The Michigan Department of Natural Resources announced Aug. 3 that samples taken from a June fish kill at Kent Lake at Kensington Metropark indicate the presence of koi herpesvirus.
An estimated 300-500 common carp died at the lake within a span of a few days in late June.
Koi herpesvirus had not been found previously in wild fish samples in Michigan, though it has been detected in a private koi pond near Grand Rapids in 2003. It does not pose any human health risk.
“This virus is capable of large-scale common carp die-offs as seen in Ontario in 2007 and 2008,” said Gary Whelan, DNR fish production manager. “The virus is an internationally reportable disease, and it is being officially reported at this time.”
Whelan said the koi herpesvirus affects common carp, goldfish and koi. At this time, the impact of the virus on native minnow species, which are members of the carp family, is unknown. He said koi herpesvirus is found worldwide and likely was introduce to Michigan waters from the release or escape of infected ornamental fish.
Initially, DNR officials investigated the die-off as possibly related to a virus called spring viremia of carp, but laboratory analysis confirmed that disease was not involved in the kill.
Huron-Clinton Metroparks Chief of Communications Denise Semion said the die-off continued for only a few days after dead carp were first reported by boaters at Kent Lake and a segment of the Huron River just east of the lake in Milford.
Semion said cleanup crews worked diligently to remove dead fish to reduce any risk posed by dead or decomposing fish, like E. coli bacteria. The lake, which borders Livingston and Oakland counties, remained opened without further issue.
DNR officials said the die-off is a reminder to boaters and anglers to make sure they’re more mindful when they enter new waters.
“This disease outbreak is another example of why the DNR reminds anglers and boaters that they need to drain bilges and live wells upon leaving a boat launch,” said Jim Dexter, acting chief of the DNR’s Fisheries Division. “Anglers should clean their boats, disinfect their gear and not move live fish, to reduce the possibility of any fish diseases being transferred to new locations.”
The public is reminded to contact the DNR when they see unusual fish kills at www.michigan.gov/fishing.
— Frank Konkel, Gannett News Service