Lake trout fishermen plying the waters of Lake Superior this coming summer might not notice the difference in numbers of fish caught this year, but in the coming years it will be interesting to see if the strong return of the lake trout continues, or slips backwards in part because the Minnesota Department of Natural Resources (DNR) is looking at ending its stocking program for lake trout in the big lake.
And while lake trout were going to be planted in the lake this summer that likely won’t happen because of a disease that shut down the hatchery where the lake trout are raised.
An important trout hatchery near Altura in southeastern Minnesota was closed in December so it could be disinfected to remove a pathogen that causes furunculosis, a disease that forms boils and lesions on fish and eventually kills them. All of the fish were killed in the process.
“Killing the hatchery’s fish is unfortunate and a choice we’d prefer not to make, but immediate and aggressive action is necessary to eliminate this pathogen,” said Paula Phelps, Coldwater fish production supervisor for the DNR.
Fewer native brook trout strain will be available for stocking over the next three years, and DNR fisheries will develop a plan to determine where the most effective and efficient locations will be to stock these fish to meet recreational demand, said Phelps.
The hatchery at Crystal Springs produces brook and lake trout that are stocked primarily in southeastern and northeastern Minnesota lakes and rivers.
Lake trout from Crystal Springs Hatchery are stocked only in Lake Superior, a practice now being revisited as part of a revision to the 10-year Lake Superior fisheries management plan. Should the DNR still plan to stock Lake Superior with lake trout this year, lake trout from Ontario could replace at least some of the Crystal Springs trout.
The pathogen, Aeromonas salmonida that infected the hatchery was likely carried there by floodwaters from the Whitewater River. While it occurs naturally and can kill fish in the wild, this pathogen is far more likely to kill fish kept in confined areas like hatcheries.
Now that Crystal Springs hatchery has been disinfected, it must be disease free for three years before any fish from it can be stocked in Minnesota lakes or streams.
As far as supplying lake trout for Lake Superior, the DNR is in its final draft stage of its Lake Superior Fisheries Management Plan, and that plan, which includes a recommendation from most members of a citizen panel called the Lake Superior Advisory Group, recommended the DNR stop stocking lake trout after 2016.
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