Located at the junction of two major botanical regions, the Shark Bay World Heritage Area supports more than 820 plant species, including at least 53 found nowhere else. Temperate plants from southwestern Australia mingle with desert-adapted species, creating a unique blend of Acacia, samphire and spinifex scrublands alongside members of the Proteaceae and Myrtaceae families.
This overlap occurs where the Southwest Botanical Province meets the arid Eremaean Province. Cooler-climate species dominate areas such as Nanga Peninsula, Tamala and the Zuytdorp coast, while desert species prevail on Peron Peninsula. Several plants reach the edge of their natural range here, making Shark Bay botanically distinctive.
Tree Heath
Tree heath is Shark Bay’s most diverse and distinctive plant community and occurs nowhere else in Western Australia. Found in the overlap between the two botanical provinces, it was a key reason for Shark Bay’s World Heritage listing and contains around half of the region’s endemic flowering plants.
Characterised by scattered low trees and a dense, varied understorey, tree heath includes unusually large forms of shrubs—sometimes described as “gigantism”—and supports many rare and priority species. Several plants are almost entirely restricted to this habitat, making it critical for conservation and scientific research.
Sandalwood
Sandalwood was one of Shark Bay’s earliest industries, harvested for its aromatic timber and oil for more than a century before commercial licences ended in 2000. Unlike sandalwood elsewhere, Shark Bay populations can resprout after cutting, allowing sustainable use and long-term survival.
The species is semi-parasitic, relying on surrounding plants for nutrients, and produces edible fruit dispersed by emus. Its unusual resilience may be linked to local soils, host plants or natural herbivore deterrents, making Shark Bay sandalwood ecologically distinctive.
Seagrass
Shark Bay contains the largest seagrass meadows on Earth, covering about 4,000 square kilometres of seabed. Twelve of the world’s 60 seagrass species occur here, thriving in the bay’s shallow, sheltered and low-energy waters.
These meadows underpin Shark Bay’s marine ecosystems, supporting fish, turtles and one of the world’s largest dugong populations. Different seagrass species dominate different habitats, with some forming dense stands and others providing key seasonal food sources for marine animals.
Threatened Plants
At least 53 plant species are endemic to Shark Bay, and many have very limited distributions. Two species are nationally listed as threatened, while more than 50 others are classed as priority species requiring further study or monitoring.
Many of these rare plants occur in specialised habitats such as tree heath, highlighting the importance of habitat protection. Ongoing research and conservation programs are essential to ensure these plants remain secure in the long term.
