Harbor porpoises are the smallest and most endangered cetaceans in European waters. Bycatch, underwater noise, and pollution threaten their welfare and population viability in North Sea and Baltic Sea populations.
Harbor porpoise welfare involves both the acute suffering of bycatch drowning and the chronic welfare costs of noise and pollution in degraded marine environments. Porpoises drowned in fishing nets experience a death that takes several minutes and involves panic from entanglement and failed breathing attempts. The acoustic ecology of harbor porpoises — highly dependent on echolocation in murky Northern European waters — means that pile driving and shipping noise causes navigation disruption, social communication interference, and chronic stress that represent ongoing welfare costs. Pingers that reduce bycatch are one of the most cost-effective welfare interventions in any marine context; their consistent use across European fisheries would prevent thousands of painful drowning deaths annually.