300-plus trout found dead in urban stream in northeast Cedar Rapids

An unknown foreign substance in Iowa's only urban trout stream, likely killed more than 300 fish over the weekend, according to the state Department of Natural Resources.

Paul Sleeper, the DNR's fisheries biologist, said Monday at least 319 dead trout were found in McLoud Run in northeast Cedar Rapids. The cause of the fish kill has yet to be determined and may never be, added DNR environmental specialist Brett Meyers, who continues to investigate.

Sleeper, who walked the spring-fed creek Monday, said the dead trout first became apparent below 42nd Street and became more numerous as he proceeded downstream along the 4-mile course of the creek that parallels Interstate 380 before emptying into the Cedar River near Cedar Lake.

The heaviest concentrations of dead trout were in the deeper pools near Glass Road, he said.

Most of the dead trout, he said, were in the 8- to 12-inch range, with some as long as 16 inches. If the deaths were caused by some kind of substance, it apparently did not affect other species of fish, as both Sleeper and Meyers observed plenty of white suckers in the stream.

Sleeper said the water was clear and had no discernible odor.

Meyers said an angler noticed dead trout Friday afternoon and reported it Saturday morning. By the time he arrived and began taking water samples around noon Saturday, Meyers said there was no indication of anything toxic in the water.

Water temperature, dissolved oxygen levels and pH all were within normal tolerances, he said.

'It looks like whatever it was had passed through the system by then,” he said.

Meyers said his checks with Cedar Rapids personnel on stormwater discharges, water main breaks and hydrant flushing turned up nothing.

DNR officials said anyone seeing a fish kill or spill can report it to DNR's 24-hour Environmental Emergency Response number at 515-725-8694. The sooner a spill is reported, the more likely the pollutant can be identified, officials said.

The DNR typically does not remove dead fish from streams, according to Meyers, who noted that those not consumed by animals rapidly decompose.

No advisories to avoid the creek have been issued, he added.

McLoud Run has experienced several fish kills since the DNR began stocking trout there in 1997. Some have been attributed to pollutants, while others have been caused by influxes of warm water running off hot concrete after heavy summer rains.

Sleeper said McLoud Run - the state's southernmost trout stream - is stocked annually with 3,000 brown trout, 2,000 rainbow trout and 1,000 brook trout - all fingerlings in the 3- to 5-inch range.

When the creek is restocked in June, Sleeper said he hopes to get some adult fish to replace some of the larger trout lost in the kill.

Though natural trout reproduction has not been documented in McLoud Run, Sleeper said he suspects it is occurring based on a pair of 2 1/2-inch-long brown trout he recovered Monday among the dead fish.