A new invasive species has been found at the Wolf Lake State Fish Hatchery in Mattawan.
The Michigan Department of Natural Resources says it’s confirmed the presence of invasive red swamp crayfish in an outdoor rearing pond at the hatchery. The invasive crayfish is bigger than most native crayfish in Michigan and can outcompete the species that belong here.
DNR Fisheries Division program manager Aaron Switzer tells us crews at the hatchery found the carcasses of two of the crayfish in a pond collection basket and then deployed traps in adjacent ponds, finding one live red swamp crayfish. Fish that had been raised in those ponds were previously released in two lakes, and now the DNR is testing them for the crayfish. However, Switzer it’s unlikely any are there.
“We want to be cautious about this, but it’s highly unlikely that we transferred anything with those fish,” Switzer said. “Those fish were all individually handled and were tagged. So they were out of the source water, tagged, and then in a recovery tank and put into the well water that was on the truck.”
The DNR’s Lucas Nathan tells us the red swamp crayfish can be a problem because in high densities, it can burrow along shorelines and destabilize banks and other infrastructure. The fish can mostly be found around southeast Michigan and is popular for consumption and as pets, but the DNR doesn’t want it spreading in Southwest Michigan.
Everyone’s asked to report any species they notice in waterways that seem like they might be out of place.