Atlantic mackerel is one of the most important wild-caught fish used as aquaculture feed. Capture welfare at sea involves crowding, crushing, and suffocation affecting billions of fish annually.
Wild-catch welfare for feed fish is an enormous but nearly invisible welfare issue in aquaculture. The fish meal and fish oil used in salmon, shrimp, and other farmed species diets comes from wild-caught fish — primarily mackerel, anchovy, herring, and sardines — caught in purse seines at scales of billions of fish annually. The capture process involves severe crowding in closing nets, physical damage from compression as nets tighten, and asphyxiation as oxygen is depleted. Death is not instantaneous. The welfare impact scales with feed fish inclusion rates — high-feed-fish salmon diets require enormous numbers of wild-caught fish per tonne of salmon produced. Reducing fish meal inclusion through plant proteins, insects, and single-cell proteins simultaneously improves sustainability and indirectly reduces feed fish welfare impacts.