Otago Conservancy
A Directory of Wetlands in New Zealand OTAGO CONSERVANCY Sutton Salt Lake (67) Location: 45o34'S, 170o05'E. 2.7 km from Sutton and 8 km from Middlemarch, Straith-Tari area, Otago Region, South Island. Area: 3.7 ha. Altitude: 250 m. Overview: Sutton Salt Lake is a valuable example of an inland or athalassic saline lake, with a considerable variety of saline habitats around its margin and in adjacent slightly saline boggy depressions. The lake is situated in one of the few areas in New Zealand where conditions favour saline lakes (i.e. where precipitation is lower than evaporation). An endemic aquatic animal, Ephydrella novaezealandiae, is present, and there is an interesting pattern of vegetation zonation. Physical features: Sutton Salt Lake is a natural, inland or athalassic saline lake with an average depth of 30 cm and a salinity of 15%. The lake has no known inflow or outflow. The soils are saline and alkaline at the lake margin (sodium-saturated clays), and surrounded by yellow-grey earths and dry subdygrous Matarae. The parent material is loess. Shallow boggy depressions exist near the lake, and there is a narrow fringe of salt tolerant vegetation at the lake margin. Algal communities are present, and often submerged by lake water. The average annual rainfall is about 480 mm, while annual evaporation is about 710 mm. Ecological features: Sutton Salt Lake is one of only five examples of inland saline habitats of botanical value in Central Otago. This is the only area in New Zealand which is suitable for the existence of this habitat, since in general rainfall is high, evaporation is low, and endorheic drainage systems are absent.
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