Project number: 2009-006
Project Status:
Budget expenditure: $74,288.75
Principal Investigator: Ian Potter
Organisation: Murdoch University
Project start/end date: 30 Jun 2009 - 29 Sep 2011


Implementation of ecosystem-based fishery management requires sound knowledge of food webs if the indirect effects of fishing on trophic structure are to be understood. There is an urgent need to construct a quantitative food web so that we can understand the ways in which the marked declines in the abundances of important fish species off the lower west coast of Australia, which led to the recent closure of the metropolitan commercial fishery, are likely to have impacted on the ecosystem. While there are sound dietary data for most of the more abundant and important species in this region, no such data are available for Snapper (Pagrus auratus) and Silver Trevally (Pseudocaranx dentex). Snapper was a primary target species for commercial fishers, and Snapper and Silver Trevally both continue to be of great importance to recreational fishers. Sound dietary data for these species, which take into account the ways in which their diets change with body size and season, are essential for the construction of a reliable food web. There is a need to combine the new dietary data for these species with those that were collated in the database developed in FRDC 2002/016 and with the results from more recent studies, converting them into common dietary categories, size categories and a common format before they can be used to construct a reliable food web. The opportunity exists, while Ian Potter remains actively involved in research, to apply the experience and knowledge that he and Margaret Platell possess (noting that these two biologists have been involved in collecting much of the available dietary data for the demersal fish species of south-western Australia) to bring together the results of approximately 15 years of research to create a food web for this region that will be invaluable for future research and management.


1. To determine the diets of Snapper and Silver Trevally on the lower west coast of Australia and how they change with body size and season
2. To construct a reliable food web derived from quantitative dietary data for a wide range of demersal fish species off the lower west coast of Australia

Final report

ISBN: 978-1-921877-06-3
Author: Ian Potter

Related research


National Snapper Workshop - Rebuilding our iconic Snapper stocks

1. To identify key issues and challenges for Snapper, review Snapper research, and critique jurisdictional management arrangements.
Department of Primary Industries and Regions South Australia (PIRSA)