Serving Gogebic, Iron and Ontonagon Counties
Serving Gogebic, Iron and Ontonagon Counties
By RALPH ANSAMI
Walleyes in two Gogebic County lakes will be collected for mercury testing this spring after the ice cover leaves.
The Great Lakes Indian Fish and Wildlife Commission will survey Cisco and Thousand Island lakes in Gogebic County. Up to 12 adult walleyes will be taken from each lake for mercury testing, according to Mark Luehring, a fisheries biologist for GLIFWC, which has an office in Odanah, Wis.
Mercury testing will be done at the Lake Superior Research Institute at the University of Wisconsin-Superior.
GLIFWC will test for mercury in eight of the 25 lakes it will electrofish this spring to collect information on spawning walleyes. Other fish will be released.
Each fish survey will last from three to five days. Surveys are conducted in spring because walleyes concentrate in shallows, where they spawn.
Crews capture adult fish and measure them, determine their sex and mark them with fin clips or tags. They also collect a spine sample for aging purposes and then release the walleyes back into the lakes or flowages.
During a recapture phase, a one-night electrofishing survey is conducted along the entire shoreline and the number of marked and unmarked fish is recorded.
The ratio of marked to unmarked fish is used to estimate the adult population of walleyes.
A survey of the Turtle-Flambeau Flowage in southern Iron County will be conducted in cooperation with the Wisconsin Department of Natural Resources. That flowage effort will not include collecting fish for mercury testing, according to GLIFWC.
Other lakes throughout northern Wisconsin and two in Chisago County, Minn., are also included in the spring survey plans.
