In the seventeent and eighteenth centuries intensive European whaling and walrus hunting took place in the waters around Spitsbergen, with many stations on the coast of the islands. The hunt was carried out in areas along the edge of pack ice and is therefore very sensitive to changes in the ice situation and climate. When, around 1650, climate and ice distribution changed, whales moved to the north. The whaling stations in the south of Spitsbergen were abandoned when stations in the north were still functioning. When, later, the ice situation deteriorated in the north as well, the stations were abandoned there too. Shore whaling changed into pelagic whaling. Because of these whaling and walrus hunting activities two very numerous large mammals were largely depleted and almost disappeared from the Spitsbergen waters. The pelagically feeding Greenland Right Whale and the bentically feeding walrus, whose initial stocks are estimated at 46,000 Greenland Right Whales and 25,000 walrus, were eliminated. This elimination has caused a major shift in the foodweb. The plankton feeding seabirds and polar cod strongly increased because of the elimination of the Greenland Right Whale, and the eider ducks and bearded seals increased because of the decrease of the number of walruses. This development has led to the enormous amount of seabird rookeries on the West coast of Spitsbergen.