Flying over California’s coastal waters in the darkness of a new moon night, the ashy storm petrel, a nocturnal seabird with smoky-grey plumage, forages for small fish and plankton to feed its fledglings. Once an abundant inhabitant of the waters of the continental slope along the shores of California and Northern Baja California, Mexico, the ashy storm petrel has been dwindling in numbers in the past few decades. Now only about 5,400 breeding birds remain. The Center for Biological Diversity, a crusader in the plight of the petrel, filed a federal lawsuit April 1 against the U.S. Fish and Wildlife Service (USFWS) for illegally delaying the process of determining whether the status of the ashy storm petrel warrants federal protection under the Endangered Species Act.
Alarm bells have been sounding for years, said Shaye Wolf, a biologist for the Center for Biological Diversity. “We need to stop the decline of these birds before it gets too far to save them.”
Pelagic birds, the ashy storm petrel only come ashore to breed, nesting in the rocky crevices of six offshore islands and several offshore rocks. Almost half of the global breeding population nests on the Channel Islands and the other half on the South Farallon Islands. As nonmigratory birds with a small global population, ashy storm petrels are especially vulnerable to changes that occur within their highly restricted area of habitation.
Rising water temperatures and ocean acidification from global warming continue to decrease the birds’ food supply in the California coastal waters. Oil contamination and chemical pollutants, such as DDT, decrease breeding success and increase mortality. Since ashy storm petrels nest on remote islands and forage for food at night, artificial light pollution from commercial and recreational boats around the islands makes them more susceptible to avian predators that are not normally active in the dark. Introduced species on the islands have also increased the predation of these birds. Long-term persistence of the ashy storm petrel requires rapid action.
Protection of the ashy storm petrel under the Endangered Species Act would lead to regulation of activitiesthat threaten the survival of the birds at the island breeding sites and in the waters surrounding the sites. These measures would benefit other species as well. “Reducing the threats to the ashy storm petrel will also increase the health of California’s coastal ecosystem as a whole,” Wolf said.
In the federal court case, the center expects to decide on a date with the Department of Justice to make a decision about the endangered status of the ashy storm petrel. The original date for the decision was October 16, 2008.