VHS at a glance

WHAT IS IT?

Viral Hemorrhagic Septicemia (VHS) is a fish disease that may cause bulging eyes, bloated abdomens, inactive or overactive behavior and hemorrhaging in the eyes, skin, gills, and at the base of the fins. It also attacks the internal organs of fish, leaving them bloody looking. Fish mortality is highest in low water temperatures between 37-54ºF. The virus poses no threat to humans.

WHAT SPECIES ARE AFFECTED?

VHS has been found in 37 species, including muskellunge, smallmouth bass, northern pike, freshwater drum (sheephead), gizzard shad, yellow perch, black crappie, bluegill, rock bass, white bass, redhorse sucker, bluntnose sucker, round goby and walleye. It has not been confirmed in salmonids in the Great Lakes, but has been known to infect those species.

WHERE IS VHS FOUND?

VHS was observed as early as 2005 in freshwater drum in Lake Ontario and in muskellunge in Lake St. Clair. In 2006, VHS was blamed for fish die-offs in muskellunge in Lake St. Clair, freshwater drum and yellow perch in Lake Erie, and round gobies in Lake Ontario.

HOW IS VHS SPREAD?

Fisheries managers don’t know for sure how VHS has spread. They’re guessing the virus moved to the Great Lakes from the Maritime Provinces via ballast water from ocean-going ships in 2002. Biologists believe the virus can move between fish populations, making them worry all of the Great Lakes could eventually have a VHS presence.

WHAT CAN BE DONE TO STOP VHS?

In the short term, boaters and anglers can disinfect their equipment with a bleach cleaning solution. Managers are urging anglers not to move fish from known infected waters to uninfected waters. They also ask anglers to leave all bait and livewell water in the lake from which it was taken