People given seabird warning at Farallones Sanctuary

Pilots, boaters, paddlers, drone operators and visitors are all being asked to avoid disturbing nesting seabirds in and around the Greater Farallones National Marine Sanctuary, according to the National Oceanic and Atmospheric Administration.

The advisory comes as seabird breeding is underway in the sanctuary, a 3,300-square-mile area of ocean and coastal waters located west of the Golden Gate Bridge and stretching as far north as the Mendocino County coast.

Nesting areas include the Farallon Islands, as well as mainland areas such as Point Reyes National Seashore, the Marin Headlands, Devil’s Slide Rock and the Sonoma Coast, NOAA officials said.

Activities near the San Francisco coast such as boating, tours and wildlife viewing can be disruptive to the breeding seabird colonies.

Parent seabirds are capable of flying away from their colonies if disturbed, potentially leaving eggs and chicks vulnerable to ravens and gulls. Repeated disturbances, even small ones, may result in entire colonies being abandoned, according to the NOAA.

Such disturbances can further harm already declining seabird populations.

Data retrieved from the sanctuary between 2014 and 2015 revealed the death rate for Cassin’s auklets, a small seabird which breeds in the sanctuary, had risen 320 times higher than normal. Scientists attributed the deaths to warming ocean waters, NOAA officials said.

“Seabirds are excellent indicators of changes in ocean conditions, an early warning system for scientists and managers of fisheries and marine protected areas,” sanctuary superintendent Maria Brown said in a statement.

“Many species have been reduced by human activities such as habitat destruction. Healthy colonies are our best are our best baseline for detecting the type and severity of changes that occur in our oceans,” Brown said.