2023 Catching Crayfish

In August of 2023, the CRWC team finished monitoring Red Swamp Crayfish for the year.  

Red Swamp Crayfish are a large, aggressive invasive species of crayfish that create large burrows that disrupt streamside and aquatic habitats, causing significant erosion. They also outcompete native aquatic life for food while causing algae blooms through their eating habits, degrading the habitat further. The presence of Red Swamp Crayfish has been confirmed in both the Clinton River (2019 & 2023) and Rouge River (2017) watersheds. 

CRWC staff members Lydia Nicholas and Mikela Dean led CRWC’s effort, aided by Kaleigh Snoddy, Pronoye Kapali, and CRWC’s summer interns, Emma Delie and Ray Gilbert. The team scouted over 30 potential sites, searching for locations that contained crayfish habitat characteristics but were also accessible. Some locations proved nearly impossible to survey due to high water levels, high plant density, and unstable stream conditions. Fifteen full surveys were successfully conducted, covering a range of aquatic environments. These included the Clinton River itself in four distinct areas, as well as three drains, three creeks (including Paint Creek in three separate locations), and three ponds. 

CRWC staff assembling crayfish traps.

Using dry dog food as bait, staff baited, set, and checked traps at identified sites. Each site was monitored over a three-day period. Overall, the survey spanned an impressive 3,375 meters, which is over two miles! 

Officially, 150 traps were set across the sites, with each location intended to house ten traps. However, due to logistical constraints and unsuitable site conditions, an additional 20+ traps were temporarily placed across various locations. This strategic trap deployment allowed for a more comprehensive examination of the Red Swamp Crayfish presence within the watershed. 

The survey brought to light a diverse array of native crayfish species inhabiting the watershed’s lakes, rivers, and streams. Among the 290 crayfish caught, CRWC staff identified several native species including Virile Crayfish, Big Water Crayfish, Devil Crayfish, Calico Crayfish, and Northern Clearwater Crayfish. Notably, a single Rusty Crayfish, categorized as an invasive species, was also identified. However, the debate regarding its invasive status within the watershed persists due to its historical presence in the Lake Erie basin and its distribution. 

CRWC Environmental Scientist, Lydia Nicholas, fastening crayfish trap to creek bed using rebar.

While the survey team celebrated the absence of Red Swamp Crayfish within their survey locations, a new population was discovered at Greystone Golf Club in Washington Township in mid-July. Another population within the Newland Drain in Shelby Township is under management by the Lake St. Clair Cooperative Invasive Species Management Area (LSC CISMA). 

Amidst the myriad findings and challenges, a whimsical note was struck by one of CRWC’s staff members. Expressing both satisfaction and a hint of weariness, Nicholas stated “I never want to see another crayfish again, at least not until we do it all again next year.” This sentiment echoes the commitment and dedication that define CRWC’s tireless efforts to preserve the health and balance of the watershed. 

This project is being conducted in partnership with Friends of the Rouge and the Michigan Department of Natural Resources. In the 2024 field season, the second year of the grant period, CRWC will continue to develop a critical data set of Red Swamp Crayfish populations to inform solutions that will limit the spread of this troublesome invasive species. 

Author(s): Cole Pachucki, Mikela Dean, Lydia Nicholas