Investigating gastropod habitat associations in saltmarsh

Recent studies have provided new information on the taxonomy of gastropods snails in Australian saltmarsh but little is known of their ecology. For fauna colonisation to be used as a measure of the success of restoration or rehabilitation of degraded saltmarsh, a detailed understanding of the microhabitat associations of the target species in ‘reference’ locations across a range of latitudes is necessary. This study measured the densities of saltmarsh gastropods in two locations in northern New South Wales to determine microhabitat associations that could influence the results of rehabilitation assessment using fauna colonisation in Australian saltmarsh. In this study, Ophicardelus spp. were common in tall vegetation, in particular, Juncus kraussii. Phallomedusa solida was commonly on mud substrates but was more evenly distributed across the saltmarsh than Ophicardelus ornatus. This study has implications for the design and assessment of restoration projects. If habitats of the individual species are not created by rehabilitation actions, or do not occur for whatever reason, densities of particular species will be lower than at reference sites, thus influencing assessment of the ‘success’ of saltmarsh rehabilitation using gastropod snails.