White-capped albatross by a fishing vessel near Dunedin. White-capped albatross are one of the bird species that are incidentally killed by New Zealand fishing operations.
Seabirds, marine mammals, and turtles are caught during commercial fishing operations. In order to monitor the impacts of fishing on these species, government observers on fishing vessels record any protected species bycatch incidents that occur. Observer data on protected species captures are maintained by the Ministry for Primary Industries, with identification of captured animals carried out by the Department of Conservation. The data have been summarised in a series of reports, with the most recent report covering the period from 2002–03 to the end of the 2008–09 fishing year (Abraham and Thompson 2011b).
This website provides a summary of protected species bycatch in trawl and longline fisheries, from the 2002–03 to 2013–14 fishing year (fishing years run from October 1 to September 30).
Observers are only present on some fishing vessels. To estimate total captures in a fishery, it is necessary to use statistical methods to extrapolate from the observed fishing to the unobserved fishing. The total observable captures are an estimate of the captures that would have been reported, had observers been present on all fishing vessels. There may be additional mortalities (such as birds that are struck by fishing gear but not brought on board the vessel) that are not recorded by observers. These are referred to as ‘cryptic mortalities’ and are not included in the estimates of total captures, nor is there any evaluation of potential survival of seabirds recorded as captured but subsequently released alive. The methods used for the estimation follow those described in technical reports on bycatch estimation for seabirds (Abraham and Thompson 2011a, Abraham et al. 2013), and marine mammals (Thompson et al. 2013).
Currently available datasets include:
Abraham, E. R., & Thompson, F. N. (2011a). Estimated capture of seabirds in New Zealand trawl and longline fisheries, 2002–03 to 2008–09. New Zealand Aquatic Environment and Biodiversity Report No. 79. 74 pages. Download from Ministry for Primary Industries.
Abraham, E. R., & Thompson, F. N. (2011b). Summary of the capture of seabirds, marine mammals, and turtles in New Zealand commercial fisheries, 1998–99 to 2008–09. New Zealand Aquatic Environment and Biodiversity Report No. 80. 170 pages. Download from Ministry for Primary Industries.
Abraham, E.R., Thompson, F.N., & Berkenbusch, K. (2013). Estimated capture of seabirds in New Zealand trawl and longline fisheries, 2002–03 to 2010–11. Final Research Report for Ministry for Primary Industries project PRO2010-01 (Unpublished report held by Ministry for Primary Industries, Wellington).
Thompson, F. N., Berkenbusch, K., & Abraham, E. R. (2013). Marine mammal bycatch in New Zealand trawl fisheries, 1995–96 to 2010–11. New Zealand Aquatic Environment and Biodiversity Report No. 105. 73 pages. Download from Ministry for Primary Industries.