Marion Island is one of two islands that form part of the Prince Edward Island group in the sub-antarctic, approximately 1769 km south-east of Port Elizabeth, forming the southernmost part of South Africa. Marion Island has an area of 290 km2, a steep coastline of 72 km and a maximum elevation at Mascarin Peak of 1242 m above sea level. The island is part of the Southern Indian Ocean Islands tundra ecoregion that is host to a wide variety of species that are critical to conservation. As a result, the South African government declared the Prince Edward Islands a Special Nature Reserve in 2003 and 180 000 km2 of ocean around the islands a Marine Protected Area in 2013, one of the world’s largest environmental protection areas. 10 SHALLOW MARINE AND COASTAL RESEARCH INFRASTRUCTURE 11 Marion Island Sentinel Site Global climate change in the Southern Ocean is causing shifts in the position and intensity of the major frontal systems and changes in oceanic circulation patterns within the region of the islands. The islands’ climate has as a result changed significantly over the last few decades, becoming warmer and drier, causing the loss of the ice plateau and permanent snow cover on Mascarin Peak. The SMCRI, in collaboration and in consultation with the Department of Environmental Affairs, the South African Marine and Antarctic Research Facility, the South African National Antarctic Programme and various other research entities, will establish a suite of observatories in the coastal zone to study environmental drivers, ecological processes and change.