This is a copied from the Lambton Shores Endangered Fish Adventure Facebook page.
Update on the fish die-off in Lake Huron
While the cause of the ongoing fish die-off in Lake Huron has not yet been confirmed, after seeing some new photos over the weekend, I came to suspect that the die-off may be due to an outbreak of viral hemorrhagic septicemia (VHS). VHS poses no danger to humans, dogs, or other mammals but can be devastating to fishes and some other aquatic life.
There are several reasons I suspect VHS.
- Someone found 6 dead mudpuppies, a type of aquatic salamander, on north beach in Grand Bend. Mudpuppies aren’t known for spring die-offs due to weather conditions, however, they are susceptible to septicemia.
- Many of the photos of dead fish that I’ve seen have bright red spots on their sides, which are present in some (but not all) fishes infected with VHS.
- Although the bulk of the fishes washing up dead are Gizzard Shad, multiple species of fishes are dying. Gizzard Shad are known for large die-offs in the spring due to sudden changes in weather conditions. As such, many have shrugged off this event as a ‘normal’ spring die-off. However, I have seen photos of or heard reports of dead Rainbow Trout, Largemouth Bass, Northern Pike, Rainbow Smelt, Yellow Perch, Longnose Gar, and Channel Catfish. I have found reports of most of these fishes being susceptible to VHS.
- My supervisor, Dr. Nicholas Mandrak, has heard from colleagues on the US side Lake Huron that they are seeing an outbreak of VHS this spring.
While the OMNR has yet to collect specimens for testing, biologists in the Pinery Provincial Park along with some community members have collected specimens and have sent them to the Canadian Wildlife Health Cooperative in Guelph for testing. Testing to confirm disease can take time, so it may be a little while before there are definitive results on whether or not this is a VHS outbreak.
As an endangered fish researcher, I am particularly concerned that the virus might be accidentally spread to critical endangered fish habitat areas like the Old Ausable Channel in Grand Bend, and L Lake and Old Mouth Lake in Port Franks.
While we wait for results, there are things you can do to help control its spread.
- Do not move fishes, including baitfish, between waterbodies.
- If you do move boats or aquatic equipment from one waterbody to another:
a. Drain all water from the boat and bilges, prior to leaving the shore of the waterbody.
b. Clean boats and equipment (particularly boots) of all mud, plants, and other debris as these can hold the virus.
c. Disinfect all surfaces and gear that has come into contact with lake water or fish with a 10% bleach solution (100 mL bleach per 900 mL of water). Soak items for 10 minutes where possible.
d. Let all boats and equipment fully dry in the sun prior to use in a different waterbody.
e. Spread the word! The more people who are aware, the better.
Thank you to everyone who has taken an interest in this die-off, sent me photos and information, and helped to collect samples. You are all rockstars!
I will keep you posted when I hear more.
Information on VHS:
