Invasive species like the common carp (Cyprinus carpio) threaten the health and integrity of aquatic ecosystems. The Nebraska Sandhills region consists of 57,000 km2 of grass-stabilized sand dunes and topographic lows between the dunes are generally occupied by shallow lakes, wetlands, or wet meadows. These wetlands and their associated shallow lakes are an ideal environment to evaluate the impacts of carp introduction and removal because of the large number of water bodies in the Sandhills that are vulnerable to carp invasions. To help understand the influence of carp on these ecosystems, I collaborated with the Nebraska Game and Parks Commission (NGP) to conduct an ecological assessment of 21 Sandhills lakes. I collected water quality samples and characterized benthic and littoral macroinvertebrate community data from 11 lakes infested with carp (3 medium density and 8 high density), and 10 carp free lakes in 2018 and 2019. I created a macroinvertebrate Index of Biological integrity (IBI) that shows carp had a significant negative effect on both benthic and littoral macroinvertebrate communities in these lakes. Non-carp lakes had lower turbidity, higher submergent vegetation coverage, and lower phytoplankton biomass. Heavy carp had higher turbidity, high phytoplankton biomass, and less submersed vegetation. Lakes with low to medium carp densities varied. Our study suggests that in order to improve water quality, and maximize invertebrate and plant resources, efforts should be made to eradicate carp from Nebraska Sandhill lakes
