DNR unveils new Leech management plan
Walker, Minn. — General satisfaction with walleye numbers, walleye catching, and walleye regulations led to a five-year plan for northern Minnesota’s Leech Lake that perhaps wasn’t as walleye-focused as has been the case in the recent past. That’s not to say walleyes didn’t demand lots of ink in the most recently approved plan for the 112,000-acre lake.
“The previous plans … have really been walleye plans, for lack of a better term,” said Doug Schultz, DNR area fisheries manager in Walker. “This one’s much more objective.”
Which, most fish biologists would agree, is best, especially in a fishery as diverse as Leech, known not only for walleyes, but for fine muskellunge fishing, panfish, big northern pike, two types of bass, and a host of issues – including, notably, double-crested cormorants – that affect fish and fishing.
“The plan (2016-2020) aims to provide a quality, sustainable sport fishery in Leech Lake for the long term,” said Henry Drewes, DNR northwest region fisheries manager, in a department press release.
The Leech Lake plan was developed with the aid of 16 input group members “representing local and statewide interests in Leech Lake management activities,” according to the release.
Group members ranged from the Leech Lake Band of Ojibwe’s Steve Mortensen to fishing guide Al Maas to Jed Shaw, from the city of Walker, along with others. Schultz praised their work with the plan, stating that the group met monthly for at least half the year.
While other fish species received greater collective shares of attention this time around, the Leech plan still devotes extensive space to walleye management.
Schultz said walleye regulations were a “key component” of the process, and that for now, the plan recommends keeping the 20- to 26-inch protected slot in place. The rule allows for a four-fish bag limit, with one over 26 inches allowed in possession.
The plan leaves open the door for change, however, based on a number of factors.
According to the plan: “Adjustments to the (slot) will be considered if mature female biomass continues to exceed the objective range of 1.5 to 2.0 pounds per acre and other key population metrics indicate signs of an unbalanced walleye population.” The plan says that data will be reviewed annually by input group members.
In 2014, that density of mature females was at 2.5 pounds per acre.
Prior to 2005, the walleye regulation for Leech was the statewide rule at that time. However, an 18- to 26-inch protected slot was implemented that year, along with a four-fish bag (one over 26 inches allowed in possession).
When the lake plan was reviewed in 2010, there was support for the plan, but also for “loosening” the slot should spawner stock increase. When that occurred, the current rule took effect in 2014.
The plan also addresses walleye stocking, something just a few years ago was done extensively.
For now, walleye fry aren’t being stocked in the lake, though the plan notes that stocking from 2005 until 2014 ranged from 7.5 million fry to 22.5 million fry during spring stocking. That was done during a decline in the walleye fishery during the early to mid-2000s, according to a DNR; some of it was the result of state legislation. Some of those fish were marked with oxytetracycline, a marker that shows up in subsequent catches of those fish.
By studying those marked fish, a number of things were determined, the plans says.
• higher fry stocking rates haven’t resulted in more walleyes reaching “catchable” sizes;
• higher rates have resulted in slower growth rates for young-of-the-year walleyes;
• higher fry densities have increased predation on young-of-the-year yellow perch, resulting in fewer yellow perch surviving to age 4.
Stocking was discontinued this year “based on strong empirical evidence indicating negative impacts of supplemental fry stocking.”
That said, the plan still addresses when it would be appropriate to stock fry, including when a three-year “moving average” of walleye recruitment falls short of objectives.
Another key number regarding walleyes: The gill-net catch rate this year was about 12.4 per net, according to Schultz.
“We’re in a really good spot,” he said.
Getting more attention this time around by input group members were Leech Lake’s bluegills and crappies, and potentially more restrictive fishing regulations.
Dropping the bag limit to five for each species likely would have anglers wondering why that’s necessary on a lake the size of Leech, Schultz said. But only a fraction of the lake contains suitable panfish habitat, he said, and in the winter, as vegetation dies off, that area is even further reduced.
Right now, the panfish population of Leech exhibit “high size quality,” he said. But the fish could be impacted by excessive harvest.
A special regulation for panfish “would be more preventative than anything,” Schultz said of preserving the current size structure. “We think it has some long-term merit.”
Schultz said creel surveys of Leech anglers will take place the next two years, and during those surveys anglers will be asked about their thoughts on a restrictive panfish regulation.
If there’s support, a proposal could come as early as 2018, he said, meaning implementation in 2019. “But there are a lot of moving parts,” he said.
The Leech Lake plan calls for continued muskie spawn-take operations on the lake every four years “to maintain genetic diversity in brood stock lakes.” As compensation, Leech will get about 600 muskie fingerlings as part of the DNR’s “put-back policy.”
Also, department fisheries biologists will continue to seek an effective way to better measure the muskie population in the lake.
Schultz said northern pike management could be dictated by the advancement of the DNR’s statewide plan for three pike zones.
In the meantime, overall goals call for a modest population with good size quality.
Schultz said the yellow perch population continues to be depressed, but he hopes recent changes reverse that trend – changes like no walleye fry stocking, and less restrictive walleye harvest rules than just a few years ago. “We’re hoping (those changes) will help (perch) to come back normally,” he said.
According to the plan, while perch initially responded positively to the 2005 changes regarding walleye fishing and cormorant control, the population began declining by 2008. Recent abundance is near historic lows, and perch recruitment has been declining since 2007. The size structure, too, has been falling off.
That’s not good news for a lake where perch are A) the top prey fish in the system, and B) an angler favorite. By pounds, perch are the third most popular fish in the summer, and are first among winter anglers.
DNR records indicate fish-eating birds can’t be blamed entirely for perch problems.
Some possibilities, according to the plan:
“A strong negative relationship exists between yellow perch recruitment and total walleye fry densities from the same year,” the report says. “And record yellow perch harvest was documented during the 2010-11 and 2014-15 winter angling seasons. Although many anglers perceive cormorant consumption of yellow perch as a significant influence on recruitment, consumption by cormorants has been reduced by 90 percent relative to 2004 levels and has been similar to pre-2000 levels for several years.”
According to Schultz, much of what occurs within the waters of Leech “all comes down to fishing pressure,” and this winter, thus far that’s been light, given slow-to-develop good ice.
In recent years, however, ice-fishing pressure has risen dramatically, from about 350,000 anglers hours in 2010-11 to nearly 650,000 hours last winter.
The plan also calls for expanded sampling of things like largemouth bass and tullibees.
The final plan, approved by DNR Commissioner Tom Landwehr, can be viewed at: http://bit.ly/1R9Ird8. Electronic copies of the plan can be obtained by emailing the Walker area fisheries office at firstname.lastname@example.org