WAMSI Node 4.3.1b - Determination of the diets of Snapper and Silver Trevally and construction of a food web for the demersal fish community in South-western Australia

From June 2009, for two years Snapper (Chrysophrys auratus) and Silver Trevally (Pseudocaranx georgianius) stomachs were sampled for their contents to create food webs. An understanding of the dietary composition of these two species is crucial for developing a food web involving the main demersal fish species found along the coast of south-western Australia. The production of ecosystem models using these food webs will facilitate the development of effective management strategies to sustain these species within the context of EBFM. Currently, there is little known of the dietary composition of these two species. Knowledge of these diets during each life cycle stage and each season will provide, in conjunction with data for other demersal fish species, an understanding of how food resources are partitioned among and within the different species and life stages. By including these data with large existing data sets for approximately 40 other demersal fish species from the lower south west coast, a holistic food web can be constructed. Such a food web will be the first of its kind in Western Australia and will provide an invaluable tool in fisheries management and evaluation. Samples were collected seasonally over two years from inshore waters ranging from Kalbarri to Esperance.