Interconnections Between Agriculture and Aquaculture: Implications for a Sustainable and Resilient Food System.

Aquaculture is the farming of fish, crustaceans, shellfish, and aquatic plants, which plays an important role in the global food system and human health. Aquaculture production has grown at 7% per year for the past several decades and now more seafood comes from farms than from wild harvests. Through globalization, aquaculture is increasingly connected to global agriculture and soils in new and important ways. Many have recognized that farmed fish consuming a wild fish-based diet is unsustainable for ocean ecosystems, and the aquaculture industry has responded by shifting to crop-based feed ingredients. Soy, maize, rapeseed, and wheat are replacing wild fish as feed, which allow for continued industry growth. This shift raises several concerns, including: reduced nutritional content in farmed fish, health impacts from industrial crop production practices, and environmental impacts related to land and water resources. We reviewed current evidence regarding the link between omega-3 fatty acids in aquaculture feed and farmed seafood products, and public health risks associated with industrial crop production. We also conducted new analyses to estimate the land, water, and fertilizer resources associated with producing the top five crops used in aquaculture feed. Increasing use of crop-based aquaculture feeds has implications for human health and fundamentally links seafood production to terrestrial agriculture. Aquaculture can provide animal protein more efficiently than many terrestrial species, but its rapid growth adds to the rising demand for crop-based animal feed. The shift in aquaculture feed ingredients must be viewed in the context of a food system that is using both aquatic and terrestrial resources at unsustainable rates. Additional information is needed on the nutritional content of farmed fish and the crops used in feed, including how and where they are produced, to more fully assess the implications for human and environmental health.