In California, for example, nesting and migrant seabird populations are significant resources with colonies throughout the state. Over time, these populations have been impacted by a variety of man-made sources, including oil spills, gill-net and other fisheries, various contaminants, habitat destruction, introduced predators, and human disturbance.
These disturbances can cause nesting seabirds to flee from and abandon their nests, leaving eggs or chicks exposed to predators, or causing eggs to fall from the nest. In some cases, disturbances can cause complete breeding failure of a seabird colony, and ultimately may cause colony abandonment. These disturbance events can result in a reduction of the long-term health and survival of affected marine species, and when coupled with changing oceanic conditions and other human-induced stressors, cumulative small impacts can impart large-scale harm.The Seabird Protection Network at Gulf of the Farallones National Marine Sanctuary addresses human disturbance to breeding seabird colonies along the central California coast. These efforts are accomplished through an organized outreach and education program combined with law enforcement and other seabird management actions. Monitoring of California seabird breeding colonies helps guide outreach, education, and management efforts of the Network.
Original article: What threats do seabirds face?