Dr. Sascha Hallet (OSU Microbiology) , Spring Rivers Ecological Sciences, USFWS, and CDFW are developing a quarantine protocol and release criteria to reduce the risk of introducing a trout parasite along with the crayfish when they are reintroduced into a restored creek.
Shasta crayfish, Pacifastacus fortis, found only in California are endangered due to habitat loss, predation and competition. Efforts to rescue a genetically diverse population from a lake and reintroduce them to a restored creek are underway. However, this creek is the headwaters for a trout hatchery and the source lake is endemic for a parasite of trout, Ceratonova shasta.
qPCR is being used to test crayfish carapace swabs, fecal and water samples (from the source lake, quarantine flume and destination creek) for both the trout parasite and its polychaete host. Crayfish are held in a quarantine flume with naive trout that are highly susceptible to low doses of the parasite. The trout act as the “canary in the mine”- if they show no signs of infection after co-exposure with the crayfish and spore levels from qPCR swabs are undetectable, the crayfish can safely be reintroduced into the creek.
California Department of Fish and Wildlife 2019. Endangered Shasta Crayfish Have New Refuge in Rock Creek.