A review of Mediterranean albacore (Thunnus alalunga) biology and growth studies

Abstract

Growth parameters are used to estimate catch-at-age data which is required as an input to many stock assessment models. In the case of Mediterranean albacore stock no assessment has ever done (ICCAT, 2009). This study presents growth information based on spine section interpretation of annual time marks. A preliminary age-length key is presented for males, females and two sexes combined, based on 249 albacore (Thunnus alalunga, Bonn.1788) spine samples caught around the Balearic Islands and Western Mediterranean sea between June and November from 2004 thru 2006. The albacore length ranged from 52 cm to 94 cm for females and from 53 cm to 96 cm for males. Available length-weight data for 138 males and 162 females was analysed separately. New estimates presented in this study were compared with assumed biological length-weight relationship for Mediterranean albacore stock. As well, mean length by age estimates derived from the age-length-key obtained by reading fin ray section were compared with other studies that used hard parts to age Mediterranean albacore.