Australian Marine Parks

Andrew S. Hoey, Morgan S. Pratchett, Katie Sambrook, Sallyann Gudge, and Deborah J. Pratchett, 2018.



Elizabeth and Middleton Reefs are the world’s southernmost open ocean platform reefs, supporting a unique mix of tropical and subtropical species.

In-water field surveys were conducted in 2011, 2014 and 2018 using consistent methods at the same locations, enabling rigorous assessment of trends in benthic habitats and associated assemblages of reef fish and mobile macro-invertebrates.

The most recent surveys were conducted from February 25th to March 4th, 2018, with 4 days (25-29 February) spent at Middleton Reef and 4 days (1-4 March) at Elizabeth Reef. Surveys were conducted at a total of 17 sites across both Middleton and Elizabeth reefs.

Where possible, surveys were conducted in two distinct habitats (shallow reef crest or top and deep reef slope or base) at each site. Benthic composition and habitat structure, as well as coral health, densities and biomass of functionally important reef fishes, densities of site attached and endemic fishes, and densities of non-coral invertebrates were recorded along four replicate 50 m transects in each habitat at each site.