The islands contain two precipitation zones:Higher-rainfall areas (located on the Loyalty Islands, Isle of Pines (Île des Pins), and on the eastern side of Grande Terre) which support New Caledonia rain forests, and a more arid region, home to the now exceedingly endangered New Caledonia dry forests, located in the rain shadow on the western side of Grande Terre. Europeans settled on the dry west coast of Grande Terre, leaving the east (as well as the Loyalty Islands and the Isle of Pines) to the Kanaks, and resulting in an ethno-cultural division which coincides with the natural one. Extensive farming by Europeans in the dry forest areas, has caused these forest ecosystems to virtually disappear.It is a vast oversimplification, however, to merely describe New Caledonia's extremely important, complex and diverse ecology in terms of precipitation zones. Species and ecological diversity is further complicated by soil type (degree and type of mineralization), altitude, and geographic location (for instance, Loyalty Islands and Isle of Pines have flora that is distinct from Grande Terre). In addition to the remarkable terrestrial environment of New Caledonia, the country is also home to important aquatic ecosystems. Its freshwater ecology also evolved in long isolation, and the New Caledonia rivers and streams are home to many endemic species. Moreover, the New Caledonia Barrier Reef, which surrounds Grande Terre and the Isle of Pines (Île des Pins), is the second-largest coral reef in the world after Australia's Great Barrier Reef, reaching a length of 1,500 kilometres (930 mi). Like its terrestrial counterpart, the Caledonian reef system has great species diversity, is home to endangered dugongs (Dugong dugong) , and is an important nesting site for the Green Sea Turtle (Chelonia mydas) . The island is also a home for vagrant fur seals. The Nautilus is a living-fossil species, common during the age of the dinosaurs, which survives today in the waters surrounding New Caledonia. In January 2002, the French government proposed listing New Caledonia's reefs as a UNESCO World Heritage Site. UNESCO listed New Caledonia Barrier Reef on the World Heritage List under the name The Lagoons of New Caledonia:Reef Diversity and Associated Ecosystems on 7 July 2008.