Spatial segregation within the spawning migration of north eastern atlantic mackerel (scomber scombrus) as indicated by juvenile growth patterns

• Main Authors: Jansen, Teunis, Campbell, Andrew, Brunel, Thomas, Worsøe Clausen, Lotte
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Public Library of Science (PLoS) 2013
• Subjects: stocks; North East Atlantic
• Online Access: http://hdl.handle.net/10379/12071; https://doi.org/10.13025/26780; https://doi.org/10.1371/journal.pone.0058114

A comparison of growth data (fish length) with latitude shows that southern juvenile mackerel attain a greater length than those originating from further north before growth ceases during their first winter. A similar significant relationship was found between the growth in the first year (derived from the otolith inner winter ring) and latitude for adult mackerel spawning between 44 degrees N (Bay of Biscay) and 54 degrees N (west of Ireland). These observations are consistent with spatial segregation of the spawning migration; the further north that the fish were hatched, the further north they will tend to spawn. No such relationship was found in mackerel spawning at more northerly latitudes, possibly as a consequence of increased spatial mixing in a more energetic regime with stronger currents. This study provides previously lacking support for spawning segregation behaviour among North East Atlantic mackerel - an important step towards understanding the migratory behaviour of mackerel and hence the spatiotemporal distribution dynamics around spawning time.