Autopsy report for seabirds killed and returned from observed New Zealand fisheries: 1 October 2006 to 30 September 2007By D.R. Thompson
DOC Marine Conservation Services Series 3. 37 p.
What's it about? Large numbers of seabirds frequent New Zealand commercial fishing waters. The accurate determination of the taxa of seabirds captured in New Zealand fisheries is vital for examining the potential threat to population viability posed by incidental fisheries captures. Further, the assessment of the age-class, sex and provenance of captured individuals requires autopsy in the majority of cases. Between 1 October 2006 and 30 September 2007 (the 2006/07 fishing year), a total of 324 seabirds comprising 22 taxa were incidentally killed as bycatch and returned for autopsy by on-board New Zealand government fisheries observers. Birds were returned from longline, trawl and setnet vessels. Seabirds returned during the 2006/07 fishing year were dominated numerically by two species (sooty shearwater Puffinus griseus and white-capped albatross Thalassarche steadi). Most birds (76%) returned from longline fisheries had injuries consistent with being hooked or entangled in the bill or throat, while most birds (70%) returned from trawl fisheries were killed through entanglement in the net. Warp interaction was the likely cause of death in 29% of trawl specimens. Mean fat scores were generally higher in birds from the 2006/07 fishing year than in most previous years, although mean fat scores were lower in 2006/07 than in 2005/06. Seabirds returned from the 2006/07 fishing year, and from trawl fisheries in particular, showed clear size-related differences in the likely cause of death, and offal appears to continue to be an attractant for many taxa.
The above new publication is now in press and can be downloaded from:
http://www.doc.govt.nz/upload/documents/science-and-technical/dmcs3entire.pdf (2168 KB)
