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.
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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.