Correlation Between Reef Terrain Variables and Species Diversity in Spiny Lobster Habitat

Crayfish or spiny lobster occur in physically complex reef habitat in shallow waters off the west coast of Ireland. These habitats provide shelter for larvae that are settling out from the overlying water column and for juvenile and adult lobsters that use these areas to shelter and forage. Fisheries for spiny lobster occur in these areas and remove lobsters from the reef. The consequence of this for the structure and function of reef habitat is unknown. In this study the distribution of reef habitat was estimated from multibeam acoustic data collected in previous campaigns by the INFOMAR programme. Sub-sets of this area were re-mapped at higher resolution to provide further detail of the topography of the reef from which terrain variables were derived. Underwater video and SCUBA methods were used to identify the flora and fauna in areas with different topographies. Weak correlations between the terrain variables and the biological data were found. This was used to model the distribution of areas of high and low biodiversity over broader areas where only terrain data were available. Capacity to model the distribution of biological communities and crayfish over broad areas using physical terrain data remains difficult. Other physical variables that may be important in regulating the biology of reef need to be included and the association of crayfish with particular types of reef terrain needs to be established by higher resolution sampling. The benefits of the work reported here include increased capacity to monitor the distribution of biodiversity in marine reef habitats, to detect change that may be brought about by sector activities such as fishing or climate change, to estimate the population size of exploited reef species for fisheries management and to identify positive changes to biodiversity and lobster abundance that may occur through spatial management of reef habitat.

URI

http://hdl.handle.net/10793/1896

Citation

O’Keeffe, E., Scally, L., Clarke, S., Pfeiffer, N., Smith, B. and Tully, O. (2024). Correlation Between Reef Terrain Variables and Species Diversity in Spiny Lobster Habitat. EMFF 2014-2020 Marine Institute Report Series. Marine Institute, Ireland