The marine environment from Kalbarri to Eucla is globally significant for its unique and threatened species, underwater features and ecosystems including:
- globally high levels of unique marine species (70–90 per cent found nowhere else on Earth) as a result of geological isolation, an unusual major southerly current bringing temperate and tropical species together, and a history free of major environmental disturbance in geological time
- a series of hotspots for marine life including the Houtman-Abrolhos Islands, the Perth Canyon, Geographe Bay, Cape Mentelle, the Naturaliste Plateau, the Diamantina Fracture Zone, the Albany Canyons and the Recherche Archipelago
- critical habitat for a range of significant species including the world’s largest animal, the endangered blue whale. Perth Canyon is one of only two blue whale feeding grounds known in Australia. It is a key to the survival and recovery of blue whales
- one of the world’s largest sharks, the threatened white shark; and the world’s largest marine turtle, the endangered leatherback turtle
- a greater southerly range for major tropical coral reefs than anywhere else in the Indian Ocean
- an unusual collection of fish life and habitats as a result of low nutrients, clear water due to limited river runoff, and waters warmer than are normally found so far south
- geologically and ecologically significant subsea features including the deepest point in Australia’s oceans, an island under the sea—a large submerged fragment of continental shelf—Australia’s highest underwater mountain range, and Australia’s largest marine canyon.