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03-11-2018, 10:35 AM
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Join Date: Dec 2007
Location: Central Alberta
Posts: 1,807
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Whirling Disease
Folks,
Below is and abstract from a ACA funded report.
TESTING RAINBOW SENTINEL TROUT FROM
SOUTHERN ALBERTA RIVERS FOR
WHIRLING DISEASE
(2004)
Prepared for
Alberta Conservation Association
By:
Dr. Jacob John
John Derksen, M.Sc.
Aquculture Centre of Excellence
Lethbridge Community College
March 2005
Abstract
This report presents the results of testing larval, sentinel rainbow trout (Oncorhynchus
mykiss), exposed to lentic areas populated by T. tubifex, for the presence of the Whirling
Disease pathogen (Myxobolus cerebralis) in Southern Alberta waters, specifically, the
Crowsnest, Castle, Bow and Elbow rivers. The methodology adopted for detection of the
organism in fish, was the Single Round, Polymerase Chain Reaction (PCR), designed
against the 18S rDNA gene in the organism. A total of 1545 sentinel fish, pooled in
groups of 5, were processed for DNA extraction from a total of 9 sites. Positive and
negative test controls revealed no signs of contamination or false results. Results from all
tested fish indicated no presence of the pathogen.
The takeaway from the report is that it only took from 2003 when the samples were caught to 2017 for the disease to scatter to every water shed tested. Parks are working Johnson Lake but by the spread, the source or sources could have been anywhere. The rivers tested are the most heavily visited rivers in Alberta.
If you wish a copy of the full report, I can send it along [ need your real email] or you can contact the ACA directly.
regards,
Don
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03-29-2018, 05:53 PM
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Join Date: Jan 2008
Location: Calgary Perchdance
Posts: 19,285
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Quote:
Originally Posted by Don Andersen
Folks,
Below is and abstract from a ACA funded report.
TESTING RAINBOW SENTINEL TROUT FROM
SOUTHERN ALBERTA RIVERS FOR
WHIRLING DISEASE
(2004)
Prepared for
Alberta Conservation Association
By:
Dr. Jacob John
John Derksen, M.Sc.
Aquculture Centre of Excellence
Lethbridge Community College
March 2005
Abstract
This report presents the results of testing larval, sentinel rainbow trout (Oncorhynchus
mykiss), exposed to lentic areas populated by T. tubifex, for the presence of the Whirling
Disease pathogen (Myxobolus cerebralis) in Southern Alberta waters, specifically, the
Crowsnest, Castle, Bow and Elbow rivers. The methodology adopted for detection of the
organism in fish, was the Single Round, Polymerase Chain Reaction (PCR), designed
against the 18S rDNA gene in the organism. A total of 1545 sentinel fish, pooled in
groups of 5, were processed for DNA extraction from a total of 9 sites. Positive and
negative test controls revealed no signs of contamination or false results. Results from all
tested fish indicated no presence of the pathogen.
The takeaway from the report is that it only took from 2003 when the samples were caught to 2017 for the disease to scatter to every water shed tested. Parks are working Johnson Lake but by the spread, the source or sources could have been anywhere. The rivers tested are the most heavily visited rivers in Alberta.
If you wish a copy of the full report, I can send it along [ need your real email] or you can contact the ACA directly.
regards,
Don
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Sounds like everywhere from North Saskatchewan river south. Likely in northern rivers also.
We may have things going for us that benefits trout. Colder water. Shorter seasons. Spawning creeks separate from river populations. Maybe a tubifex community that is different. Maybe spring floods?
I have not heard of major impacts.
__________________
Observing the TIGSCJ in the wilds of social media socio-ecological uniformity environments.
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03-29-2018, 08:04 PM
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Join Date: May 2007
Posts: 7,063
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Do trout feed when they are affected by whirling disease. I caught a cutthroat about 15" in the North Ram last year that seemed to fight strangely, it just rolled around and swam in circles not really fighting as I quickly retrieved it, hooked only in the lip with barbless hook. When released without taking it from the water it circled about aimlessly also rolling over until it slowly disappeared into deeper water. It's tail appeared to be cocked off to the side. Seemed completely disoriented.
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03-30-2018, 08:11 AM
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Join Date: May 2007
Posts: 2,988
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Sometimes fish get broken backs from electrofishing as well (another possible explanation)
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03-30-2018, 09:07 AM
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Join Date: Dec 2007
Location: Claresholm, Ab
Posts: 4,021
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Given the current proven reach of the disease in Alberta I'm willing to bet that whirling disease first got here not long after it was identified in Montana.
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03-30-2018, 09:24 AM
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Join Date: Jun 2007
Posts: 1,258
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Quote:
Originally Posted by Bushrat
Do trout feed when they are affected by whirling disease. I caught a cutthroat about 15" in the North Ram last year that seemed to fight strangely, it just rolled around and swam in circles not really fighting as I quickly retrieved it, hooked only in the lip with barbless hook. When released without taking it from the water it circled about aimlessly also rolling over until it slowly disappeared into deeper water. It's tail appeared to be cocked off to the side. Seemed completely disoriented.
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Whirling disease affects juvenile trout,,,, something like up to 90% die from symptoms related to the disease (predation,,, inability to feed).
Apparently, a few fish do survive contact and will maintain their skeletal deformity.
There are very specific conditions needed,,, a combination of trout size (under 2 inches) when the TAMs are released,,, water temps of 10 - 15C ,,, and habitat (tubifex worms need mud) for whirling disease to exist. It may very well be that many Alberta streams do not typically have optimal conditions in most years for high levels of the disease to become established.
There are other reasons that cause skeletal deformities in adults (electro fishing as mentioned,, surviving an attack from an avian predator etc). We cannot rule out WD in the 15" North Ram River cutthroat mentioned, but I would be more inclined to suspect something other than WD in this case.
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