Ashmore Reef was first proclaimed a marine reserve in 1983 under the National Parks and Wildlife Conservation Atc 1975. The marine park surrounds the largest of three emergent oceanic reefs in the region, and is considered a biodiversity hotspot for benthic and pelagic organisms. Reef ecosystems within the marine park are covered with hard and soft corals, huge sea fans, a variety of sea sponges and many different encrusting organisms. Seagrass meadows provide foraging grounds for dugongs and turtles, and the fish community is one of the most diverse in Western Australia. Ashmore Reef Marine Park is also an important breeding and foraging site for many shore and migratory seabirds, and is listed as a Ramsar Wetland of International Importance.

The park is in the Australian External Territory of Ashmore and Cartier Islands, 630 kilometres north of Broome and 111 kilometres south of the Indonesian island of Roti. It covers 583 square kilometres, and is predominantly a Sanctuary Zone. – Parks Australia

Ashmore Reef ranges from the high tide mark to 297 metres depth, with an average depth of 39 metres. The majority of the park (51%) falls within the shallow zone (less than 30 metres) [view on map].

Based on annotations from publicly available seafloor imagery (Squidle+), the five most dominant seafloor categories in this Park are:

• Shallow: coral biota (34%), macroalgae (29%), sand (20%), sponges (7%), unconsolidated hard substrata (6%)
• Mesophotic to Upper-slope: no public imagery available