BEIJING, Dec. 3 (Xinhaunet) -- There is no oil spill in sight so scientists blame a red tide of marine algae for the hundreds of dead or injured seabirds that have washed up on the beaches of Monterey Bay, California, in recent weeks.

About 600 birds have been found stranded on beaches in Monterey and Santa Cruz counties since a large rust-colored algal bloom began circulating in the bay about three weeks ago, scientists say. About 70 of the birds have died, while 530 have been taken to wildlife rescue centers, said Michael Ziccardi, director of the Oiled Wildlife Care Network.

Algal blooms are increasing in frequency and intensity around the world, a trend scientists say may be connected to climate change as well as the use of pesticides and fertilizers.

The affected birds include loons, pelicans, western grebes, northern fulmars and surf scoters, said Dave Jessup, a veterinarian with the state Department of Fish and Game. Fish and marine mammals do not appear to be affected.

Officials initially believed the birds were victims of the San Francisco Bay oil spill that has killed or injured at least 2,800 birds. But tests found that the sticky, yellow substance found on the Monterey Bay birds was not petroleum or vegetable oil.

Scientists now believe the birds were injured by a protein that sticks to the birds' feathers and disrupts their ability to stay dry and warm, forcing them from the water where they live and feed.

Researchers believe the protein is produced either directly or as a byproduct of the red tide, which is common in Monterey Bay this time of year.

The algal bloom likely will stay in Monterey Bay and continue injuring birds until a major weather system pushes the red tide out, Jessup said.

(Agencies)