Saturday, April 28, 2007

Deadly algae killed dophins and seals

Hundreds of seals, dolphins and marine birds have been killed in recent weeks by an upsurge in a sea toxin linked to overfishing, the destruction of wetlands and pollution, the Los Angeles Times reported Friday.

The report was triggered by the sight on local beaches of sick and dead pelicans, sea lions and dolphins. Scientists believe that the toxin, domoic acid, is produced by microscopic algae that are flourishing because of overfishing, marine farming and other man-made causes.

'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,' said Jay Holcomb, director of the International Bird Rescue Research Centre in San Pedro.

Domoic acid, which accumulates in shellfish and fish and is then passed on to the birds and animals that eat them, has occurred each spring over the past decade as ocean water warms and algae bloom. But this year's algae are 'especially virulent,' according to the rescue centre.

Dead birds, including grebes, gulls, cormorants, American avocets and loons, began littering Southern California beaches in March while dozens of sea lions, dolphins and even whales have also washed ashore in recent weeks.

Scientists believe the explosion of harmful algae causes toxins to move through the food chain and concentrate in the dietary staples of marine mammals, causing poisoning that scrambles the brains of the animals and leads them to wash ashore.

Quick "Facts about Dolphins"