New DNR plan aims to get Mille Lacs Lake back on track (Released January 21, 2014)
National review of management part of effort to boost walleye numbers
Unprecedented change is occurring at Mille Lacs Lake and the Minnesota Department of Natural Resources is taking unprecedented actions to address it. The agency will convene a blue-ribbon panel of national fisheries experts to review past and current management practices as part of a new effort to increase the legendary lake’s walleye population as quickly as possible with minimal impact to the local community.
“We will have nationally recognized fisheries experts review our work and offer recommendations,” said Don Pereira, DNR fisheries chief. “We want the lake back on track. This is one strategy to do that.”
Panel members are: Drs. Jim Bence and Travis Brenden, Quantitative Fisheries Center at Michigan State University; Dr. Paul Venturelli, University of Minnesota; Dr. Nigel Lester, Ontario Ministry of Natural Resources and the University of Toronto; and Dr. Lars Rudstam, Cornell University and Oneida Lake Field Station.
Mille Lacs, a 132,000-acre lake in central Minnesota, is long-favored by anglers due to its abundant walleye population. However, the walleye population has been in decline for a number of years. Pereira said a key problem is the vast majority of walleye that hatch do not survive to their second autumn in the lake.
He said that while the lake continues to have adequate walleye spawning stock and more than enough egg production and fry to repopulate the lake, the lake hasn’t produced a strong year-class of walleye since 2008.
To further help solve the problem, Pereira said the agency intends to contract with a nationally recognized fisheries expert to do an intensive review of the state’s fish tagging and fishing population estimates.
These reviews, combined with a new predator diet study to determine impacts on small walleye survival and fishing regulations that aim to protect young walleye, are all part of a systematic approach to improve walleye fishing. The diet study also includes winter sampling of predator fish under the ice.
The DNR acknowledges that state and tribal fisheries management has played a role in the decline but long-term solutions will involve better understanding an evolving system that now has clearer water, a variety of unwanted aquatic invasive species, growing walleye predator populations and decreasing prey populations, such as perch and tullibee.
Pereira said the problem of promising walleye year classes that disappear year after year is linked to “system change.” Change includes:
- Increased water clarity: Water clarity has nearly doubled since the mid-1980s. Improvement began about 25 years after the implementation of the federal Clean Water Act in the early 1970s and has trended sharply upward since zebra mussels were discovered in the lake in 2006. Improved water clarity has been linked to movement of young of the year walleye off-shore at smaller sizes, and may also have benefited sight-feeding fish that prey on walleye and perch. - Increased walleye predator populations: Northern pike and smallmouth bass populations have risen significantly since the early 1990s. In 2013, the northern pike population increased to the highest level ever observed. The 2013 smallmouth bass population was the second-highest ever recorded. Smallmouth bass populations have been on the increase throughout Minnesota and Canada. - Multiple aquatic invasive species: Once devoid of aquatic invasive species, Mille Lacs now contains zebra mussels, spiny water fleas, and Eurasian watermilfoil. While it’s unknown exactly what implications these infestations are having, it’s suspected the increase in milfoil is providing more ambush cover for northern pike. Also, water-filtering mussels are contributing to water clarity that allow more aquatic vegetation to grow at deeper depths and in more dense stands. - Changing zooplankton community: First detected in 2009, spiny water flea numbers have fluctuated but show no signs of declining. Spiny water fleas may be having a negative impact on the native zooplankton community by directly competing with small fish for food and altering the historic aquatic food chain. - Long-term changes in key forage species: The most prominent change is a decline in tullibee, likely the result of warmer water temperatures. A decline in tullibee is likely negatively affecting walleye in Mille Lacs, especially larger walleye, as walleye grow significantly faster when they are able to feed on this species because it is higher in calories than other prey species, including yellow perch.
“Clearly, Mille Lacs is undergoing system change,” Pereira said. “As we work to rebuild the walleye population these factors will influence management decisions.”
Pereira said the DNR is also exploring new and innovative ways to engage citizen input on future management decisions and will help support a new tourism marketing initiative that is being formed by the local community and Explore Minnesota Tourism.
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.”
Changes
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.
what is the 5 year plan and how can the lake be managed like that if its going to all these changes?
Here it is in all it's glory:
A Proposal for Walleye Management in Mille Lacs Lake 2013‐2017
Minnesota Department of Natural Resources
June 11, 2012
Summary
For more than a decade harvest management of Mille Lacs walleye has been successful at
ensuring that harvest (including post‐release angling mortality) does not exceed estimates of
harvestable surplus. Under the current management system it appears that conservative protected‐
length slot limits keep the angling harvest well within its share of the harvestable surplus in most years,
in fact falling far below that share in most years. Despite the large remaining harvestable surplus in
most years since around 2000 and from both the Bands’ and State’s fisheries, some measures of the
walleye population status have not necessarily responded expectedly. Looking more closely at the sex,
size, and age‐specific harvest information, it appears that perhaps some size/age classes have are
exploited at consistently high rates, and differential growth between sexes, and the harvest
management strategies employed by both fisheries may have contributed to size/age and sex‐specific
patterns in population status indicators. It is fair to assume that goals between the fisheries are
common, focusing primarily on the health of the stock, but also on improving or at least maintaining the
abundance of targeted fish. Therefore at this time it is proposed that a modification to management of
Mille Lacs walleye be pursued that focuses on establishing management targets/goals based on walleye
population characteristics and design management actions that seek to get us to or keep us at those
population characteristic goals.
Background
Walleye Harvest Regulation
The shared fishery on Mille Lacs has been executed for 14 years (1998‐2011). To date walleye
harvest is being managed successfully with the State and Bands remaining within the harvestable
surplus most years. Overall the State has managed the angling fishery such that total angling mortalities
(angler harvest and hooking mortality) have been substantially lower than its share of harvestable
surplus (allocation) over the entire time period (Table 1). The State exceeded its share of harvestable
surplus in 1998‐1999 and again in 2002. However, once protected slot limits were established in 2003
(Table 2), only one small overage occurred in 2007, and in general very large underages in the State’s
fishery have resulted (Table 1).
Summing across all 14 years the State’s kill was approximately 75% of the State’s allocation.
Over the same time period Band kill was 72% of its allocation. During this period the State has exceeded
its allocation 4 times, with 2 overages occurring during the grace period granted to the State by the
court at the beginning of the shared fishery (Table 1). These overages totaled 337,737 pounds; 151,211 pounds in 1998, 86,597 poundsin 1999, 82,060 poundsin 2002, and 13,869 poundsin 2007. The largest
overage occurred in 1998 under a 15‐inch minimum angling regulation. Since 1999 more restrictive size
regulations have been in place and overages have been smaller.
Successive State overages occurred only in 1998 and 1999. The 2002 overage of 82,000 pounds
was followed by four consecutive years of underage totaling more than 900,000 pounds. The 2007
overage of 13,869 pounds was followed by three consecutive years of underage from 2008‐2011 ranging
from 140,000 to 273,000 pounds and totaling more than 813,000 pounds. Since the beginning of
conservative protected slot limits for anglers on Mille Lacs (2003‐2011), the State’s underage of more
than 1.73 million pounds has outweighed its overage (0.014 million pounds) 128 to 1.
Regulations imposed on the State’s angling fishery (Table 2) have influenced walleye kill.
However, factors unaffected by angling regulations also appeared to influence walleye angling
exploitation, such as forage abundance and angling effort. For example from 2004 to 2006, under
identical annual angling regulations and similar safe harvest levels, State walleye kill ranged from 79,000
to 479,000 pounds (Tables 1 and 2).
Walleye Exploitation
Age‐specific exploitation rates estimated by a sex‐specific SCAA model shows that total
exploitation rates have declined since 1998, averaging approximately 13% compared to an average of
19% during 1987‐1997. However, exploitation rates on age‐4, age‐5, and age‐6 male walleyes have
generally increased during each five‐year time period since 1998 (Table 3; Figure 1). Exploitation rates
on age‐3, and age‐4 female walleyes were similar between time periods but have declined for older ages
(Table 3; Figure 1).
At some ages both males and females have been exploited at relatively high rates but generally
the male walleyes in the age classes presented were exploited at a higher rate for more consecutive
years (Tables 4 and 5).
Looking at exploitation rates by fishery type (angling and tribal) suggests that the size‐based
regulations have reduced angling exploitation rates for male walleyes in age classes 4‐6, but tribal
fishery exploitation rates on these same age classes have increased over the same period resulting in
the overall increase in exploitation rates on males in age classes 4‐6 (Figure 2). In addition the angling
regulations have successfully reduced female angler exploitation rates (Figure 3).
So perhaps these exploitation rates at or above historical levels combined with physiological
differences between male and female walleye could be contributing to the decline in harvestable‐sized,
primarily male, walleyes in Mille Lacs (Figure 4 and 5).
Conceptual Management System
The current management system may have some flaws that do not account for sex and size‐
specific impacts to the walleye population. Therefore despite the apparent overall success at staying
within harvestable surplus levels, maintaining levels of target‐sized fish has been unsuccessful to the
point that continued harvest management under the same system may not be possible (Figure 6).
What we are proposing is a significant departure from the current management system and
considers four primary changes:
1) Change to sex‐specific management of the Mille Lacs walleye fishery;
2) Modification of sex‐specific target harvest levels;
3) Adoption of a “sliding target harvest rate” that modifies the target harvest rate based on walleye
population status; and
4) Using model‐derived population status metrics in place of survey‐derived metrics.
Lotta mumbo jumbo from a bunch of biologists that probably have never even SEEN Mille Lacs Lake, much less fished it.
Listening to this crap, they sound like there is no problem AT ALL!
HELLO, McFly !
40 year low? Remember????????????
-- Edited by fishnpole on Wednesday 22nd of January 2014 03:35:08 PM
After 10 years of listening to our dnr experts tell us only they know how to improve fishing on Mille Lac, now they are going to bring in some more experts to try and correct the solutions that were shoved down our throats for the last 10 years. When the small fish were on the decline, we were forced in accepting changes that focused on the harvesting of small fish. How many people actually believe that the way to increase the number of small walleyes is to continue to harvest only the small fish. I think its time to do away with the special regulations on Mille Lacs and let the lake adjust the natural way. There will be years of ups and down but at least there will be some ups. If that doesn't work, we could always bring in some experts in 10 years and do another study. Is it only by chance that the problems on Mille Lacs started shortly after the netting started, and all solutions that were tried didn't work as long as netting continued. I think that the current condition on Mille Lacs is a conservation issue and all solutions should be on the table. If not, stop wasting my time and our money by over regulation. How much money and state resources have been wasted by shirting the issue of does netting have a negative affect on the walleye population. Now that Dayton is going to run again, maybe he can give us another round of empty promises to help to make us feel better until after the election.
They see it Johnnie, they just do not say anything about it, to start an uproar, in witch is needed
It is like the drunks/drug addicts on disability, the illegal aliens on welfare/social security, or the best dressed person in the grocery store using food stamps, loading them into a $50,000 grocery getter SUV - They know it is incorrect, but it would cause an uproar to appeal it
It is all government hoopla, somehow they see, or get satisfaction with living in a the land of make-believe
They(the government) can not even figure out how to spend the money they get that comes in guaranteed
They have to shut down for a couple weeks to get that straitened out
I am sorry, but I think they will say they have bigger fish to fry, other than the ones on Mille-Lacs lake, and let the nets keep on setting every year during the spawn, because, by golly that's tradition
Total BS, even Fred Rodgers in the land of make believe, will tell you that
"The Department of Natural Resources can hire all the experts it wants to study the Mille Lacs walleye problem. And in fact the agency plans to do just that, given its announcement earlier this month that it will form a “blue ribbon’’ panel to review the big lake’s fish population surveys and other data.
But in the end, experts or no experts, two things should happen.
Should being the operative word.
• Mille Lacs anglers this summer should be limited to catch-and-release walleye fishing.
• The Chippewa should suspend their walleye harvest from Mille Lacs. If they refuse, the DNR should return to federal court to argue that the lake’s walleye dilemma qualifies as a legitimate “conservation’’ crisis to be decided by the court, in accordance with its previous treaty rulings.
• • •
Consider the following.
• The big problem at Mille Lacs is that, despite the massive spawning power its larger walleyes amass, and the spawning success they’ve had, baby walleyes aren’t growing up to be big walleyes.
• In fact, the last good-sized year-class of walleyes in Mille Lacs was hatched in 2008. These are fish that this summer will edge into the 18- to 20-inch harvest slot that governed Mille Lacs walleye anglers last year.
• DNR fisheries chief Don Pereira says neither he nor his staff knows exactly why, or how, the small walleyes are disappearing. They suspect — probably with high assurance — that the little fish are being eaten by big fish. The question is, by which big fish, exactly? The lake’s bigger walleyes? (Almost surely, to some degree.) The lake’s growing northern pike population? (Almost surely, to some degree.) Its many smallmouth bass? (Almost surely, to some degree, given their abundance in the lake — even though smallies don’t typically feast on walleyes.)
• Unknown is to what degree other factors are helping to accelerate, or perpetuate, the loss of young walleyes. The DNR suspects the lake’s clearer water plays a role in increasing predator efficiency (environmental regulations in force beginning in the late 1990s, together with the more recent arrival in Mille Lacs of zebra mussels, have increased water clarity). Additionally, invasive species other than zebra mussels are now in Mille Lacs in relative abundance, not least spiny water fleas and Eurasian water milfoil. Perhaps some combination of these, the DNR figures, could help big fish more effectively target little walleyes.
• Last summer, the DNR allowed Mille Lacs anglers to keep two walleyes between 18 and 20 inches — a slot some anglers hit early in the season but which became increasingly difficult to target as summer wore on (which is typical).
• Perhaps the DNR’s new panel of experts will in fact divine the exact reason, or reasons, why small walleyes in Mille Lacs aren’t reaching maturity.
• But regardless, if you’re Pereira, what do you do this summer? You can’t direct harvest pressure to the lake’s smaller walleyes, because they’re the ones that are increasingly rare. Nor can you focus pressure on the 2008 year class — fish that will be about 17 to 19 inches long this summer. And what of the lake’s tremendous spawning biomass, e.g., walleyes 19 to 24 inches? You probably don’t want these fish to be taken either — they’re the future.
• OK, but why not let anglers this summer keep one walleye over, say, 26 inches? Arguably, this would reduce the lake’s predator population while also giving anglers something to fish for. So maybe that could be done. But how many walleyes 18 to 26 inches would be caught and released — some of which would subsequently die — before an angler found one over 26 inches? Probably quite a few, especially as summer progresses and the lake water warms. So, the possible adverse effect on these smaller walleyes would have to be accounted for in the harvest calculus undertaken in the run-up to establishing this summer’s regulations.
• Now consider the Chippewa nets, which have been strung in the lake during the spring spawn since the late 1990s. In and of themselves, the nets are not the lake’s problem. Not entirely, anyway. But don’t forget: The harvest slots that govern walleye angling on Mille Lacs are a corollary of the nets. One (the nets) begot the other (the harvest slots) as the DNR and the Chippewa have attempted to manage the lake’s harvest cooperatively. But now it seems clearer that each, probably in combination with the other, has contributed to, or perhaps even entirely caused, the current Mille Lacs walleye problem.
• The Chippewa could increase the size of walleyes they take by requiring members to use nets of larger mesh size than is currently the case. The DNR also (as stated earlier) could steer the angling harvest toward bigger fish. But remember: The lake’s walleye harvest quotas are determined not by fish numbers but by fish pounds. So the quotas would be reached relatively quickly under these changes, thus limiting harvest opportunity.
• What to do? Clearly, in my view, Pereira and his boss, DNR Commissioner Tom Landwehr, should appeal to their boss, Gov. Mark Dayton, to let them ask the Chippewa to pull their nets from Mille Lacs until, and unless, the lake’s walleye population recovers. As a secondary possibility, the Chippewa should be asked to focus their harvest on bigger walleyes. If they refuse either option, the state should take them to court. That’s what the court’s for.
• • •
Regardless which actions are taken, the local economy will suffer.
Which is unfortunate. But perhaps one of the region’s savvy legislators can think up a relief plan, in working with the state tourism folks and the governor’s office, that can ramp up visibility of the lake’s, and the region’s, attractions other than walleyes.
Releasing a tagged smallmouth bass or northern pike in Mille Lacs every month this summer that’s worth $10,000 or more to the angler who catches it certainly would drive some traffic to the lake.
Got a better idea how to manage Mille Lacs walleyes?"