September 30, 2008

Dead Sponges Fouling Calif. Bay

The gunk fouling parts of Mission Bay south of San Diego has proved to be dead sea sponges, health department officials said.

Parts of the bay were closed to swimming and diving because of the apparent pollution and tests that showed a high bacteria count, the San Diego Union-Tribune reported Tuesday.

When the blobs began coming ashore on beaches on Sept. 17, investigators thought that human sewage was illegally being dumped in the bay. Clay Clifton of the San Diego County Department of Environmental Health said that the gunk has now been determined to be decaying sponges.

The beach closings ended Friday.

Sea sponges are among the most primitive of multi-celled animals. They are essentially large groups of cells held together in a gell and feed by pumping water through their bodies, filtering out food material.

Keith Merkel, a marine biologist hired as a consultant by the city and county, said he does not know why sponges are dying in large numbers. He said that in two decades doing research in Southern California he has never seen such a big die-off.