The Michigan Department of Natural Resources announced that it finished its investigation into what killed hundreds of common carp on Lake Orion in July.
According to the DNR, the deaths were caused by the koi herpesvirus.
"As the case with most herpesviruses, KHV is very specific on which fish species it will infect and only affects common carp, koi and goldfish," said Gary Whelan, Fisheries Division Research Program manager, in a press release. "This is only the third detection of this non-native virus in Michigan waters, and it is known to kill large numbers of its host species at times. KHV does not affect any other fish species and has no implications for any other birds, mammals or humans."
It is reported that between 300 to 600 mostly adult fish were killed in northeast Oakland County during that time.
The DNR notes that viruses that affect fish are not usually human pathogens because of a difference in body temperature.
They are strongly encouraging that people fully cook freshwater fish for safe consumption.