BOULDER JUNCTION — Most amazing fish stories are hard to believe without the facts to back them up, but one story out of northern Wisconsin has been around for almost 75 years and is all about facts, figures and careful research.

“There are not a lot of places in the entire world, if any, that have the amount of data that we have here, from weather records, to ice-on/ice-off dates, to everything about fish populations, to things that the angler is doing,” said Greg Sass, who likes to tell the story of the Northern Highland Fishery Research Area near Boulder Junction in Vilas County.

The NHFRA was established in 1946 when the Wisconsin Conservation Commission, a predecessor to the Wisconsin Department of Natural Resources, set aside five representative lakes in Vilas County to research the effects of overpopulation of fish on northern lakes. The Five Lakes Research Project, as it was called then, included tea-colored water and crystal clear lakes as well as stand-alone pothole and drainage lakes connected by rivers and streams.

At the time, local anglers were concerned that overly abundant fish populations on some of the lakes were overwhelming the lakes’ natural food resources, resulting in stunted fish.

“Basically, too many mouths to feed,” explained Sass, who is supervisor of fisheries research for the DNR and director of the Escanaba Lake Research Station.

To study the problem, the commission set aside Escanaba, Pallette, Mystery, Nebish and Spruce lakes and set up a check station on Escanaba to record all fish catches and weights of fish harvested. There was no permit fee, no bag limit, no size limit and no closed season. One of the early goals was to be able to estimate “sustainable exploitation rates.” In other words, how much harvest can a fish species handle and still remain sustainable?

By state statute, anglers have to check in and out at the station when fishing any of the five research lakes. Catch-and-release fish are self-reported as to how many of what species were caught within several size ranges. Harvested fish must be brought back to the check station to be identified by species, sex and age and then measured and weighed.

“We’ve done that every day since June 20, 1946,” Sass said.

Over time, the information from the research station and from annual creel surveys on other northern lakes have been able to inform researchers about exploitation rates in the fisheries, angler behavior, targeted species, types of baits, how much effort it takes to catch the fish, whether anglers were guided or not, how long they are on the lake, and demographics, like where the angler is coming from. On average, 3,000 to 5,000 anglers stop by the Escanaba Lake station annually, “and that doesn’t include people who are going hiking or kayaking or using our skiing trails or other activities we interact with as well,” Sass said.

“From the fishing standpoint, the part that is most important for people is that they are directly involved in the experimenting,” he said.

Experiments have included setting trial regulations on some of the lakes to test research theories and effectiveness of those regulations on size and bag limits to satisfy both the angler who wants to fill the boat and the angler looking for a trophy mount.

“Fisheries management is very much a balance between catch rates and trophy potential, and you really can’t have one or the other,” Sass said. “Most of our regulations are to, number one, sustain those fisheries in the long term and, number two, to provide diverse angling opportunities.

“We can do that on these lakes under a lot of control, and if we find (for instance) that this maximum length limit for an overabundant smallmouth bass population is really good for improving size structure and still balance catch rates, then we can take that (regulation) and apply it to other systems where a manager says we’re having these issues with bass and want to try it here,” Sass said.

“It’s a really neat thing to see people embrace the science because, frankly, we can’t test these regulations without anglers,” he added.

Although the mission of the research team is directed toward fishery health, their physical location in the American Legion-Northern Highland State Forest offers crossover opportunities with other areas of state government.

“For example, we are conducting a test right now to study whether dropping trees into a lake can increase the amount of fish that lake can produce or sustain,” Sass said. “When there are planned cuts close to a lake, we’ll walk through with a forester to be sure that the riparian zone buffer is wide enough ... (or) to ensure that any of those trees that die or maybe are struck by lightning or something like that have a chance to fall into the lake and provide that natural habitat that fish need.”

NHFRA data were also important beginning in the 1980s when Native American treaty rights in northern Wisconsin were affirmed. There was little research available on walleye sustainable exploitation rates in other lakes, “but we had a ton of it (from here),” Sass said.

“Escanaba is the most studied walleye lake in the world, from anglers to population, so Escanaba was leaned on heavily to make the decision of what would be considered a sustainable exploitation rate for walleye,” he said.

Besides daily record keeping, research staffers do early spring netting or electrofishing on the lakes to estimate populations and mark targeted species. There is something going on daily for the three full-time people at the Escanaba station and five or six limited-term technicians added during the summer, Sass said.

Funding is primarily from the federal Fish and Wildlife Service, which collects a portion of the money spent on the purchase of fishing and hunting gear, marine fuel, boat sales and other outdoor equipment. That money is redistributed to states based on numbers of licenses sold and is earmarked for managing and sustaining fisheries, providing docks and landings, and other specified uses having to do with wildlife.

“Wisconsin has a lot of licensed anglers and hunters, so we receive a pretty good chunk of that overall pot of money,” Sass said.

While studies were initially limited to the five lakes, the program has grown to apply to the whole state. There are other studies, like a woody habitat study near Boulder Junction, lake sturgeon studies farther afield, effects of chemical weed control on a Florence County lake, issues of largemouth bass competing with walleye on an Iron County lake, and a statewide assessment of cisco status and trends.

Researchers are also taking into account new variables, like changing water quality, invasive species and climate change, but doing it in terms of offering “a safe operating space” for fisheries.

“We’re not going to reverse or stop climate change in the short term, so we have to be able to manage the things that we can control,” Sass said. “If there are certain variables that are outside of our control that are pushing a fishery in a direction that we don’t want it to go, (we ask ourselves), what can we actually change or do in another way to kind of push it back in a way to keep that population sustainable?”

Sass said he sees a bright future for the NHFRA and its ability to address questions for stakeholders, anglers and the fisheries management program.

He also extends an invitation.

“Come on and give these lakes a try,” he said. “They’re beautiful lakes and can be a great experience for a family.”