Fisheries and Aquaculture By-Products Are a Key Ingredient for Sustainable Aquaculture Feeds

A recent study by researchers at the Johns Hopkins Center for a Livable Future identifies opportunities to re-purpose the inedible portions of seafood created by industrialized fisheries and aquaculture sectors. These inedible portions, also called by-products, are used to create fishmeal and fish oil, which are valuable as animal feed and for human nutrition as fish oil supplements. Fishmeal and fish oil (FMFO) have historically come from wild caught fisheries. About 20% of global wild caught fisheries or 16 million tonnes per year are turned into FMFO. Byproducts present a promising alternative to using wild caught fish to produce FMFO.  

The research, titled, “Fisheries and aquaculture by-products: Case studies in Norway, United States, and Vietnam,” and published in Marine Policy, collected data on production and by-product generation from seven industrial fisheries and aquaculture sectors that included Norway farmed Atlantic salmon, US farmed catfish, Vietnam farmed shrimp, Vietnam farmed pangasius, US wild Alaska pollock, US wild pink salmon, and US wild sockeye salmon.   

Fishmeal and fish oil (FMFO) are typically made from small whole fish such as anchoveta, sardine, and menhaden and in some cases from larger pelagic fish. Using wild fish for FMFO creates competition between human food and feed. By-products such as the inedible portions from fish processing plants can also be used for FMFO without creating competition with fish as human food. FMFO are packed with healthy proteins and easily digested by animals. Fish oil contains omega-3 fatty acids and amino acids such as EPA and DHA, which are nutritious for humans.  

The aquaculture industry is the single largest consumer of FMFO and is highly reliant on these marine ingredients in feed. “There is tremendous potential for increasing the global production of FMFO by using by-products,” says David Love, PhD, lead author and Research Professor at the Center for Livable Future. “We need more work to get the economics and policy landscape to align to fully utilize by-products because the demand is there, and we can’t let these resources go to waste.” 

The study population produced 5 million tonnes per year of aquatic food products. Almost 3 million tonnes per year (59%) were destined for human consumption and the remainder, just over 2 tonnes per year (41%), was inedible or discarded as food loss. Of the by-products available for rendering, 72% were actually rendered.  

The aquaculture sector had higher rendering rates (an average of 70%) compared to the capture fishery sector (an average of 59%). Lower rendering rates from capture fisheries may be due to the short fishing seasons, operating in remote locations, the cost of building and operating rendering plants that are not used year-round, and regulations allowing dumping of processing waste. Each sector in the study had their own strategies for capturing and using by-products, but case-specific solutions are needed to amplify use of by-products to produce FMFO. 

The researchers also found that differences in utilization of by-products may be impacted by the scale of operation. “While our study focuses on industrial-scale sectors, it can still shed light on key considerations for policies to promote increased by-product utilization,” said Liz Nussbaumer, one of the authors of this study and project director at the Center for Livable Future. “Both industrial- and small-scale fisheries and aquaculture sectors must recognize the need for significant investments in FMFO production, policies to regulate these markets and promote the profitability of using by-products where suitable, and the coordinated effort to achieve sustainability.” This study calls for prioritization in reducing barriers to utilizing these alternative raw materials for FMFO production. Additionally, it is important to ensure that these by-products are used and not remain as wasted resources.  

“Fisheries and aquaculture by-products: Case studies in Norway, United States, and Vietnam,” was co-authored by David C. Love, Frank Asche, Jillian Fry, Mark Brown, Ly Nguyen, Taryn M. Garlock, Elizabeth M. Nussbaumer, Gabriela L. Sarmiento, Sigbjørn Tveteraas, and Roni Neff. 

This work was supported by the US Department of Agriculture under an INFEWS grant [#2018-67003-27408].