Invasive carps, bighead, black, grass, and silver carps, escaped aquaculture and entered the mississippi river during floods in the 1970S

Since that time they have advanced throughout the mississippi basin, including into the ohio river. Our proposed work is in collaboration with the ohio river invasive carp partnership and our primary objective is to monitor the ohio river mainstem and key tributaries for evidence of spawning success in areas upstream of the markland DAM where there have been only sporadic observations of adult invasive carps. This area marks the leading edge of the invasion and therefore is important to monitor so that rapid response and sustained management actions to reduce the probability of successful advancement and establishment. We WILL1. Continue past ichthyoplankton surveys to identify evidence of reproduction upstream of markland DAM,2. Initiate juvenile invasive carp surveys, AND3. Apply community size spectra to fish assemblage data, i.e. community data, to identify targets for invasive carp harvest as a proof of concept project.monitoring and documenting the existence and distribution of eggs, larvae, and juvenile invasive carp is critical for tracking the status and rate of expansion, or contraction, of the on going invasion. Understanding where reproduction is occurring, the habitats and locations where each life stage is found along with relative abundance will inform rapid control measures, e.g. targeted harvest, barriers, or deterrent placements. With limited staff and resources we need strong monitoring data to assure that efforts and resources are optimally used. We intend to sample juveniles ahead of what we believe is their current zone of reproduction, this will provide US critical before invasion or baseline information into the other species utilizing the same nursery habitat that may be negatively affected if invasive carp reach upstream currently univaded river reaches. This also provides a robust second avenue to measure active reproductive success, which we use to determine where impacted and leading edge areas are, which in turns allows for the optimal use of available control resources.at the opposite end of the invasive carp management spectrum are policies and methods to control adult fish in areas where they are fully established. Great resources are going into commercial harvest to reduce densities, but we are doing so without clear targets or harvest goals. We accept that eradication is impossible, so we need to determine acceptable densities to protect the food web and native species from adverse effects. We are proposing a community size spectra, CSS, framework to establish targets for invasive carp removals. CSS describe the size structure of communities by quantifying the decrease in abundance among increasing body size classes. CSS have been used extensively as indicators of fishery sustainability, and overfishing, and to set fishing harvest limits in marine systems, however, to date CSS have not been used to address invasive species management. We will compare and contrast annual CSS among ohio river pools and over time to evaluate how they have responded to increases in invasive carp from existing partner data. We will utilize earlier years in impacted pools as well as long term averages in upstream unimpacted pools to serve as a reference or the historic target condition. Utilizing this approach as a backdrop, we will strive to estimate the level to which invasive carp abundance need to be reduced to restore the CSS to target conditions. Targets are energetically based, scientifically defensible, and connect to broader food web properties thus provide direct connections between invasive carp management and ecological services.