Welcome to the interactive web schedule for the 2019 Midwest Fish & Wildlife Conference! Please note, this event has passed. To return to the main Conference website, go to: www.midwestfw.org.
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CONFERENCE SCHEDULE UPDATES & CHANGES: As a result of the prolonged government shutdown, we experienced a number of cancellations and changes to the schedule. Cancellations and changes are listed here (as of January 26, 2019).
AUTHORS. Kasia Kelly, Meredith B. Nevers, Murulee N. Byappanahalli – U.S. Geological Survey; Charles C. Morris, Joshua Dickey – National Park Service; Dawn Shively, Ashley Spoljaric – Michigan State University
ABSTRACT. Introduced rusty crayfish (Orconectes rusticus) are frequently found in Lake Michigan tributaries during routine fish surveys. While some locations are heavily occupied by the invasive crayfish, others support only small populations or resist invasion. Certain streams may be more likely to attract establishment of rusty crayfish populations due to habitat type, existing fish communities, or other biotic and abiotic conditions. Current monitoring for crayfish in rivers includes laborious sampling such as electroshocking or trapping, but the use of environmental DNA (eDNA) may present a more efficient method. While eDNA has the advantage of broader spatial coverage with less intense effort, the relationship between eDNA estimates and traditional surveys must be established. We explored the relationship between eDNA and electroshocking for detection and quantification of rusty crayfish, along with the interactions with habitat and water quality assessments and fish community surveys. The goal was to assess the usefulness of targeted eDNA in stream surveys and to attempt to model future invasion potential. Copy numbers of rusty crayfish DNA marker by quantitative PCR (qPCR) were positively correlated with electroshocking catch (Pearson R= 0.747, P= 0.033) and crayfish biomass (Pearson R= 0.845, P= 0.008). The eDNA assay for rusty crayfish discerned between highly and scarcely infested sites in streams of northern Indiana. Fish assemblage data revealed similar species composition in infested and non-infested sites, frequently including green sunfish, creek chub, white sucker, rainbow and brown trout. Neither eDNA marker nor crayfish count by electroshocking was correlated with any of the water chemistry measures or habitat quality scores, implying that rusty crayfish is highly adaptable to different habitat conditions. Future efforts will include development of a predictive model using the habitat data and fish species composition to predict the future spatial and temporal spread of rusty crayfish between watersheds.
