FOR IMMEDIATE RELEASE – by Adam Hinterthuer
As lakes across the upper Midwest warm, cool-water species of fish are finding it harder to thrive. In Wisconsin, that trend is especially noticeable in struggling walleye populations. Walleye are important to many Indigenous communities, a top target in the state’s sport fishery, and a popular item on many restaurant menus.
Like many states, Wisconsin spends millions each year on efforts to keep the walleye fishery running. But, according to a report in a special issue of the journal Fisheries Management and Ecology, it is time to rethink some of those efforts.
Current fishery management practices rely too much on “resistance,” says Zach Feiner, a research scientist at the UW-Madison’s Center for Limnology, who was lead author on the report. Under such strategies, he says, the goal is to “restore” struggling fish species, not accept or adapt to new conditions that now favor different species.
In Wisconsin, “we try to prevent and resist change and keep walleye coming out of lakes,” Feiner says. That adds up to millions of dollars’ worth of investment in raising walleye in hatcheries and stocking them in lakes as well as “a ton of harvest management, including strict regulations like closing walleye fisheries or severely limiting harvest.”
But, Feiner says, for many lakes, these efforts “are just not working very well.” For example, in Wisconsin, lakes that have historically been havens for walleye are now so warm that the scales are tipped in favor of species of fish like bass and bluegill. No amount of effort is going to fix the fact that walleye’s living conditions have changed.
This is a fact that Holly Embke, a research fish biologist with the U.S. Geological Survey, knows all too well. Embke recently completed a five-year research project aimed at giving walleye a boost in McDermott Lake in northern Wisconsin. Her primary objective was to remove as many bass, bluegill and other fishes in the warm-water “centrarchid” family as possible from the lake. The thought was that, free of competition for food and habitat, walleye would have a chance to rebound and reestablish a healthy population.
Despite this “intensive resistance” approach – which resulted in the removal of nearly 300,000 centrarchids from the lake – Embke’s team has yet to detect any sort of improvement in walleye numbers. Her findings appear in the same special issue of Fisheries Management and Ecology as Feiner’s.
“We threw tons and tons of effort out there,” Embke says, “much more than would be feasible for a management agency, and we didn’t get a response from walleye.”
It’s clear, she says, that interactions between walleye and the warm-water species in the centrarchid family are “not something that’s under the control of fisheries managers to fix.” More often than not, warm water species are simply going to come out on top in warming lakes.
The news isn’t all bad. Even under the more extreme warming models, Embke and Feiner point out, there will still be lakes that provide cold-water refuges for walleye. In fact, Embke and Feiner are currently working on a project to identify these “bright spots” in hopes that fisheries managers can focus their limited time and money on keeping healthy walleye habitat and naturally reproducing populations in those lakes.
For the majority of lakes, however, it will cost too much time and money to keep them all supplied with enough stocked fish to support a “grow and take” walleye fishery. Which means it is time, Feiner says, to accept the things we cannot change.
“Much of the work in the future is, I think, going to be on the social side, laying the groundwork for people to be able to accept changing fisheries,” Feiner says.
It’s a shift that is going to come with growing pains. Right now, walleye are tops in Wisconsin’s recreational fishery in terms of desired species even though warm water fishes, like bass or bluegill, are what an angler is more likely to catch.
While bluegill are a popular panfish, there is a misconception that smallmouth and largemouth bass aren’t suitable table fare.
“Bass are perfectly good to eat,” Feiner says. It’s just that, due to a combination of fishing attitudes and fisheries management decisions, they have become synonymous with “catch and release.”
“It’s an attitude that can shift,” Feiner says. “It already shifted one way and it can shift back. I think anglers are more flexible than a lot of people give them credit for.”
Embke agrees that anglers can be flexible to changes in the fishery, citing numerous studies that have shown this in action. “What comes out in the data is that angling harvest follows species abundance trends,” she says, “People when they’re out fishing are going to catch what’s available. The average angler when presented with a bluegill is going to catch a bluegill rather than only going for walleye.”
That kind of fishing flexibility is going to be key, Feiner says, because “within our lifetime, we’re going to be at a place in our Wisconsin lakes where it’s mostly a warm-water fishery. The fishing we did as kids in Wisconsin is not the kind of fishing my daughter is going to be doing when she’s my age. It’s going to be a different landscape and there’s going to be different opportunities and you’ve just got to be willing to take those opportunities.”
“There will be fish,” he says, “they will just be different fish.”
CONTACTS:
Zach Feiner, zachary (dot) feiner (at) wisconsin.gov (608) 221-6331
Holly Embke hembke (at) wisc (dot) edu, (703) 648-5953
Press officer, Adam Hinterthuer, hinterthuer@wisc.edu, (608) 630-5737
PAPERS AVAILABLE HERE:
https://onlinelibrary.wiley.com/doi/10.1111/fme.12549
and
https://onlinelibrary.wiley.com/doi/full/10.1111/fme.12544