POSSIBLE NAO AND SST INFLUENCES ON THE EASTERN BLUEFIN TUNA STOCK- THE IN-EXFISH APPROACH

• Main Authors: Christopher R. Bridges, Oliver Krohn, Michele Deflorio, Gregorio De Metrio
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.505.2451; http://www.iccat.int/Documents/CVSP/CV063_2009/no_1/CVOL63010138.pdf

Through the auspices of the EU-Project IN-EXFISH an analysis of historical data sets on catch and also model generated data on spawning stock biomass (SSB) and recruitment (R) have been used to look for possible influences of the North Atlantic Oscillation (NAO) on the eastern North Atlantic Bluefin Tuna stock. Initial evidence has shown that total catch can be correlated to the Winter NAO but only after a lag of 2 years. A further analysis of remote sensing sea surface temperature (SST) data for the main spawning areas in the Mediterranean (Balearic, central Mediterranean and Levantine Seas) revealed a SST anomaly which is increasing and already indicates values in summer during the spawning season of up to +3 ° C above the norm. These changes in SST anomaly do not appear to be correlated with changes in the NAO. The influence of SST on SSB and recruitment are discussed and their possible influence on short and long terms stock changes. RÉSUMÉ Sous les auspices du Projet de l’UE IN-EXFISH, on a utilisé une analyse des jeux de données historiques sur les captures et les résultats d’un modèle sur la biomasse du stock reproducteur (SSB) et le recrutement (R) en vue de déterminer l’éventuelle influence de l'Oscillation Nord-