IT'S A TRAP! AN EVALUATION OF DIFFERENT PASSIVE TRAP TYPES TO CONTROL THE INVASIVE RED SWAMP CRAYFISH (PROCAMBARUS CLARKII) IN SANTA MONICA MOUNTAIN STREAMS.
Angela De Palma-Dow; Invasive Species Coordinator, Department of Water Resources ; 255 N. Forbes Street, Lakeport , CA, 95453; (530) 304-1809; adepalmadow@gmail.com; Joseph N. Curti
The invasive red swamp crayfish poses a significant threat to physical and aquatic diversity in Santa Monica Mountain streams. Crayfish are known to consume adult, juvenile and egg forms of native fish, frogs, and benthic macroinvertebrates. In addition, crayfish can disrupt nutrient and sediment dynamics by burrowing into streambanks. Mountain Restoration Trust has managed crayfish populations in the Santa Monica Mountains for ten years, yet evaluation of trap type effectiveness has been constant source of uncertainty. In this two-week field experiment, we compared effectiveness across 12 standard and modified trap designs in catching the most crayfish while catching the least bycatch. The most effective trap for catching crayfish was the black cylindrical mesh trap, followed by the red mesh trap, and both the standard and silver modified black traps. When considering effect on native arroyo chub bycatch, both standard and modified black traps caught less chub than cylindrical and red mesh traps, however, the cylindrical mesh was the best performer by catching the most crayfish and not catching any tadpoles. When managing for crayfish in streams, we recommend deploying a combination of trap types in order to maximize crayfish catch efficiency and limit negative impacts on native bycatch.
Poster Session