AUTHORS: Colin Assenmacher, Michigan State University; William Ota, Michigan State University; Kathleen Quebedeaux, Michigan Department of Natural Resources, Fisheries Division; Brian Roth, Michigan State University
ABSTRACT: Procambarus clarkii are the world’s most widespread invasive crayfish species established in Michigan since 2017. P.clarkii is of high concern due to their extensive burrowing behavior, which can damage human infrastructure through bank erosion and decreased bank stability. Our research aimed to investigate how soil and environmental characteristics of pond banks relate to P.clarkii burrow density. We measured key soil characteristics and potentially influential environmental variables from July to August of 2024 at 74 sites invaded by P.clarkii in Southeast Michigan to quantify which physical properties influence variations in burrow density within a waterbody and across multiple waterbodies. These sites were spread across 13 invaded waterbodies at three golf courses with varying burrow densities. Calculated burrow density was based on surveys conducted during the 2023 and 2024 field seasons and ranged from 0 to 8.42 burrows per square meter across sample sites and targeted waterbodies. We collected soil cores at each site to determine particle size, percent organic matter, penetration resistance, bulk density, and profile soil horizons. Bank slope, percent vegetation cover, and canopy cover were measured at each coring location. Preliminary analysis indicates regions of low burrow density are associated with steeper pond banks, particularly in the first 50 cm from the waterline. Mean vegetation cover ranged from 80 to 84% across burrow density classes and 35 to 99% over all sites. Penetration resistance was highest in areas of no burrow activity. We found less variation in soil bulk density and percent canopy cover in areas with high burrow density. This indicates that P.clarkii has preferred soil and environmental characteristics when burrowing. These findings help to identify the physical characteristics of high burrowing areas, which will be used to assist in the development of preventative management strategies against P.clarkii establishment and burrowing.
