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Illinois

Jason's Journal: Going Below the Icy Surface

Large-mouth bass make up a large portion of the fish population at Emiquon.

By Jason Beverlin
Deputy Director of the Illinois River Program

December 2010 — Islands of ice are now dappled across the surface of Emiquon's lakes as they begin to freeze. The patches of white ice drastically contour the dark blue, unfrozen water. Even with this eye-catching contrast, my attention goes beneath the water's icy surface. I think about the fish that are slowing down to survive the winter months.

We have stocked Emiquon with 31 different types of fish species, and recent surveys are tracking their growth. Survey results from 2009 showed native fish including large-mouth bass, black crappie, bluegill and pumpkinseed make up greater than 90 percent of the fish population at Emiquon. The remaining percentage primarily includes native fish species such as warmouth sunfish, green sunfish, black bullhead catfish, brown bullhead catfish, bowfin, longnose gar, spotted gar and lake chubsuckers. Additional populations of another 18 native species are likely present in numbers too small to be representative in the 2009 survey. This past April, we released 200 of the state-threatened red-spotted sunfish into Thompson Lake at Emiquon, and we're hoping this release will add more diversity to the overall population in future surveys. Non-native fish such as common carp were also found at Emiquon in 2009. Even though we know common carp can cause ecological issues, we are hopeful our healthy, large populations of native, predatory fish like bass, bowfin and gar will help keep their population in check.

In our long-term restoration efforts, we have a goal to harbor at least 25 native fish species that will make up at least 50 percent of the total number of fish at Emiquon. In the 2009 results, native fish species made up 99.4 percent of all species caught in the fisheries survey, which is great!

This past April through October, Nerissa Michaels and Greg Sass from the Illinois Natural History Survey came to Emiquon and again surveyed the fish populations living here. We're looking forward to the 2010 survey results, which will be ready late winter. Their surveys not only determine the health, diversity and quantity of fish, but they also help us measure the success of our fisheries restoration here at Emiquon.

So, as you drive along the Illinois River Scenic Byway and you see the islands of ice forming on top of the lakes at Emiquon this month, think about what's also below the water’s surface and know these lakes are swimming with life.

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