Ngari Capes

Ngari Capes Marine Park is one of WA's largest marine parks, protecting approximately 243,000 hectares of coastal and open ocean waters between Cape Naturaliste and Cape Leeuwin in the Margaret River region. The park encompasses the biologically diverse waters where the Indian Ocean meets the Southern Ocean — a zone of exceptional productivity driven by the mixing of two major ocean systems. The marine park protects humpback whale migration routes, diverse reef ecosystems, sea lion foraging areas, and the extraordinary marine biodiversity of the southwestern Indian Ocean. The name Ngari Capes is a composite of 'Ngari' (from the Noongar Wardandi language) and 'Capes' (referring to Cape Naturaliste and Cape Leeuwin).

Ngari Capes Marine Park supports outstanding marine wildlife. Humpback whales pass through in large numbers during their annual migration (May–October), with mothers and calves using the inshore waters. Blue whales, the world's largest animal, occasionally visit the deep offshore waters. Australian sea lions and New Zealand fur seals inhabit the park's rocky reef and island habitats. Dusky dolphins and common dolphins are resident year-round. White sharks patrol the offshore waters. Diverse reef fish communities inhabit the limestone and granite reefs. Sea turtles forage in the kelp and seagrass habitats. The marine park's extraordinary biodiversity reflects the meeting of tropical, temperate, and sub-Antarctic ocean influences.

The marine park's primary plant communities are seagrass meadows (Posidonia and Amphibolis species) in the shallower waters and kelp forests (Ecklonia radiata) on the subtidal reefs. The seagrass meadows provide critical habitat for sea turtles, dugongs (occasional), and juvenile fish. Kelp forests create complex three-dimensional habitat supporting hundreds of associated species including lobster, fish, and invertebrates. The productivity of these marine plant communities underpins the marine park's exceptional fish and marine mammal diversity.

The marine park encompasses the underwater extensions of the Leeuwin Block's Precambrian geology and the Tamala Limestone platform that forms the coastal landforms. The submarine topography includes granite and limestone reefs, sandy plains, and deep offshore channels. The collision zone between the Indian and Southern Ocean systems creates oceanographic conditions — upwelling, mixing, and temperature gradients — that drive the biological productivity of the marine park.

The marine park's surface waters experience the Mediterranean climate of the Margaret River region — mild summers and cool, wet winters with frequent Southern Ocean swells. Water temperatures range from 14–22°C depending on season and depth. The convergence of the warm Leeuwin Current (flowing southward from the tropics) and the cool Flinders Current creates the unique thermal environment. Whale watching is best May–October when humpbacks are present.

The Wardandi Noongar people's sea country encompasses the Ngari Capes Marine Park. The two-ocean convergence zone created exceptional marine abundance that sustained coastal Aboriginal communities. Cape Leeuwin and Cape Naturaliste were important navigation landmarks in the era of European maritime exploration. The Margaret River coast has been a significant fishing ground for European and commercial fishers since the 19th century.

Ngari Capes Marine Park was established to protect the exceptional marine biodiversity of the two-ocean convergence zone and coordinate management of the diverse activities that occur in these waters. The marine park is jointly managed with the adjacent Leeuwin-Naturaliste National Park. Management zones regulate different activities from whale watching and recreational fishing to commercial lobster fishing.

Whale watching tours from Augusta and other ports are the marine park's most popular activity. Dive and snorkel tours to the limestone and granite reefs offer extraordinary encounters with sea lions, reef fish, and kelp forests. Recreational fishing is popular at the reef systems. Kayaking along the cape coastline provides coastal perspectives.

The marine park's shores are accessible from Augusta, Prevelly, and the broader Margaret River region. Boat tour operators provide whale watching, diving, and fishing excursions. Augusta provides accommodation and services. Marine park entry conditions apply for some activities.

The convergence of Indian and Southern Oceans creates unique conservation management challenges — species from three major ocean systems overlap in the park. White shark conservation is particularly significant, as the southwest coast is critical habitat for this apex predator. Climate change is driving range shifts in both temperate and subtropical species. Commercial lobster fishing under strict quota management occurs within the marine park.