STATE OF THE ART: USING ARTIFICIAL REFUGE TRAPS TO CONTROL INVASIVE CRAYFISH IN SOUTHERN CALIFORNIA STREAMS
|Joseph N Curti; Ph.D. Student, UCLA; firstname.lastname@example.org; Emi Fergus, Angela De Palma-Dow|
In Southern California, the invasive red swamp crayfish Procambarus clarkii poses a significant threat to native aquatic fauna. Studies have suggested that artificial refuge traps (ARTs) resembling crayfish burrows can be used to remove invasive crayfish, but, to date, no studies have focused on optimizing ART design and deployment to maximize crayfish catch. This month-long study tested the effect of modifications on ART diameter, color, and soak time on crayfish catch effectiveness across 160 traps. During the study period, ARTs removed a total of 240 crayfish with no incidental bycatch. Larger crayfish (2–6-cm carapace length) were found more frequently in 5.1-cm-diameter traps, and smaller Crayfish (1–4 cm) were found more frequently in 2.5-cm-diameter traps. Catch numbers varied between trap types, with black-colored 5.1-cm-diameter traps removing the greatest amount of crayfish and black-colored 2.5-cm-diameter traps removing the least amount. Further, ART deployment duration was an important predictor variable for candidate models, where ARTs with 4-d and 7-d deployment durations had lower catch/unit effort than traps with 1-d and 2-d deployments. This study demonstrates that ARTs can be a valuable tool for conservation managers interested in restoring streams through invasive crayfish removal, especially where there are sensitive biological resources.