Age determination analyses of Atlantic bluefin tuna (Thunnus thynnus) within the Biological and Genetic Sampling and Analysis Contract (GBYP)

• Main Authors: Rodriguez-Marin, Enrique, Luque, P.L., Quelle, Pablo, Ruiz, Marta, Pérez-Guerrero, Bernardo, Macías-López, Ángel David, Karakulak, F.S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2013
• Subjects: Pesquerías; Centro Oceanográfico de Santander; North East Atlantic
• Online Access: http://hdl.handle.net/10508/4096; http://hdl.handle.net/10261/327056

This paper presents direct ageing of Atlantic bluefin tuna based on otoliths and dorsal fin spines sampled in the North East Atlantic and Mediterranean Sea, with the aim of estimating the age of the catch of the eastern stock. Six month age-length keys (ALKs) were obtained through length-stratified sampling. Half year ALKs were insufficiently sampled, thus, it was suggested to use annual ALKs with calcified structures from 2011 and 2012. Asymptotic lengths and growth coefficients obtained from ALKs derived from both structures did not present significant differences. Inter-reader precision within each structure, described by Coefficient of Variation and Average Percent Error, was high with low values of both indices.