SAN DIEGO -- Heads turn on Pepper Park Fishing Pier as one of the men gives a shout, and a flash of silver breaks through the water, wriggling on the end of his line. Yet this meal, caught fresh from San Diego Bay, comes with a risk to one’s health.

"We have a lot of contaminants that are out there that are very persistent," said Katie Zeeman, a toxicologist with the U.S. Fish and Wildlife Service.

"This one's small kind of, but it's still good," said Israel Juarez as he held up his catch.

A large yellow sign warns of the dangers in four languages: “Fish from the bay may contain chemicals believed to cause cancer and birth defects." The warnings are posted all around the bay. But many still fish despite the warnings. For some fishing is a necessity, while others shrug off health concerns.

"Sometimes I make them into tacos," said Juarez.

"The one you hear about a lot in San Diego Bay is PCBs," said Zeeman.

Polychlorinated biphenyls, or PCBs, are man-made chemicals that were once widely used in items such as plastics and electrical equipment. Cancer, behavioral and immune system problems have all been linked to PCBs. They were banned in 1976 because of their toxicity and persistence; they remain in the environment for an extremely long time, growing in concentration as they move up the food chain.

"Even if you use them for a short time, they're there for so long," said Zeeman.

Zeeman has been studying contaminants for 25 years, including a recent study on seabirds in South San Diego Bay whose eggs failed to hatch.

"That's a crushed egg -- indicates that they've got thin eggshells," said Zeeman.

She said she suspects they're thin because the fish the birds eat are contaminated from the toxic sediments on the bottom of the bay. She found PCBs, along with DDT and other toxins in the fish and in the thin eggshells.

"The contaminant levels are high enough that we would like to figure out if they're causing this crushing," said Zeeman.

If that proves to be true, it would be more evidence that PCBs are still a serious threat 30 years after they were banned.

"It’s a classic lesson that it's easier to prevent the problem than it is to fix it once it's been introduced into the environment," said David Gibson, executive officer of the San Diego Regional Water Quality Control Board. It’s the agency responsible for monitoring local water bodies, including the bay, and ordering cleanups.

Past studies have shown San Diego Bay as one of the country's most toxic.

"Some sediments that are contaminated, the best thing to do is actually to leave them there. They're deep enough that they won't become disturbed and release their toxins again. In some cases, what you have to do is go in and dredge," Gibson explained.

The water board is expected to make a landmark recommendation on Dec. 22 to dredge one toxic hot spot along the shipyards south of Coronado Bridge, on the eastern shore of the bay: 60 acres of sediment. It was first proposed four years ago, but got stalled while documents were produced and mediation begun. Now the board hopes to bring the cleanup order back on track.

Tuesday's recommendation will revise the four-year-old cleanup. After a public comment period, a hearing will be held to determine the final cleanup order. The board hopes the final order will come in mid to late 2010.

In past reports, the water board determined these groups as the responsible polluters of the shipyard sediment site: National Steel and Shipbuilding Company, BAE Systems, Marine Construction and Design Company and Campbell Industries, Inc., the city of San Diego, San Diego Gas and Electric, and the U.S. Navy.

"The overall goal is to take these pieces of the bay one at a time as best as we can do and as best as we can afford it as a society and clean them up," said Gibson.