The clearest freshwater ever reported - Rotomairewhenua, New Zealand
Blue Lake (Rotomairewhenua in Maori) is a small lake in Nelson Lakes National Park, in the northern reaches of New Zealand's Southern Alps. The lake has the clearest natural body of fresh water yet reported. A 2011 study found its visibility ranged from 70 to 80 metres (230 to 260 ft), clearer than the 63 metres (207 ft) measured for Te Waikoropupu Springs, a previous record holder. For comparison, laboratory measurements show distilled water has a visibility of approximately 80 metres (260 ft). Scientists attribute the lake water's clarity to its passage underground from Lake Constance, which filters out nearly all the particles suspended in the water. Its clarity reveals water's natural blue-violet colour. This research was funded by NIWA, and supported by the Department of Conservation. NIWA is currently planning future surveys with DOC approval to more thoroughly investigate the biodiversity of Blue Lake, the limnology of Lake Constance and the connections between the two.
Freshwater Ecoregion of the World : #811 New Zealand
Major Habitat Type: temperate coastal rivers
Landscapes : Rotomairewhenua or Blue Lake
On the way to Rotomairewhenua
All Photographs Copyright 2013© Michel Roggo