There are many components to renovating a fishery, including addressing undesirable species and improving habitat. The lake’s outlet structure was replaced, which can be an important tool for manipulating water levels to improve the fishery. Fish habitat structures (cedar trees, catfish hides, lake-edge benches, and rock piles) were installed as well.
Story County Conservation (SCC) and the Iowa Department of Natural Resources (DNR) are partnering to renovate the remaining fishery in Hickory Grove Lake. The DNR will treat Hickory Grove Lake late this summer or early fall (pending workable weather conditions) with rotenone, a botanical pesticide, to eliminate the remaining fish population.
An attempt was made last fall/winter to drain and dry the lake basin to rid the lake of Common Carp, Grass Carp, and Black Bullhead. These injurious fish species reduce water clarity, destroy aquatic plants, and prevent the fishery from reaching its full potential. Unfortunately, Common Carp were observed this spring as the lake was refilling. “The most effective method to eliminate the remaining fish population at this point is to apply rotenone to the lake basin and tributaries.” said Ben Dodd, DNR Fisheries Management Biologist. Rotenone is a natural pesticide derived from the roots of certain members of the bean family from South America and is a common tool that fisheries managers use to manage sport fish, improve water quality, and manage endangered species.
Eliminating injurious fish species is an imperative and final step so water quality and fishery improvements can be achieved.
The DNR will treat Hickory Grove Lake on August 4, 2020 (pending workable weather conditions) with rotenone to eliminate the remaining fish population. The project area includes Hickory Grove Lake and a portion of the associated watershed. The treatment area includes both public and private property.
Click each photo below to learn more about the injurious species inhabiting Hickory Grove Lake