Instead, the rainbows and German browns were measured, weighed and wrapped for shipment to a laboratory in Steamboat Springs, Colo., where more scientists will analyze their muscle tissue for mercury.

East Canyon Reservoir is the third Utah water body where state Water Quality and Wildlife Resources workers have gathered preliminary samples while developing a mercury-related fish monitoring program.

The Division of Water Quality is heading up the new program, which could result in fish consumption advisories if test results reveal enough mercury in the fish to pose risk to those who eat them. All but five states already have such programs in place. In the West, only Utah and Wyoming don't have mercury-related fish advisories.

Mercury has become more of a concern in Utah since February, when federal scientists reported finding high levels of methylmercury, the heavy metal's organic form, in the Great Salt Lake, its brine shrimp and a species of duck that feeds on the shrimp and organic material in the lake. Also raising concerns are gold mines upwind of Salt Lake City near Elko, Nev., that emit thousands of pounds of mercury every year.

Last week, sample fish were taken from Gunlock Reservoir in Washington County and Mill Creek near Moab. By the end of this month, the scientists will take fish from Lake Powell and from the Green River in Desolation Canyon. Test results are expected by Sept. 1.

Fish taken from those water bodies by state and federal agencies since the 1990s have shown mercury levels higher than the federal agency's risk standard. The state wants to resample them to test the earlier data.

"Those are where we have had hits already. We want to see if we have hits again," said John Whitehead, a state environmental scientist.

Water Quality director Walt Baker ordered up the summer testing in response to concern from the public, environmentalists and hunters. A Salt Lake Tribune poll of 400 Utah residents in June showed 62.5 percent of respondents supported the state's plans to test for mercury in fish and birds.

The program will include a "Mercury Work Group" to develop fish and wildfowl monitoring, to coordinate public and private mercury-related research and disseminate information to the public.

The state has ordered a $40,000 piece of equipment that will allow the Health Department lab to do the testing. It's expected to be up and running by September, just in time to test fish the scientists plan to gather from some of the state's more popular fishing spots, including Willard Bay, Strawberry Reservoir and Lake Powell.

The concern is two-fold, said Richard Denton, Water Quality monitoring section chief. "What are people eating?" he said. "The other is the ecological side," that is, how elevated levels of mercury might be affecting the fish themselves.

At East Canyon Reservoir, gill nets were set at the north and south ends to broaden the sample. The reservoir's fish are raised in hatcheries and tend to be about two or three years old.

That's significant because mercury "bioaccumulates" in fish tissues as they age and eat more fish.