Determining the impact of environmental variability on the sustainability, fishery dynamics and economic performance of the West Coast Prawn Trawl Fishery
Characterising the fish habitats in the Recherche Archipelago, Western Australia
Fisheries WA demonstrated in their Aquaculture Plan for the Recherche Archipelago (Fisheries WA 2000) that one of the major factors slowing development in this region is lack of accurate spatially explicit data on the distributions of benthic habitats and the influence of currents and wind generated waves. This information is required to aid the selection of suitable offshore aquaculture facilities and in the development of multiple use management plans.
This FRDC application, rather than focusing on cultural, economic and social elements of resource planning concentrates on the physical and biological data requirements. Many important cultural, economic and social issues have been identified in community and industry consultation by Fisheries WA during the development of the Aquaculture plan for the recherche Archipelago (Fisheries WA, 2000). The major outcome from these documents was that most other users of the Archipelago (Tourism, Shipping, Recreational and other commercial fishermen) indicated they were not happy with wholesale aquaculture development until accurate assessments of the benthic habitats and oceanography were completed over a wide spatial scale within the Archipelago. The recognition of this need has provided impetus resulting in aquaculture proponents (MG Kailis, Maritime Training Centre of Esperance), other fisheries (Esperance Professional Fishers Association, Esperance Professional Abalone Divers Association, 2 Recreational Angling Clubs), shipping concerns (Esperance Port Authority and industries utilising the port), tourism (Goldfields Esperance Development Commission), government departments (CALM, Fisheries WA, The Esperance Shire) and local concerned citizens (Recherche Action Group, Local Environmental Action Forum) all providing formal support for this application.
These groups see the need for representative broad scale bio-physical information to be used in the integrated planning to ensure the compatibility and sustainability of a diverse range of marine a coastal activities. This will ensure that the quality of the environment and the quality of life experienced by the populace living in Recherche Archipelago region is balanced with the need for new job creation in the region.
The 2.5 year research program we describe in this proposal will fulfil bio-physical data requirements for that planning process. This data will be available for incorporation into existing regional planning documents written in conjunction with cultural economic and social components that have been collected by Fisheries WA. It will also compliment and enhance information collected and developed by the Marine Group of the Department of Conservation and Land Management as part of the community and industry consultation involved in the MPA planning process.
Final report
This project is a joint Esperance community (through the Recherche Advisory Group - RAG), research scientist and resource management project. The commitment of RAG has allowed the researchers to efficiently transfer scientific information to the general public of Esperance and the South Coast of Western Australia and keep the research focused on management outcomes.
The outcomes of this report are:
- The design of a hierarchical classification scheme of benthic habitats in the Recherche Archipelago.
- An extensive habitat map of the Western Recherche Archipelago at both broad and functional habitat classifications and less detailed habitat maps of duke of Orleans Bay and Cape Arid to Middle Island.
- An oceanographic model of the influence of ocean swells on the Western Recherche Archipelago. This model includes an assessment of swell driven shear at the benthos.
- A broad scale fisheries-independent non-destructive survey of the demersal fish of the Recherche from Esperance Bay to Cape Arid. The survey was designed to capture habitat differences in fish assemblages.
- A broad scale (within the Western Archipelago) survey of the infauna found in a range of soft bottom habitats including coarse sands, rhodoliths and sparsely vegetated sands.
- Fine scale diversity surveys of reef communities on islands in the archipelago from Figure of Eight to Middle Island. These surveys integrate information from both habitat mapping and physical oceanographic modelling.
Keywords: habitat, classification, mapping, oceanography, benthic, algae, infauna, sessile invertebrate
Determining ecological effects of longline fishing in the Eastern Tuna and Billfish Fishery
The ET&BF is presently dealing separately with a number of ecological issues. For example, impacts of longliners on shearwaters and turtles are current high profile problems. However, other issues such as depletion of swordfish, SBT bycatch, availability of tunas in relation to oceanographic features, bycatch of sharks and finning have all taken centre stage at different times in the short history of the domestic fishery. This approach is often reactionary, rather than strategic, and may not be the best use of research resources over the long-term. If the ET&BF is to move substantially toward ecosystem-based fishery management, as it is required to do under the EPBC act, rather than continue the individual species management approach, an ecosystem analysis providing ecosystem metrics must be developed. If, for example, ET&BF managers opt for time area closures as part of their management strategy to protect key species, developing these on a species-by-species basis has the potential to impact the whole fishery. To develop and evaluate time area closures that allow for minimizing risk of adverse impacts to the suite of key species, while allowing for optimal efficiency of fishing, understanding the associations, linkages and interactions between species is essential. This is the ecosystem approach. Developing an understanding of how ecosystem-associations relate to oceanographic features is also essential in open ocean systems where the dominant influence on distribution and local abundance is oceanography. The approach we are taking will provide the information needed to support an ecosystem-based management framework. Through the analyses we are proposing we will identify regional “hot spots”, detail their linkages and provide detailed scenarios as to how we think different management strategies and fishing practices will or will not impact pelagic food chains, ecologically related non-target species, competitors (e.g. sharks, marlins etc.) and their associated ecosystems. The need for ecosystem-based fishery management for the Western Pacific region has also been supported by PrepCon for the soon-to-be formed WCPFC (Working Paper 9, 2002).