White Cap -- I guess it was bad enough I got the credits wrong once, let alone twice...but I did. So, my thanks go rightly to Grey Ghost (Gus) for the pics of the sick laker and the follow up on my post on whirling disease.
It would be a good idea to get clarification from John Viar as to how he'd like us to deal with these diseased fish. To minimize the spread of the parasite causing the disease it would definitely be best to remove all diseased fish regardless of size. (Also we may need to learn decontamination procedures in the event we look to release fish after we catch a sick one -- need to read up on this). As others noted, killing small diseased fish puts us up against "the letter" of the law. However, removing all infected fish of any size makes the best sense in terms of fishery management. If we could document this better going forward perhaps John Viar and others can provide a "special directive" recommending that we kill / remove all fish with obvious signs of the whirling disease regardless of size.
Also, if indeed lakers are supposedly resistant to whirling disease, these observations are troubling in that it may indicate the parasite has adapted if not evolved to attack lakers in Winni. Another reason to remove any diseased / deformed fish and get them to a fisheries biologist for examination.
I also sent an e-mail to John Viar to attempt to clarify some of these issues/questions and to alert him to these fish. I will post any reply from him to the board for all of us to learn from.
It look like that lake trout are susceptible, to a much lesser degree, to this disease according to the following articles.
Among species found in Utah, rainbow trout are the most susceptible, followed by kokanee salmon, golden, cutthroat, brook, brown trout and splake. Recent discoveries show whitefish may be infected as well. Lake trout may be infected under laboratory conditions and other game fish species such as bass, bluegill, perch or walleye do not get whirling disease UTAH
Conversely, Wagner et al. (2002) exposed lake trout to 1,000 tams per fish at 10 weeks of age and sampled at either 5 or 20 weeks. Interestingly, by PCR 100% of the 20 lake trout sampled were either positive or weakly positive at 5 weeks, as were 100% of brook trout. However, at 10 weeks by spore enumeration only 13.6% of 22 lake trout were positive, while 100% of the brook trout remained positive. Blacktail and whirling behavior were not observed for any of the lake trout, however, 9.5% did show cranial deformities. This correlates well with follow-up studies conducted at Leetown using labeled tams. Preliminary results suggest that the tams are able to attach and enter the epithelium of the lake trout but do not progress to infections of cartilage and development of mature myxospores. USGS
