County Warns Against Eating Local Shellfish

Overpopulation of the San Diego area is the prime suspect in the contamination of mussels, clams, scallops and oysters that led the county to issue an advisory not to eat bivalve shellfish picked up along the county’s coast.

“We just have too much sewage, too much runoff, too many pets that are putting their waste on lawns, and all this accumulation is finally coming home to roost,” said Gary Stephany, deputy director of the county’s Environmental Health Services.

Stephany said no reports of illness because of shellfish contaminated by fecal coliform bacteria have been received but such illnesses often go unreported since the side effects are similar to a common stomach flu. Side effects include a mild to severe upset stomach and diarrhea, Stephany said.

The advisory, issued Wednesday, does not apply to shrimp, crabs, lobsters or other crustaceans, nor does it apply to commercially sold shellfish in restaurants or markets. State and federal authorities inspect commercial shellfish, while crustaceans have feeding systems different from bivalve shellfish, Stephany said.

Seafarms West in Carlsbad, the only U.S. commercial grower of bivalve shellfish south of Santa Barbara, has been filtering and disinfecting the water used by its shellfish since the state last June found high levels of fecal coliform bacteria, according to state health officials.

But the finding at Seafarms West prompted county health officials to test mussels along the rest of the county’s coast for fecal coliform, a bacterium found in sewage.

The county sampled mussels from Oceanside to San Diego Bay in November. Because bivalves have similar feeding systems, county officials presume clams, scallops and oysters are also contaminated. It was the first such test ever conducted by the county because of its high cost.

The state then conducted tests by putting uncontaminated mussels in San Diego County waters and retesting them. Those tests in December verified the county’s finding of high levels of bacteria in the ocean.

Stephany said the county will step up its testing and confer with sewer agencies “to map out a plan to find out exactly what the cause is.”

“The best thing that we can do is reclaim the sewage and the water and up the treatment of sewage for irrigation purposes, and maybe save a lot of the water that we do have,” Stephany said.

Stephany said bacteria levels are not high enough to hurt swimmers.

“It’s still safe to swim, from our standpoint,” he said. “An occasional gulp of sea water if you’re jumping waves won’t make a difference.”

Officials at San Diego’s Point Loma Waste Water Treatment plant agreed that “the beaches have always been safe for body contact.”

Frequent tests of the bacterial water quality at nine shore stations from Imperial Beach to Ocean Beach have consistently shown “excellent water quality,” especially in the beach areas, said Patty Vainik, senior marine biologist at the city’s treatment plant.

But the waste water in the ocean comes from many sources, not just sewage treatment plants, Vainik said.

“The more we pave Southern California, every bit of rain that falls, every bit of irrigation that we do will be washed into the ocean, the bay and the estuaries,” Vainik said.