Minnesota DNR may stop stocking lake trout on big lake
Last year, fisheries officials with the Minnesota Department of Natural Resources proposed ending decades of lake trout stocking in Minnesota waters of Lake Superior after 2016.
Now, a fish disease in the hatchery where the DNR raises its lake trout has made it unlikely that the agency will stock lake trout this year either.
A fish disease, furunculosis, at the DNR’s Crystal Springs Hatchery in southeastern Minnesota required all fish there to be killed in December. The lake trout raised there are the only DNR source for Lake Superior stocking.
DNR fisheries officials had proposed the end of lake trout stocking in Lake Superior as part of their revised Lake Superior Fisheries Management Plan, now in final draft stage and due out for public comment soon. A majority of the Lake Superior Advisory Group, a citizen panel advising the DNR on the revised fish management plan, had recommended the DNR discontinue stocking of lake trout after 2016.
“We have not felt an urgency to find alternate sources for stocking this spring,” said Cory Goldsworthy, DNR Lake Superior area fisheries supervisor.
As a result, it appears likely that for the first time since recovery efforts began in the 1960s, the DNR will no longer stock lake trout in its waters of Lake Superior.
Lake trout usually are stocked in April and May, Goldsworthy said. Many years of successful natural reproduction of lake trout have allowed the DNR to meet all of its criteria to end stocking of lake trout in zone MN-1, which extends from Duluth to the Encampment River near Two Harbors, he said. Lake trout stocking had ended in the state’s two other zones in 2007 and 2003.
“The proposal to discontinue stocking lake trout does not mean we are going to walk away from lake trout management,” Goldsworthy said. “Rather, just the opposite. We will have to be even more diligent and attentive to ensure the sustainability of rehabilitation.”
Members of the Western Lake Superior Trolling Association are unhappy with the DNR’s decision to end lake trout stocking in Minnesota waters, said club president Jim VanLandschoot.
“We’re a little concerned and disappointed, to say the least,” VanLandschoot said. “They’re going to continue the steelhead and ‘looper (Kamloops rainbow trout) programs. Our concern is they’re going to neglect Lake Superior completely. We’re grateful we have Wisconsin right next door. They continue to stock lake trout.”
Steelhead rainbow trout and Kamloops rainbow trout are primarily near-shore and stream fisheries and not targeted by Lake Superior trollers.
Wisconsin has stocked about 90,000 lake trout fingerlings per year in Lake Superior from Superior east to Bark Point near Herbster, said Brad Ray, Wisconsin DNR Lake Superior fisheries biologist at Bayfield. That will continue in 2016. The Wisconsin DNR has no plans to discontinue lake trout stocking, Ray said.
“However, data from our spring assessment and creel survey do demonstrate the rehabilitation is progressing,” Ray said. “If natural recruitment of lake trout maintains consistent, we may begin the process of decreasing stocking.”
Wisconsin recently tightened its lake trout fishing regulations in the Bayfield area because of decreasing numbers in those waters, where commercial fishing also takes place.
Duluth charter fishing captain John Stieben of Lake Superior Fishing has concerns about the Minnesota DNR’s curtailment of lake trout stocking.
“We can’t ask for any better lake trout fishing than we have now,” Stieben said. “It’s excellent. I just don’t want them to screw it up … The other states near us are having trouble with lake trout populations. They’re lowering limits and putting size restrictions on. What’s to keep our fish from migrating through that invisible border to their waters? We suffer from another state’s commercial fishing, and we have no ability to help MN-1 with the stocking program.”
Lake trout stocking became necessary starting in the 1960s to rebuild the lake trout population after it was decimated by lampreys and commercial overfishing. Stocking was discontinued in zones MN-2 and MN-3, from the Encampment River to the Canadian border, as native lake trout stocks recovered. It continued in MN-1, where more sportfishing occurs. In MN-1, about 140,000 yearling lake trout have been stocked annually in recent years, Goldsworthy said.
According to preliminary reports from 2015, anglers fishing Minnesota waters of Lake Superior caught 29,077 lake trout, DNR officials said. Of those, 999 were inspected by DNR creel clerks, who found that 89 percent of the lake trout caught near Duluth and 99 percent caught near Grand Marais were wild, not stocked, fish.
Wild fish have comprised at least 50 percent of the catch of spawning-size lake trout in the DNR’s annual spring assessment netting since 2001 in MN-1, according to the agency.
In addition, survival of stocked lake trout in MN-1 has been very low since the late 1990s, Goldsworthy said.
“The rehabilitation of lake trout has long been a goal of fishery managers around Lake Superior,” Goldsworthy said. “These are the same folks that developed the criteria for when stocking as a tool for rehabilitation should be discontinued, and this is what we’ve monitored through time. We’ve met most, if not all, of the criteria since 2001.”
Goldsworthy said he expects the recovery of Minnesota’s lake trout to follow patterns where stocking has been discontinued in other parts of the lake.
“Based on what was observed with post-rehabilitated lake trout populations in eastern Lake Superior, it can be expected in Minnesota waters that wild lake trout abundance will continue to increase to its peak and subsequently decline to a point of equilibrium,” Goldsworthy said. “The big questions now are where will that point of equilibrium be, how does that compare to angler expectations, and perhaps most importantly how do the effects of invasive species, low forage base, and better fishing technology impact lake trout management in the future.”
Forage species such as herring are currently at or near all-time lows, he said.
“Adding more predators (in the form of stocked lake trout) than what’s natural is only going to further impact that prey base,” he said.