Hopen is an arctic island, mostly covered by rocks and continuous permafrost, with a very narrow beach from which the landscape rises sharply. In the north of the island there are steep cliffs with horizontal shelves which are ideal for breeding seabird species, including the globally vulnerable Atlantic puffin Fratercula arctica. The birds are important in the transfer of nutrients from the ocean to support the island’s mammal, invertebrate and plant species. The Site also supports 40,000 breeding pairs of the black-legged kittiwake Rissa tridactyla, over 1% of the breeding population. The island is also important for marine mammals. Polar bears use the Site for denning and migration, and the shallow waters surrounding Hopen (which make up most of the Ramsar Site area) are important for walrus, with the south of the island being a traditional resting place for the species. Five trapper huts from the 19th century are protected as cultural heritage sites and there is a meteorological station on the island. Climate change and its effects may be the most serious threat to the Arctic environment.