A spokesman for the Iowa Department of Natural Resources says they have been unable to find the source of the pollution that caused a weekend fish kill in Backbone State Park.

The DNR’s Tom McCarthy has been investigating after the kill that included trout and other fish was reported Richmond Springs and Fenchel Creek. “Looked all through the watershed, tested the water, looked at some potential sources — and nothing. I am not sure what happened,” McCarthy says.  “With all the rain — who knows what washed in.”

McCarthy  says other specialists were counting the fish and he doesn’t believe it was a large kill. McCarthy says they hope to find a source to prevent any additional kills. One positive is the water levels are very high. “We have had very high flows, little bit cooler temperatures over the weekend, so that would help elevate the oxygen levels. With all that dilution, a lot of times fish can kind of get out of the way of contaminants,” he says.

McCarthy says they’ve had several days in a row with rain recently and that makes livestock operations vulnerable to spills as they fill with water and the late harvest leaves them without fields to spread the manure. “It’s tough because not only do we have the rain — but now the crops are delayed a few weeks and now its wet again,” McCarthy says. “A lot of storage facilities are designed for only a certain number of days.” He says there could have been manure runoff that caused the kill, or it could have been normal runoff from the heavy rains.

People fishing for trout reported the kill right away and that normally helps in finding the source. He encourages anyone who sees a fish kill to report it to the DNR as soon as possible.