Aquaculture Feed Sustainability and Fish Welfare

The feed used in aquaculture has welfare implications both for the fish being farmed and for the wild fish harvested to make fishmeal and fish oil. Sustainable feed transitions affect the entire welfare equation.

Key Facts

Atlantic salmon require approximately 1.1-1.4 kg of wild fish (as fishmeal/oil) per kg of salmon produced.
Forage fish (anchovies, sardines, herring) used in fishmeal are sentient; their harvest involves massive bycatch and ecological disruption.
Alternative feed ingredients — insect meal, algal oils, soy protein — are increasingly replacing fishmeal in aquaculture diets.
Nutritional imbalances from poorly formulated alternative diets can cause health and welfare problems in farmed fish.
Offshore species like tuna and sea bass require higher proportions of marine-origin feed than carp or tilapia.

Welfare Considerations

Feed sustainability in aquaculture is a welfare issue on two levels. At the farm level, the nutritional adequacy of feed affects farmed fish health and welfare directly — poorly formulated diets cause disease and immune deficiency. At the capture level, the wild fish harvested for fishmeal are sentient beings whose welfare in harvest is almost completely unaddressed. The transition to alternative feeds reduces dependency on wild fish harvest and, if nutritionally well-designed, can maintain welfare in farmed fish. Getting both dimensions right simultaneously is the challenge for sustainable aquaculture.

What You Can Do

Choose aquaculture products from species with low feed conversion ratios (oysters, mussels, carp, tilapia).
Support certification schemes that require sustainable feed sourcing.
Reduce consumption of high-trophic-level farmed fish (salmon, tuna) that require large feed inputs.
Support research into algal and insect-based alternatives to fishmeal.