Characterizing seabird bycatch in the eastern Australian tuna and billfish pelagic longline fishery in relation to temporal, spatial and biological influences
Article first published online: 23 APR 2010
Copyright © 2010 John Wiley & Sons, Ltd.
Aquatic Conservation: Marine and Freshwater Ecosystems
Volume 20, Issue 5, pages 531–542, July/August 2010
How to Cite
Trebilco, R., Gales, R., Lawrence, E., Alderman, R., Robertson, G. and Baker, G. B. (2010), Characterizing seabird bycatch in the eastern Australian tuna and billfish pelagic longline fishery in relation to temporal, spatial and biological influences. Aquatic Conserv: Mar. Freshw. Ecosyst., 20: 531–542. doi: 10.1002/aqc.1115
- Issue published online: 28 JUN 2010
- Article first published online: 23 APR 2010
- Manuscript Accepted: 15 FEB 2010
- Manuscript Revised: 6 FEB 2010
- Manuscript Received: 6 NOV 2009
- eastern tuna and billfish fishery (ETBF);
- longline fishing;
- fisheries bycatch;
- incidental mortality;
- bycatch mitigation
- 1.Seabirds killed incidentally in Australia's eastern tuna and billfish (ETBF) longline fishery between September 2001 and June 2006 were examined to evaluate species composition and to relate, where possible, capture events to operational and environmental factors.
- 2.During this period 2.129 million hooks on 2202 shots were observed, and 369 birds were reported killed. The majority (78%) of these were flesh-footed shearwaters (Puffinus carniepes), 53% of which were male and 44% female. Smaller numbers of medium to large sized albatrosses (Diomedeidae, predominantly female) and other shearwaters (Puffinus spp.) and petrels (Pterodroma spp.) dominated the remainder of the bycatch.
- 3.Of the 369 birds reported taken as bycatch, 280 were available for necropsy, and species identifications performed in situ by observers were assessed. While observer identifications were generally correct for common species, performance was poor for less common ones.
- 4.The geographical location (latitude) of shots, season, time of day at which shots were set, and bait type and life status (dead or alive) influenced the seabird bycatch rate. The majority of captures (87% overall) occurred between 30 and 35°S, with bycatch being lowest in winter, and remaining at similar levels across the other seasons.
- 5.The use of live fish bait was generally associated with increased captures of both seabirds overall, and flesh-footed shearwaters in particular. Copyright © 2010 John Wiley & Sons, Ltd.