key The RoboBatcher Flex is a highly flexible system designed for high throughput and accuracy of fixed-weight and catch-weight packing of fish fillets into trays. With the capability to intelligently batch and style various portions of fish products, the RoboBatcher Flex accommodates a wide range of plastic and polystyrene trays. The system handles up to three individual tray jobs simultaneously and provides full traceability for individual portions. For more than 30 years, Marel has produced innovative equipment and solutions for the fish processing industry that have improved yield, quality and throughput across the value chain for countless customers. By continuously transforming food processing, we enable our customers to increase yield and throughput, ensure food safety and improve sustainability in food production. Please visit our pages for the whitefish and salmon industries to learn more about our fish processing solutions.

Marel have sponsored this article *For more information, please visit:https://marel.com/en/ news/fish-packing-perfected-with-robotics

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NET RESILIENCE IN THE TIMES OF COVID By: Production & Human Resource departments, Fibras Industriales S.A. - FISA

he past 18 months have probably been the most dynamic times for most industries. Normally when some kind of economic “disaster” occurs it affects certain industries at a time. It can be the real estate industries together with the financial industries or mining industries together with production industries and so on. But only once in a century does it happen that almost the entire world economy goes into a spin with domino effects that don’t seem to end.

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It all started with a pandemic that closed industries and production lines for a few weeks and that’s without mentioning the full lockdowns most of us had to endure. After full closure of industries, there was a ramp up period that had to be managed together with high infection and mortality rates thus forcing companies to alter entire production methods and redesign safety and working procedures, while trying to maintain production efficiency levels.

Following the initial “shock” period there were periods of relative tranquility on the Covid front but then we all started feeling the butterfly effects of each regional lockdown. Great fluctuation in prices of raw material, extended delivery times as a result of the production stoppages and ramp up periods and after all of the above, issues with global logistical supply in turn also causing unheard of shipping industry price increases and now companies are grateful if they can get rea-

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A first step we took was guaranteeing raw material. In April and May 2020 it was very unclear what industries and countries would remain open or closed and for how long.

sonable shipping schedules even at the higher prices. It is under these and other local political and economic restraints that FISA has been as creative and dynamic as possible in order to overcome as many obstacles as possible and maintain its status as a leading supplier of nets and cages that always delivers on time and never leaves an existing customer unattended. When dealing with the above mentioned difficulties, FISA proceeded to implement some major changes in its working methods and it is here we would like to share some of these adaptations. First, we had to reduce to a minimum potential Covid transmission to personnel in the company. This implied reducing maximum capacity per m2 leading to reduced man power attending certain machines and a loss in efficiency. As a result, we had to increase working hours to include Sundays and some unnecessary night shifts. It is during these past months that we have greatly digitalized our company and managed to neutralize some of these effects with a brighter future in the horizon. At the same time as reducing the number of workers at any given OCTOBER - NOVEMBER 2021

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We believe that over time all companies have to adapt to existing realities and learn how to produce more efficiently in a dynamic world.

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time, we had to increase traceability capacity thus separating personnel into clearly identified groups via color wrist bands that helped identify all those in contact with any worker that tested positive to Covid and allowed to implement the adequate isolation procedures. As part of the requirements for maintaining isolated teams we had to split the lunch break so what was normally a single 45-minute lunch break turned into four and even five 45-minute breaks for different teams. This same procedure had to be applied to the changing rooms hours and the work entrance and exit hours. In addition to the above, for some exceptional cases we had to organize specialized transport for

the high risk personnel so they could avoid the crowded public transport. In the case of very high risk workers we had no choice but to request they remain at home while receiving full pay. In order coordinate and succeed with the above mentioned targets, we had to create an entire new department that we called the “Covid Human Resource department” and this department is still active during 3 shifts the 7 days of the week and has to serve both our production plant located in Lima and our highly labor intensive net loft located 90km north of Lima. Following the initial shock and stabilization period FISA had to start ramping up production and OCTOBER - NOVEMBER 2021

guaranteeing deliveries. A first step we took was guaranteeing raw material. In April and May 2020 it was very unclear what industries and countries would remain open or closed and for how long. It was under this uncertainty that FISA decided to increase its strategic stocks of raw material by 50% and not risk potential inadequate volumes on the production line. This meant placing immediate orders with suppliers despite not having confirmed sales. In addition to increasing raw material volumes, it was decided necessary to maintain higher inventories of goods in process and in some cases finished goods, this in order to avoid potential future working closures in Peru. OCTOBER - NOVEMBER 2021

Fortunately, the above mentioned steps proved fruitful and during the second half of 2020 FISA managed to fully supply its customer base with existing and new orders. The current additional increase in shipping costs and instability of shipping capacities has forced FISA to further increase strategic volumes of raw materials despite the financial costs and the increased capital allocation that is further affected by fast increase in petrol prices that has led to even higher prices of our raw materials. We believe that over time all companies have to adapt to existing realities and learn how to produce more efficiently in a dynamic world. In addition, it would seem that the world

is going thru a ramp up period that will hopefully lead to stabilization period with a balance between supply and demand in the entire production chain. We hope that our supply consistency continues to prove itself and our increased efficiency will lead to future price cuts once raw material prices and shipping conditions stabilize.

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REALISTIC AQUACULTURE SOLUTIONS

Recirculating Aquaculture Systems The Good, the Bad and the Ugly By: Yedod Snir

Preface RAS provides us with an alternative to ponds, cages and wild catch. In RAS we grow Seafood on land, with minimum resources and isolated from the Environment. The growing demand for seafood and protein to feed the billions of people on earth and the scarcity of natural resources, has made the development of RAS a necessity, not a choice. Despite the steep learning curve of RAS, many companies are invested in large projects to offset the high investment required per production unit capacity (Economy of scale) This magnified risk is not necessary with the right technologies and design. With regards to the cost of production, growing fish in RAS which is designed and operated correctly, can be cost-competitive.

Market advantage - Potential for a fresh locally produced wholesome product that can hit the markets daily with consistent quality and a competitive price (Freight savings). Ecological - Primary oxidation of Nitrogen (No3) and Carbon (Co2), or with further efforts completion of C&N cycle through degassing or N&P via crop root uptake. Biosecurity - A land-based Ecosystem that reduces the propagation of common pathogens such as Sea lice and/or Bacterial and Viral agents.

The BAD Small footprint – High fish densities demand efficient oxygen dissolving systems which require complex gas fundamentals understanding and management. Controlled conditions – Many parameters cannot be measured practically inline or controlled and the greater Recirculation to control those parameters conversely decreases control. Reduced labour – A smaller staff requires retaining a carefully selected

The GOOD Small footprint - with avg. densities at approx. 4-5 x cages and 40 x ponds, RAS is compact, allowing its convenient deployment in population centers. Controlled conditions - Temps, Salinity, Photoperiod are some of the most critical drivers of the major physiological processes. Reduced labour - A smart Ergonomic design will achieve significant cost saving through mechanization and automation. 64 »

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“A team” of dedicated professionals with a deep understanding of the system. Market proximity – The Carbon footprint is not necessarily lower than other culture systems, contingent on, location, RAS design, and operations. Ecological – In absence of Denitrification or Crop Nutrient assimilation, RAS basically converts Organic to Inorganic Nitrogen and increases Phosphate. Biosecurity – Poor water or feed quality in RAS may create novel pathogens which are unique to the system and do not respond to generic treatments developed and applicable to vast regions of culture.

The UGLY Capital investment – RAS is capital intensive and is set for unexpected maintenance and depreciation costs OCTOBER - NOVEMBER 2021

if built wrong. The real ROI for most RAS systems is still very low. Operating expenditure – A poorly executed design exacerbated by a poor operation will increase OPEX to a point where the Economy of scale is considered as a strategy for the wrong reasons. The Environment – RAS started as an environmentally friendly concept to save water and reduce impacts. Today in many parts of the world, water scarcity and partial nutrient cycles are simply not technically or economically sustainable. The Image – Crowded culture conditions gives RAS a bad image as if the fish are “swimming in their own waste”. It doesn’t help to have projects that have rusty corrosive buildings.

Summary The RAS Paradox: “Everything is under “Control!”

The term “Technology” is being tossed around for marketing purposes these days to confer a sense of mechanical predictability, but the economic success of an Intensive RAS company is more dependent on people than any other standalone factor! Every single link of the Value Chain is critical, and this goes on 24/7. Monitoring and even control Technology is advancing and supports RAS redundancy, however, adds to the complexity so must be used strategically.

References cited by the author available under previous request to our editorial team. Tel: +1 413 7689300 E-Mail: yedod@mapaqua.com www.mapaqua.com

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TECHNICAL GURU

OZONE CONTACT, WASTE NOT, WANT NOT……. As things continue to heat up in the Aquaculture Industry in the United States, it is becoming more and more important to understand the key pieces to success. One piece to being successful is to avoid waste. As we all know, the lower the production costs, the more by Amy Stone*

zone is a major capital cost for a production facility so maximizing its efficiency only makes sense so that nothing is wasted. In a prior article, we discussed different types of ozone generators. In this article, we will review typical ozone contact vessels. Important ozone considerations that can never be reiterated enough. Ozone is a deadly gas. It attacks all organic material, including animals and humans. When using ozone, proper safety and maintenance protocols

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possible profit there is to be had and a quicker return on investment.

are critical to avoid injury. It is a very powerful disinfectant and when used properly, can help facilities avoid disease and remove off-flavors. In marine systems, it can help increase the efficiency of protein skimmers. Regardless of how the ozone gas is generated, it still must be dissolved into the system water in order to work properly. There are several types of contact vessels and methods.

Unpressurized Contact Chambers Unpressurized contact chambers are any open to atmosphere vessel that

is meant to provide contact time for the ozone and water. These can be repurposed Low Head Oxygenators that have been modified to include ozone safe materials. They can be degassing towers that have ozone safe materials, including media in some cases. When using unpressurized chambers, a vacuum should be applied to remove any residual ozone and send it to an ozone destruct system. Ozone gas destruction can be done through heat or by having the gas pass through a special “de-

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Speece Cones Speece cones are a more novel way of dissolving ozone into water. They work on the concept of creating a bubble of gas that is sheared as the water travels down the cone. With Pressurized Contact Chambers this cone style vessel, the ozone gas Pressurized contact chambers are ex- is not wasted to atmosphere. It stays actly what they sound like. They are in the cone until it is dissolved into often made from structured fiber- the water. Traditional contact vessels glass tanks made to withstand high are unable to dissolve 100% of the pressures. The concept behind these ozone into solution so a portion of chambers is that it is sized to match the ozone is wasted through a dethe volume that the engineer has struct system. determined to be the contact time. Meaning, if the engineer has created Other Considerations a system that has a two-minute con- As with all designs, there are pros tact time and the flow is 100gpm, the and cons. Some are more capital inchamber will be around 200 gallons in tensive than others. Some are more volume. labor intensive than others. These tanks can vary in their comIn general, unpressurized champlexity based on the engineer’s require- bers are less capital intensive but they ments. Some of these tanks include tend to be least efficient in dissolvintricate internal plumbing to assist ing ozone. Pressurized chambers are with mixing and others are merely an more capital intensive but tend to be empty vessel. Ultimately, the water just more efficient than contact towers in needs to be able to mix with the ozone dissolving ozone. The Speece cones for the required contact time. are average in pricing and highly effistruct” media. This is an important step as uncontrolled ozone gas release is not only dangerous to living animals/humans, it can also damage equipment.

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cient but also require steady gas flow and water flow as they do not react well to fluctuations in either input. Site conditions as well as the overall system design will ultimately reveal the most effective style of contact chamber.

Amy Riedel Stone is President and Owner at Aquatic Equipment and Design, Inc. She was formerly a Manager at Pentair Aquatic Eco-Systems, and she studied Agriculture at Purdue University. She can be reached at amy@aquaticed.com

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THE FISHMONGER

ARE YOU LEADING? By: The fishmonger *

You know what they say – ‘If you are not leading then you are following’ and that would often apply to many people and organisations in the seafood industry. Sad but true!

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he Fishmonger did not attend COP21 in Glasgow, besides not being invited he finds such meetings full of gloom and doom and lacking practical solutions. It has been reported that there were over four hundred private jets at Glasgow Airport carrying only a minute percentage of the audience and that speaks volumes about the lack of comprehension of the subject. Imposing your issues onto others never goes over well when your own actions are arrogant. In the end events like COP21 are just talk fests and if you are waiting for governments to do something then you will be waiting a long time. Remember we are where we are today because of decisions by these same people. Do not forget that ‘common sense is not so common’! It is easy to get overwhelmed by climate science, carbon sinks, renewable energy, etc and what the questions and answers are. In essence, we must take some blame as we can all be guilty of ‘taking the easy route’ instead of questioning what damage is being done to our planet if we use this product or change our systems and asking about alternatives. Hopefully, The Fishmonger can spark some action, and you can rise to the challenge – be sure to let us know what you are doing. The *Blue Food Assessment report was promoted earlier in the year, and it mentioned the crucial involvement that seafood will play in global food security and nutrition and its relationship to climate change. We are already seeing changes in various aspects of our aquatic resources and supply chains due to climate changes, so this report is important to consider. One of the key findings is that ‘increased fisheries and aquaculture production is possible and sustainable, and by 2030 could prevent undernutrition in an additional 166m people worldwide’ – how positive is that! OCTOBER - NOVEMBER 2021

Also be aware that whilst your governments will be slow to react, the apparent rise of conscious consumers in the marketplace has led to many businesses and brands, particularly those in retail, imposing tighter controls on what they promote on their shelves. This can impact your business so you cannot ignore and need to have your stories ready and

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be ready to promote your credentials. A UK processing company was recently reported as saying “We are extremely aware of our role in reducing our environmental impact through emissions, and since 2015, we have reduced our operational emissions (scope 1 and 2) by 52.5%. We understand that there is still much more to be done through the whole value

chain, from improving the availability and accuracy of data to the importance of adopting and implementing science-based targets that align with the **Intergovernmental Panel on Climate Change (IPCC) recommendations.” The Fishmonger knows that seafood as a whole has a positive story when it comes to its emissions, but sadly we are not promoting those exceptional stories. We cannot rest with that knowledge and as a global industry, we should be pro-active in collaborating, sharing our stories, information and knowledge and be leaders in sustainable food production. The report makes a positive statement up front that ‘aquatic foods are a vital component of many food systems yet have received little attention in food policy discourse.’ The description of ‘blue foods’ (animals, plants and algae harvested from freshwater and marine environments) highlights the supply of protein (and we know it is actually far more than a protein) to over 3.2 billion people, contributing a key source of nutrients in many coastal, rural and indigenous commu-

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THE FISHMONGER

Combining FAO and World Bank data, a research document by Rosamond Naylor (Stanford University) et al, estimates that the demand for fish has roughly doubled since the turn of the century and will likely double again by 2050.

nities, and supporting the livelihoods of over 800 million people, the majority of whom work in small-scale systems. Despite their contribution to food systems globally, the report acknowledges that blue foods tend to be underrepresented in discussions about how to feed the world’s population sustainably over the coming decades. It would not be the first time that seafood was a last thought which reflects on the lack of global collaboration within the industry. The ‘blue food’ sector is changing fast and demand for aquatic foods continues to grow at a strong pace despite the gloom and doom you read in the media. What is difficult for global governments to understand is that the small-scale players that lie at the heart of many aquatic food systems have to grapple with these and many other challenges, including environmental degradation, economic shocks, and 70 »

limited gender and social inclusion on top of failure of any specific strategies. Combining FAO and World Bank data, a research document by Rosamond Naylor (Stanford University) et al, estimates that the demand for fish has roughly doubled since the turn of the century and will likely double again by 2050. Focusing on the top two fish consuming countries in the five continents that make up the majority of demand, they estimate that Asia will continue to lead the way in freshwater fish consumption, with the highest demand for freshwater fish in 2050. Added to that is the fact that the majority of the worlds middle class will be constantly moving towards Asia. Their modelling projections suggest that China will consume a diverse range of species including crustaceans, demersal fish and cephalopods, Ghana and Peru will

continue to dominate the consumption of small pelagic fish, and France, Spain, the US, Mexico and Brazil will continue to consume a wide variety of species. Per capita fish consumption in Nigeria is expected to remain low, at one-third of the level seen in Ghana. But given the large and growing size of the Nigerian population, country-level demand is expected to exceed that of Ghana by some margin in 2050. In an incredibly detailed report on climate risks to aquatic food systems by Michelle Tigchelaar (Stanford University) et al, they combine data on climate hazards, exposure and vulnerability for 219 countries, and show that aquatic food systems of Africa, South and Southeast Asia and the Indo-Pacific are the most vulnerable to face high climate risk by the middle of the century under a high-emissions scenario. Reducing societal vulnerabilities, for instance by strengthOCTOBER - NOVEMBER 2021

ening governance, promoting gender equity, and reducing poverty, can lower climate risk by margins similar to meeting global mitigation targets. Missing is the need for more understanding here about the role aquaculture plays and the opportunity it also brings to this issue. Small-scale players have an essential role in global food and nutrition security, producing two-thirds of aquatic food for human consumption and much of the diversity in produce. Rebecca Short (Stockholm Resilience Centre) et al created a framework for characterizing the diversity of actors in this sector based on seventy case profiles spanning a wide range of geographies and systems. Small-scale fisheries and aquaculture (SSFA) provide livelihoods for over 100 million people and sustenance for ~1 billion people. Players vary widely in terms of inputs and assets, degree of specialization, the markets OCTOBER - NOVEMBER 2021

they serve and the type of management by which they are controlled. Despite this diversity, commonalities emerge. Activities are controlled at a local level by individuals or groups of households. Aquaculture producers often innovate and adapt. Fisher folk tend to engage in cooperative forms of management. The cultural importance of aquatic foods also comes to the fore. Modern-day governance assumes uniformity in SSFA despite the diverse nature of this sector. The framework can inform adaptive governance actions supporting the diversity and vital roles of SSFA in food systems, and in the health and livelihoods of nutritionally vulnerable people—supporting their viability through appropriate policies whilst fostering equitable and sustainable food systems. The case profiles demonstrate a multitude of benefits associated with

greater awareness of and support for the diversity within and across SSFA systems. SSFA players currently have key roles in families, communities, and nations. Many times, they are ignored in policy decisions yet there is a compelling case for their critical centrality in viable aquatic food systems. The paper highlights that there are trade-offs that policymakers have to navigate to maintain the benefits from continued engagement of SSFA players. Meeting the needs of global consumers through large-scale industry poses risks for the cultural integrity, equity, nutritional security, and livelihoods provided by SSFA and longerterm actions to redress broader power inequalities, constrain monopolies and support the diversity of SSFA capacities is critical, the report concludes. A nuanced understanding of the aquatic food sector, with its diverse produce and players, production processes and impacts, demands and vulnerabilities, can yield benefits for people and the planet. In order to realize these benefits, aquatic foods must be engaged into the fold in total food systems discourse and managed as an integral part of these systems. If managed appropriately, aquatic foods have the potential to make a meaningful contribution to the nutritious, sustainable, and just food systems of the future, particularly in some of the most food-insecure parts of the world. We can all play our leadership role - that is the challenge for us all.

Comments & References * The Blue Food Assessment is a high-level international collaboration that brings together over 100 researchers looking at all aspects of aquatic food production. **Intergovernmental Panel on Climate Change (IPCC) - is the United Nations body for assessing the science related to climate change. Blue food (nature.com) Harnessing the diversity of small-scale actors is key to the future of aquatic food systems | Nature Food *References used by the author available under previous request to our editorial team

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DIGITAL AND SOCIAL MARKETING BYTES

Tips for Improving Website Searchability Having an online presence for your business is not a case of “build

it and they will come.” You will still need to take additional steps to enhance and assure your website’s placement in search engine results By: Sarah Cornelisse*

ou want not only high website traffic, but also high-quality traffic – those individuals looking for your product or service and willing to purchase – ideally those visitors who are in your target market. This is called search engine optimization

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helping to draw consumers to your business.

(SEO). Rather than one action you take to get your website ranked highly – preferably on the first page of search results – SEO is comprised of numerous small actions that you take in the control and management of your online presences. The following are some simple steps you can take,

or ensure you have taken, to improve your online presence. With over 85% of market share among available search engines, the focus is on Google. However, it is reasonable to assume that best practices for Google will also benefit your online presence with other search engines.

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Enhance your content by using

search sites, and their hints, to discover new keywords and phrases

Be Mobile Friendly Research firm Statista reports that as of 2021 there are 6.378 billion smartphone users worldwide, an approximate 74% increase of since 2016. Layer onto this that over half (54.8%) of web traffic comes from mobile devices, and the importance of having a mobile-friendly online presence is clear (Statista, 2021). Google’s algorithm utilizes mobile first indexing so it’s looking at the mobile version of your website content. Ensure Website Usability Search engines will scan websites to determine their usability. Usability encompasses page loading speed, responsiveness, and security. These aspects impact user experience. For instance, research has found that 40% OCTOBER - NOVEMBER 2021

Complete or Enhance Website Data Whether your website is the product of a third-party website builder (e.g. Claim Your Google My Business Wix, Squarespace, etc.) or a custom Listing site developed by a web designer/ Claiming your Google Business listing marketer, make sure that all of the is straightforward and not time con- SEO settings are filled out. Some suming. Once you’ve claimed your things to look at: business on Google, fill out the details • Make sure there is a meta descripas completely as possible. Enter ad- tion with a marketing message that dress and all contact information as includes keywords that searchers complete as possible. Add photos of may be using as well as the geowhat you want potential visitors to graphic areas you serve. think of for the business. Don’t “set • Include a geographic descriptor in it and forget it.” Actively maintaining the homepage title. For example, the your listing is essential. For instance, town and state that you’re located in. if your business adjusts operating hours seasonally, make sure you take Develop Strong Content the time to update the hours on your Strong content that provides value to profile. the visitor is important in Google’s of mobile website visitors will leave a site that takes more than three seconds to load.

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DIGITAL AND SOCIAL MARKETING BYTES

algorithm. Google will prioritize sites where content offers expertise, authoritativeness, and trustworthiness (E-A-T). One of the results of this is that you can have fewer pieces of content, but with greater depth. Strong and valuable content is also more likely to be linked to from other websites, an additional factor that search engines assess when determining ranking. Here are some things to think about when developing your content. • What is your business about? • What makes you different? • What “problem” does your product solve for customers, or how does it enhance their lives? • Who is your ideal customer? • What areas do you serve? Enhance your content by using search sites, and their hints, to discover new keywords and phrases. For example, in Google, type “farm

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raised trout” and you will notice other related phrases and predetermined completions beginning to show up under the search box. These are what Google believes are similar to your keyword, right or wrong. Either way, they should help the creative content development process. Knowing what Google is predicting also allows you to consider incorporating the word these other words or phrases into your website text and keyword data/descriptions. If you complete the search and scroll to the bottom of the page Google will provide more suggestions. If you click on these suggestions and scroll to the bottom, it will provide more suggestions, and so on. All of these suggestions are exact phrases that people are typing into Google to search for something similar to the phrase you started with. A similar way to do this same research is to use resources such as

Answer the Public (answerthepublic. com). This site will follow the progression of a keyword or phrase and return a diagram and list to show how it believes they all relate. You may also find the results useful for developing content on your website as pages or blog articles, and for use in social media. Be mindful though to not overload your content with keywords, because Google and other search engines have become wise to that and that can damage your ranking.

Review Your Website’s Navigation Menu Google uses the top menu for extra links in the Google listing. Focus menu items on high level products and service categories that visitors will be looking for. For example, if you have an online store, offer a subscription package, and offer tours, make each of these a main

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menu item/link, in addition to the menu items everyone expects such as “about us,’ and ‘contact’.

Review Analytic Data Google tracks immense data about the traffic to, and activity on, your website. Visitor location, device used, length of stay, and pages visited are just some of the data that is available to you. Routinely reviewing this data can help you identify weaknesses – perhaps pages visitors quickly leave due to slow loading photo or video content or overly long pathways to their destination – or strengths – such as popular information or products – that you can utilize in an additional manner. Summary Improving your online presence takes time; make some changes and wait (how long is debatable). If search results don’t improve, revisit the above points and make some tweaks. Search engines also regularly update their algorithms, and this will require you to routinely assess your

website and adjust. Remember that search engine optimization is both art and science.

References cited by the author available under previous request to our editorial team. *Sarah Cornelisse is a Senior Extension Associate of agricultural entrepreneurship and business management at Penn State University in the Department of Agricultural Economics, Sociology and Education. Sarah has expertise in direct marketing, valueadded dairy entrepreneurship and marketing, the use of digital and social media for agricultural farm and food business marketing, and business and marketing planning and decision making. Originally from New York State, she has a B.A in mathematics from the State University of New York at Geneseo, and M.S. degrees in Agricultural Economics and Animal Science, both from Penn State University. Correspondence email: sar243@psu.edu Editor’s note: references cited by the author within the text are available under previous request to our editorial team.

THE GOOD, THE BAD AND THE UGLY

EHP update By: Ph.D Stephen G. Newman*

EHP is caused by a spore forming microsporidian, Enterocytozoon hepatopenaei. The spores are how it infects. When the spore is ingested, directly by consuming infected tissues or feces or indirectly through the water, it germinates by infecting specific types of cells in the hepatopancreas and intestinal tract. It uses the metabolic machinery of the cell to make more spores until the infected cell ruptures, killing it and releasing many more spores to spread throughout the animal.

any microsporidians have intermediate hosts for some of the life stages and it has been theorized that this could help to explain why live feeds can be carrying the spores. No one has of yet identified an intermediate host. Despite the availability of common-sense measures to mitigate the spread of this obligate pathogen of P. vannamei (as well as others) it continues to spread. Its impact is significant and growing. We are seeing increasingly frequent reports of serious impacts. It takes an accumulation of spores in the animal for the symptoms to reach the point where the syndrome is noticeable, and the impact becomes obvious. The animals grow slowly if at all and continue to consume feed. They do not grow uniformly, and they are increasingly susceptible to opportunistic pathogens.

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There appears to be a relationship between rearing densities and the severity of the disease with low density production paradigms in general experiencing less of a problem. Higher density systems have worse problems. It stands to reason that in environments where the shrimp are closely packed there is a greater potential for the spores to pass between animals. Animals can be carrying a fairly high level of spores before they are affected. Sluggish growth and excessive feed consumption follow. While for some types of microsporidians certain drugs work to suppress them, EHP is refractory to them (as most microsporidians are). The only way to control this pathogen is to exclude it and control the levels through common sense biosecurity measures. Some of these are:

Break the cycle. Screen all life stages repeatedly using RT-PCR

Eliminate sludge build up Use automatic feeders.

Ask questions.

Dry ponds Lining ponds

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Do not use broodstock that are carriers or have been exposed to non-controlled production environments (like broodstock ponds outdoors). Live feeds are a serious risk if not screened or from bio secure sources (such as krill). Take frequent random samples and look for weak animals. Make sure that you are using a primer that has been thoroughly vetted. There are many microsporidia in aquatic ecosystems that have nothing to do with shrimp some of which can cross react, leading to false positives. where fecal material infected with spores accumulates. Shrimp forage on detritus and eat bacteria that are attached to it and can readily ingest spores as they look for food. Besides wasting less feed this reduces stress and discourages foraging. Proper use prevents areas of accumulated feed detritus from accumulating. If you are properly monitoring your population for growth and survivals you will know when your problem starts. If PLs are carrying moderate levels of spores, odds are you will have problems eventually. It is important to appreciate that even low levels of spores can be amplified rapidly to undesirable levels if the conditions are ripe for it. The hatcheries that manage this the best will have more customers that are not heavily affected. Out as frequently as the weather and your cycles allow. Heavily lime and allow the sun to bake the soil. This will reduce the spore loads. Changes the pond ecology dramatically by eliminating the soil/water interaction. It is important to appreciate that spores are passed into the environment through shrimp feces and subsequently into other shrimp. Keeping pond bottoms clean is helpful and properly disposing of the accumulated organic matter is essential. Untreated, this is a huge source of spores.

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Use our proprietary blend of bacteria, tableted for ease of use, PRO 4000X, to reduce accumulated organic matter during the cycle. Anything and everything you can do to lower the spore loads is the only path towards minimizing the impact for now. Genetic selection could give us shrimp that are refractory to spore infection or even resistant. This could turn out to be easy or impossible. Only time will tell. There are no drugs that could clear the animal of the very heavy spore loads that can accumulate. There are no quick fixes that would meet regulatory approval in the buyers’ countries. The only way to deal with this for now is to push it back as far as you can, i.e., control the levels of spores at all phases of the process and take the steps needed to ensure this. Amplification of pathogens via broodstock through PLs onto farms has cost the shrimp farming industry tens of billions of dollars over the last three decades. For shrimp farming to have a chance at sustainability this cycle needs to be broken. Progress is being made but there is more work to do. Greater oversight of broodstock production in many countries would be a good start. Screening for pathogens needs to be comprehensive, not focused on what regulators have determined to be solely of concern. Many pathogens are missed because of this. The presence or absence of a pathogen in captive broodstock held in a biosecure environment should not be based on population sampling. Every individual brood animal needs to be tested. The technology exists today to do this economically, although it will double the price of most commercial broodstock. Given the losses and the role of pond reared broodstock in ensuring the continued increase in the incidence and severity of this disease this is easily economically viable. This is the only path that will lead to the cessation of this end» 77

THE GOOD, THE BAD AND THE UGLY

Amplification of pathogens via

broodstock through PLs onto farms has cost the shrimp farming industry tens of billions of dollars over the last three decades.

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less cycle of profit limiting diseases that have impacted shrimp farming since its inception. The fact that a pathogen like EHP is thriving despite the known role of broodstock, inadequate pond preparation, infected larvae and PLs in the process is not a positive statement about shrimp farming. The industry is poorly regulated and more than likely there will continue to be dogmatic approaches with attention to myth rather than the science of what is taking place even with added oversight. EHP can be dealt with. Until there are truly resistant animals this disease is here to stay. Even in countries where there seems to be little impact at this time, ignoring the commonsense measures could eventually result in the disease becoming problematic. There are two ways to make sure that broodstock are free of EHP spores to start with. These are screening and following the performance of the animals in the field, history. Screening is essential. RT PCR is a powerful tool, but it

has serious limitations much as all population-based testing of PCR does. Primers must be specific or there will be false positives. Tissues being sampled must contain the organism of interest. Too small of a sample or targeting tissue that is not infected early in the disease process can lead to false negatives. Even if these were not issues, PCR use in population testing is a statistical exercise. You take a sample of animals and test them. Most of the animals in the population are not tested. One can never be 100% sure using this approach that EHP is not present at some level. For PLs this is of course understandable. Less so for broodstock. Following the larva and PLs from each spawn is essential. If they are PCR positive as determined by routine testing, they should be destroyed and the presence of the pathogen in the broodstock should be considered. If they are “clean” then performance on the farm will provide additional clues. If it is a serious problem, how early it occurs will give some indication of OCTOBER - NOVEMBER 2021

the spores loads. Soon after stocking suggests that the spore load is high to start with. Proper animal husbandry is essential for sustainability. If the above practices were routine, the impact of WSSV and many other diseases would be dulled considerably. Perhaps what is the most important message to take home here is that by ignoring these practices, taking short cuts, hoping it will go away or desperately seeking magic bullets, the industry is guaranteeing that disease problems will be a constant n shrimp farming. Shrimp farming cannot be sustainable if this is the case.

Stephen G. Newman has a bachelor’s degree from the University of Maryland in Conservation and Resource Management (ecology) and a Ph.D. from the University of Miami, in Marine Microbiology. He has over 40 years of experience working within a range of topics and approaches on aquaculture such as water quality, animal health, biosecurity with special focus on shrimp and salmonids. He founded Aquaintech in 1996 and continues to be CEO of this company to the present day. It is heavily focused on providing consulting services around the world on microbial technologies and biosecurity issues. sgnewm@aqua-in-tech.com www.aqua-in-tech.com www.bioremediationaquaculture.com www.sustainablegreenaquaculture.com

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