Hundreds of fish die in Lake Arlington

Arlington Heights Park District officials investigating the deaths of hundreds of fish in Lake Arlington don't believe there is any reason to restrict people from using the lake.

“We definitely want to make the public aware that there's no cause for concern,” said Anita Pacheco, superintendent of marketing and communications for the park district.

Though swimming never has been allowed in Lake Arlington, the use of the lake's boathouse and paddle boats, as well as fishing, is continuing as normal, Pacheco said.

The type of fish which is showing up dead in large numbers is Gizzard Shad, a species which the park district does not stock in the lake. Approximately 500 dead fish have been removed since the phenomenon was discovered Sunday morning, but Pacheco said she can't be sure every dead fish was a Gizzard Shad.

The park district is working with the Illinois Department of Natural Resources to test the water and investigate the fish deaths.

Though investigators are trying to avoid early speculation, they are examining whether Gizzard Shad initially got into the lake as a baitfish, Pacheco said.

According to a news release issued by the park district, the most common cause of such concentrated, localized deaths of fish is reduced oxygen in the water which could be triggered by drought, algae, overpopulation or a sustained increase in water temperature.

Other possibilities are infectious diseases and parasites, with water toxicity being a far less common cause.