Federal study shows that fish caught off L.A. County still contain the world's highest levels of the pesticide 35 years after it was banned.
By Marla Cone, Times Staff Writer
January 28, 2007

Many fish caught off Los Angeles County still contain extremely high levels of DDT, a sign that anglers and consumers remain at risk and that the ocean's ecosystem may be far from recovery 35 years after the pesticide was banned.

Newly released data from a federal survey indicate that fish caught in the area contained the world's highest-known DDT concentrations. Among 1,200 fish caught from Ventura to Dana Point, 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, collected primarily in 2002, offer the most comprehensive look at the scope of contamination from a 100-ton deposit of DDT that still covers several square miles of the ocean floor decades after the pesticide flowed into county sewers beginning in the late 1940s.

More recent annual sampling by Los Angeles County, far less extensive than the federal survey, suggests that the DDT levels in fish may be improving but still far exceed safe levels.

In response to the new federal findings, the state's environmental health agency is reevaluating the risks of eating locally caught fish, which could result in updates to a health advisory and a commercial fishing ban that have been in effect since 1991.

Fish from local waters are often eaten by recreational anglers and subsistence fishermen, who catch them from piers and boats. Some highly contaminated white croaker is still showing up in a handful of Asian markets in Los Angeles and Orange counties.

The levels "are lower than what we historically have seen" in the 1970s and '80s, "but they are still levels of concern to us," said Sharon Lin, a Superfund project manager at the Environmental Protection Agency's San Francisco office.

Banned in the United States in 1972, DDT is classified as a probable human carcinogen and has been linked to liver disease, reproductive damage and altered hormones in lab animals and wildlife. So much DDT remains in bald eagles on Santa Catalina Island that their chicks die unless the weakened eggs are removed from the island to hatch.

The data from the federal survey by the National Oceanic and Atmospheric Administration and the Environmental Protection Agency suggest that there has been no improvement since the late 1980s, when the last regional fish survey was conducted. Some scientists have long theorized that the DDT on the ocean floor has been breaking down into less-toxic compounds and would soon disappear from marine life.

Yet at least through 2002, when most of the fish were caught for the survey, the DDT - as well as industrial compounds called PCBs, or polychlorinated biphenyls - remained a threat to people eating white croaker and several other species of local fish, particularly in waters off the Palos Verdes Peninsula and in San Pedro Bay.

"Things have not changed a whole lot in the last decade or so," said David Witting, a National Oceanic and Atmospheric Administration fish biologist who directed the survey. "The biggest concern is still lower Santa Monica Bay, Palos Verdes Shelf and much of San Pedro Bay. The species that is consistently the most highly contaminated is still white croaker."

Manufacturing pesticides at a plant near Torrance from 1947 to 1971, the Montrose Chemical Co. released about 2,000 tons of DDT into county sewers, which empty into the ocean via an outfall off White Point on the Palos Verdes Peninsula. The pesticide adheres to sediment and continues to seep into marine creatures.

Mark Gold, executive director of the Santa Monica-based environmental group Heal the Bay, said the scope of the contamination revealed by the new fish data was worse than he thought.

"Not only have things not improved for contaminated fish off Palos Verdes, but this data shows that the concern is more far-ranging than we originally thought," Gold said. "Hot fish off Palos Verdes is no surprise, but we're finding hot fish all the way from the Redondo Pier throughout San Pedro Bay, and it's for a wide variety of species, not just the bottom-dwelling ones."

The goals of the survey are to update health advisories on which fish are unsafe to eat and to help the EPA decide whether to attempt to seal off the ocean deposit with a thick cap of sand, which could cost tens of millions of dollars.

In addition to white croaker - which feeds on the ocean floor - kelp bass, barred sandbass, scorpionfish and rockfish also contained some high levels above half a part per million.

The highest readings were in white croaker from the middle of San Pedro Bay - about 1.5 miles offshore in an area called Horseshoe Kelp - and near the Cabrillo Pier, half a mile beyond the breakwater. The average at Horseshoe Kelp was 3.2 parts per million of DDT, with one fish reaching almost 13 ppm.

Generally, 10% of the white croaker caught in San Pedro Bay were highly contaminated while the rest had lower levels. The "hot" ones probably migrated from the DDT deposit off White Point, Witting said.

Waters at the southern end of Santa Monica Bay, between Redondo Beach and Palos Verdes Estates, also had some highly contaminated croaker and barred sandbass. Pacific mackerel, opaleye and jacksmelt had the lowest concentrations.

All fish caught off Ventura County - even white croaker - had little contamination, and low levels also were found in fish off Long Beach, Seal Beach and Huntington Beach.