Blue whiting ("Micromesistius poutassou") has benefited from the decline of the herring and capelin stocks as it assumed the role of major predator of plankton. The blue whiting spawns near the British Isles. The sea currents carry their eggs to the Norwegian Sea, and the adults also swim there in order to benefit from the food supply. The young spend the summer and the winter until February in Norwegian coastal waters and then return to the warmer waters west of Scotland. The Norwegian Arctic cod mostly occurs in the Barents Sea and at the Svalbard Archipelago. In the rest of the Norwegian Sea, it is found only during the reproduction season, at the Lofoten Islands, whereas "Pollachius virens" and haddock spawn in the coastal waters. Mackerel is an important commercial fish. The coral reefs are populated by different species of the genus "Sebastes".