From the MNR, re: Carp dieoff and VHS updates.

[Ron]

Hello all,

 

I recently received this email and thought I would forward it along to others, I hope you find the info useful.

 

Cheers, Ron...

 

 

Folks,

 

This email is intended to bring you up to speed on two items: 1) the carp situation; and 2) VHS Surveillance monitoring.

 

Carp

The results from most of the fish tested at the UofGuelph and the Federal abs are in. The only pathogen these fish tested positive for is the bacteria that causes columnaris. No viruses were found. We believe columnaris, in concert with a variety of stressors (temperature, spawning, etc.) is the primary cause of the die-offs. I have attached a fact sheet about columnaris FYI. Here are some additional points:

 

. Testing by the University of Guelph Fish Health Lab and the Fisheries and Oceans Canada lab has been completed for most of the carp submitted from the Kawartha Lakes this summer.

 

· The tests results indicate the bacteria Columnaris to be the primary cause of death in the fish die-offs. There were no viruses or other diseases found in the carp.

 

· Columnaris, a disease of fresh water fish, is caused by bacteria that lives naturally in water and mud.

 

· Columnaris has been associated with fish die-offs in the past, eg in channel catfish in the Ottawa River, 2006. It does not pose a threat to human health however it is still a good idea to wear gloves if handling dead fish.

 

· Large die-offs can occur when fish are under some type of stress and unable to fight off a disease. Stress in fish can be caused by high water temperatures, low levels of oxygen in the water, crowding such as occurs during spawning, or a combination of these factors. Bacteria like Columnaris can grow rapidly in these conditions and fish may become sick and die.

 

· Outbreaks of Columnaris do occur from time to time in the wild, and are almost impossible to prevent or treat.

 

· MNR has not documented any new locations of carp die off throughout the month of August within the Kawartha Lakes. MNR staff have been on Rice Lake over the last two weeks (and will be again this week) and have not observed any sick or dead carp.

 

· We have public information sessions scheduled for Wednesday August 29th in Coboconk (3:00pm) and Bobcaygeon (7:00pm). Feel free to attend, I believe I have already shared some of the details.

 

 

 

VHS

 

 

 

Regarding our VHS surveillance monitoring the good news is that samples from local lakes came back negative for VHS. Some positive tests did occur in other areas of Ontario. Please see the attached news release.

 

 

 

Feel free to pass along any questions on either of the above items.

 

 

 

Regards,

 

On the MCI website, I have posted the PDF files, under "From the MNR"

[Roy]

Thanks Ron.

[fishindevil]

Thanks for the info..at least it gives us a piece of mind now knowing its not VHS...so now we know thanks ron for the update...cheers

[lookinforwalleye]

If it is/was Columnaris like they claim why did it not affect any other specie of fish in the lake and why did it only affect the larger of Carp.

 

I don`t buy the explaination.

[Riparian]

I dont understand why people choose to turn this into a conspiracy... And we are talking about carp here... a bottom feeding species that thrives in poor water conditions. The same water conditions Columnaris would also thrive in. It makes sense to me that the nature of the animal caused the die offs.

 

It is also possible that other species were in fact effected by the bacteria. Just because they didnt wash up on shore dosent mean they arent dead at the bottom of the lake. And why would a species of fish that lives higher in the water column, dosent frequent silty muddy areas and feeds on baitfish be expected to be as suceptable to the bacteria as a fish that does all of the above?

[Terry]

thanks for the info

 

I got to wondering if you were still around......

good to see you still pop in now and then

[bigfish1965]

If it is/was Columnaris like they claim why did it not affect any other specie of fish in the lake and why did it only affect the larger of Carp.

 

I don`t buy the explaination.

 

It's easy biology. Larger fish require more oxygen to survive. Larger fish are more likely to be attacting several mates during spawn increasing their exposure level. Larger carp are older and nearing their end of the life cycle. There is no other rational explanation. The outbreak occured during spawn which created a natural positive environment for the virus. The other species of fish, like the cats, were not in the area and not congregated like the carp were when the heat wave and subsequent O2 level drop occured.

It is a natural phenomenon that actually has a healthy end result for the fish. Only when populations get too high do these types of problems occur. The non-resistant fish or the older less hearty fish die off in the process.

Fish die offs happen all the time. Just look at any beach in early June or late fall for massive die offs from thermal shock.