Joe's Valley splake have tested for high levels of mercury. Three sites were previously noted as having concerns with certain fish.
Now 14 additional sites have been included in this alert adding Joe's Valley Reservoir to the list.
Paul Birdsey is the regional aquatics manager for the Utah Division of Wildlife Resources. He said, "We collected fish from Joe's Valley for mercury testing as part of a statewide program with the Department of Environmental Quality.
"The majority of the fish that we collected for testing were larger splake.
"These fish are the top predators in the system and may live more than 10 years.
"Because of their predatory nature and longevity, splake will bio-accumulate anything that happens to be in the water, such as mercury.
"We will be collecting other fish (cutthroat trout and smaller splake) during 2007 for additional testing to see whether the current consumption advisory can be limited to just large splake," said Birdsey.
Mercury pollution may come from contaminants released by coal-fired power plants or from the soil. Joe's Valley tested the highest level of mercury at 0.82 in splake trout.
The Environmental Protection Agency's level of concern is set at 0.3 milligrams per kilogram of fish.
Toxicity could result if someone ate a lot of these fish with elevated mercury levels over a long period of time.
Someone eating a large amount of these fish could still take months or years to develop any toxicity.
Extra caution is urged against consumption by pregnant women, nursing mothers and children.