Major overhaul in management on Lake Mille Lacs?
St. Paul — For a number of years, Minnesota DNR Fisheries officials have noticed a disturbing trend regarding the walleye population in Lake Mille Lacs – a continued slide in the abundance of young males.
Last week, upon review of a fish management/harvest plan submitted by eight Chippewa bands that net walleyes from Mille Lacs, the DNR responded with a letter expressing concerns that “center on conservation and affect the management of fish populations in Mille Lacs.” Matters of conservation are grounds for seeking management changes, per the court ruling that affects Mille Lacs management.
DNR officials believe recent data collected from fish assessments could lead to drastic measures, possibly “a major overhaul in how we’re managing the system,” according to Don Pereira, DNR fisheries research and policy manager.
A meeting with the band’s representatives and those from the Great Lakes Indian Fish and Wildlife Commission already was slated for July. Pereira said that unlike most years, that one-time get-together likely won’t cut it this summer.
“It might be a complete re-working (of the management plan),” he said. “That would be difficult to do in one day.”
Information from last year’s walleye assessments are the reason state anglers must now abide by a protected 17- to 28-inch slot for walleyes, versus last year’s less restrictive 18- to 28-inch slot.
Chief among the DNR’s concerns in the plan review is the possibility that tribal harvest – by the Mille Lacs and Fond du Lac bands in Minnesota, and six bands from Wisconsin – is threatening the male walleye population. Likely, Pereira said, the harvest method already has. The assumption, in harvest modeling, is that the tribal take consists of 80 to 85 percent male walleyes.
State officials say the bands’ minimum allocation – under a proposed 5-year plan – “would greatly exceed 50 percent of the total male harvestable surplus, and possibly even exceed the entire male harvestable surplus.”
Besides the fact that spring tribal gill nets tend to target male walleyes that arrive early in shallow water, protective slots in place for the past several years also force state-licensed anglers to keep smaller fish, as well. Pereira says there’s “emerging information” regarding the effects of a protective slot, coming from other large lakes, though exploitation of young male walleyes is “nowhere near the level it is on Mille Lacs.”
While much of the past attention has been focused on the lake’s spawning females, Pereira said the importance of smaller males is less recognizable, but if the decline continues, could be revealed in poorer year-classes. One female walleye’s eggs might be fertilized by three to five males, he said, and if the level of male walleyes drops low enough, it’s possible some eggs might not be fertilized, reducing the possibility of a strong year-class.
“That’s the ultimate concern,” he said.
Pereira said there’s likely no clear indicator how dire the situation is, currently. However, he adds, waiting to make changes could jeopardize the walleye fishery.
“It’s hard to detect when (the decline in young males affects the fishery), but when we do, it might be too far down the road,” he said. Instead, department officials believe it’s best to act now, since recent assessments continue to show a falling population of male fish.
“How long do you want to let it go?” he asks.
Female walleyes are less vulnerable, Pereira said, because they hit the protected slot more rapidly than male walleyes, rendering them off-limits to state anglers sooner.
The DNR’s response to the tribal plan suggests that, given the methods and timing of the tribal fishery, “band declarations should be a function of the male spawning stock biomass, not of total safe harvest level, and no longer an arbitrary value based on growth in the tribal fishery.”
The bands’ plan includes new “triggers” that could raise tribal harvest to 169,000 pounds during the year. This year, the eight tribes harvested about 80,000 pounds, though their declaration was 142,500.
Only once since state/tribal co-management began has the tribal harvest exceeded 100,000 pounds of walleyes. And only twice since 1997 have state anglers exceeded their allocation of walleyes.
The timing of gill-netting
Another point raised by the state DNR: The current tribal fishing season ends March 31, and, given early ice-out, bands could harvest walleyes prior to that date to the previous year. The take after that date would apply to the new season.
“This would invalidate the current harvestable surplus estimates because those fish would not have been included in stock assessment analyses,” the DNR’s review says.
The situation could’ve occurred this spring, as the bands had “significant 2011 quota remaining, and could have harvested the remaining 2011 quota (about 80,000 pounds) prior to March 31, and then taken their 2012 quota of 142,500 pounds, resulting in the true removal of 222,500 pounds of fish from the 2012 harvestable surplus.”
Count all pike
The DNR’s third point: The tribal fishery needs to account for all sources of northern pike mortality due to their fishing activities, including release mortality.
“Just as it is necessary for the state to account for angler release mortality of walleye and northern pike, it also is necessary and prudent for the bands’ fishery to account for all sources of mortality in their fishery,” the DNR’s letter states. Further, it states, “Harvest data indicate that some bands may be releasing substantial numbers of northern pike.”
A Fond du Lac Resource Management memo regarding tribal netting and spearing on Mille Lacs this year addressed pike release:
“The (Fond du Lac Resource Management Division) also would like to stress the importance of releasing northern pike from gill nets, if the pike appear able to survive. This is extremely important this year. Fond du Lac has a 25,428-pound walleye allocation, but only a 1,387-pound northern pike quota. Note that even though this is a 423-pound increase over last year, it is not likely the FdL will be able to gain additional pike throughout the season.
“The regulations state that once FdL harvests their quota for any species, then netting is shut down for all species. So once FdL has harvested 1,387 pounds of northern pike, we are done netting, even if we’ve only harvested 100 pounds of our 25,428-pound walleye quota. …”
The DNR’s fourth and final point addresses the “chronic declaration of a tribal allocation that is not subsequently harvested may reduce the effectiveness of that state’s management and increase the chance of state overharvest.”
For the past two years, tribal harvest on Mille Lacs has hovered near half the tribes’ declaration.
“Management actions (slots) imposed on state anglers are based on bands taking their full quota,” the DNR writes. “If band harvest is substantially less than their declared quota, the effectiveness of the state’s management actions may be reduced because more fish will be available for angler harvest.”
Other relevant information, like future harvestable surplus, spawner biomass, and other data might be skewed because of tribal under-harvest.
Are there solutions? Pereira says he won’t speculate at this point. Should the tribes not agree that changes are necessary, it’s possible the matter could go to mediation, something that hasn’t happened in a decade.
The argument this time around would be “fundamentally different,” Pereira said, in that it would be based strictly on conservation concerns.
Charlie Rasmussen, a spokesperson for the Great Lakes Indian Fish and Wildlife Commission, said officials with the commission recently had received the notice from the Minnesota DNR, and were reviewing the information.
“Like any management plan, we’ll make the best decision for the sustainability of the resource on Mille Lacs,” he said.
Rasmussen said the Minnesota and Wisconsin tribes also monitor the walleye situation in Mille Lacs, typically through fall electro-fishing.
He also said tribal nets can be fished to a select size of fish.
State angler walleye harvest continues to easily outpace last year’s catch. Through June 15, the total harvest was about 164,000 pounds, about twice that of a year ago.
Of note: the catch-and-release walleye take was about 570,000 pounds during the first 15 days of June, of which about 23,200 pounds counted toward hooking mortality. The total kill during the typically most productive time of the open-water season on Mille Lacs was about 63,400 pounds.