Gear interaction of non-targeted species in the Lakes and Coorong commercial and recreational fisheries of South Australia
Effects of Trawling Subprogram: collaborative extension program by the Department of Primary Industries and Fisheries, Seanet and Ecofish for the development and adoption of square mesh codends in select prawn and scallop trawl fisheries in Queensland
In recent years, increased community awareness of bycatch in prawn trawl fisheries and scrutiny from conservation agencies have brought pressure upon governments and fisheries management agencies to implement bycatch reduction initiatives. This is of particular importance in Queensland as about 70% of the effort in the east coast trawl fishery occurs within the boundary of the Great Barrier Reef Marine Park.
As such, several stakeholders have stated that bycatch reduction is a high priority area. This project will address the following priorities:
1) Priority 1.3 of QFIRAC’s current goals and priorities as reviewed with stakeholders "Effects of fishing activities on fish and their ecosystems", specifically point b, "Bycatch reduction, reduce volume of bycatch, improve bycatch reduction devices"
2) Section 2 of the Queensland Fisheries Business Group's Trawl Research Priority Areas for 2004/05, specifically "the development of management tools to reduce bycatch including alternative devices that minimise impacts and/or increase bycatch survival"
3) Part of Recommendation 26 of the Great Barrier Reef Marine Park Authority’s audit of the East Coast Trawl Fishery which states "that designs need to be developed to increase the chances of escape for unwanted bycatch, but do not result in significant product and by-product losses".
Further, the implementation of the Environment Protection and Biodiversity Conservation Act 1999 allows the Commonwealth Government, through the Department of Environment and Heritage, to assess the sustainability of all export fisheries within Australia. The Act is designed to ensure ecologically sustainable development through the conservation and ecologically sustainable use of natural resources, including both targeted and non-targeted animals. A significant reduction in bycatch is a favourable step in this regard.
Results from the FRDC research project number 2000/170 “Bycatch weight, composition and preliminary estimates of the impact of bycatch reduction devices in Queensland’s trawl fishery” highlight that bycatch can be reduced by 78% in the scallop fishery and 28% in the deepwater eastern king prawn fishery without significant reductions in catch. This represents the reduction of bycatch in the order of thousand’s of tonnes annually. Although robust estimates of bycatch reduction are unavailable for the black tiger (leader) prawn fishery, significant reductions in bycatch will occur if square mesh codend BRDs are used. Given the large size of the target species, bycatch reduction could be in the order of 50%.
Given the slow uptake of square mesh codend BRDs by commercial fishers, it is necessary to promote the use of this technology via a dedicated extension program. Success of previous extension programs, most notably the FRDC-funded extension project "Commercialisation of bycatch reduction strategies and devices within northern Australian prawn trawl fisheries" (FRDC Project No. 96/254), is evidence that such programs are crucial for the transfer of new technologies to industry.
Final report
Effects of Trawling subprogram: reducing the impact of Queensland's trawl fisheries on protected sea snakes
1) Legal obligation.
In Australia, sea snakes are a protected species group under Schedule 1 of the National Parks and Wildlife Regulations 1994, but despite their protected status, tens of thousands of snakes are caught incidentally in the Queensland trawl fishery each year. In the Northern Prawn Fishery (NPF) it has been estimated that between 81,000 and 120,000 were caught annually in the early 1990s (see Wassenberg et al. 1994 and Ward 1996). Wassenberg et al. (2001) reported that 48.5% of sea snakes caught from research and commercial prawn trawling die as a result of being trawled. The Queensland Government and the Queensland commercial trawl fishers are legally obliged to address the problem and minimise sea snake – trawl interactions.
2) Recommendations by the Department of Environment and Heritage (DEH)
The impact of prawn trawling on the sustainability of sea snake populations on the Queensland east coast is a major concern to DEH. In their review of the strategic assessment of the Queensland east coast trawl fishery, DEH recommended to the Queensland Government that research into the impact of trawling on sea snakes be promoted, and that all reasonable steps should be undertaken to reduce interactions between protected species and the Queensland trawl fishery.
In summary there is a strong legal case in support of research that reduces the impacts of trawling on sea snake populations. In addition, addressing the DEH recommendations will help to ensure that that the Queensland east coast trawl fishery remains on the list of fisheries that are accredited for export, thus securing the continuation of the export of seafood produced from the fishery.
References
Ward TM (1996) Sea snake by-catch of prawn trawlers on the northern Australian continental shelf. Marine and Freshwater Research 47, 631-635.
Wassenberg TJ, Milton DA, Burridge CY (2001) Survival rates of sea snakes caught by demersal trawlers in northern and eastern Australia. Biological Conservation 100, 271-280.
Wassenberg TJ, Salini JP, Heatwole H, Kerr JD (1994) Incidental capture of sea-snakes (Hydrophiidae) by prawn trawlers in the Gulf of Carpentaria, Australia. Australian Journal of Marine and Freshwater Research 45, 429-443.