Identification of seabirds captured in NZ fisheries 2010/11
Published:
Latest report: January 2012Download the publication
Summary
New Zealand waters support a diverse range of seabird species and much of the commercial fishing activity in the region overlaps with these seabirds.
The accurate identification of seabirds captured in New Zealand fisheries is vital to determine the potential impact of fisheries interaction with these seabird populations. The autopsy programme has been in place to accurately determine the identification (and age, sex, diet and provenance) of specimens recovered dead by observers, but the identification reported for captured seabirds released alive and were not previously confirmed by an expert and were of unknown accuracy.
Between 1 October 2010 and 30 June 2011 a total of 191 seabirds comprising of 12 taxa were incidentally killed as bycatch and returned for autopsy by onboard New Zealand Government observers. Birds were returned from longline (n=44) and trawl vessels (n=147).
Seabirds returned were dominated numerically by five species (white-chinned petrel Procellaria aequinoctialis, sooty shearwater Puffinus griseus, New Zealand white-capped albatross Thalassarche steadi, Flesh-footed shearwater Puffinus carneipes and Buller’s albatross Thalassarche bulleri bulleri). Two-thirds (66%) of the birds returned from the longline fisheries had injuries consistent with being hooked or entangled in the bill or throat, while most birds (89%) returned from trawl fisheries were killed through entanglement in the net.
Warp interaction was the likely cause of death in 11% of trawl specimens. Mean fat scores were lower than birds in previous fishing years. Discards, including offal, appears to continue to be an attractant for many seabirds.
The photography programme was developed to enable observers to record and return images of birds incidentally captured by vessels (whether alive or dead) which would enable correct identification to be determined. All images were provided to Wildlife Management International Ltd in November 2011, which delayed the identification and reporting process. Out of 299 records of seabird captures on fishing vessels, there were photographs taken of 164 seabirds consisting of 9 taxa.
Quality of the images varied widely and several could not be identified past family group. Poor images were common for birds that were alive and seen onboard for short periods (when photographs were taken from a long distance). A number of seabirds were recorded as captured and released alive, but no images were taken of these birds and as a result, identification of these birds could not be confirmed. In addition, there were a number of seabird photographs provided that were not recorded as captures. Most of these birds were alive and were likely to have left the vessel on their own.
Publication information
Author: Elizabeth Bell, Wildlife Management International Limited
Contact
Conservation Services Programme
Department of Conservation
PO Box 10-420
Wellington 6143
Email: csp@doc.govt.nz