Deformities in Wildlife at Second Site Suggest Wider Water Poisoning

Avian birth deformities similar to those that devastated bird populations at the Kesterson National Wildlife Refuge and forced its closure have been found in wildlife at another site 100 miles to the south, federal officials report.

Preliminary results of a yearlong study by the U.S. Fish and Wildlife Service found that the rate of deformities among some birds at the second site is even higher than at Kesterson.

The tests, in the fertile Tulare Lake Basin farming area in Kings County, are continuing and no cause yet has been determined for the deformities. However, the similarities to problems at Kesterson have raised fears that the deformities may be linked to selenium poisoning.

Selenium poisoning from agricultural waste water has been blamed for wildlife deaths and deformities at Kesterson. If the Tulare Basin deformities are also linked to selenium, it would represent a widening of the problem.

Malformed Embryos

Researchers report that nearly three of eight duck eggs randomly sampled from nests near one large agricultural waste water evaporation pond in the Tulare Basin contained embryos with missing eyes, malformed beaks, deformed legs and wings. Deformed embryos of both water fowl and shore birds were discovered in samples taken from nests around four out of the five ponds studied.

The reproductive study was conducted by wildlife biologists from the Fish and Wildlife Service’s Patuxtent Wildlife Research Center in Laurel, Md. Nests around the ponds were marked and monitored weekly and sample eggs were collected from many of the nests for chemical analysis and inspection of the embryo, the researchers said.

“Prior to this study, Kesterson Reservoir was the only evaporation facility . . . in the San Joaquin Valley where deformed embryos had been found in the nests of aquatic birds,” according to the Wildlife Service’s Research Information Bulletin, released to other government agencies in June.

Further Study Needed

The findings represent a small sample but the researchers say the results demonstrate the need for further study.

The dry lake basin--one of the richest farming areas in the state--was once covered by a marshy lake. Dams now control the rivers that flooded the lake and a system of levees and canals keep most of the lake bed dry for agriculture. Aquatic birds are attracted to the large evaporation ponds, which are used for drainage of agricultural irrigation water. These ponds cover 5,000 to 7,000 acres in the basin and offer wildlife a rich food supply that biologists now fear may be contaminated with high concentrations of selenium.

“Statistically, the rate of abnormality (among ducks) is at least twice as high as was ever recorded at Kesterson,” said Joseph P. Skorupa, one of the research biologists conducting the study. The rate of deformities found in the four species of ducks and two kinds of shore birds that were studied ranged from a low of 2% to a high of 37.5%.

The natural rate of severe embryonic deformities among water birds at uncontaminated sites is less than 1%, according to Skorupa.

Refuge Closed

The Kesterson refuge was closed in 1985, its 1,283-acre reservoir was dried out and the state ordered the federal government to clean up the toxic wastes contaminating the site, a job that experts estimate will cost millions of tax dollars.

While chemical analysis of the deformed embryos found in the Tulare Lake Basin ponds has not been completed, Skorupa said the similarities to Kesterson poisonings make selenium, or a combination of selenium and arsenic, the prime suspects in this outbreak of birth defects.

Selenium, a trace element, occurs naturally in valley soils and, in minute quantities, is beneficial to wildlife. However, higher concentrations of selenium are toxic to water birds. Arsenic is also being found both in the water and the food chain, but its effects are still not understood, Skorupa said.

Not Enough Information

Government biologists, farm experts and environmentalists agreed that while the new findings were startling, there still is not enough information to decide what remedial actions may be needed, other than to try to protect the wildlife until a permanent solution can be found.

Central Valley Regional Water Quality Control Board officials, working with the state Department of Fish and Game, are drafting emergency guidelines for pond operators. The temporary regulations will require farmers to frighten birds off the ponds when selenium levels reach 8 parts per million in the food chain. In addition, vegetation that can provide wildlife habitat will have to be removed, officials said.

When word of the Tulare Lake Basin findings reached Sacramento, a bill that would exempt agriculture waste water evaporation ponds from the provisions of the 1984 Toxic Pits Cleanup Act was put on hold. Backers of the bill, which has passed the Assembly and waits a floor vote in the Senate, say farmers need more time to find other ways to dispose of the drain water. Environmentalists are lobbying for tougher wildlife and ground water protections.

Two Problems

The whole agricultural waste problem has to do both with the way the valley was formed eons ago and the high-tech methods used to import water and irrigate these once arid plains. To farm successfully on the west side of the valley, growers say they must solve two problems, one resulting from the other.

The valley is like a giant bathtub, its bottom covered by a thick layer of earth. To grow crops, farmers must first get rid of the naturally occurring salts in the soil by applying enough irrigation water to leach the salts below the root zone.

However, without a drainage system to carry away this brackish water--and concentrations of chemical elements such as selenium and arsenic--the toxic salts will fill the bottom of the tub and rise back up through soil, killing plants and turning farms into wastelands.

With the help of the government, farmers tilling 42,000 acres in Fresno and Merced counties built drainage systems that carried millions of gallons of waste water to Kesterson, where the federal government used the water to flood the ponds and marshes, creating the wildlife habitat. That was in the 1970s and no one suspected the problems that lay ahead.

Evaporation Ponds

While farmers in the northern and central parts of the valley dumped their waste water in the San Joaquin River or the Kesterson wildlife refuge--until toxic levels of selenium began killing off wildlife--the farmers in the southern part of the valley had no place to put their waste water. So they built huge evaporation ponds to get rid of it.

“Prior to our studies, no one gave much thought to wildlife (on the ponds), these were just waste disposal sites, like piles of manure behind the barns,” Skorupa said. The new research proves that “Kesterson is indicative of wider problems,” the biologist said, adding that the studies also suggest that selenium may not be the only toxic element involved.

“We were surprised by the findings,” said Steve Hall, who is executive director of the Land Preservation Assn. that represents farmers cultivating 1 million valley acres. He explained evaporation ponds are the only way farmers in the southern valley can get rid of the waste water and urged government regulators not to take any hasty actions.

‘Some Sort of Problem’

“We know there’s some sort of a problem,” said Gary Rose, manager of the 213,000-acre Tulare Lake Drainage District. “And it is obvious we need more research. . . . (The study results are based on) a very small sampling . . . too small to get any conclusive results.”

Skorupa acknowledged that the sampling was small and he agreed that the findings were not conclusive. However, he said, the results did reveal a “statistically elevated rate” of birth defects.

“We can say that with a 95% level of confidence,” Skorupa said. “We have definitely confirmed there is something radically wrong here.”