Effects of Trawling subprogram: reducing the impact of Queensland's trawl fisheries on protected sea snakes
Department of Agriculture and Fisheries EcoScience Precinct
Tony J. Courtney
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.
1. Collate and review existing data and literature on sea snake distribution and abundance on the Queensland east coast. This will enhance the detail and precision of the recently introduced CFISH logbook data program on Species of Conservation Interest.
2. Implement a crew-based data collection program to quantify information on sea snake catch rates, species composition and distribution. Where possible, consider areas that are closed and open to trawling (contingent upon GBRMPA approval to sample closed areas).
3. Quantify post-trawling mortality rates of sea snakes by undertaking survival experiments at sea on commercial vessels.
4. Test effectiveness of BRDs, including square mesh panels, on sea snake catch rates and promote the uptake of effective devices by industry.
Principal Investigator: A. Courtney, B. Schemel, R. Wallace, M. Campbell, D. Mayer and B Young
Key Words: sea snakes, Acalyptophis peronii, Aipysurus duboisii, Aipysurus eydouxii, Aipysurus laevis, Astrotia stokesii, Disteira kingii, Disteira major, Enhydrina schistosa, Hydrophis elegans, Hydrophis mcdowelli, Hydrophis ornatus, Lapemis curtus, trawl bycatch, prawns, redspot king prawn Melicertus longistylus, Lapemis curtus, trawl bycatch, prawns, redspot king prawn Melicertus longistylus, eastern king prawn, Melicertus plebejus, tiger prawns, Penaeus esculentus, Metapenaeus ensis, Metapenaeus endeavouri, saucer scallops, Amusium balloti, BRD, square mesh codends, fisheye BRD