Sea lions face welfare harms from fishing gear entanglement, tourist boat harassment, and marine debris, while playing important roles in marine ecosystem health.
Sea lions entangled in netting or strapping experience progressive constriction injuries as they grow, causing lacerations, infection, and eventual strangulation. Repeated vessel harassment during pupping and nursing causes abandonment of pups. Plastic pollution ingestion causes internal obstruction. Sea lions struck by boat propellers suffer traumatic injuries. Their intelligence and social complexity means welfare harms extend beyond physical injury to social disruption and stress.