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World Aquaculture Association | Sustainable Aquafeed and Aquaculture Production Systems Affected by Global Food Security and Climate Change Challenges

The global population continues to grow and is expected to reach 9.5 billion by 2050.With this growth, total protein demand is estimated to increase by 40% to 75%, with 72% occurring in countries currently identified as developing countries, of which 70% of the estimated population is expected to live in urban areas (National Academy of Sciences). National Research Council (NRC), 2015).In these areas, higher socioeconomic levels will be achieved, resulting in greater demand for animal-derived proteins.To meet this demand, livestock production will need to increase by 25-300 million tons
In response to projected growth in the global population, the goals of global food security must be realigned to a collective belief in sustainable development consisting of several goals (NRC, 2010) that are based on environmental, economic and social returns on producing positive results now and for future generations.The results depend on overcoming the many inherent challenges arising from the varying demands and efficiency levels of current production systems, which are influenced by the reality of significant depletion of essential natural resources and ongoing global changes in consumption preferences for different protein sources.Existing production systems contribute to varying degrees of carbon footprints in the form of greenhouse gases (GHGs), which contribute to climate change and its adverse effects on the environment, such as average increases in global temperature and changes in weather patterns.Furthermore, the potential impact of current intensification of production systems on animal health and safety has become a very relevant concern (FAO, 2009).Even if future technological advancements aim to further improve the efficiency of intensive management practices, existing food production conditions will not be able to successfully address the growing global demand for protein due to limited land and freshwater resources (NRC, 2015).Collectively, these problems are complex, uncertain, interdependent, contentious, and subject to various opinions, and thus never reach a certain point that yields an ideal/model solution.This situation is defined as an evil problem (NRC, 2015).By its very nature, a nefarious problem can only be actively confronted by major adjustments that somehow mitigate the potential level of destructive interrelationships to produce the best possible outcome.
A key element of a holistic approach to global food security is achieving the required balance among the various components of the evil problem.The sources of meat produced for human consumption differ in how each different production system affects the environmental, economic and social dimensions of sustainable development.Multiple challenges will be faced when seeking to establish regional and national food policies based on sustainability guidelines, including deciding on protein sources for direct consumption versus protein sources in feed formulations.Qualitative and quantitative changes in human consumption of existing and newly developed different protein sources will be an inevitable end product.So what we grow, what we feed our animals, and what we eat should all change dynamically.
The expected growth in seafood protein demand is well aligned with the overall demand for animal-based protein sources.Compared to other animal production systems, aquaculture has the highest overall efficiency.For example, each kilogram of farmed beef produces 90% more carbon dioxide (carbon footprint) than 1 kilogram of salmon (Marine Harvest, 2017).In addition, the percentage of protein retention and the percentage of edible meat produced by equal amounts of feed to salmon and other fish exceeds that of beef, pork, and poultry (Tidwell, 2012).Despite these striking features, this approach requires new management strategies that do not further deplete the dwindling supply of available land and freshwater resources.
The contribution of aquaculture production continues to increase and accounts for a significant portion of all livestock production globally, and provides a path to the balance that is needed to actively address evil.As of 2018, global aquaculture production rose to 45.8 percent of total global fisheries (seafood of animal origin), up from 9 percent in 1980 (FAO, 2020).Seafood produced by marine production systems accounted for 37.5% of total aquaculture production.In addition, human consumption from cultured fisheries accounts for 52 percent of total global seafood, exceeding consumption from traditional hunting/capture fisheries (42 percent).Global aquaculture production in 2018 is expected to increase by 33% to 109 million tonnes by 2030 and is expected to grow by 33%.This figure will continue to grow annually as the potential of marine fish farming is further realized, which will be a noteworthy sustainable solution to the total global meat demand estimated at 25-300 million tonnes by 2050 (NRC, 2015).
Fish and crustaceans as feed species accounted for 55.2 percent (61.8 million tonnes) of total global aquaculture production in 2017 (FAO, 2019).By 2025, an estimated 73.15 million tonnes of aquafeed will be required to meet the estimated production levels of forage species (Boyd et al., 2020).Therefore, sustainable aquafeeds based on ingredient composition selection play an important role in meeting the overall goal of meeting the growing demand for seafood through sustainable aquaculture production.For the new generation of sustainable aquafeeds, “dietary sustainability goes beyond nutrition and the environment to include economic and sociocultural dimensions” (FAO, 2010).Furthermore, meeting the demand for sustainable aquafeeds in feed production systems is influenced by many confounding and competing factors driving other agricultural production systems.What pathways and solutions are needed to ensure that sustainable aquafeeds are fully exploited to realize the opportunities offered by aquaculture?Management strategies need to be developed to at least maintain and improve aquaculture production levels, especially to address the effects of climate change (D’Abramo & Slater, 2019).Therefore, the composition of aquafeeds must evolve accordingly as part of a dynamic process to ensure sustainability.Mitra (2021) provides a comprehensive review of the characteristics, policy directions and trade-offs of alternative aquafeeds in achieving sustainability goals.
To meet the principles of aquafeed sustainability, changes driven by a holistic approach are required, including the use of feed ingredients with reliable supplies, minimal imports, relatively low carbon footprints, and most explicitly, policies that meet quality assurance standards.In the pursuit of economic sustainability, variables such as the cost of each ingredient, potential for production scalability, import dependence and transport logistics must be factored into decisions about sustainable ingredient use.The choice of feed ingredient composition used in other agricultural animal production systems will correspondingly affect the choice of ingredients for feed aquaculture systems and must be addressed.In fact, even the pet food industry may intervene financially by sourcing traditionally used feed ingredients as well as ingredients assessed as potential substitutes at higher prices, as consumers (pet owners) are willing to pay higher per- Retail price per unit of feed.
Effective achievement of qualitative and quantitative levels of essential dietary nutrients, nutrient digestibility and assimilation, and production practices are the primary goals of aquafeed production.This paradigm has to abandon the idea that one ingredient is a “necessity”.All actions regarding compositional changes must be based on the results of rigorously executed nutritional research, with a strong a priori recognition that sustainability must be the main guiding factor.Interactions/synergies between or between nutrient sources influenced by specific production system properties and the effect of specific aquafeed additives to achieve growth promotion must be a key research area.For example, the recognized beneficial effects of dietary probiotic and prebiotic supplements on sustainability, as revealed by qualitative and quantitative changes in the microbiome (D’Abramo, 2018), must be weighed against the additional cost of inclusion.
Columbo and Turchini (2021) aptly describe an example of a change in the feed composition of a formula feed as the transition from Aquafeed 1.0 to Aquafeed 2.0.This ‘upgrade’ is mainly achieved by significantly reducing the amount of fishmeal and fish oil used as protein and lipid sources, respectively, in aquafeed formulations, which appear to ‘require’ fishmeal and fish oil as major feed ingredients.Taken as a whole, this remarkable achievement brings the complementary advantage of increasing the quantity of fish products available for direct human consumption.Other ingredients with significant potential for aquafeed development are protein sources derived from single-cell (bacterial/fungal/algal) cultures and insect meal.These ingredients are usually produced by using agricultural or biotech waste as a source of nutrition.Single-cell protein sources and insect meal provide additional advantages as the nutrient composition can be altered by the source of nutrients provided for growth.Refined products, such as poultry by-products, blood and feather meal, are a major source of dietary protein and other nutrients and are currently used as ingredients in aquafeed formulations.These products have proven to be a source of good growth and health when added at relatively high levels (Bureau, 2006; Trushenski & Lochmann, 2009).Whether currently in use or in pilot production, all of these ingredients come directly or indirectly from waste and have a low carbon footprint.
Aquafeed successfully negates the ecological concept that species occupying higher levels in the food chain are associated with lower efficiency and therefore less attractiveness for sustainable agriculture (Cottrell et al., 2021).For example, the reduction in nutrient levels (3.48-2.42) achieved in salmon (a fish-eating fish) farming demonstrates the ability to improve feed efficiency by adjusting the mix of ingredients and other additives to meet nutrient requirements for desired growth rates.Improvements in feed efficiency for aquatic species can continue to be achieved as new ingredients are identified and incorporated into feeds for their sustainable properties.
Globally, food loss and waste account for 8 percent of the total anthropogenic contribution to global warming every year, measured in CO2-equivalent production (FAO, 2011).Waste recycling with the goal of effectively reducing waste generated over time is defined as a circular economy.The use of waste as an aquafeed ingredient or as an independent source of nutrition is more specifically referred to as a circular bioeconomy.While the reuse of nutrients and resources through the integration of various aquatic and terrestrial crops dates back to the earliest aquaculture systems, the need for effective waste management in current production systems, especially intensified systems, is greater than ever bigger.The use of waste in the formulation and manufacture of aquafeeds as part of an overall strategy is likely to improve sustainability.The circular bioeconomy is considered the ultimate driver for the realization of Aquafeed 3.0 (Columbo and Turchini, 2021).Integrated aquaculture (IA), especially integrated multi-trophic aquaculture (IMTA), is a unique example of a circular bioeconomy.Waste from one feeding organism is provided as a source of nutrients to grow another plant or animal (non-feeding) occupying a different habitat niche.For both producing species, the production efficiency is increased because the same amount of aquafeed is fed for the co-production of both species (Boyd et al., 2020).The promise of the IMTA system has been demonstrated in recent laboratory findings in which satisfactory growth of marine shrimp species is maintained solely by the provision of gesta from sea urchins (Jensen et al., 2019).However, beyond the integration of invertebrates (scallops) into macroalgae in Sanggou Bay, China (Shi et al., 2013), the management and financial viability of commercial-scale IMTA production has yet to be demonstrated.Neori, Shpigel, Guttman, and Israel (2017) review the early evolution of polyculture to IMTA and discuss the challenges of optimizing multiple crops coupled into a single system.In fact, as Nolle, Chopin, Martinez-Espinella, Niori and others have said.(2020), the results of field testing have yet to establish any widespread acceptance to facilitate commercial efforts.However, evaluations of IMTA-based aquaponics do suggest the potential to be economically viable under specific conditions (Greenfeld, Becker, McIlwain, Fotedar, & Bornman, 2018).
By adding specific organic matter to the pond production system, cultured organisms produce and consume an abundant food source (biofloc).Feed efficiency is increased as the amount of aquafeed required can be reduced while still meeting expected production targets.For some management practices, supplemental feed (corn gluten meal pellets) designed as a source of supplementary nutrition for terrestrial animal production is often introduced into aquaculture production ponds as a nutritionally incomplete source.Some of these nutrient sources are directly consumed, and the remaining uneaten feed pellets are rapidly broken into small pellets that are consumed by growing and reproducing benthic organisms.Thus, two nutrient sources, feed and natural pond biota, work together to meet nutrient requirements (D’Abramo & New, 2010).The latter two examples show how reduced levels of direct-fed feed can be used to achieve desired growth rates and product.
The extent of the impact of aquafeed really depends on the efficiency and flexibility of the chosen feed ingredients and the different ways of meeting nutritional needs.These characteristics complement the high efficiency of aquatic animal production.Transformational change based on efficiency and balance must be publicly and collectively accepted and ultimately triumphant.
Tacon, Metian, and McNevin (2021) provide guidance on sustainability issues for the future of aquafeed.Action points are provided for requirements, recommendations or encouragement regarding ingredient selection and quality, feed manufacturing and feeding practices, some of which complement, repeat or extend what I have presented.Aquaculture nutritionists, feed manufacturers and farmers themselves must heed this information in an effort to continue to improve management practices, including those that have been identified as sustainable.Researchers must operate under some common guidelines.Otherwise, scientific literature that is confusing and ultimately has little or no value in application can be a source of unwanted interference.A recent assessment of the environmental impact of the use of insect meal in aquafeeds is a good illustration of sustainability-based efforts in aquafeed ingredient research (Tran, Van Doan and Stejskal, 2021).In addition, many potential plant-derived feeds, such as wheat and corn gluten meal, are by-products of the production process and have nutritional qualities that require further research to meet nutritional requirements.Processing protein sources through fermentation can improve quality by producing a more efficiently digested product, and is therefore a promising ingredient in sustainable aquafeeds (Dawood and Koshio, 2019).As part of a holistic approach to sustainability and food security, the above feeds offer the opportunity to use feed-grade rather than food-grade (for human consumption) ingredients in feed formulations.If feeds from these and possibly other similar sources are judged to be satisfactory, then more plant protein may become a direct source for human consumption.
The ominous situation we face clearly requires a broad, swift and determined response based on a highly collaborative effort and responsible oversight.In countries where such controls do not exist, a comprehensive quality control system for feed ingredients must be established.Intellectual property issues related to feed additives must be negotiated so that favourable progress is not hindered.Collaboration and information sharing among publicly funded academic and private sector researchers and among feed manufacturers must be established for maximum benefit.These progressive visions must be complemented by the supportive efforts of those involved in the sourcing of feed ingredients and the intricacies of feed supply chains, which are high-risk and require effective delivery management.Regardless of the source of raw materials used to produce sustainable aquafeeds, these efforts must be complemented by effective feeding/feed management practices in an effort to reduce waste and further increase the efficiency of highly sustainable production systems such as aquaculture.While not the only panacea, sustainable aquafeed production combined with novel feeding systems will play an important role as part of long-term, sustainable aquaculture production practices.
JWAS Section Editor – Professor in the Department of Wildlife and Fisheries at Mississippi State University and scientist at the Mississippi State Agricultural and Forestry Experiment Station.His 23-year career at Michigan State University has focused on developing efficient and environmentally friendly management strategies for alternative species, including freshwater prawns, crayfish, and hybrid striped bass.The results of his work include several shellfish and finfish dietary options that reduce feed costs, as well as a better understanding of crustacean and mollusk nutrition.
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Post time: May-17-2022