Ak Fishing News: Anchorage's Ship Creek Infected with Whirling Disease?
This news clip is from Alaska Fishing News. Discussion is welcome. This news feed is robot generated.
While no Alaska fish have displayed clinical symptoms of whirling disease, testing earlier this winter by the ADF&G has confirmed the presence of the parasite that causes the "whirling" behavior, the Anchorage Daily News reports. The disease has dramatically reduced populations of trout in some parts of the Lower 48.
ADFG investigators detected the parasite using a sensitive DNA testing system in rainbow trout at the Elmendorf Hatchery....just upstream from the popular Ship Creek fishery in Anchorage.
Read the entire story in the Anchorage Daily News >>>
Some anglers on the Alaska Fishing Forum are calling for fishermen to take preventative steps.
The story was originally reported in an ADFG News Release:
After years of negative results from microscopic testing by the Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service, a new, much more sensitive molecular test based on DNA (called Quantitative Polymerase Chain Reaction or QPCR) has detected evidence of the parasite Myxobolus cerebralis (Mc) in some rainbow trout from Elmendorf State Fish Hatchery in Anchorage. However, there has been no evidence of the fish disease associated with this parasite, nor has any form of the parasite itself been observed in Alaska.
Sixty rainbow trout, divided into 12 groups, were tested by Oregon State University. Results were positive in one batch of 5 trout. A second test of 60 different individual fish confirmed the first test by finding 3 rainbow trout that had DNA from the parasite.
The Mc parasite causes “whirling disease” in rainbow trout and other members of the salmonid family. The heads of diseased fish may contain up to 2 - 3 million spores of Mc. The Elmendorf Hatchery rainbow trout samples contained an estimated 100 to 1,000 spores, a level too small to be detected with standard microscopic tests, and too small for the fish to show any signs of the disease. Using national standard methods for fish health certification, these fish would be considered free of Mc infection because of the absence of observable parasite spores from enzymatic digests or histologic sections of the head cartilage. Eating or handling fish that have any form of Mc poses no health risk to humans, pets, birds, or other non-salmon wildlife.
To date there is no evidence of the presence of the Mc parasite anywhere else in Alaska outside of Elmendorf Hatchery. There is no way of knowing whether the presence of Mc in the Elmendorf Hatchery dates from the last rainbow trout transferred there from the Lower 48 states about 30 years ago or is a new introduction into Ship Creek from sport fishing activities.
ADF&G has a rigorous fish disease policy, which would require the agency to depopulate the hatchery if there had been any evidence of clinical whirling disease or actual observation of any Mc parasite life stage. Although this has not happened, the Mc-positive QPCR results are confirmed. Therefore, as a precautionary measure, no fish of any species from Elmendorf State Fish Hatchery will be transplanted into an open watershed. Fish will only be stocked into lakes that have no inlet or outlet at any time of year (landlocked) and have no reproducing salmonid fish populations. As a result, over 94,000 hatchery fish that otherwise would have been destined for open watersheds will be transplanted into closed systems in 2007. King salmon will continue to be stocked in Anchorage’s Ship Creek, the most likely source of the parasite and because the stream has already received potentially contaminated discharge water from Elmendorf Hatchery. However, no Elmendorf Hatchery fish will be transferred to the Fort Richardson Hatchery. The stocking of open systems will resume when the state builds a new well-water-only hatchery near the existing Elmendorf facility in the next 4 -7 years which will eliminate the potential of introducing Mc from Ship Creek water.
The Department is planning to investigate populations of rainbow trout in selected high risk watersheds in Alaska using the new, more sensitive QPCR test in conjunction with other standard methods for the detection of Mc. Fish at the Elmendorf Hatchery will be closely monitored for clinical signs of whirling disease and visible life stages of the Mc parasite.
The Department urges everyone to remember that Alaska’s laws against moving fish among waterways are very strict. No live fish may be transported or released into the waters of the state, except with a special ADF&G permit. Alaskans are now especially cautioned not to move members of the salmonid family from one waterway to another. If fish are cleaned in the field, clean them only in the waters from which they were caught.
For more information on whirling disease, consult the Whirling Disease Foundation website, http://www.whirling-disease.org/. For more information on Alaska’s hatchery program, fish disease policy and invasive species, visit the Alaska Department of Fish and Game online at http://www.adfg.state.ak.us/, or contact Dr. Theodore Meyers, Chief Fisheries Pathologist in Juneau at (907) 465-3577.
Read the individual article on Alaska Fishing News...
We welcome news tips that are useful to the community. Please send tips and links to complete stories by email to