Updated Standardized Catch Rates Of Swordfish (Xiphias gladius) Caught by the Spanish Surface Longline Fleet in the Indian Ocean During the 2001-2021 Period

This paper provides an updated of the standardized catch rates per unit of effort (CPUE) in number and in biomass for the swordfish Indian Ocean stock using Generalized Linear Models. A total of 2,832 trips, representing 90% of coverage of the Spanish surface longline fleet targeting swordfish, are analyzed for the period 2001-2021. The main factors considered in the analysis were year, quarter, area, targeting criteria of skippers, gear and the interaction quarter-area. The results indicate that the target criteria of the skippers was the most important factor which explained the CPUE variability followed by year and in less extent the other factors considered. The model explained 54% and 57% of CPUE variability in number and weight, respectively. The standardized CPUE show a slight decrease until 2005 followed by a stable trend until 2021.