Bouvet Island is a Norwegian uninhabited protected nature reserve. As a subantarctic volcanic island, it is situated in the South Atlantic Ocean at the southern end of the Mid-Atlantic Ridge, making it the world's most remote island. It is not part of the southern region covered by the Antarctic Treaty System.
The harsh climate and ice-bound terrain limits non-animal life to fungi and non-vascular plants, The flora are representative for the maritime Antarctic and are phytogeographically similar to those of the South Sandwich Islands and South Shetland Islands. Vegetation is limited because of the ice cover, although snow algae are recorded. The remaining vegetation is located in snow-free areas such as nunatak ridges and other parts of the summit plateau, the coastal cliffs, capes and beaches. At Nyrøysa, five species of moss, six ascomycetes, and twenty algae have been recorded. Most snow-free areas are so steep and subject to frequent avalanches that only crustose lichens and algal formations are sustainable. There are six endemic ascomycetes, three of which are lichenized.
The island has been designated as an Important Bird Area by BirdLife International because of its importance as a breeding ground for seabirds. In 1978–1979 there were an estimated 117,000 breeding penguins on the island, consisting of macaroni penguin and, to a lesser extent, chinstrap penguin and Adélie penguin, although these were only estimated to be 62,000 in 1989–1990. Nyrøysa is the most important colony for penguins, supplemented by Posadowskybreen, Kapp Circoncision, Norvegiaodden and across from Larsøya. Southern fulmar is by far the most common non-penguin bird with 100,000 individuals. Other breeding seabirds consist of Cape petrel, Antarctic prion, Wilson's storm petrel, black-bellied storm petrel, subantarctic skua, southern giant petrel, snow petrel, slender-billed prion and Antarctic tern. Kelp gull is thought to have bred on the island earlier. Non-breeding birds which can be found on the island include the king penguin, wandering albatross, black-browed albatross, Campbell albatross, Atlantic yellow-nosed albatross, sooty albatross, light-mantled albatross, northern giant petrel, Antarctic petrel, blue petrel, soft-plumaged petrel, Kerguelen petrel, white-headed petrel, fairy prion, white-chinned petrel, great shearwater, common diving petrel, south polar skua and parasitic jaeger.
The only non-bird vertebrates on the island are seals, specifically the southern elephant seal and Antarctic fur seal, which both breed on the island. In 1998–1999, there were 88 elephant seal pups and 13,000 fur seal pups at Nyrøysa. Southern right whale, humpback whale, fin whale, southern right whale dolphin, hourglass dolphin, and killer whale are seen in the surrounding waters.