Data from boat-based surveys north and south of Kaikōura Peninsula between 2013 and 2018 were analysed to assess potential impacts of the November 2016 earthquake on abundance and distribution of Hector’s dolphin (Cephalorhynchus hectori) in the Kaikōura region. A binomial mark-resight model estimated 250 – 450 adult Hector’s dolphins in the area for most survey periods. Results do not indicate a substantial change in the number of adults using the area in the 16 months following the earthquake.

Electronic monitoring (EM) for seabird capture data for the 2017/18 fishing year was compared with a NIWA audit of the footage and observer data. For the 26 trips in common, the audit recorded 5 seabird captures, as did the EM data reviewed by Trident Systems. However, both missed a seabird capture that was recorded by the other. For the observer data on trips with reviewed EM, 5 seabird captures were recorded, the same number as EM for these trips.

The present study provides estimates of seabird bycatch in commercial fisheries in New Zealand waters. Estimates were derived using statistical models that integrated fishing effort and observer data up to the 2017–18 fishing year. In 2017–18, there were 3328 (95% credible interval, c.i.: 2971–3782) estimated seabird captures, including 1506 (95% c.i.: 1344–1696) captures in trawl, and 1186 (95% c.i.: 913–1589) and 635 (95% c.i.: 536–758) captures in bottom and surface longline, respectively.

Using GPS tracking data obtained from yellow-eyed penguins since 2003, habitat models using the maximum entropy method were developed. Main factors determining habitat use were bathymetry, seafloor sediment composition, and colony distance. Acceptable model outputs were generated for North Otago and the Otago Peninsula as well as northern Stewart Island and Codfish Island. No adequate data were available for the Catlins, the eastern Foveaux Strait region, and southern Stewart Island; extrapolation from other regions proved unreliable. Habitat use maps are presented.

A survey of high-density breeding colonies of Westland petrels Procellaria westlandica, an endemic New Zealand seabird, undertaken between 2007 to 2011, conservatively estimated the population size to be 2827 (95%CI, 2143–3510) annual breeding pairs. The population may have been underestimated by up to 10% but is unlikely to have exceeded 4000 annual breeding pairs at the time of this survey. This estimate is the first detailed population estimate for all known breeding areas of this species.

Commercial catch-effort data and fisheries observer records of catch and discards by species were used to estimate the rate and level of non-target catch and discards in the ling longline fisheries for the fishing years 2002–03 to 2017–18. Estimates were made for broad categories of catch and discards including target species, QMS species, non-QMS fish, and non-QMS invertebrate species, and estimates of annual catch were made for several of the major individual non-target species.

This report presents an updated assessment of the risk of commercial fisheries in New Zealand for 71 seabird taxa breeding in this region, including data to the 2016–17 fishing year. The risk for seabirds was estimated as the ratio of total fishery-related deaths to the Population Sustainability Threshold, with 18 species having an estimated risk ratio that was non-negligible. Black petrel continued to be identified as the species most at risk from commercial fisheries in New Zealand waters.