Endangered Species Act Protection Sought for California's Ashy Storm-petrel, A Declining Seabird
SAN FRANCISCO, Calif. — The Center for Biological Diversity filed a scientific petition with the U.S. Fish and Wildlife Service October 15 to protect the ashy storm-petrel under the federal Endangered Species Act.
The ashy storm-petrel (Oceanodroma homochroa) is a small, smoke-gray seabird that nests and forages almost exclusively on the offshore islands and waters of California near San Francisco, Los Angeles, and San Diego. These waters are heavily impacted by development, including offshore energy terminals, shipping traffic, commercial fishing, and pollution, as well as by global warming. Faced with these multiple threats, the seabird has experienced sharp population declines in recent decades. The largest colony of ashy storm-petrels decreased by over 42 percent in 20 years, prompting the World Conservation Union and BirdLife International to list the species as endangered.
"The ashy storm-petrel is a barometer of the health of California's coastal waters," said Shaye Wolf, a biologist with the Center for Biological Diversity who has studied the ashy storm-petrel as well as the effects of ocean climate change on California's seabirds. "The declines we've observed in its numbers and breeding success are indicative of troubling changes we're seeing throughout the ocean off the West Coast."The marine ecosystem off the California coast is changing due to global warming, resulting in warmer, less productive waters with less food available for seabirds like the ashy storm-petrel. Also, ocean acidification caused by the ocean's absorption of excess carbon dioxide may lead to declines in the storm-petrel's prey. Sea-level rise from global warming threatens to drown important breeding habitat for the bird in sea caves and on offshore rocks.
Our fossil-fuel demand is also spurring the proliferation of proposed offshore liquefied natural gas terminals off California's coast, which not only increase pollution but also add artificial lighting at night. "Artificial light attracts nocturnally active seabirds like the ashy storm-petrel like moths to a flame, and the effects can be devastating," said Wolf. Instead of going about their natural foraging and breeding activities, storm-petrels will continuously circle or collide with lighted structures at night, leading to exhaustion, injury, and even death.
The storm-petrel faces a variety of other threats at sea and on its island breeding colonies, including (1) the threat of oil spills near breeding and foraging hotspots that could decimate the population in one fell swoop; (2) ingestion of floating plastic pieces that can lead to starvation of adults and the chicks that are fed these plastics; (3) lower breeding success caused by eggshell thinning from persistent pollutants like DDT and PCBs that continue to affect southern California seabirds; and (4) depredation by introduced predators such as rats on the bird's island breeding sites.
"Protecting the ashy storm-petrel under the Endangered Species Act will not only provide critical protections to this unique seabird," noted Wolf, "but also enhance the health of California's coastal ecosystem as a whole."