Growth of young‐of‐the‐year mackerel in the Bay of Biscay

Abstract

The first growth season of young‐of‐the‐year (0+ year) mackerel Scomber scombrus, sampled in the Bay of Biscay, was parameterized to determine growth patterns. Daily increments were identified on sagittae otoliths, for calculation of age and growth of 92 larvae and 54 juveniles over the range 3·6–215·0 mm standard length (LS). A Gompertz curve was fitted to the length‐at‐age data. At the end of the first year of growth LS was 194·2 mm, with a maximum growth increment of c. 2 mm day−1, observed 62 days after hatching. Backcalculated growth increments for mackerel juveniles, during their larval stage, were higher than those observed for sampled larvae; only 10·9% of sampled larvae were estimated to survive. Growth for north‐eastern Atlantic mackerel was slower than that published for north‐western Atlantic mackerel. Backcalculated hatching dates for mackerel were consistent with the typical temporal distribution of mackerel spawning in the Bay of Biscay.