Australian Marine Parks

Monday 20 September 2021

In a first of its kind for this remote marine park, scientists have completed one of the most comprehensive ‘health checks’ of Ashmore Reef’s ecosystems.

Isolated by hundreds of kilometres of ocean and visible only by four specks of land, Ashmore Reef Marine Park - established in 1983 - is a place of global importance recognised nationally and internationally as a biodiversity hotspot, including a wetland of international importance under the Ramsar convention.

A multi-disciplinary team of scientists lead by CSIRO (Australia’s national science agency) used a mix of trusted and new technologies for the collection of information that will support Parks Australia’s management of this ocean oasis. Applying new and emerging technologies like eDNA and high-resolution imagery from drones, is important for driving continuous improvement and finding more efficient and cost-effective ways for assessing and monitoring our marine parks.

Observations from two voyages to Ashmore Reef, which is located 630 km north of Broome, suggest that the park retains significant biodiversity values, but that if we are to protect these values into the future there is some important work to do. The islands and their plant communities continue to support immense numbers of seabirds, many of which were nesting or showing signs of breeding.

Under the water, corals appear to be in good health, continuing to support an array of marine life, and showing no signs of coral bleaching or disease, nor signs of recent stress or damage. Seagrass beds at Ashmore Reef were shown to be very widespread but the cover is generally low. However, the surveys indicated that the seagrass beds are heavily grazed and are a critical habitat for other species such as turtle and dugong - despite being sparse.

Despite its high level of marine park protection and management, the surveys found that the park is still vulnerable to a range of threats. Across all islands, Tropical fire ants are ever-present, putting nesting seabirds and turtle hatchlings at risk. Several introduced plant species also call Ashmore Reef home, such as Buffel grass, which threaten native plants and vital nesting habitat for seabirds.

Below the ocean’s surface, certain species such as sea cucumber and clam (both the target of illegal foreign fishers) are struggling to recover, with some species of sea cucumber now believed to be locally extinct. And despite extensive searching across Ashmore’s shallow reef, the once abundant and species-rich community of sea snakes was absent during the voyages.

This project has contributed to our understanding of Ashmore Reef’s biodiversity across its islands and shallow reef habitat. The research has also established a targeted, repeatable monitoring framework for collecting comparable data on future visits. Regular monitoring will be important to understand how Ashmore’s habitats and species are interacting and changing over time.

Get all the technical details about this project in the Ashmore Reef Marine Park Environmental Assessment, read more on the CSIRO website, and watch this space for further updates.