LOS ANGELES – Fish caught off Los Angeles County's coast still contain high levels of banned DDT decades after a manufacturer dumped tons of the pesticide into sewers, creating a toxic plume on the ocean bottom.

There has been no improvement since the last regional fish survey was conducted in the late 1980s, according to a federal survey based on data collected mainly in 2002 but only recently released.

Of 1,200 fish caught off the county coast, white croaker off San Pedro and the Palos Verdes Peninsula were the most highly contaminated. Fish off Orange County and areas north of the Redondo Beach Pier had low concentrations.

The data has prompted the state to reevaluate the risk of eating the locally caught fish. There already is a commercial fishing ban in the contamination area.

The levels “are lower than what we historically have seen” in the 1970s, “but they are still levels of concern to us,” said Sharon Lin of the U.S. Environmental Protection Agency, which conducted the survey along with the National Oceanic and Atmospheric Administration.

DDT was banned in the United States in 1972 after it was classified as a probable carcinogen, and has been linked to liver disease and reproductive damage.

Montrose Chemical Co. manufactured DDT from 1947 to 1971, releasing about 2,000 tons of the pesticide into sewers that flowed to the ocean. DDT adheres to sediment and continues to infect marine creatures. The contamination covers several square miles of the ocean floor near the Palos Verdes Peninsula.