An update on the New Zealand large-scale seabird monitoring and tracking programme with improved insights into trends, distribution, and overlap with pelagic longline fisheries

We analysed 184 population counts across 1945-2024 and 1,151 tracks for 11 New Zealand albatross and large petrel taxa vulnerable to longline fisheries bycatch. We estimated long-term population trends (annual growth rates 𝑟𝑡) over various time periods using a Bayesian framework and generated year-round maps to improve understanding of the distributions of these seabirds within the Western and Central Pacific Ocean (WCPO). We expanded our spatial analyses and included 583 tracks of three Northern Hemisphere albatrosses to develop combined WCPO seabird distribution maps. Finally, we conducted fine scale overlap analyses for two taxa of particular concern, Antipodean and Gibson’s Albatross, in which we assessed spatiotemporal overlap of 235 albatross tracks with commercial pelagic longline fishing effort inferred from automated identification system data, sourced from Global Fishing Watch. Our results show that 73% of the studied New Zealand taxa have exhibited population declines, with biannually and semi-biannually breeding albatrosses showing the greatest rates of decline. Growth rates across taxa did not improve over time (mean 𝑟1990−2010= -1.07% (-1.56; -0.58), mean 𝑟𝑝𝑜𝑠𝑡−2010 = -0.84% (-1.29; -0.40).

It is recommended that WCPFC SC20: • Notes the analysis of New Zealand albatross and petrel populations, showing significant, long-term, population declines, most likely caused for some species by bycatch in commercial pelagic longline fisheries. • Notes the analyses of the distribution of 11 New Zealand albatross and petrel taxa, the distribution of three Northern Hemisphere albatross taxa, and fine-scale tracking of Antipodean and Gibson’s albatross, which all show an extensive coverage within the WCPO. These analyses highlight: o Key areas of importance in Southern Hemisphere waters up to 25°S around New Zealand, the Tasman Sea, and the South Pacific east of New Zealand (but several vulnerable taxa frequent waters further north up to 20°S); and o Key areas of importance in Northern Hemisphere waters around the Japanese and Hawaiian seabird colonies, east of Japan and the Kuril Islands, the Bering Sea, south of the Aleutians and some core areas in the central North Pacific. • Notes that the majority of tracked Antipodean and Gibson’s albatross overlapped with commercial pelagic longline fishing effort, including in areas with reduced (25°-30°S) or no mandatory bycatch mitigation requirements (20°-25°S).