This Tactical Research Fund Project has been undertaken by SARDI Aquatic Sciences in response to the Spencer Gulf Prawn Fishery’s (SGPF) need for an ecosystem-based reporting framework to support ongoing Marine Stewardship Council (MSC) certification. We reviewed the relevant literature to identify an appropriate reporting framework, assessed the data available for the SGPF, and its suitability for use in ecological assessment, developed a conceptual ecosystem-based assessment framework for the fishery and highlighted the research required (i.e. knowledge gaps) for full implementation. The approach developed would be of use to other prawn trawl fisheries that were seeking a transition from target-species to ecosystem-based assessments to underpin ecosystem-based fisheries management (EBFM) and ecologically sustainable development (ESD).
There is worldwide recognition of the need to move beyond single-species fisheries management to a more comprehensive understanding of the impacts on the ecosystem in which fisheries operate. ESD concepts were expanded into a global action plan at the UN Conference on Environment and Development in Rio de Janeiro in 1992 and ratified by countries including Australia, leading to the National Strategy for ESD and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act 1999). EBFM facilitates ESD and has been recognised worldwide as having the potential to provide a mechanism for integration of ecosystem attributes into fisheries management. For EBFM to be effective, development of appropriate frameworks to integrate ecological and target species data are required.
Prawn fisheries are an important contributor to Australian fisheries production (17,000 t valued at $266 million in 2011/12; Skirtun et al. 2013). Given the evolving need to manage fisheries in a more ecologically sensitive manner, there has been increased environmental awareness of the biological impacts of trawling. Whilst these impacts are difficult to assess because of the complexity of the biological communities and frequent limited understanding of their variability, there is an opportunity to establish a framework for ecosystem-based assessment of the SGPF that could be broadly adopted across benthic prawn trawl fisheries in Australia.
The SGPF operates in Spencer Gulf in South Australia (SA), produces approximately 1,800 t of Western King prawns annually, and is the third most valuable prawn fishery in Australia ($30.3M in 2010/11) behind the Queensland East Coast Otter Trawl Fishery ($90M) and Commonwealth Northern Prawn Fishery ($62.2M).
The overall aim of this project was to develop an environmental reporting framework for Australian prawn trawl fisheries using the SGPF in SA as a case study. Our approach included (i) a review of relevant literature to identify an appropriate reporting framework; (ii) a review of data available for the SGPF, and its suitability for use in ecological assessment; (iii) development of an ecosystem-based assessment framework for the SGPF including identification and development of potential performance indicators; and (iv) the research required (i.e. knowledge gaps) to fully develop the necessary ecological performance indicators for full implementation.
Despite the substantial, diverse, often long-term data sets available for the SGPF, most of the data have been collected for stock assessment of the target species. This resulted in development of a conceptual, rather than a complete ecological assessment framework. Implementing ecological assessment in the SGPF requires further development of relevant performance indicators and reference points across each of the five key ecological components identified as important for fishery management – (i) habitats; (ii) ecosystems (ecological communities/trophodynamics); (iii) target species; (iv) non-target species including by-product and by-catch; and (v) threatened, endangered or protected species (TEPS) – and the development of a framework linking ecological and target species assessments (with decision rules to drive management decision making through the formal management plan for the fishery). While some potential performance indicators, reference points and decision rules have been developed through this project, successful implementation necessitates that these should be developed collaboratively. This process should include at least Primary Industries and Regions SA (PIRSA) Fisheries and Aquaculture, Spencer Gulf and West Coast Prawn Fishermen’s Association (SGWCPFA), SARDI and the Conservation Council of SA (CCSA) and needs to recognise the considerable spatial and temporal (both inter-annual and seasonal) variation evident in the five key components across Spencer Gulf and the numerous potential impacts on the Spencer Gulf environment (e.g. other fisheries, aquaculture, shipping, harbours and wharfs, pollutants, climate change).
