The efficacy of crab condos in capturing small crab species and their use in invasive marine species monitoring

Abstract

Crab condos are designed to sample for invasive species, which are not specifically targeted using current Australian biosecuritymethodologies. Smaller crab species are often excluded, overlooked and damaged to be collected via current trapping or collection methods.An artificial habitat collector such as the ‘crab condo’ (PVC tubes 25cm long and 50mm diameter arranged in a 3×3 square matrix) aims toprovide shelter among an animal’s natural environment. Twenty condos were deployed on a weekly basis for 48 hours during the months ofApril and July 2012 within Hillarys Boat marina, Western Australia. Condos proved to be highly successful, capturing a total of 555specimens from five different phyla, with over half (n=332) of specimens identified as crabs. The detection of 223 other smaller non-crabindividuals, covering four different phyla highlighted the versatility of condos to sample a range of other small species, not only crabs. Giventhe recognized importance of early detection of marine pests at their early life stages and current lack of methods targeting small andcryptogenic species, the crab condo sampling method may fill an important gap in marine pest surveillance capacity.

Keywords

• marine pest
• monitoring
• biosecurity
• artificial shelter
• crustacean