Assessment of the risk of Southern Hemisphere surface longline fisheries to ACAP species

New Zealand has been utilising and refining a spatially explicit assessment of risk to seabirds from commercial fishing since 2009. New Zealand has been intending to extend the risk assessment framework applied to main fishing methods within the New Zealand Exclusive Economic Zone (EEZ) to a broader set of fisheries. This paper presents the progress on this to date, where the methodology has been applied to public tuna RFMO fishing data throughout the southern hemisphere for the 26 ACAP listed seabird species that breed in the southern hemisphere. This version of the risk assessment is updated from that presented to CCSBT in March 2017 due to the inclusion of effort data from north of 25 degrees S from WCPFC.

Across all the seabird species and surface longline fishing effort included in this study, the total estimated annual potential fatalities were 6275 (95% c.i.: 4918–8054). The risk ratio is defined as the ratio of the annual potential fatalities to the population sustainability threshold (PST), a measure of the productivity of seabird species. Black petrel had the highest risk ratio, followed by three wandering-type albatross species (Tristan albatross, Amsterdam albatross, and Antipodean albatross). All other seabird species had risk ratios that were entirely less than one.

This paper is a report on progress, and the data used in this initial iteration contain some deficiencies. In particular, the vulnerability of seabirds to capture was estimated using New Zealand data only; the seabird distributions were simplistic; and effort data that was not reported to RFMOs was not included. The analysis can readily be updated however, if improved data become available.