Fisheries Managers' Workshop
Assessing and managing interactions of protected and listed marine species with commercial fisheries in Western Australia
Incidental mortality in commercial fishing activities is acknowledged as an issue for many protected and endangered species throughout the world. Whilst Australia is considered a world leader in managing
these interactions, further improvements and development of additional knowledge is still required to
meet the expectations of the community. Within WA, to address the variety of interactions with protected
and listed marine species across all our commercial fisheries in a cost effective manner, an holistic and
integrated approach needs to be taken. Several protected species issues have already been identified through existing management processes, including entanglement of whales in fishing ropes and interactions between seals and demersal gillnets. These two issues involve protected species on the Commonwealth threatened list (i.e the Australian sea lion, Humpback and Southern Right Whale) which generates attention from both an ecological and political respect. A greater understanding of the factors involved in these interactions will be needed to design mitigation programs. Assessments at both the individual fishery and bioregional level will be required to input into the ecosystem-based fisheries management (EBFM) frameworks that are being developed for each WA bioregion. There is also the ongoing requirement for all fisheries to satisfy the protected species criteria under the EPBC Act which for some is vital to maintain their export certification. Moreover, there is the potential for significant pressure from advocacy groups to press for regulation of fishing effort or methods unless well-formulated management systems to address these pressing issues are developed.
Final report
Effects of Trawling Subprogram: development of biodiversity and habitat monitoring systems for key trawl fisheries in Western Australia
The need for this project was identified through the ESD/EA Risk Assessment workshops held for the Shark Bay and Exmouth Gulf trawl fisheries in May and October 2001. Research is required to provide baseline data on biodiversity on and off the trawl habitats in Shark Bay and Exmouth Gulf to allow an assessment of the effects of trawling on bycatch and to set up reference sites for long-term monitoring of the environmental impact of trawling. The study will examine seasonal variation in biodiversity and efficiency in capture of bycatch species to provide a rigorous scientific basis for determining references sites in other fisheries. Understanding seasonal variability will allow the selection of the appropriate timing of long-term monitoring. Depletion experiments will ensure that bycatch catch per unit effort is related to actual abundance. The sampling undertaken in Shark Bay will cover both prawn and scallop ESD requirements to enable similar reference sites to be established in all WA trawl fisheries. Bycatch issues in the Shark Bay and Exmouth fisheries were identified as a moderate risk through an Ecological Risk Assessment workshop. There is a need for a better understanding of the faunal composition and habitat preferences of bycatch species in both trawled and untrawled areas will aid in determining the most appropriate level of risk to bycatch species. This may allow management strategies to be developed to ameliorate any detrimental impacts on those species that are found to be highly vulnerable to trawl impacts. This information will also enable the Department of Fisheries and industry to effectively respond to information required by Environment Australia on the risk level, objectives, performance indicators and management responses for each issue in order to continue to provide quality and highly valued seafood to both export and local markets. It will also provide a basis to answer queries from conservation and community groups.