In the proposed research the objectives are to determine the extent of behavioural impairment due to distraction effects across tactile, visual and chemical domains. We will use the European hermit crab P. bernhardus as a model study system. Hermit crabs are routinely collected from local field sites. We will use recordings of boat motor noise, played through a hydrophone at 40dB (Chan et al 2010), housed in experimental aquaria. Behavioural data will be collected using The Observer XT 11 event recording software.