DNR biologists studying changes in fish populations

Indiana DNR Release:

COLUMBIA CITY – To better understand how fish populations and fishing conditions change from year to year, the DNR Division of Fish and Wildlife (DFW) will begin a series of surveys in June at five natural lakes in northern Indiana.

The surveys are designed to track annual changes in number, size, weight, and growth of various fish species in each lake over the next five years.

Lakes selected include 308-acre Adams Lake in LaGrange County, 206-acre Crooked Lake in Whitley County, 32-acre McClure Lake in southern Kosciusko County, 22-acre Mud Lake in Fulton County, and 187-acre Waubee Lake in northern Kosciusko County.

The lakes were chosen because they represent a variety of lake sizes, habitat conditions, and fish communities.

“We know fishing fluctuates from year to year, but we don’t know the magnitude of the changes or reasons for the changes,” said Steve Donabauer, DFW assistant fisheries biologist and coordinator of the project.

“We also don’t know how lakes change through time and how factors such as habitat damage, watershed management practices, and climate may affect fishing,” Donabauer said.

Donabauer labeled the five lakes as “fixed sites” because they will be monitored annually. However, DFW biologists will also sample 11 other natural lakes that will be chosen randomly each year. A variety of information will be gathered at each.

“We will use shocker boats, gill nets, and traps to sample fish communities in each lake during June. We will also monitor basic habitat features, such as depth, water clarity, oxygen content, aquatic plants, and microscopic zooplankton,” Donabauer said.

Dubbed the “Status and Trends Project,” the five-year study will enable biologists to predict how fish populations in all of Indiana’s 450 natural lakes are changing based on what they find at the study lakes.

“We don’t have the manpower or resources to survey every natural lake in the state,” Donabauer said. “This project, therefore, will help us track what is happening throughout the natural lakes region and form the basis of any region-wide approaches we take to protect and manage fish populations.”

All data obtained from the project will be compiled annually and then electronically stored, analyzed, and made available to anglers, lake associations, government agencies, universities and the general public.

In addition to the fixed sites, other lakes to be surveyed this year include Everett in Allen County, Banning and Fish in Kosciusko County, Emma and Mateer in LaGrange County, Clear in LaPorte County, Thomas and Koontz in Marshall County, Big and Upper Long in Noble County, and Henry in Steuben County.