Meeting Abstract
Invasive grass carp (Ctenopharyngodon idella) were first introduced into the United States in 1963 as a biocontrol agent and have since been released or have escaped into multiple freshwater basins. Their feeding on submerged aquatic vegetation destroys food sources, shelter and spawning areas that are vital to native species. Even though grass carp are bred as triploid and still distributed in some regions, diploid individuals have been previously captured in Lake Erie. Recently, multiple individuals have been captured in the Laurentian Great Lakes and while the overall extent of their impact is not fully known, grass carp pose a significant risk to native fisheries populations. With both diploids and triploids being captured in the western basin of Lake Erie, the extent of the population that is reproductively viable has yet to be delineated. In this study, grass carp captured by commercial fishermen and government agencies in Michigan ad Ohio waters of Lake Erie were sampled to determine the reproductive status of this population. Thirty-six individuals were screened between May 2014 and July 2015. Ploidy for each individual was determined by flow cytometry or visualization of nuclear morphology via microscopy. The resulting data are being used to determine the ploidy status of current populations within western Lake Erie. This work will enable management to understand the extent of the current invasion and determine means to manage population expansion.
