Owing to adverse weather conditions and the abundance of ice floes, the vessels taking part in Operation Wunderland did not venture beyond the Vilkitsky Strait. Therefore, the Kriegsmarine campaign only affected the Barents Sea and the Kara Sea. By mid-September it had to be stopped because of the freezing of the sea surface with thick pack-ice, especially in the Kara Sea, which not being affected by the warmer Atlantic currents freezes much earlier.[6]