Posted by on June 05, 2005 at 09:39:23:
In Reply to: Red tide - King Harbor posted by jlyle on June 04, 2005 at 18:04:33:
Experts say algae bloom and its rusty aftereffect are killing shallow-water fish but not sea lions -- or humans.
One of the worst "red tides" to hit the Los Angeles County coastline in recent years has left boat cleaners without work, swimmers stranded on beaches and scads of fish dead.
Red tide, a naturally occurring ocean phenomenon, is caused by excessive growth of algae, which turns the water brownish-red about once a year. Since it showed up May 28, red tide has kept many beachgoers confined to the sand and made it impossible for divers who clean the underside of boats to see through the murky waters.
The overabundance of algae also contributed to the deaths of hundreds of fish in King Harbor Marina in Redondo Beach on Wednesday. The fish, starved of oxygen, floated to the surface and left a rancid smell in the air for days.
"The smell was so bad that I had to stay inside," said Frankie Greco, 29, of Lomita, who spent Wednesday night in his boat docked at the marina. "I shut all the windows and doors and lit some candles."
The rapid growth of red algae in recent weeks has caused ocean bacteria, which feed on the tiny plants as they die, to multiply exponentially. As the bacteria use up limited supplies of oxygen in shallow waters such as King Harbor Marina's, many smaller fish such as garibaldi and red sea bass suffocate.
"If you're a fish living in the harbor, you're out of luck," said Giancarlo Cetrulo, director of the Los Angeles Conservation Corps' S.E.A. Lab in Redondo Beach.
Although the dead fish -- easy prey for seagulls and crabs -- were all eaten by Friday, the red tide might not clear for weeks.
Michael Aaker, dockmaster at King Harbor Marina, said this year's red tides were among the worst he has ever seen.
"This is the first time I've seen it kill so many fish," said Aaker, who has worked at the marina for 15 years.
Despite the off-putting color of the ocean water, the algae are not dangerous to humans.
"It doesn't look too appetizing, but it's not a concern to swim in it," said Bob Mosby of the Los Angeles County Public Health Department. "Someone would have to drink so much seawater to be poisoned (by the red algae) that they would die from drinking the seawater first."
Still, the murky color has many would-be swimmers assuming they should stay on dry ground.
"It freaks people out," said beach lifeguard A.J. Lester. "Everyone thinks the water is polluted."
The most severe red tide on record occurred last year, when algae "bloom" -- the term for a sudden surge in algae growth caused by favorable weather and ocean conditions -- tainted ocean water for more than a month, Cetrulo said.
The red tide phenomenon also has been implicated in the recent deaths of beached sea lions, but experts say a separate act of nature is at work.
At least eight sea lions have been poisoned by a brain toxin -- domoic acid -- produced by algae; these algae, however, are different from those that cause red tide, said Peter Wallerstein, a marine rescuer for the Whale Rescue Team.
The algae killing the sea lions are eaten by fish, which pass the poison up the food chain to the sea lions. The toxin leads to seizures and paralysis in sea lions, while the fish are unaffected.
The simultaneous appearance of the red algae and the sea lion-killing algae is coincidental.
Despite the headaches caused by algae proliferation, it is a way of life for ocean lovers like John Gusstafsom, who visits King Harbor Marina regularly.
"You have to deal with it," said Gusstafsom, 29, of Redondo Beach. "It's part of nature."