A morass of toxic ocean algae swamping sections of California's coastline has sickened hundreds of birds, sea lions and dolphins, environmentalists said Friday.
Animal protection agencies have reported a sharp increase in fatalities and illnesses amongst wildlife because of the thick "blooms" of algae that have appeared in the state's coastal waters.
The International Bird Rescue Research Center in San Pedro compared the environmental impact of the algae to an oil spill, saying in a statement that several species of animals had been affected.
"I have been doing this work for 35 years and I have never seen anything like this as far as the number of species affected, other than an oil spill," IBRRC director Jay Holcomb said.
"We have very serious concerns about what is happening to seabirds, and how it may affect populations."
Animals are being sickened by domoic acid, a naturally-occurring microscopic algae. Birds and sea mammals ingest the toxin by consuming fish and shellfish which consume the algae.
Although algae blooms appear every year, environmentalists say this year's crop is unusually thick and appears to be carrying higher concentrations of the acid, making it deadlier than normal.
Exact numbers of the animals were not immediately available, but individual agencies reported dozens of cases.
Debbie McGuire, the director of the Wetland and Wildlife Care Center in Huntington Beach, south of Los Angeles, told AFP her center had seen 78 deaths from the algae since Sunday, with 11 more animals still being treated.
"We've had outbreaks before but it just seems to be a little bit more potent this time around," McGuire said.
Most concern focused around California brown pelicans, an endangered species, McGuire said. Symptoms of birds poisoned by domoic acid were disorientation, head bobbing, she added.
"We had one report of a bird sitting in a car park of a supermarket when of course they should be at the beach or in the ocean," McGuire said.
Holcomb said domoic poisoning caused birds to have seizures while flying, causing them to drop out of the sky. He said he believes many seabirds suffer seizures at sea and drown, and that the death toll could be far higher.
Emily Wing, a director at the Pacific Marine Mammal Center in Laguna Beach, southern California, 50 miles (80 kilometers) south of Los Angeles, said 22 animals, including a dolphin, had been treated at the center.
"So far 11 of the animals brought into the center have died," Wing told AFP, adding that most of the cases involved pregnant adult female sea lions.
"Because they are pregnant they are consuming more food, so they have higher concentrations of the toxin in their system," she said.
"In several cases it has been too late for us to treat them. A few animals have died on the way here."
An outbreak of domoic-acid carrying algae in 2002 and 2003 in California killed or sickened more than 1,000 sea lions and around 50 dolphins, according to the National Marine Fisheries Service.