Results of walleye population estimate on Hubbard Lake
The DNR has completed a number of walleye population estimates across Michigan lakes for many years, but most of the time they're done on lakes in tribal waters. Recently the Northern Lake Huron Management Unit decided to conduct an estimate on a gem of a waterbody, Hubbard Lake in Alcona County.
Tim Cwalinski, a DNR fisheries biologist based out of Gaylord and the Northern Lake Huron Management Unit, helps to manage Hubbard Lake. He refers to Hubbard as a good walleye lake, despite the fact it hasn't been stocked with walleye since 1991. It was previously considered a yellow perch lake until interested constituents requested the managers consider walleye.
Ideally, managers have data at their disposal that allows for proactive management. Conducting a point-in-time estimate about the number of walleye in the lake will help current and future managers better understand the lake's walleye populations over time.
"Twenty years from now, if people are asking us to stock more walleye we'll have baseline data (as a result of this survey) that will help us determine if we should do that," Cwalinski explained.
The purpose of the population estimate was to evaluated walleye growth, abundance and angler catch rates. After ice left the lake in April 2017 crews went out and used trap nets and nighttime electrofishing to capture as many walleye as they could. The crews tagged or fin clipped 3,763 adult walleye. All of those fish were released with the intention to conduct a re-capture survey days later.
"We then electrofished for one full night to recapture marked fish," said Cwalinski. "We collected 959 walleye, of those, and 141 had either the tag we put on or were fin clipped."
Based on the formula used to determine what percent of the total population those tagged and clipped fish represent, it's been determined that Hubbard Lake has approximately three adult walleye per acre - which Cwalinski believes is a conservative estimate.
"That's a very good estimate for a lake that we do not have to invest in with stocking," he shared.
Hubbard Lake anglers are also asked to return any tags they find on the jaws of walleye caught there. Since the 2017 estimate about 85 tags have been returned. Anglers are asked to continue to report those tags in the future which will provide insight into exploitation, and will also allow the DNR to get to know the Hubbard Lake anglers better.
Fish that were captured and tagged were between 12 and 25 inches, with some fish as old as 20 years!
Again the valuable information collected during this estimate will assist fisheries managers greatly in the years to come. Cwalinski acknowledges that although Hubbard Lake was always thought to be a great yellow perch lake, the abundance of adult walleye in there will always subdue the perch numbers to some degree.
"This baseline data is critical for us as we make decisions on this lake in the next 20 to 40 years," he said. "There's nothing worse than having a question on a fish population and having no data to back it up or give us information to base our decisions off of. That won't be the case now. This estimate was done after Hubbard Lake had recent invasive species enter the lake (round goby and zebra mussels), so it allows us an estimate during this transition period."
For more information, contact the Northern Lake Huron Management Unit at 989-732-3541.