Marine protected areas improve fish welfare by reducing fishing pressure and allowing natural behaviors and population recovery.
Marine protected areas benefit fish welfare in multiple dimensions simultaneously. Fish within well-enforced MPAs face dramatically reduced fishing mortality and the associated chronic stress of gear encounters, injury, and capture. Population age structure normalizes — large, old fish that have escaped fishing accumulate. Behavioral ecology normalizes as well — fish adopt natural activity patterns rather than stress-adapted behaviors driven by fishing pressure. The recovery of predator populations within MPAs also restores natural trophic dynamics, allowing fish communities to function as they evolved to. Expanding well-enforced MPAs is among the highest-leverage interventions for improving the welfare of wild marine fish populations.