The fish-killing virus is known as viral hemorrhagic septicemia and it has been found in this region since 2003, according to the College of Veterinary Medicine at Iowa State University. Massive fish die-offs were first recorded in the 2005.
Now, another die-off has been found. From the Associated Press:
HARRISON, Mich. (AP) - A fish-killing virus has been detected again in a lake near the mid-Michigan community of Harrison.
The Michigan Department of Natural Resources on Tuesday announced that viral hemorrhagic septicemia, or VHS, has been confirmed in Budd Lake.
The 175-acre lake in Clare County experienced a die-off of largemouth and smallmouth bass, bluegills, and pumpkinseed sunfish in April and May. Test results indicate that largemouth and smallmouth bass were positive for VHS. Other results were pending.
A similar die-off involving bluegill, black crappie, largemouth bass and muskellunge occurred in the spring of 2007, and VHS was identified in the lake after those deaths. The state says VHS was undetected through 2010 in testing that took place each year.
Budd Lake is one two Michigan inland lakes where VHS has been confirmed.
The virus is troubling, especially when it attacks 60 pound sport fish like the muskellunge. The Environment Report captured what the virus means to sport fisherman in a piece by David Sommerstein.
Sommerstein reports that fish exposed to the virus can develop immunity, but biologists worry that new generations of fish won't carry that immunity with them, so they're vulnerable when the virus comes around.