Stock assessment of southwest Pacific swordfish, 2021, N. Ducharme-Barth, C. Castillo-Jordán, J. Hampton, P. Williams, G. Pilling, P.Hamer, Oceanic Fisheries Programme, Pacific Community (SPC), Nouméa, New Caledonia
This paper describes the 2021 stock assessment of swordfish (Xiphias gladius) in the southwest Pacific Ocean (SWPO) using a sex-aggregated model structure in MULTIFAN-CL. A further four years of data were available since the last full stock assessment conducted in 2017, and the model extends through to the end of 2019. New developments to the stock assessment include:
- A new approach for developing a model ensemble and characterizing uncertainty in man-agement reference points, capturing both the model and estimation uncertainty based on (Ducharme-Barth and Vincent, 2021).
- Updates to the biological assumptions and definition of reproductive potential.
- Implementation of an “index” fishery approach.
The assessment is supported by the development of a new framework for developing a model ensemble and presenting the uncertainty in reference points (Ducharme-Barth and Vincent, 2021), background analyses of biological parameters, preparation of the length-weight composition data and definition of the fisheries structures (Ducharme-Barth et al., 2021b), re-analysis of tagging data to create a movement prior for the stock assessment (Patterson et al., 2021), and a review of swordfish biology, status and stock structure in the Pacific (Moore, 2020).