Much of what you stand upon along the Gascoyne Coast was once coral reef, formed 3 to 5 million years ago in a shallow tropical sea by the accretion of billions of polyps and shellfish. Then it uplifted, forming the Cape Range of limestone hills, but reef formation continued offshore, and does to this day. It has to, because there are natural cycles of destruction followed by regeneration. Corals need a "goldilocks" zone: not too deep or shallow, in water not too hot or cold, and not too saline or fresh. The present Ningaloo reef is about 8000 years old, replacing older structures as sea levels rose, and these "fossil" reefs can still be traced.

Ningaloo in the Aboriginal Wajarri language denotes a cape or promontory. It's a barrier reef, a narrow strip 260 km long, with very few "cuts" or navigable channels through it. It was a significant block to European exploration and colonisation of this region, which lacks harbours. Its northern reaches around Exmouth and the Northwest Cape lie only a few hundred metres offshore, enclosing a tranquil lagoon. This dry region has little in the way of river drainage, agricultural run-off or industry, so the reef has suffered little from human activity, including tourism - far fewer visit here than Queensland's Great Barrier Reef. Ningaloo occasionally suffers bleaching, when high water temperature renders the algae poisonous to their host coral so they're expelled. However the bleaching event of 2021 / 22, which badly afflicted the GBR, had little effect here.

The reef's biodiversity is fuelled by the meeting of two currents. The Leeuwin current is warm, flowing south several kilometres offshore. The Ningaloo current is cold, flowing north close to shore and carrying more food supply, so big marine life migrating towards the tropics April-May will hug the coast.

Ningaloo Marine Park was designated in 1987 and includes the reef and surrounding seas; in 2011 it was inscribed as a UNESCO World Heritage Site. It comes under a series of jurisdictions and managements:

• Deep waters, from about 10 km offshore, are regulated by the Commonwealth of Australia - this mainly affects fishing.
• Inshore waters are regulated by the State of Western Australia.
• Landside activity is regulated by the State in Cape Range National Park and other Protected Zones (such as turtle nesting beaches), while the town councils govern other areas.

For the visitor the main relevance is what activities are permitted. Each area has a mosaic of zones, segregating general use, various recreational activities, and specially protected areas, so you need to look these up locally.

$1°$2′$3″S $4°$5′$6″E

Ningaloo Reef

• -21.933056114.1280561 Exmouth is the largest town with access to the reef.
• -23.145113.7762 Coral Bay is a tiny resort by a tranquil lagoon.

• -22.1233113.9211 Cape Range National Park has camping and easy access to the reef.
• -24.031113.4482 Red Bluff, Quobba and Gnarlaroo are at the southern limit of the marine park.
• -21.688114.323 Muiron Islands at the north limit of the park are reached by boat from Exmouth.

• Whale sharks (Rhincodon typus) are sharks, true fish, not whales. They're filter-feeders, some 9-14 m long, and April-May they migrate close to shore. They may be spotted from shore but boat trips go out, and you can get in the water as they cruise by.
• Humpback whales (Megaptera novaeangliae) are baleen whales, feeding on krill which they gulp rather than filter. They're seen from June to November as they migrate south with their calves to feed off Kerguelen and Antarctica. It may be possible to swim with them, but their distinctive behaviours can be enjoyed from the boat: breaching, fluke-slapping and singing.
• Dugongs (Dugong dugon) are mammals, Sirenia. They graze on shallow sea-grass meadows right round the Australian coast from Shark Bay through Gascoyne, Pilbara, Kimberley and Northern Territory to Queensland.
• Turtle species include loggerheads, green turtles and hawksbills. The females haul ashore every couple of years to lay eggs.

• Snorkelling is the main attraction from Exmouth through the National Park to Coral Bay. The reef is close to shore so you just walk in off the beach.
• Scuba diving in greater depths is possible at Exmouth and Coral Bay.
• Boat trips go out for wildlife spotting and to admire the corals.
• Wind-surfing needs more exposed conditions: lots of sites along the coast.
• Surfing gets interesting around Gnarlaroo and Red Bluff. The south end of the reef is a long way offshore, so ocean breakers roar in unchecked, and the only tranquil lagoon is behind you in the salt lake.

• Mid West Region to the south has the Houtman Abrolhos Islands, a coral archipelago 60 km off Geraldton.
• Pilbara Region east has the Mackerel Islands reached from Onslow and the Dampier Islands just off Karratha.
• Diving in Australia describes some other sea areas to explore - best known is the Great Barrier Reef but there are plenty more.