Research on wild and captive marine mammals raises welfare questions about capture, handling, tagging, and the ethics of captive marine mammal maintenance for science.
Marine mammal research welfare is shaped by the extraordinary difficulty of studying these species in the wild, creating pressure to use captive animals or invasive tagging methods. Suction cup tags are minimally invasive but have short duration. Dart tags penetrate blubber and cause tissue damage at attachment sites. Satellite tags on seals require capture, handling, and gluing to the fur — significant stress for wild animals. Captive cetacean research allows physiological studies with high scientific value but involves long-term captivity welfare costs. Non-invasive research through eDNA, passive acoustics, and photogrammetry is advancing as a partial alternative. Welfare assessment should be integrated into every marine mammal research protocol.