How prey depletion, pollution, and acoustic disturbance affect orca welfare across global populations.
Wild orcas face a convergence of welfare threats driven by human activities. Southern Resident killer whales are experiencing chronic nutritional stress from Chinook salmon depletion — a form of prolonged hunger that causes physiological stress, reproductive failure, and population decline. High PCB loads in their blubber impair immune function, causing disease susceptibility. The acoustic environment they depend on for hunting and social communication is increasingly disrupted by vessel traffic. The combination of cognitive sophistication, social complexity, and cultural transmission in orca populations gives their welfare harm particular moral weight.