Hundreds of carp in Michigan lake have died from herpes outbreak

• The Michigan Department of Natural Resources says the herpes koi virus is responsible for the death of fish in Lake Orion.
• The virus killed between 300 and 600 fish in July.
• Koi herpesvirus only affects common carp, goldfish, and koi carp, not humans.

Local authorities understand why hundreds of fish were found dead in Michigan’s Lake Orion in July. The reason – koi herpesvirus, a deadly disease of fish that kills carp.

The Michigan Department of Natural Resources released the results of its fish death investigation last week.

The fish deaths were first reported in late July when people spotted what they thought were 250 to 500 dead fish floating in Lake Orion, a lake north of Detroit. The Michigan Department of Natural Resources collected carp samples for testing on July 23 and received help from Michigan State University’s Aquatic Animal Health Laboratory to investigate fish mortality.

The department estimated that a total of 300 to 600 adult carp died from koi herpesvirus infections.

“As with most herpesviruses, the herpes koi virus is very specific on the species of fish it will infect and only affects common carp, koi carp and goldfish,” said Gary Whelan, Program Director, Michigan Fisheries Research Division.

“This is only the third detection of this non-native virus in Michigan waters, and it is known to occasionally kill large numbers of its host species. The herpes koi virus does not affect any other species of fish and has no implications for other birds, mammals or humans. “

According to the Department of Food and Agricultural Sciences at the University of Florida, koi herpesvirus is highly contagious in fish. It is spread to sensitive fish through the skin, including the gills. The virus itself kills fish within 24 to 48 hours of onset of symptoms. Symptoms include fish lingering near the surface of the water, swimming sluggishly and panting.

The Michigan Department of Natural Resources added in its Sept. 17 statement that while fish viruses are not generally human pathogens and cannot infect humans, freshwater fish like carp should be fully cooked. before being consumed.