Mermaid Reef Marine Park is situated about 280 kilometres north-west of Broom. Originally proclaimed a marine park under the National Parks and Wildlife Act 1975 in 1991, Mermaid Reef Marine Park is one of three coral atolls that form the Rowley Shoals, which have been described as the best geological examples of shelf atolls in Australian waters. Mermaid Reef Marine Park includes biodiverse ecosystems associated with emergent and deep reef flats, lagoon and submerged sand habitats, and is home to over 214 coral species, 530 fish species and a huge array of invertebrate fauna.

The park covers 540 square kilometres and is a National Park zone. – Parks Australia

Mermaid Reef ranges from the high tide mark to 442 metres depth, with an average depth of 303 metres. The majority of the park (83%) falls within the upper-slope zone (200-700 metres). [View on map] The mapped areas of the seafloor are dominated by Plane (78%) and Slope (8%) geomorphology. [View on map]