The South-east Marine Region spans approximately 1 632 402 km², from the warm temperate waters in the north of the Region, through the cool temperate waters around Tasmania, to the subantarctic Southern Ocean waters around Macquarie Island. While the South-east Marine Region is relatively low in nutrients and primary productivity, localised areas of relatively high productivity, combined with significant variation in water depth and seafloor features, contribute to its recognition as a major marine biogeographic region.