At this time of year we get a lot of questions and comments regarding the lake drawdown. There are many issues involved in this process, but the decision to draw down over winter presently is part of an agreement with the Indiana Department of Natural Resources. IDNR is conducting a large and comprehensive research project across the state to collect usable data on controlling Gizzard Shad populations. Gizzard Shad are an invasive species that do great harm to sport fisheries, like West Boggs. The IDNR project is using a variety of methods, including winter drawdowns, drawdowns combined with other treatments, and control areas where nothing is done. This data collect is schedule to be completed in 2010, and then Biologists will look at all the data to determine the best management practices to apply under different conditions. There are other benefits to the drawdown; and there are some downside issues as well. On the positive side it allows opportunities to expose the lakebed to sunlight and oxygen, which helps break down phosphorus stored in the sediment. Long term, breaking the phosphorus cycle will improve water quality. Some benefits also take place in erosion patterns, and in opportunities to do work projects and maintenance. On the downside we know that changing water conditions is stressful for game fish as well as shad, and that some hibernating animals that normally winter in the bottom mud may die when their beds are later exposed to freezing weather. None of this is taken lightly, but those species are normally quick to replace the lost numbers. Why don’t we just drawn the lake all the way down and kill all fish and restock, like we did in 1994? Biologists are convinced that the Gizzard Shad were brought back intentionally by anglers who often think they are just adding more food for game fish. The reintroduction took place in 1998 or 1999, meaning that the $250.000.00 spent in 1994 to get rid of them only lasted four or five years. The same project today would cost far more, and there is no reason to think we will be able to prevent another reintroduction. So we are looking for a way to manage fisheries with shad, because we don’t think we’ll ever be rid of them again.
Mike Axsom
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