Dr Elisabeth Strain1, 2, Ms Ashlee Bastiaansen1, Prof. Maria Byrne3, Dr Jemina Stuart-Smith1, Karen Parsons4
1Institute for Marine and Antarctic Science, University of Tasmania, Hoabrt, Australia, 2Centre for Marine Socioecology, University of Tasmania, Hobart, Australia, 3School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia, 4Ecomarine Consulting, Hobart, Australia
The live bearing seastar Parvulastra vivipara, is endemic to SE Tasmania. This species is one of six seastars globally capable of producing live young. With its limited dispersal, geographically restricted range and low levels of genetic diversity, P. vivipara is considered highly vulnerable to multiple stressors. In the early 2000’s populations of P. vivipara were recorded in thirteen key locations. Recent surveys show that the area with the largest known population of P. vivipara has experienced rapid declines, with ~90% of the population lost in the last 20 years. However, the census methods differ through time and there is no current information in the remaining 12 locations. Here we conducted population surveys of P. vivipara and its surrounding habitat, across all 13 locations. Our results show that populations of P. vivipara are now locally extinct in 4 locations, with >80% declines in abundances at 6 locations and increases in abundances at the remaining 4 locations. This species has been identified as a high priority for re-assessment to critically endangered status. Key threats included increasing urbanisation, nutrient enrichment, sedimentation and abundances of non-native species, and accumulation of wrack and debris. Future efforts should focus on protecting key populations of P. vivipara and rocky intertidal platforms, building a Noah’s arc facility, and conducting trials to inform restoration and management options.
