Scientists to net data on toxins in sport fish

At the end of October, teams of scientists will begin collecting sports fish from Lake Mead to discover whether their tissue contains any harmful chemicals or substances that interfere with the fish's gender characteristics.

An earlier study by the U.S. Geological Survey published in 1996 reported that bottom-feeding carp in the Las Vegas Bay contained the highest levels of endocrine disruption in the nation.

Male carp had high levels of a protein found in female egg sacs. Male fish should show no sign of the protein.

Endocrine disruption in fish, frogs and alligators has been discovered around the world. Scientists suspect chemicals that mimic estrogens, water-soluble estrogen from prescription drugs or runoff from sewage-treatment plants might contribute to the problem.

Other water problems occurring in other parts of the country include pfsteria, an organism that attacks the central nervous system, toxins from algae and runoff from massive chicken and hog farms. Whether these problems in fish will translate into a human threat is unknown.

No warning signs have been posted against fishing at Las Vegas Bay or Lake Mead.

For James Pollard, program director of the Harry Reid Environmental Research Center, the idea for the $100,000 study in Lake Mead came from fishermen themselves.

"They would come up and ask us, 'Is this fish safe to eat?' "

The scientists did not have an answer. They will be trying to determine whether the fish contain harmful levels of insecticides and pesticides once made at an industrial plant in Henderson. They also will check fish organs to see whether they contain large amounts of heavy metals, such as mercury, and whether they are developing cancerous tumors.

Pollard, a fisheries biologist, is working with funds from UNLV and the Nevada Division of Wildlife to collect and study tissues from about 400 game fish such as stripers and large-mouth bass.

The fish will be gathered from eight sampling areas in the lake. The results will be presented to the Lake Mead Water Quality Forum, a panel of federal, state and local water and waste-water agencies concerned with Southern Nevada's drinking-water quality.

The research will be conducted at Boulder Basin, Virgin Basin, Echo Bay, the Muddy River Arm, Virgin Bowl, Temple Basin, Gregg Basin, Grand Wash and Las Vegas Bay.

"We don't expect to see anything in game fish, but right now we do not have enough information to answer the fishermen's questions," he said. In more than 20 years at the lake, Pollard said he has never seen any growths or abnormal lesions on fish.

During the study, when the fish first land in the boat, scientists will look for lesions or cancerous tumors. After that, the tissues and organs such as the liver, the brain and the blood, will be analyzed for heavy metals, phosphates created by industrial pollution and carbon-based chemicals that react with living cells.

Lake Mead and the Las Vegas Wash raised scientific concerns after the endocrine disrupters were discovered in the carp, followed by perchlorate, a salt found in a rocket-fuel booster manufactured in Henderson.

The perchlorate first appeared in Southern California's drinking water. Although there are no regulations set for perchlorate, California set a drinking-water guideline of 18 parts per billion after a test was developed in 1997 that could measure the salt in parts per billion.

Perchlorate levels in Lake Mead have ranged from 8 parts per billion to 12 parts per billion. The highest level ever found in the Las Vegas Valley was 16 parts per billion in a reservoir on West Oakey Boulevard.

The perchlorate was made at two plants in Henderson since World War II.

Kerr-McGee Chemical Corp. is still operating there. American Pacific Corp. operated the Pacific Engineering and Production Co. until the plant exploded and was destroyed by fire in 1988. American Pacific moved its operations to Cedar City, Utah.

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