Standardized catch rates in number of fish by age for the north Atlantic swordfish (Xiphias gladius) of the Spanish longline fleet, for the period 1983-2011

• Main Authors: Mejuto-García, Jaime, García-Cortés, Blanca, Ramos-Cartelle, Ana
• Format: Report
• Language: English
• Published: 2014
• Subjects: Swordfish; Pesquerías; Centro Oceanográfico de A Coruña; Age specific CPUE; GLM; longline; North Atlantic
• Online Access: http://hdl.handle.net/10508/2346; http://hdl.handle.net/10261/322135

Standardized catch rates in number of fish by age were updated using log-normal General Linear Modeling (GLM) from trips carried out by the Spanish surface longline fleet fishing swordfish in the North Atlantic stock. Indices were developed for a 29 year period (1983-2011) for ages ranging from 1 to 5+, using a sex-combined growth model for ageing the size data per trip. The criteria used to define areas, time periods and models were similar to those used in previous papers. However, the models also take into consideration new information such as gear style and a target variable as the analyses by age carried out in the past hadn’t taken into account these two important changes in the fishing strategy which have occurred in recent periods. The base case models explained between 42% and 45% of the CPUE variability. The age 1 standardized index suggests a more positive scenario of recruitment after 1996 with a mean overall level around double that of the previous and less favorable phase occurred up to that year.