Schooling dynamics of Northeast Atlantic mackerel (Scomber scombrus) in the Norwegian Sea using multibeam sonar ...

• Main Authors: Diaz, Justine E., Nøttestad, Leif, Pena, Hector, Huse, Geir, Fernö, Anders
• Format: Conference Object
• Language: unknown
• Published: ASC 2013 - Theme session N 2024
• Subjects: Fisheries and aquaculture; Pressures, impacts, conservation, and management; Norwegian Sea; Northeast Atlantic
• Online Access: https://dx.doi.org/10.17895/ices.pub.24753858; https://ices-library.figshare.com/articles/conference_contribution/Schooling_dynamics_of_Northeast_Atlantic_mackerel_Scomber_scombrus_in_the_Norwegian_Sea_using_multibeam_sonar/24753858

No abstracts are to be cited without prior reference to the author. Pelagic fish in the Norwegian Sea perform seasonal migrations from overwintering, via spawning, to feeding grounds. Northeast Atlantic mackerel (Scomber scombrus) are highly migratory, fast-swimming, and an obligate schooling fish. Mackerel schooling dynamics in nature is unknown because they lack a swimbladder, resulting in a weak acoustic signature, and therefore are difficult to detect in the summer when in loose schools. However, high frequency omnidirectional SONAR is capable of detecting mackerel in the acoustic echosounder blind zone close to the surface. Mackerel schooling dynamics were studied in relation to temperature, zooplankton abundance and density of conspecifics in four geographically separate regions of the Norwegian Sea during summer. The thermocline depth had a profound influence on the depth distribution of schools. Mackerel were found shallower than 40 m depth where the temperature was at least 6° C. The fish generally ...