ISLE, Minn. – Walleye management techniques on Mille Lacs have been affirmed by a panel of four outside experts who reviewed the practices and compared them favorably to systems at other major walleye lakes in the Midwest and Canada.
Results from the highly anticipated audit fit with what the Department of Natural Resources (DNR) has been telling its critics for years. Gov. Mark Dayton was the first to be briefed on the report in a private meeting Monday at the governor’s residence in St. Paul.
“The science and the assessment program that the Minnesota DNR is implementing on Mille Lacs appears to be appropriate given the scale and size of the fishery,’’ said Chris Vandergoot, the federal research fisheries biologist who led the external review from Ohio.
A leader of the Mille Lacs walleye community ripped the report as superficial.
“It’s disappointing because we really expected more,’’ said Mille Lacs resort owner Dean Hanson, co-chair of the DNR-appointed Mille Lacs Fisheries Advisory Committee (MLFAC). “It did very little to satisfy the questions I had.’’
In the wake of the report, which was presented Monday night at a MLFAC meeting at McQuoid’s Inn, DNR fisheries chief Don Pereira said Tuesday that no changes will be made in the way his staff estimates walleye abundance or how the agency measures the harvest and fish mortality.
Business owners, lakeside cabin dwellers, fishing pros and other anglers have accused the DNR of underestimating the lake’s walleye population and setting low harvest quotas. The recent restrictions have caused temporary fishing shutdowns and regulations that have made it illegal for summer anglers to keep any walleyes.
Those protections will remain in play this year even as the biggest crop of walleyes now swimming in Mille Lacs has grown into sexual maturity and is helping to boost natural reproduction. Still, the DNR has said most baby walleyes in Mille Lacs die before their third year — a critical, unresolved problem.
Dayton and DNR officials have acknowledged that economic hardships have coincided with the collapse of walleye fishing, but they have stood behind scientific analysis that they say calls for protection of a changing walleye fishery.
In announcing the external review last summer, the DNR said it wanted an external team of scientists to “take a fresh look’’ at the Mille Lacs walleye fishery. The agency said the review “will provide additional recommendations to improve fisheries management of the lake.’’ No such recommendations will be forthcoming.
Vandergoot said Monday at McQuoid’s that the panel’s review was merely observational, and its report has not been peer-reviewed. He said it will take more work to put the report in writing.
Still, he said his panel found no significant flaws in the DNR’s technical approach on Mille Lacs. In areas such as the tagging of walleyes to study population trends in the lake, Minnesota exceeds standards, he said.
“It may sound like I’m singing their praises,’’ Vandergoot told MLFAC members. “I’m just giving the facts.’’
Hanson said MLFAC members initially submitted nine pages of questions and concerns to Vandergoot as part of what they expected would be a comprehensive review. He said Vandergoot was overwhelmed by the volume of issues raised by the committee, but didn’t have time and resources to tackle them.
“Don’t sell it as a comprehensive review of the entire management system of Mille Lacs because it was certainly not like that,’’ Hanson said.
In a Facebook video, Hanson likened Vandergoot’s report to a “DNR rubber stamp.’’
Vandergoot, of U.S. Geological Survey’s Great Lakes Science Center, once managed the massive walleye population in the Ohio waters of Lake Erie. Other panel members were James Randy Jackson, a fisheries researcher at Cornell University who has studied walleye in New York’s Lake Oneida; research scientist Troy Zorn of the Michigan DNR; and Doug Watkinson, who has studied walleye in Lake Winnipeg for the Department of Fisheries and Oceans in Canada.
They reviewed techniques used on Mille Lacs in relation to techniques used on Lake Erie, Lake Oneida, Lake Winnipeg, Devil’s Lake in North Dakota, Sharpe Lake in South Dakota as well as other Canadian and Midwestern walleye lakes.
Certain MLFAC members have alleged that the DNR underestimates walleyes by continuing to place its fall survey gill nets in areas of Mille Lacs that no longer hold fish because of increasing water clarity and other ecological changes. The survey is vital to estimating the lake’s walleye population and setting the year’s walleye quota.
Hanson said the netting locations in the survey haven’t changed in 45 years and fail to count large numbers of walleyes that have moved to deeper water. That includes expansive mud flat locations that local fishing experts say are underrepresented in the gill net survey.
But Vandergoot said the DNR follows standard procedures by sticking to the same netting locations year after year, producing standardized results.
“No agency chases fish with nets,’’ he said. Getting strong spatial coverage with nets is important and the DNR’s net placement during the fall walleye survey is intense, Vandergoot said.
He said Minnesota’s gill nets are unlike nets in other states because they don’t include a large mesh size to capture the biggest walleyes. But he said the difference is “not a game changer’’ and added that a larger mesh size now would confuse data comparisons.
He also said Minnesota uses a white-tinged multifilament netting material that could be more visible to walleyes than monofilament nets used by fisheries manager on other big walleye lakes. But remaining consistent in the type of netting — rather than changing materials — is most important for accurately detecting walleye population trends, Vandergoot said.
Hanson said MLFAC members doubt the validity of DNR estimates on fishing pressure. The estimates are vital to calculating how fast anglers are approaching each season’s walleye quota.
Vandergoot said the estimates are based on solid surveying of anglers about their catch. In fact, the DNR puts more effort into the so-called creel surveys on Mille Lacs than do fisheries managers on Ohio’s portion of Lake Erie, a recreational walleye fishery three times the size of Mille Lacs, he said.
Hanson said critics of the DNR don’t question the intensity of creel surveys. Rather, they wanted the panel to evaluate whether the DNR’s “expansions’’ of creel data exaggerate overall fishing pressure on the lake.
Vandergoot’s panel looked at the DNR’s use of “hooking mortality’’ to estimate how many fish die after being caught and released. Some MLFAC members believe hooking mortality is overestimated. Vandergoot said the practice of calculating hooking mortality for fish caught and released is standard on certain Canadian walleye lakes. In addition, the DNR used sound science in arriving at the hooking mortality rates that it applies to the fishing season depending on temperatures and other factors.
Vandergoot said he was “blown away’’ to discover that Mille Lacs receives as much or more fishing pressure per unit of water than other large walleye lakes. He said the pounding has coincided with significant ecological changes in Mille Lacs that have included an explosion of invasive zebra mussels, a large decline in nutrients and stark increases in sunlight penetration.