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Dead carp on the shore of Lake Monona last month. Dead carp have been washing up on the shores of Madison-area lakes since August.

Q: Why are dead carp washing up on the shores of Madison lakes?

A: The carp, an invasive species, likely were killed by the koi herpes virus.

The virus was confirmed in Lake Kegnosa by the Wisconsin Department of Natural Resources in August. The virus has likely infected dead carp found recently in the Yahara River and Lakes Monona and Mendota, the DNR said.

The virus can’t be passed to humans or animals, but the DNR said people should avoid direct contact with the dead fish to prevent contact with other harmful bacteria associated with decaying fish carcasses.

The virus weakens the immune systems of the carp, making them vulnerable to other infections, according to the DNR.

However, the recent die-offs of the fish won’t likely significantly lower the population of the invasive fish in area lakes.

Clean up of dead fish falls on lake shore property owners. The DNR said decomposing carp can be buried, put in garbage bins, composted, placed in landfills or used as fertilizer. People should use gloves and other means to avoid direct contact with the fish.

As water temperatures decrease, the die-offs should subside, as the virus is most deadly when water temperatures are between 71 and 79 degrees, according to the DNR.

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