How many walleye are there in the Saint-Louis River?

By on May 1, 2021 0


They hope to put green, numbered tags on 8,000 gold this spring, like clothing tags on clothes in stores, attached to the dorsal fin.

Fisheries biologists use electroshock to stun fish, pick them up, bring them ashore to mark and measure them, record the data and then quickly release them. But the crews are also in the process of taking back already marked fish.

A green tag attached to the dorsal fin indicates that this walleye was tagged in 2021 as part of a walleye population study in the Saint-Louis River estuary. A few walleye can still swim with purple tags used in the last population survey in 2015. (Photo courtesy of Paul Piszczek, Wisconsin DNR)

As they net into May, they keep track of how many people have the new green tags. MNR experts will then pump those numbers into a computer model over the summer. The ratio of the total number of fish tagged to the number of fish recaptured provides an estimate of the total population.

Newsletter subscription for email alerts

“The goal is to score 5-10% of the total population for the best results,” said Paul Piszczek, fisheries biologist with the Wisconsin Department of Natural Resources in Superior.

This effort is taking some time this spring, as large fluctuations in weather and water temperature caused walleye to spawn in spurts for several weeks. Some days the crews handled over 500 walleye; the other days it was less than 200.

The results of the survey, which should be available to the public by the end of 2021, are eagerly awaited by the fishermen who frequent the estuary. Many avid river fishermen say they have seen walleye numbers gradually decline over the past decades.

In fact, the most recent demographic survey, conducted in 2015, showed it to be true. The estimated population of walleye in the estuary has generally ranged from 60,000 to 90,000 over the past 40 years. But the most comparable and accurate surveys, carried out with similar methods, showed around 76,232 walleye in 1981 and only 46,862 walleye in 2015, the last major survey conducted.

PREVIOUS: According to the survey: walleye from the Saint-Louis river descend

A drop of 30% to 50% “is a huge number. And that coincides with our growing concern for the walleye population, ”said Brandyn Kachinske, President of the Twin Ports Walleye Association. “We have noticed that the number and size structure of the walleye population has dropped from what it was years ago.

Anglers land a pretty walleye from the Saint-Louis River on opening day in 2018. MRN teams capture and tag walleye this spring, then let them go and recapture them to get a good estimate of the walleye population of the estuary.  (Clint Austin / News Tribune)

Anglers land a pretty walleye from the Saint-Louis River on opening day in 2018. MRN teams capture and tag walleye this spring, then let them go and recapture them to get a good estimate of the walleye population of the estuary. (Clint Austin / News Tribune)

Fisheries biologists counter that there will always be fluctuations in populations as each spring produces varying conditions and varying spawning success, and each fishing season brings varying fishing success. But they also note that there is good news for the walleye and the people who like to catch them.

“There was definitely some concern with that number (46,862 walleye) among anglers… but we believe it was a low estimate and we’ve seen a rebound since then,” said Pisczcek.

This optimism is based on a different type of fish survey, carried out each summer by the Minnesota MNR, which films the small walleye that spend their summers in the estuary. (The larger walleye spend much of their year foraging in Lake Superior.)

These summer surveys generally show higher numbers of young fish in the river since 2016, which should mean more larger walleye in the years to come. The 2012 and 2013 classes were particularly good, Piszczek noted, with these fish now 20 to 24 inches long and well into their spawning years – the kind of meaty walleye anglers love to catch.

Good year classes also seem to have come in 2016, 2017 and 2018.

“We expect to see some of these year classes enter the breeding (population) assessment this year, which is why we think the population estimate (this year) will increase” from 2015, said Piszczek.

Minnesota DNR fisheries biologist Alisha Hallam agrees.

“Our summer gillnet rating last year was above average… and, in fact, it has been most of the past few years,” said Hallam.

Last year’s summer survey found 7.3 walleye per fillet, up from the long-term average of 6.6. The survey ranged from a minimum of 2.3 walleye per fillet in 1993 to 10.5 in 2016.

Will the regulations change in the future?

Some seasoned St. Louis River fishermen claim that too many large fish are kept and caught by fishermen, both in the estuary and, in particular, along the south shore of Lake Superior, where many of the larger people of the river spend their summers.

While anglers can only keep two walleye in the river – as long as they are 15 inches or larger – the same fisherman’s boat can go through Superior Entry and then catch five walleye (including one over 20 inches long) in Lake Superior. .

This is the same population of migrating walleye, the same fish that move between the lake and the estuary at different times of the year, and it is not known how or why the boundary of Lake Superior in Wisconsin is different from the limit of the river. (Anglers on the Minnesota side of Lake Superior can only keep two walleye, like the river.)

Other fishermen have called for a maximum size limit, or a slot limit, for fish caught in the river. Right now, anglers can keep two larger walleye with no restriction in size, which could deplete the best breeding fish in the population.

The two current walleye over 15 inches “obviously protect small fish. But that leaves the larger class at high risk. Every year we notice that some anglers keep bigger fish as their limit is only two especially anglers who are from out of town or don’t share the concerns we have Kachinkse noted. “As a club we would like high class fish to have some protection as well. Perhaps an established 15-19 inch slot, for example, which can be kept with one larger than 28 inches for trophy purposes. “

Piszczek said MNR biologists will review the results of the population survey to see if it’s time to change the boundaries to make them consistent across the lake and river, and whether to protect the larger walleye. to reduce the harvest.

“We are looking at that and how we might put them online,” he said. “The more we learn about how they (estuary walleyes) use the lake, it probably makes sense to look at this.”

Any regulatory change should not only clear officials from the DNR, but also the Wisconsin Conservation Congress, often a two-year process, and then the State Natural Resources Council, Legislature, and Governor before they take effect. , said Piszczek. In addition, any changes should be made in concert with the Minnesota Department of Natural Resources, which shares management of the fishery for the 12,000-acre estuary.

“Wanting special regulations in St. Louis is not just for us to catch bigger and bigger walleye,” said Kachinske of the Walleye Association. “But at the end of the day, to make sure the resource is there for everyone, and especially future generations, to benefit from.”

Fishing teams from the Wisconsin and Minnesota MNRs hope to tag up to 8,000 walleye in the St. Louis River estuary this spring and then capture as many as possible to estimate the walleye population in the estuary.  Anglers can report all tagged fish they catch, but their reports are not required for the study.  (Photo courtesy of Paul Piszczek, Wisconsin DNR)

Fishing teams from the Wisconsin and Minnesota MNRs hope to tag up to 8,000 walleye in the St. Louis River estuary this spring and then capture as many as possible to estimate the walleye population in the estuary. Anglers can report all tagged fish they catch, but their reports are not required for the study. (Photo courtesy of Paul Piszczek, Wisconsin DNR)

If you catch a walleye from the Saint-Louis River

You can release it or keep it (if it is a legal size fish). MNR does not need to know if you have caught a tagged walleye. They themselves recapture fish for population study. But they will provide anglers with information about that particular fish – like its age and when and where it was caught. Record the four-digit code from the label and email [email protected] with the information. Green tags are used in the 2021 survey. If you find a fish with a purple tag, that fish was tagged in 2015.



Source link