Identification of seabirds captured in New Zealand fisheries 1 July 2020- 30 June 2021
Published:
December 2022Download the publication
Summary
The New Zealand Exclusive Economic Zone (EEZ) supports a diverse range of seabird species. Much of the commercial fishing activity in the region overlaps with seabird foraging ranges. The accurate identification of bycatch seabirds interacting with New Zealand fisheries is vital for determining the impact of fisheries on these seabird populations. Between 1 July 2020 and 30 June 2021, a total of 651 seabirds were reported as incidental interactions with commercial fishing vessels by on-board New Zealand Government observers; of these 187 were returned for necropsy and 464 were interactions (photographed (n = 190) or non-photographed (n = 274)) as deceased or alive captures.
187 individual seabirds, grouped into 18 species, were incidentally killed as bycatch and returned for necropsy. Seabirds were returned from 52 individual vessels, comprised of 14 longline (n = 49 seabirds), 35 trawl (n = 133 seabirds), and three set net (n = 5 seabirds) vessels, and were dominated numerically by five bycatch species: white-chinned petrel (n = 48, 25.7%), New Zealand white-capped albatross (n = 34, 18.2%), sooty shearwater (n = 25, 13.4%), Salvin’s albatross (n = 20, 10.7%) and Buller’s albatross (n = 18, 9.6%). These five species accounted for 77.5% of all returns. All birds returned from longline fisheries had injuries consistent with being hooked in the bill, throat, or wing. Most birds returned from trawl fisheries were caught through entanglement in the net, cod-end, or pound (75.9%), with 16.5% likely to have specifically interacted with the warp. The cause of death for seven birds was deck strike on trawl vessels. Birds had a lower mean
body fat score in comparison to birds from the previous two survey years. Discards, including offal, appear to continue to be an attractant for many seabirds.
In addition to the seabirds that were returned for necropsy, examination of the Ministry for Primary
Industries (MPI) Central Observer Database (COD) and images provided by Government observers gave a total of a further 464 seabirds that were reported as interactions or photographed (as dead or alive captures) aboard 63 fishing vessels. The majority (64.9%) of the seabirds reported in these interactions and photographs were released alive. Out of these 464 records of seabird interactions, photographs were taken of 190 seabirds consisting of 18 species. Image quality varied widely, with poor images being particularly common for birds that were alive and seen on-board for short periods. Images of dead birds have improved with multiple images taken for each specimen. Recommendations are made to improve photo-identifications in the future.
Publication information
Bell, E. & Larcombe, S. 2022. Identification of seabirds caught in New Zealand fisheries, 1 July 2020 to 30 June 2021. INT2019-02 final annual report prepared by WMIL for the Conservation Services Programme, Department of Conservation. 40 p.
Contact
Conservation Services Programme
Department of Conservation
PO Box 10-420
Wellington 6143
Email: csp@doc.govt.nz