Update of the Swordfish Catch, Effort and Standardized CPUEs by the Portuguese Pelagic Longline Fleet Operating in the Indian Ocean, Between 1998 and 2022

The Portuguese pelagic longline fishery in the Indian Ocean started in the late 1990’s, targeting mainly swordfish in the southwest. This document updates that analysis with regards to catch, effort and standardized CPUE trends for the Portuguese fleet operating in the Indian Ocean. Nominal annual CPUEs were calculated as kg/1000 hooks and were standardized with Generalized Linear Mixed Models (GLMMs) using year, quarter, area and targeting ratios. The vessel effects were used as random variables. Model goodness-of-fit and comparison was carried out with AIC and the coefficient of determination (R2), and model validation with a residual analysis. The final standardized CPUE trends show a general decreasing trend in the series, with an intermediate peak in the 2008 period. The results present an updated annual index of abundance for the swordfish captured by the Portuguese pelagic longline fleet in the Indian Ocean that can be integrated in stock assessment models for that species in the region.