Dolphins, porpoises, seals, and sea lions living in coastal waters face chronic exposure to pollutants including heavy metals, PCBs, and plastic debris with serious welfare consequences.
Marine mammals living in coastal waters near human populations face a chemical exposure burden that would not be tolerated in any terrestrial environment. The blubber that provides thermal insulation also acts as a reservoir for fat-soluble pollutants including PCBs, DDT, and flame retardants, concentrating them to levels that cause immune suppression, reproductive failure, and neurological damage. Dolphins and porpoises with severely compromised immune systems are more susceptible to infectious disease and may experience chronic illness throughout their lives. The welfare harm is invisible — these animals do not strand and die immediately from pollution, but live diminished lives in polluted waters. Reducing industrial and agricultural pollution inputs to coastal waters is the only meaningful long-term remedy.