Jason Olson, Deseret News
A sign posted at the Highland Glen Pond in Highland Tuesday alerts anglers to the parasite that has been found in the fish in the pond. While the parasite can be fatal to fish, it poses no threat to humans.

HIGHLAND — Fish in Highland Glen Pond have been sick over the past month, leaving many catfish — the pond's most popular type of fish — dead on the shores of the busy fishing spot.

Wildlife officials have been monitoring the problem and say that the fish have been dying because they're infected with a common parasite found in aquariums, called ichthyophthirius multifiliis.

"It is a parasite that is present nearly everywhere," said Chris Penne, Utah community fisheries biologist. "It could have been in water already, in a certain fish, or it could have been in the ones we stock into the pond, but we test every 30 days and have not had a problem like this in other ponds."

The parasite lives on the skin of the fish and can colonize on the gills that help the fish breathe. When the parasite colonizes on the gills they get inflamed, and the inflammation leads to the fish suffocating.

Penne, who oversees community fisheries throughout the state, says that the biggest cause for the outbreak is most likely the temperature of the pond over the past month. This particular parasite thrives in water temperatures between 68 and 75 degrees, which is right where the water has been as of late.

"With this parasite being nearly ever-present, it is not always lethal; this is an extreme circumstance," Penne said.

The state Division of Wildlife Resources will continue to monitor the pond, and it expects that as the temperature changes the problem should clear up.

Penne said that contrary to some previous media reports, mostly catfish were affected by the parasite, and most of the bass and other fish in the pond are fine. He also said that early reports that the pond was not being stocked this summer are untrue — confirming that the pond has been stocked eight times this summer and that workers will once again stock more trout into the pond in a month from now when the pond is in the optimal temperature range.

A recent children's fishing derby that is part of the Highland Fling celebration was canceled because of the number of fish that had died in recent weeks. Emily Gillingwater, Highland city community enhancement coordinator, said volunteers have been picking up the lifeless fish on the shores of the pond for the past few weeks, and that canceling the fishing derby was unfortunate.

"The fishing event is very popular with the children," Gillingwater said. "The kids were all sad to hear that the fish died, but they understood why we had to cancel the event."

Officials confirmed that anyone who may have caught and eaten a fish from the pond in the past months need not worry, as the parasite causes no risk to humans.

E-mail: [email protected]