The Nakanai Mountains - A Brief Review

The Nakanai first came to attention in the late 1960s because of the immense dolines and shafts, first recognised from the air, and progressively explored since. As a generalisation, the major caves can be entered from the large dolines on the plateau, and explored largely by trying to follow the major watercourses, some of which have defeated exploration because of their volume and turbulence. Others have involved progressive descents down vertical shafts, diving through submerged sections of tunnel at intervals, and (hopefully) emerging from the springs that mark the resurgence of the river system. It is widely agreed that these immense and powerful river caves are amongst the grandest in the world. The concept of sublimity provides a very appropriate description – they are more than beautiful.

The area has been explored by expeditions from Australia , France and Great Britain1. A detailed list of these and other expeditions can be found in Audra et al 2001: 37-38. The deepest cave to date is the Muruk-Berenice system – a through cave of 17km. in length and 1178 m. in depth – the deepest cave in the Southern Hemisphere.

The rich surface biodiversity of this region is currently being investigated and assessed by Conservation International. This must be supplemented by examination of the marine ecosystems, especially within the coastal reefs. The known subterranean fauna has been reviewed and summarised by de Coninck2. Most collection has occurred in the big high-energy caves, and so not surprisingly, relatively few species have been recorded. However a number of these are cave-adapted species of considerable interest, and further systematic study is likely to yield further important species.

1 Reports include Pernette, J.F. 1980 L’Abime sous la Jungle. Grenoble: Aventures Extraordinaires; Pernette, J.F. (ed.) 1981. Papua New Guinea . Spelunca, Supp. 3: 1-47; Gill, D.W. (ed.) 1988. The Untamed River Expedition. Chinley , UK : The Expedition; Sounier, J-P. 1996. Muruk: The Southern Hemisphere’s first 1,000m. InternationalCaver, 17: 17-25; Sounier, J-P. 1998. Papua New Guinea. International Caver, 23: 42; Audra, P., De Coninck, P. & Sounier, J-P 2001. Nakanai1978-199: 20 Years of Exploration. Antibes : Association Hémisphère Sud.

2 De Coninck, P. 2002 Faune cavernicole et épigée de Nouvelle-Bretagne. In Nakanai1978-199: 20 Years of Exploration. Pp. 109-114.