Surveys help DNR get an idea of fish population trends
By Jordan Travis
The Alpena News
ALPENA, Mich. (AP) — As Department of Natural Resources summer workers Sam Black and Joe Stutesman lifted a large-mesh fyke net in Lake Besser, the two reacted as the thrashing fish inside splashed their faces.
Caught in the net were walleye, pike, three kinds of bullhead catfish, a few panfish, some painted turtles and one massive snapping turtle. Tim Cwalinski, DNR Northern Lake Huron Fisheries Unit senior fisheries biologist, measured the fish, calling out the lengths to Unit Fisheries Technician Supervisor Pat Van Daele, collecting scales from panfish under 6 inches and dorsal or anal fin spines from larger predator fish. Black collected the samples in a paper envelope and wrote on them.
It’s all part of a fish community assessment being conducted on Lake Besser, according to The Alpena News. The crew of four set each net back, leaving some in place while relocating others. They set down three different kinds of nets at various locations in the man-made lake and checked them later. After conducting a round of electrofishing, Cwalinski said he should have a pretty good idea of what’s swimming around in the lake.
“These fish are pretty normal for a shallow impoundment with weeds, but there are some big walleye in there that people should fish for,” he said. “I’m sure some people do.”
The lake was last surveyed in 1985 and 1998, Cwalinski said. Taking these surveys over time helps the DNR get an idea of fish population trends. However, the two previous surveys were done with different gear types, so the results aren’t directly comparable. Now the gear is standardized.
Surveyors use different gear types because certain species are more susceptible to others, Cwalinski said.
“Pike are more susceptible to gill nets or trap nets, but not to electrofishing,” he said. “Largemouth bass are really susceptible to electrofishing, but with their big eyes they can see the gill nets and avoid them.”
Lake Besser was picked at random through the department’s stats and trends sampling program, Cwalinski said. The department already has surveyed Little Wolf and Big Bear lakes near Lewiston, and Van Daele said Fisheries techs will conduct walleye estimates in East Twin and West Twin lakes. A creel catch survey clerk will work on these lakes throughout the summer. Also on schedule is a survey of Burt Lake, Cwalinski said, and a few teams will spend two weeks working on this vast lake.
The DNR will survey lakes through June, the same time its fisheries techs are collecting walleye fingerlings from rearing ponds, Cwalinski said. They’ll switch to streams by July, and in September will begin their fall walleye evaluations. Then from early to mid-October they’ll evaluate lakes where trout are stocked.
Cwalinski and Van Daele work in a management unit that contains roughly 600 lakes, Cwalinski said. While a crew typically can survey one lake a week, Van Daele said the department has been able to hire summer help for the first time in nearly a decade, allowing survey crews to double their efforts, thanks to additional funds from a recent license fee restructuring.
Over the winter the DNR will compile data collected from surveys of lakes and streams taken over the summer. Biologists will use the scale and spine samples collected to determine the age of the fish, and Cwalinski will write a report about the survey findings, including for Lake Besser.
These surveys are generally used to make stocking decisions, although for Lake Besser that’s likely not the case, Cwalinski said. The DNR already is stocking muskellunge into the lake, and stocked 1,176 eight-inch Great Lakes strain muskies in the lake over two years. Otherwise the only species it would stock are walleye.
Cwalinski said anglers should be careful where they fish.
“When people see our floats, there’s a net down there, so you don’t want to fish over the top of them,” he said. “’If you drop a jig on a net, you’re going to lose. It’ll bust off and the next day we’ll have to deal with a hook in our hands.”
