The Península Valdés in Argentina was inscribed on the World Heritage List in 1999. The site is home to important breeding populations of the southern right whale, southern elephant seal, and southern sea lion. The Econcentro museum focuses on local habitats and wildlife while offering beautiful views of the Golfo Nuevo.

The Great Barrier Reef is the world’s most extensive stretch of coral reef with probably the richest animal diversity anywhere. There are over 1,500 species of fish, ~400 types of coral, 4,000 types of mollusk, and diverse sponges, anemones, marine worms, crustaceans, and other invertebrate and vertebrate species. The “GBR” provides refuge, habitat, and resources for several endangered species, including dugong, and feeding grounds and nesting grounds for green turtles and loggerhead turtles.

The Macquarie Island site in Australia is the exposed crest of the undersea Macquarie oceanic ridge, raised to its present position where the Indo-Australian tectonic plate meets the Pacific plate. It is a site of major geo-conservation significance, with exposures that include excellent examples of pillow basalts and other extrusive rocks. The island hosts southern elephant seals, sub-Antarctic fur seals, albatross, giant petrels, king penguins, and a meteorologist at the station.

The Shark Bay site in Australia was inscribed on the World Heritage List in 1991. The site is home to the world's richest and largest sea-grass beds; five species of endangered marine mammals, including dugongs, which feed on the grass; and stromatolites, dome-shaped structures created by cyanobacteria, one of the oldest forms of life on earth.

The Sundarbans site in Bangladesh was inscribed on the World Heritage List in 1997. The site’s mangrove forest is one of the largest remaining areas of mangroves in the world and supports a rich animal community, including 230 kinds of birds, the estuarine crocodile, Indian python, and endangered Bengal tiger.

The Belize Barrier Reef Reserve System, inscribed on the World Heritage List in 1996, is an outstanding natural system, consisting of the largest barrier reef in the northern hemisphere, offshore atolls, and several hundred sand cays, mangrove forests, coastal lagoons, and estuaries. The system's seven sites illustrate the evolutionary history of reef development and are a significant habitat for threatened species, including marine turtles, manatees, and the American marine crocodile.

The Brazilian Atlantic Islands site joined the List in 2001. The rich waters of the Fernando de Noronha Archipelago and Rocas Atoll are extremely important for the breeding and feeding of tuna, shark, turtle, and marine mammals. The site is home to the largest concentration of tropical seabirds in the Western Atlantic. Baia de Golfinhos has an exceptional population of resident dolphin, and at low tide, the Rocal Atoll provides a spectacular seascape of lagoons and tidal pools teeming with fish.

The Kluane/Wrangell-St Elias/Glacier Bay/Tatshenshini-Alsek sites in Canada and the US are the largest non-polar ice-field in the world and contain some of the world’s longest and most spectacular glaciers. Featuring high mountains, ice-fields, and glaciers, the site transitions from northern interior to coastal biogeoclimatic zones, with high biodiversity plant and animal communities ranging from marine, coastal forest, montane, sub-alpine, and alpine tundra, all in various successional stages.

The Area de Conservación Guanacaste site in Costa Rica was inscribed on the World Heritage List in 1999. The site has the most intact inshore Pacific marine ecosystem between the Panama Canal Zone and Mexico, with major nutrient-rich upwelling currents, resulting in high biological productivity. The area includes key habitat for notable threatened or rare animal species, such as the jaguar, jabiru stork, saltwater crocodile, olive ridley sea turtle, and leatherback sea turtle.

Cocos Island's position as the first point of contact with the northern equatorial counter-current, and the myriad interactions between the island and the surrounding marine ecosystem, make the area an ideal laboratory for the study of biological processes. The site hosts critical habitats for marine wildlife, including large pelagic species, especially sharks (like the hammerhead Sphyrna lewini), but also rays, tuna, and dolphins.