2013 Volume 15 Issue Supplement Pages 60-65
Understanding changes in marine biodiversity relies on monitoring programmes that give accurate indications of the biological response to natural and anthropogenic drivers. Historic approaches have provided poor indications of nocturnal macro-invertebrate assemblages, particularly fisheries-independent methods that rely on visual assessments of transects, or video collection devices deployed for fixed time periods. Permanent artificial habitats, specifically designed for monitoring all invertebrate species, including those that are cryptic or nocturnal, could provide an ideal solution to this critical knowledge gap. Marine Invertebrate Collection Equipment (MICE) are artificial habitats that have been designed in Western Australia over a period of five years and are now deployed in many coastal locations where they are regularly sampled. The present study was conducted in Geographe Bay, Western Australia where replicate MICE units were deployed to determine the impact of placement on seagrass versus the standard protocol of deployment on a sandy substrate. A total of 4,403 individual macro-invertebrates were collected and categorised into 104 Parataxonomic Units (PTUs), which were then aggregated into 21 intermediate classification groupings, and again into 7 broader groupings. At the intermediate level of identification, gastropods dominated the community composition, followed by worms, bivalves, sponges and amphipods. At the broader level of identification, molluscs were the most prevalent, followed by crustaceans, worms and sponges. Placement of MICE on a seagrass substrate resulted in a significantly lower abundance of invertebrates than those placed on sand (p<0.05). These differences were adequately explained using broad and intermediate levels of identification and no significant additional information was gained by identifying organisms to the level of PTU.
