Giant spider crab ecological assessment in Port Phillip Bay

Giant spider crabs (Leptomithrax gaimardii, also called Great spider crabs) are a charismatic, iconic species of Port Phillip Bay; yet little is known about their ecology and habitat use. They form massive gatherings (aggregations) in winter when they are coming together to moult (shed their shells in order to grow bigger). Concerns have been raised regarding the environmental performance, sustainable use and social conflict issues associated with recreational fishing targeting the annual moulting aggregations of the Giant spider crab in shallow waters of Port Phillip Bay between May and July each year. The Department of Energy, Environment and Climate Action (DEECA) has approached Deakin University to further improve the understanding of the ecology of the Giant spider crab, and to ascertain the broader conservation, social and cultural values of the species to the Victorian community. In 2022, Deakin University undertook an ecological and socio-economic assessment of the Giant spider crab (Leptomithrax gaimardii) in Port Phillip Bay. The program comprised three main projects: a citizen science project, a spider crab ecology project and a spider crab socio-economic project (separate report). The first project aimed to harness citizen science to obtain information on spider crab aggregations and ecology; the second project utilised traditional science to collect data on spider crab aggregations and their ecological significance in situ; the third project estimated some of the economic values of the species and their annual aggregation.