The closures to fishing declared as part of the Jurien Bay Marine Park are administered by the WA Department of Conservation and Land Management and are intended to conserve marine biodiversity and ecosystem function. The potential effectiveness of these closures for protecting both fished and unfished species, relative to alternative, more traditional, fisheries management strategies, is very uncertain. We propose to identify food web linkages between important fish stocks and other biota in the Jurien region and to evaluate how the food webs, and hence the fish stocks, respond to fishing closures. This research will address two of the high priority research areas for the WA FRAB: evaluating marine park planning (Priority 5); and developing an understanding of the knowledge requirements for cost-effective, ecosystem-based approaches to fisheries (Priority 6). In addition, it provides approaches to assess further the impact and role of rock lobsters and key finfish e.g. snapper, wrasse, dhufish, baldchin groper, in the broader ecosystem. This is one of the questions identified explicitly for investigation by the Rock Lobster Ecosystem Scientific Reference Group and an essential element of strategies to address the ESD obligations of fisheries. Although initially focused on the Jurien region, the qualitative and quantitative modelling approaches will increase the general understanding and develop knowledge that can be used to explore management options, including the design of protected areas, in other parts of temperate Western Australia. This project will provide approaches to promote the ecologically sustainable use of natural fisheries resources along the temperate west coast, thus helping to meet the requirements for Fisheries under the EPBC Act.