Harbor seals at haul-out sites are vulnerable to human disturbance during critical rest, molting, and pupping periods, and responsible coastal management protects their welfare and population health.
Harbor seal welfare at haul-out sites is directly affected by human behavior on adjacent beaches and waterways. Seals that cannot rest undisturbed cannot complete essential physiological processes including thermoregulation, molting, and nursing. Repeated disturbance events that force seals into the water multiple times daily impose cumulative welfare costs through interrupted rest and elevated stress hormones. The most vulnerable periods are pupping season in spring and molting in late summer, when seals are least able to tolerate disturbance. Simple infrastructure including viewing distances, rope barriers, and interpretive signage dramatically reduces disturbance frequency at managed haul-out sites. Dog access restrictions near haul-out sites are particularly important as dogs trigger stronger flight responses than humans alone.