Vast Red Tide Raises Questions

Residents in the Ventura Keys are searching for answers about a red tide, or what scientists call an algae bloom, that is proliferating in the water behind their homes in this marina neighborhood.

The thick growth of algae, which can kill marine life, naturally occurs in June and July. This year the amount has been larger than residents and harbor officials have seen in at least 15 years.

Many residents say they are concerned the algae are toxic and could harm them or local marine life.

“If they can put a man on the moon, you’d think they could clean up this stuff,” Ventura Keys resident John Trahan said.

The phenomenon has nothing to do with tides and are not always red. It happens when concentrations of single-celled aquatic plants called phytoplankton grow dense enough to discolor the water, said William Cochlan, a research scientist at San Francisco State University.

A test done Thursday of water samples from near the Ventura Pier showed that although there are red-tide variety phytoplankton off Ventura’s shores, they are not toxic, said Gregg Langlois, who runs the statewide plankton monitoring program for the California Department of Health Services.

Don Davis, waste-water superintendent for Ventura, said water in the harbor and along Ventura beaches is constantly tested, and although the city’s labs are not equipped to test for toxins found in algae, the city tests for disease-causing agents.

Reports have proliferated of unusually large red tides along the California coast in recent years. Cochlan cited one 1995 bloom stretching from Baja California to Monterey Bay, the largest reported since 1902.

While the red tide-producing phytoplankton are not usually toxic, Cochlan said they still can kill marine life because as they die by the billions they deplete the water of oxygen and fish suffocate.