Aril Slotte

Seniorforsker ved Havforskningsinstituttet Har silda glemt at det er bra å gyte på Møre? Et historisk skifte i gyting fra Møre til Lofoten kan skyldes kollektivt hukommelsestap Fangsting av sild på Møre-kysten. Vil silda vende tilbake til Møre, spør forsker Aril Slotte?Foto: KV Ålesund Publisert 14. May 2025, kl. 03.00Oppdatert 14. May 2025, kl. 03.00

Abstract Entrainment is a process in schooling migratory fish whereby routes to suitable habitats are transferred from repeat spawners to recruits over generations through social learning1. Selective fisheries targeting older fish may therefore result in collective memory loss and disrupted migration culture2. The world’s largest herring (Clupea harengus) population has traditionally migrated up to 1,300 km southward from wintering areas in northern Norwegian waters to spawn at the west coast.

Norwegian herring extending feeding season. When the Norwegian Sea became warmer in the mid-2000s, the herring became both shorter and fatter. Now researchers have seen that the herring has changed its grazing season and supplies itself with a new, unknown food dish throughout the autumn. From the mid-2000s, the Norwegian Sea became warmer. Then the number of zooplankton, which is important prey for pelagic fish that graze in the area, also fell.