Michaelmas Reef second flank

Surveyed 14 January 2013.

The second flank of Michaelmas Reef is partly exposed to the prevailing wind and sea conditions found within the lagoon of the Great Barrier Reef. Manta tow surveys were conducted on the reef slope. The reef slope is generally steep dropping off into approximately 15m of water to a gently sloping reef base composed mainly of sand. The reef structure has many features including overhangs, bommies and gullies.

The benthic community was dominated by hard coral, but soft coral and coralline/turf algae were also common. Hard coral cover on the reef second flank was moderate composed mainly of Porites species. The dominant coral lifeform was massive, but other forms such as tabulate, digitate and branching corals were also present in decreasing order of abundance. Coral bleaching was not present.

The fish abundance on the second flank of Michaelmas Reef was moderate. Conspicuous groups of reef fishes included damselfish, surgeonfish, parrotfish and snapper. Crown-of-thorns starfish were observed on the second flank of Michaelmas Reef below levels that may be expected to impact on live coral cover.

Changes in zone-wide live coral cover through time. Points indicate median coral cover in a given survey year. Solid line indicates a moving average taken over three (preceding, actual and following) survey years.

Coral cover was highest on this part of the reef.
View looking down the reef slope showing a healthy cover of soft corals.
View looking along the upper reef slope showing a benthic community dominated by Sarcophyton sp. soft corals.