Fish kill documented in Milk River, Rock Creek; cause unknown

Fish, Wildlife & Parks

A widespread fish kill on Rock Creek and the Milk River north of Hinsdale is being investigated by Fish, Wildlife & Parks fisheries biologists.

A landowner reported the incident on July 13. Upon investigation, biologists observed dead fish downstream of the confluence of the Milk River and Rock Creek. Further searching found dead fish 9.5 miles from the mouth of Rock Creek up to the Rock Creek Dam, although the full upstream extent was not determined. No dead fish were observed in the Milk River upstream of the confluence with Rock Creek.

“Whatever killed these fish was highly toxic as it killed carp, bullheads, catfish and a host of warm water fish species that tolerate poor water quality,” said regional fish manager Steve Dalbey.

Species observed included walleye, northern pike, carp, catfish, goldeye, bullhead, shorthead redhorse, river carpsucker, white sucker, freshwater drum and buffalo.

People are also reading…

Although the source of the fish kill was not determined, the timing and rate of decomposition of the fish suggest it may have occurred between July 9 and 11. The incident may be related to heavy rain that occurred on July

View Source