New Zealand’s approach to assessment of risk to seabirds associated with fishing-related mortality

A risk assessment framework is central to the implementation of New Zealand’s revised (2013) NPOA-Seabirds. The risk assessment framework adopted is designed to assess the likelihood that the biological risk objective of New Zealand’s NPOA-Seabirds will not be met. That is, it is an assessment of the extent to which incidental mortality from New Zealand fisheries exceeds a level that allows for the maintenance at a favourable conservation status or recovery to a more favourable conservation status for seabird populations that breed in New Zealand.

The method takes the “exposure-effects” approach rather the “likelihood-consequence” approach to risk assessment and is based on the spatio-temporal overlap of bird distributions and fishing effort, scaled by the vulnerability to capture of each species. The current implementation has developed through several iterations and improvements, and considers 70 seabird species or populations and all New Zealand fisheries likely to have non-trivial captures. Scalars and uncertainty for non-observable (cryptic) fatalities ( e.g. from trawl warp strikes where the carcass is lost to the sea) were included. Black petrel, Salvin’s albatross, flesh-footed sheartwater, southern Buller’s albatross, Chatham Island albatross, and NZ white-capped albatross were assessed as being at very high risk. Conversely, 44 species were assessed as being at very low risk. The remaining 20 species were assessed as being at low (7 species), medium (9 species), or high risk (4 species). Details are included in two reports tabled separately.

The framework does not address fishing-related mortality caused by non-commercial fishers or by fishing outside the New Zealand EEZ, or any potential indirect fisheries impacts, or any non-fishing impacts. Work is underway to address some of these limitations.