Performance of square-mesh codends in reducing discards and by-catch in the Shark Bay scallop fishery
Arani Chandrapavan A B , Mervi I. Kangas A and Errol C. Sporer A
+ Author Affiliations
- Author Affiliations
A Western Australian Fisheries and Marine Research Laboratories, PO Box 20, North Beach, WA 6920, Australia.
B Corresponding author: Arani.Chandrapavan@fish.wa.gov.au
Marine and Freshwater Research 63(11) 1142-1151 https://doi.org/10.1071/MF12069
Submitted: 7 March 2012 Accepted: 4 September 2012 Published: 26 November 2012
Abstract
The performance of square-mesh codends (as opposed to the conventional diamond mesh) was examined as a discard and by-catch reduction device for the Shark Bay saucer-scallop trawl fishery. Of the three different-sized square-mesh codends (50, 55, 60 mm) tested against the standard 100-mm diamond-mesh codend, the 50-mm square-mesh codend performed poorly with relatively high retention of small (<85 mm shell height) scallops, whereas the 55- and 60-mm square-mesh codends retained 22–33% less smaller scallops than did the diamond-mesh codend. Overall, a mean of 5% loss in commercial-sized scallops across all three square-mesh codends and significant by-catch reductions of up to 95% were achieved compared with the diamond mesh. Catch rate of prawns by the square-mesh codend was less than 2% of that of the standard prawn net. The performance of the 60-mm square-mesh codend presents a good basis for its use in commercial trials in the Shark Bay scallop trawl fishery. A move to square-mesh codends could result in a significant reduction of small scallops and by-catch and may potentially increase the catches of commercial-sized scallops as a result in improvements in water flow and net efficiency.
Additional keywords : Amusium balloti, codend selectivity, otter trawl.
References
Alverson, D. L., Freeberg, M. H., Murawski, A., and Pope, J. G. (1994). A global assessment of fisheries bycatch and discards. FAO Fish. Technical Paper 339. FAO, Rome.Anonymous (2007). Shark Bay prawn and scallop fisheries: draft review report. Fisheries Management Paper No. 222. WA Fisheries Department, Perth.
Bellido, J. M., Santos, M. B., Pennino, M. G., Valeiras, X., and And Pierce, G. J. (2011). Fishery discards and bycatch: solutions for an ecosystem approach to fisheries management? Hydrobiologia 670, 317–333.
| Fishery discards and bycatch: solutions for an ecosystem approach to fisheries management?Crossref | GoogleScholarGoogle Scholar |
Broadhurst, M. K. (2000). Modifications to reduce bycatch in prawn trawls: a review and framework for development. Reviews in Fish Biology 10, 27–60.
| Modifications to reduce bycatch in prawn trawls: a review and framework for development.Crossref | GoogleScholarGoogle Scholar |
Broadhurst, M. K., Millar, R. B., Kennelly, S. J., Macbeth, W. G., Young, D. J., and Gray, C. A. (2004). Selectivity of conventional diamond- and novel square-mesh codends in an Australian estuarine penaeid-trawl fishery. Fisheries Research 67, 183–194.
| Selectivity of conventional diamond- and novel square-mesh codends in an Australian estuarine penaeid-trawl fishery.Crossref | GoogleScholarGoogle Scholar |
Catchpole, T. L., and Gray, T. S. (2010). Reducing discards of fish at sea: a review of European pilot projects. Journal of Environmental Management 91, 717–723.
| Reducing discards of fish at sea: a review of European pilot projects.Crossref | GoogleScholarGoogle Scholar |
Courtney, A. J., Campbell, M. J., Roya, D. P., Tonks, M. L., Chilcott, K. E., and Kyne, P. M. (2008). Round scallops and square meshes: a comparison of four codend types on the catch rates of target species and by-catch in the Queensland (Australia) saucer scallop (Amusium balloti) trawl fishery. Marine and Freshwater Research 59, 849–864.
| Round scallops and square meshes: a comparison of four codend types on the catch rates of target species and by-catch in the Queensland (Australia) saucer scallop (Amusium balloti) trawl fishery.Crossref | GoogleScholarGoogle Scholar |
Crawford, C. R., Steele, P., McMillen-Jackson, A. L., and Bert, T. M. (2011). Effectiveness of bycatch-reduction devices in roller-frame trawls used in the Florida shrimp fishery. Fisheries Research 108, 248–257.
| Effectiveness of bycatch-reduction devices in roller-frame trawls used in the Florida shrimp fishery.Crossref | GoogleScholarGoogle Scholar |
DuPaul, W. D., Brust, J. C., and Kirkley, J. E. (1996). Bycatch in the United States and Canadian sea scallop fisheries. In ‘Solving Bycatch Workshop: Considerations for Today and Tomorrow’. (Ed. T. Wray.) pp. 175–182. University of Alaska Sea Grant Report, Fairbanks, AK.
Eayrs, S. (2007). ‘A Guide to Bycatch Reduction in Tropical Shrimp-trawl Fisheries.’ Revised edn. (FAO: Rome.)
Holst, R., and Revill, A. (2009). A simple statistical method for catch comparison studies. Fisheries Research 95, 254–259.
| A simple statistical method for catch comparison studies.Crossref | GoogleScholarGoogle Scholar |
Joll, L. M. (1987). The Shark Bay scallop fishery: Discussion paper. Fisheries Management paper no. 11. WA Fisheries Department, Perth.
Kangas, M. I., and Thomson, A. (2004). Implementation and assessment of bycatch reduction devices in the Shark Bay and Exmouth trawl fisheries. Final FRDC report on Project No. 2000/189. WA Fisheries Department, Perth.
Kangas, M. I., Morrison, S., Unsworth, P., Lai, E., Wright, I., and Thomson, A. (2007). Development of biodiversity and habitat monitoring systems for key trawl fisheries in Western Australia. Final report to FRDC on Project No. 2002/038. Fisheries Research Report No. 160. WA Department of Fisheries, Perth.
Kelleher, K. (2005). Discards in the world’s fisheries. An update. Fisheries Technical Paper 470. FAO, Rome.
Macbeth, W. G., Broadhurst, M. K., and Millar, R. B. (2005a). Fishery-specific differences in the size selectivity and catch of diamond- and square-mesh codends in two Australian penaeid seines. Fisheries Management and Ecology 12, 225–236.
| Fishery-specific differences in the size selectivity and catch of diamond- and square-mesh codends in two Australian penaeid seines.Crossref | GoogleScholarGoogle Scholar |
Macbeth, W. G., Broadhurst, M. K., Millar, R. B., and Smith, S. D. A. (2005b). Increasing codend mesh openings: an appropriate strategy for improving the selectivity of penaeid fishing gears in an Australian estuary? Marine and Freshwater Research 56, 889–900.
| Increasing codend mesh openings: an appropriate strategy for improving the selectivity of penaeid fishing gears in an Australian estuary?Crossref | GoogleScholarGoogle Scholar |
MacLennan, D. N. (1992). Fishing gear selectivity – an overview. Fisheries Research 13, 201–204.
| Fishing gear selectivity – an overview.Crossref | GoogleScholarGoogle Scholar |
Mant, J. C., Moran, M. J., Newman, S. J., Hesp, S. A., Hall, N. G., and Potter, I. C. (2006). Biological characteristics and mortality of western butterfish (Pentapodus vitta), an abundant bycatch species of prawn trawling and recreational fishing in a large subtropical embayment. Fish Bulletin 104, 512–520.
Moran, M. J., and Kangas, M. I. (2003). The effects of the trawl fishery on the stock of pink snapper, Pagrus auratus, in Denham Sound, Shark Bay. Fisheries Research Bulletin No. 31. WA Department of Fisheries, Perth.
Ordines, F., Massuti, E., Guijarro, B., and Mas, R. (2006). Diamond vs. square mesh codend in a multi-species trawl fishery of the western Mediterranean: effects on catch composition, yield, size selectivity and discards. Aquatic Living Resources 19, 329–338.
| Diamond vs. square mesh codend in a multi-species trawl fishery of the western Mediterranean: effects on catch composition, yield, size selectivity and discards.Crossref | GoogleScholarGoogle Scholar |
Rudders, D. B., Dupaul, W. D., and Kirkley, J. E. (2000). A comparison of size selectivity and relative efficiency of sea scallop, Placopecten magellanicus (Gmelin, 1791), trawls and dredges. Journal of Shellfish Research 19, 757–764.
Sporer, E., Kangas, M., and Brown, S. (2007). Shark Bay Scallop Managed Fishery Status Report. In ‘State of the Fisheries Report 2006/2007’. (Eds W. J. Fletcher and K. Santoro.) pp. 106–110. WA Department of Fisheries, Perth.
Steele, P., Bert, T. M., Johnston, K. H., and Levett, S. (2002). Efficiency of bycatch reduction devices in small otter trawls in the Florida shrimp fishery. Fish Bulletin 100, 338–350.
Sun, M. C., Zhang, J., and Xu, L. X. (2006). Size selectivity of diamond and square mesh codends for hairfin anchovy Setipinna taty in Chinese stow net fisheries. Fisheries Science 72, 530–539.
| Size selectivity of diamond and square mesh codends for hairfin anchovy Setipinna taty in Chinese stow net fisheries.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XmsVOjsLg%3D&md5=a233bb9ff593af86b8f12d3619917978CAS |
Suuronen, P., and Millar, R. B. (1992). Size selectivity of diamond and square mesh codends in pelagic herring trawls – only small herring will notice the difference. Canadian Journal of Fisheries and Aquatic Sciences 49, 2104–2117.
| Size selectivity of diamond and square mesh codends in pelagic herring trawls – only small herring will notice the difference.Crossref | GoogleScholarGoogle Scholar |
Wakefield, C. B., Moran, M. J., Tapp, N. E., and Jackson, G. (2007). Catchability and selectivity of juvenile snapper (Pagrus auratus, Sparidae) and western butterfish (Pentapodus vitta, Nemipteridae) from prawn trawling in a large marine embayment in Western Australia. Fisheries Research 85, 37–48.
| Catchability and selectivity of juvenile snapper (Pagrus auratus, Sparidae) and western butterfish (Pentapodus vitta, Nemipteridae) from prawn trawling in a large marine embayment in Western Australia.Crossref | GoogleScholarGoogle Scholar |
Yochum, N., and Dupaul, W. D. (2008). Size-selectivity of the northwest Atlantic sea scallop (Placopecten magellanicus) dredge. Journal of Shellfish Research 27, 265–271.
| Size-selectivity of the northwest Atlantic sea scallop (Placopecten magellanicus) dredge.Crossref | GoogleScholarGoogle Scholar |
