Heat’s on, but fish fine in Southland forest preserve lakes, district says
BY STEVE METSCH smetsch@southtownstar.com June 29, 2012 6:00PM
Despite the hot and mostly dry weather, fish kills are rare at Cook County forest preserve lakes, such as Maple Lake, forest preserve district officials say. | File photo
Updated: August 2, 2012 10:34AM
While a long stretch of hot, dry weather has caused some fish kills in Illinois, things are going swimmingly for fish in Cook County Forest Preserve District lakes, officials say.
The Illinois Department of Natural Resources has responded to reports of summer fish kills from private pond owners and anticipates more in the coming weeks, the agency said in a news release.
But Southland anglers or nature lovers shouldn’t see any signs of trouble should they brave the heat for a trip to Maple or Tampier lake or any of the other local forest preserve lakes.
“So far, we haven’t seen any major problems with our fish. In fact, there have been no summer kills — what we call the big die-offs — in many years,” forest preserve district fish biologist Steve Silic said. “Water levels are definitely lower than normal, but the biggest concern right now with the drought and the heat is low dissolved-oxygen levels in the water. It’s the low oxygen levels that cause fish kills.”
Friday’s storm was thus helpful.
“We’d like rain for a variety of reasons, but especially because rain re-oxygenates water by disturbing the water’s surface,” Silic said.
Statewide, heat and dry conditions will set the stage for fish kills in bodies of water from small ponds to large backwater lakes along large rivers, the IDNR said.
The agency’s fisheries division gets thousands of calls each year from private pond owners who find dead fish and assume chemicals have entered the pond. But 99 percent of summer fish kills are caused by natural conditions that fish cannot tolerate, the IDNR said.
A summer kill rarely kills all of the fish in a pond but can affect the food chain, so fishery management may be needed to restore that balance, the IDNR said. IDNR fisheries biologists can offer recommendations, the agency said.
Contributing: Sun-Times Media Wire

