COLUMN ONE : DDT Ills Still Haunt the Coast : Years after scientists thought threat from pesticide had ended, a dispute rages over whether a vast deposit off Palos Verdes is hurting wildlife.
The bald eagle collapsed on Santa Catalina Island on a spring morning, its body trembling and eyes twitching.
Accustomed to admiring the majestic birds soaring above the craggy cliffs, workers at a nearby quarry encircled its quivering body. They had seen the eagle, with its steel-like talons and wings spanning eight feet, strike down prey. But now the giant bird was too weak to struggle as the men swaddled it in a blanket and placed it in the back of a pickup truck.
Wildlife experts on the island found no wounds to heal, no diseases to treat. Mystified, they injected the eagle with nourishing fluids and drugs. The next morning it was dead.
A necropsy yielded a stunning discovery: The eagle’s body was riddled with DDT--including a lethal dose of 212 parts per million in its brain, far greater than any detected in the wild in decades.
Thirty years ago, birds around the world dropped from the sky with DDT poisoning. But this eagle died in 1993, not 1963, and biologists were astonished.
Nearly a quarter-century after the widely used pesticide was banned throughout the United States, disturbing new scientific evidence has emerged that Southern California’s marine environment suffers from a forgotten legacy of DDT.
A Times review of 3,000 pages of federal data gathered as evidence against the pesticide’s main manufacturer found that the food chain around Catalina and the other Channel Islands--from benthic worms and kelp bass to gulls, falcons and eagles--remains contaminated by high DDT concentrations. The islands’ bald eagles and peregrine falcons, both protected by the Endangered Species Act, suffer severe reproductive problems unparalleled in the nation.
Although the last drop of DDT in the United States was sprayed 23 years ago, the world’s largest deposit--100 tons of tainted sediments--remains sprawled across the ocean floor off the Palos Verdes Peninsula.
From 1947 through 1971, Montrose Chemical Corp., which manufactured the pesticide in Torrance, flushed several million pounds of DDT-contaminated waste into Los Angeles County sewers that empty into the ocean two miles off White’s Point, according to government estimates. The deposit covers 27 square miles of coastal shelf from the Port of Los Angeles up to Point Vicente.
The discovery of lingering ecological damage around the Palos Verdes shelf comes 10 years after most scientists had declared the DDT crisis over.
“We all thought the problem would go away. But we know the DDT is there, buried, and some of it, if not all, is not that far below the surface of the sediments,” said David Young, an environmental chemist who studied the deposit for a county-funded coastal research group from 1971 until 1980, when the area had begun to recover.
“This is a large reservoir that has the potential to bleed DDT into the food web for decades to come, leading up to birds and mammals and man.”
In a lawsuit filed against Montrose and six other companies, the federal government, led by the National Oceanic and Atmospheric Administration, was seeking several hundred million dollars in damages to help restore the area’s natural resources. In March, a federal judge abruptly dismissed the lawsuit after ruling the government had filed the 1990 suit too late. The Justice Department’s appeal seeking to have the lawsuit reinstated will be heard this fall.
The pesticide remains so pervasive and the ocean environment so enigmatic that scientists cannot prove conclusively that DDT found in the eagles, falcons and marine life comes from the immense Montrose deposit more than 20 miles away--and under several hundred feet of water.
Montrose and the other companies contend that they are being targeted by the government as a scapegoat with deep pockets, and that the real culprit could be DDT sprayed on Southern California farms in the 1950s and 1960s and washed off by rain.
Still, no other source of the pesticide has been identified, and although other locations, including the Columbia River, still suffer lingering damage from DDT residue on farmland, none of the ecological impacts seems as far-reaching, up and down the food chain, as on the Channel Islands and off Palos Verdes.
Effects of DDT
Sea gulls are safer feeding in urban dumps and falcons pick up less contamination feasting on pigeons in Downtown Los Angeles than foraging in the “natural” environment around the Channel Islands, according to reports by the government-hired researchers.
Even the coast of Mexico, long criticized for its pollution, seems to offer a healthier haven for breeding birds: Seven times more DDT was detected in gull eggs on Catalina and San Clemente islands in 1992 than on Mexico’s Gulf of California Islands.
One federal report--which Montrose vehemently attacks--predicts that the insidious ecological problems will endure for another century--and perhaps get worse before they get better--because the DDT is “slowly leaking” to the surface of the ocean floor. Although the bulk of the deposit has been buried beneath eight to 12 inches of sand, silt and treated sewage, hot spots remain exposed on the sea floor where the DDT-tainted sediment is consumed by fish and other aquatic animals.
“The stuff is still out there, it will stay out there for a long time and it’s accumulating in the food chain,” said Roger Helm, regional chief of the natural resource damage assessment team at the U.S. Fish and Wildlife Service, one of the agencies suing the companies. “Critters are dying and the effects are long-term.”
Although most creatures surrounding the Channel Islands are surviving the DDT accumulating in their bodies, many of their offspring die.
None of the estimated 50 bald eagles introduced to Catalina Island since 1980 has been able to reproduce. Scientists say it is because their eggs contain 10 times more DDT than the amount that causes fatal shell thinning. Even when the eggs are removed from nests, mended with glue and nursed in incubators, they rarely survive; only three of 17 eggs receiving such care hatched.
In an elaborate 15-year foster program, eaglets born at the San Francisco Zoo and in uncontaminated wild areas have been flown to Catalina and placed in nests next to DDT-damaged eggs. Mother eagles who lost their own chicks raised them as their own. Without such human manipulation, funded mostly through private donations, the island’s eagles would have vanished long ago.
“The worst find certainly has to be the complete reproductive failure of the bald eagle on Santa Catalina Island, but by no means is that the only alarming problem that has been detected by these studies,” said Daniel Welsh, the wildlife agency’s branch chief for natural resource damage assessment in California.
“With eagles, you’re talking about complete reproductive failure. With the others, you’re talking about impaired reproduction.”
Peregrine falcons are facing less severe reproductive problems, but their eggshells are believed to be the thinnest in the nation, perhaps in the world, because of DDT.
Fish near the deposit, particularly white croaker and kelp bass, also show high contamination and signs of impaired spawning and fertility, according to the government’s studies. State health officials say most humans face no danger, although people who eat the most contaminated fish--white croaker--caught in waters around San Pedro face a sharply elevated cancer risk. Commercial harvest of the fish is prohibited there and warning signs to anglers have been posted at piers.
“This confirms the problem is still with us out there at a very high level and will be here for some time,” said Ron Jurek, a state Department of Fish and Game biologist whose experience with DDT dates to 1970. “DDT has spread through the air, through the waters, through wildlife. It’s pervasive. And it’s not going away.”
In 1962, fear and outrage swept the country after author and biologist Rachel Carson decried DDT and other chlorinated pesticides as “elixirs of death” and described their toll in her best-selling book, “Silent Spring.” Banning DDT--used worldwide since the ‘40s--was a cause celebre of the fledgling environmental movement.
Montrose’s quarter-century of pumping waste water into the county’s sewers ended in 1971, and soon afterward the Environmental Protection Agency outlawed all uses of DDT in the United States.
By 1980, scientists had documented a remarkable rebound, particularly in animals that had hovered on the edge of extinction. Peregrine falcons, bald eagles and pelicans began to recover throughout much of the world. In Southern California, the DDT in mussels and sea lions dropped tenfold compared to a decade earlier.
But while most DDT-tainted waters continue to improve, time seems to be standing still off Palos Verdes, government scientists and other experts say. Contamination on the ocean floor and in some wildlife has remained almost the same for about a decade, and the recovery seems to have slowed or stopped at a level still dangerous to many animals, particularly eagles, some scientists say.
“Since the late 1970s, the levels haven’t gone down much at all,” said Robert Risebrough, a UC Berkeley research ecologist who in 1965 was the first to discover that fish off Southern California were highly contaminated with DDT.
“We didn’t realize the amounts coming out of the sediments would be keeping the levels so high.”
Since DDT is soluble in fat, it does not quickly break down or become diluted in the ocean. Instead, it binds to silt on the ocean floor and converts to DDE, which is equally as toxic and persistent.
DDE then clings to the bottom sediments, where tiny shrimp, worms and fish burrow down, stir it up and store the pollutant in their fat. Each step up the food chain, the concentration in an animal’s fat roughly doubles. Two parts per million in burrowing worms magnifies to 4 p.p.m. in a fish that eats the worms, and to 8 p.p.m. in a bird that eats the fish. At the top of the food chain, predators such as eagles and peregrine falcons absorb the biggest doses.
Female birds pass the residue to their eggs, which are so thin that they crack and lose water, killing the developing chick. A seemingly minuscule concentration (12 p.p.m. in an eagle egg) causes 15% thinning of shells, an amount that biologists say leads to extinction.
Unhealthy birds are thought to be a warning sign of an area’s poor ecological health. To many biologists, the symptoms on the Channel Islands mean the area is under severe environmental stress.
“It is definitely attention-getting,” said Mary Henry, a National Biological Service biologist specializing in the effects of contaminants on aquatic life. “Animals are built to have a lot of compensatory mechanisms, so when you’re seeing the things you are describing, it’s a pretty severe situation.”
Many biologists say the combination of so much DDT on the ocean floor and extreme amounts in marine life and birds is persuasive evidence that the ocean deposit is to blame.
But scientists hired by Montrose say that DDT in Channel Island eagles and falcons could be coming from virtually anywhere and that the government has refused to look for other sources, such as farm runoff.
The Los Angeles Basin’s farms and yards were sprayed with an estimated 15 million pounds of DDT in the 1950s and 1960s, and rain could be washing residue off the soil, especially from the farm-rich Santa Clara River Valley. Bald eagles along the Columbia River in Washington and Oregon and peregrine falcons in California’s Sierra Nevada still suffer DDT-inflicted eggshell thinning, a sign that farmland sprayed decades ago remains capable of poisoning wildlife.
“What is sitting out there in the ocean is a very small amount of the total DDT produced and used as an insecticide,” said Caltech environmental engineering science professor John List, hired by Montrose to head its technical team.
“It seems to me that it is a ludicrous position [to blame the Montrose deposit],” he said. “It is an unresolved question--where do the eagles on Catalina get their DDT from?”
With its rugged, steep cliffs 26 miles off the coast, Catalina offers the best breeding habitat left for bald eagles in Southern California. They vanished from the island in the 1950s, with many scientists pinning much of the blame on DDT. Finally, in 1980, experts thought the threat had waned, so they brought eaglets from nests in Northern California and Washington to Catalina.
“Everything seemed fine. The birds were released as youngsters and they survived reasonably well and started laying eggs,” Jurek said. “But the surprise was, the eggs were not hatchable in most cases.”
Within seven years, at the age when they begin breeding, all the transplanted eagles had amassed enough pesticide so that none could reproduce. From 1989 to 1993, their eggs contained “some of the highest DDE values ever reported for bald eagles,” according to a report by David Garcelon, a wildlife biologist who has directed the Channel Island eagle reintroduction program since 1979.
“If [the contamination continues the way it is now, I wouldn’t expect the bald eagles to breed on their own, given the levels in the [Palos Verdes] food chain.”
Bald eagles fly only a few miles from Catalina to feed, and an extensive study by Garcelon found that 86% of their diet is fish, which contain relatively low amounts of DDT. But they also occasionally consume birds and sea lion carcasses that contain extraordinary amounts that “completely preclude natural reproduction” in eagles, he reported.
DDT Source Debated
Garcelon said in an interview that he is convinced the contamination in the eagles’ prey comes from the Palos Verdes deposit.
“Look at the preponderance of evidence,” he said. “There isn’t anyplace where the [DDT] levels in prey species are as high as they are here.”
Although only one adult eagle has apparently died from DDT in recent years, Garcelon fears that the 10 to 14 others breeding on Catalina also might be building up lethal loads.
“It is not just something that this bird ate a week or month before it died,” he said. “It accumulated over its lifetime.”
For peregrine falcons, which neared worldwide extinction in the 1960s because of DDT, the Channel Islands are “a conspicuous exception to the widespread trend” of recovery, said Lloyd Kiff of the Western Foundation of Vertebrate Zoology.
Surprisingly, the islands’ peregrine falcons are just as contaminated as they were in 1969 before DDT was banned, according to a report by biologist Walter Jarman of UC Santa Cruz, who has studied the pollutant’s effect on peregrines for 15 years. The birds, known for their fast flight and dramatic dives for prey, are probably feeding on contaminated gulls and fish.
“It is likely the degree of [peregrine] eggshell thinning now observed in the Channel Islands is the highest in the world,” wrote David Peakall, a toxicologist specializing in the ecological effects of pollutants at King’s College in London.
About 83% of the eggs collected from the Channel Islands between 1988 and 1993 exceeded the threshold of thinning likely to lead to extinction, compared to 6% in San Francisco Bay, 11% around Los Angeles and 43% in northernmost California, according to Kiff’s data.
But unlike eagles, there is both good news and bad news for the Channel Islands’ peregrines: Most of 10 observed pairs produced a chick at least once between 1992 and 1994--a vast improvement over the breeding failure of the 1960s but fewer than normal for the birds, which usually lay four eggs per year.
Also, while the amount of shell thinning for the islands’ falcons is extraordinary, the amount of DDT in them is not, Jarman reported. In the Sierra Nevada, peregrines contain almost as much of the pesticide in their eggs, probably because they pick up residue from foraging on Central Valley farms, he said.
Brian Walton, coordinator of the UC Santa Cruz predatory bird research group, said peregrines in some scattered spots still suffer reproductive problems because of DDT, but the effects are not as extreme as on the Channel Islands.
“There is just so much potential for a peregrine or its prey to run into DDT residual in Southern California and the Big Sur coast,” he said. “A very young peregrine may not have a high level of pesticides, but by the time they start breeding, they have accumulated so much in their bodies. The older ones still have high levels and still have severe eggshell thinning.”
Brown pelicans, another endangered species, were nearly wiped out in the 1970s by DDT. Although they have recovered remarkably, they still suffer eggshell thinning and do not produce enough young to be deemed a stable population.
UC Davis pelican expert Franklin Gress reported that a decline in anchovies, their main food supply, is the primary cause of the problem, but that DDT is a likely contributor. “A once-acute [DDT] problem appears to have become a low-level chronic one,” he wrote.
In fish, the ovaries of white croaker collected from the Palos Verdes shelf in 1985 and 1988 contained high amounts of DDT that seemed to impair spawning, and 70% of kelp bass exposed to high concentrations in laboratory tests could not lay hatchable eggs.
Scientists, though, do not know what effect, if any, DDT has on those two fish populations because both white croaker and kelp bass seem abundant off Palos Verdes.
DDT’s effects on marine mammals also are poorly understood, although some researchers suspect that it results in aborted sea lion pups and immunity problems in dolphins. In the 1980s, bottlenose dolphins and sea lions that washed ashore in Los Angeles County had higher DDT concentrations than those elsewhere in the United States.
Risebrough, one of America’s foremost experts on DDT, called the lingering effects a local phenomenon around the Channel Islands, comparing the ecological damage to a few trees dying in a healthy forest. While a few individual animals are sick, the ecosystem as a whole will survive, Risebrough said.
In 1965, Risebrough’s discovery of extreme amounts of DDT in Southern California anchovies--which nearly led to the extinction of brown pelicans--contributed to the EPA’s decision to outlaw the chemical. Today, though, he rejects doomsday predictions. He concedes that the eagles on the Channel Islands are so contaminated that they may always need human help to produce young, but he believes that the peregrine falcons, pelicans and other species will probably rebound.
“With the documented exception of the eagles, everything else is such a vast improvement,” said Risebrough, who is not working for either side in the federal lawsuit. “A number of pairs of peregrines are producing successfully on the Channel Islands, which is a big change compared to when none could do it.
“The peregrines will certainly continue to be affected to some extent,” he said, “but my hunch is overall they will make it, because their comeback has been spectacular everywhere else.”
The government’s researchers, however, predict that the ecological damage will worsen in coming years and continue into the next century.
The major reason for the glum forecast is that the county is expected to improve treatment of sewage discharged at White’s Point, which means fewer solid materials will cover Montrose’s DDT deposit. At the same time, burrowing creatures, such as shrimp, and strong storms could keep stirring up the sediments and bring more DDT to the surface.
Because of this blend of physical and biological forces, the surface contamination around White’s Point will exceed today’s concentrations around 2015 and increase through 2030, until dropping tenfold around 2100, according to the U.S. Geological Survey and its consultants, which based their projection on a computer model.
Other government researchers reached the exact opposite conclusion just a few years earlier. The EPA in 1989 reported that “the threat of re-exposure of the bulk of the DDT-contaminated sediments is minimal.”
List, the Caltech professor hired by the chemical company, contends that the DDT deposit will be buried deeper with time, not eroded as the government contends. The government’s projection is based on a “completely unrealistic” scenario, List said, because it is based on burrowing creatures that do not exist in great numbers off Palos Verdes and a projection that currents are not carrying sediments that would bury the waste.
He says his research shows that DDE, the breakdown product of DDT, has a 10- to 12-year half-life in a low-oxygen environment similar to the ocean floor, which means its volume is dropping by half every decade or so.
“The stuff is disappearing and decaying,” he said. “Not only that, it is getting buried at a rather substantial rate. . . . This site has been depositional for 10,000 years. Why is it suddenly going to become erosional?”
Many scientists, though, still believe that DDT and DDE are virtually indestructible. If the tons of waste were degrading as fast as List says, wouldn’t the threat already be gone? Ocean dynamics remain so inexplicable that most scientists can only speculate about what occurs deep below the surface.
Yet in the skies above, the return of the nation’s noblest birds now seems a premature symbol of resurrection for the Channel Islands.
In 1981, a 7-week-old bald eagle, born at Northern California’s Shasta Lake, arrived on Catalina Island via artificial wings. Named Shasta, the female chick was one of the first of almost 50 airlifted to the island after the DDT ban.
At the age of 12--midlife for an eagle--it dropped mortally ill beside the quarry carrying a deadly load of DDT in its liver and brain. Its death was a crushing blow to Garcelon, who had brought the eaglet to Catalina and closely followed its progress.
“This was a resident bird that had been around a long time--one of those you look fondly on, like, ‘There’s old Shasta. She’s out building another nest,’ ” he said.
“I certainly wasn’t fully prepared for the thought that these birds may be killed directly by DDT. I just never thought that would happen.”
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Legacy of a Chemical
Sea life around Catalina and the Channel Islands still suffers the ill effects of DDT, the pesticide banned in 1972. Although DDT poisoning has eased around the world, eagles and pelicans here have trouble reproducing and contamination is high in some fish. The federal government and many scientists blame a huge deposit of DDT dumped no the ocean floor off the Palos Verdes Peninsula before the ban.
* Birds and mammals that feed on fish and carcasses have the highest levels of DDT. Eagles fail to reproduce on islands and other birds are affected by eggshell thinning.
* Fish that feed on bottom dwellers absorb high concentrations of DDT that impair spawning.
* Creatures on sea floor feed on DDT-tainted sediment and become contaminated.
The food chain
1) Eagles, falcons, brown pelicans, sea lions
2) White croaker, kelp bass
3) Worms, shrimp, crabs
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