N. GBR - Blue (AU122135)

Setting

The day's first dive at Unnamed Reef 122 opens in crystal-clear water with a gentle 1-knot current, sweeping past dozens of dense staghorn Acropora thickets that run down to about 20 m.

General benthic features

Of the frames described here, two are wide shots of thin, patchy pavement, scattered small colonies, and open sand corridors, with a turtle gliding over the top in each (e.g., Image 1, Image 3).

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A third is a low, open thicket of brown, pigmented staghorn branches spread across clean white sand (e.g., Image 2), the kind of thicket Anderson logged as common at 15 m.

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A fourth is a single isolated bommie carrying most of the coral in the frame, butterflyfish and surgeonfish working around it (e.g., Image 4).

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Then the fifth shows the other extreme: a dense sheet of pink and tan branching Acropora under a wall of fusiliers (e.g., Image 5).

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A large bommie at 10.5 m, some 15-20 m across and thick with Platygyra, Sinularia, and Lobophyllia, carried an estimated 60-70% live cover. Acropora was the most common coral genus on this station's transects (9.0% of the benthos), followed by Millepora (7.0%) and Pocillopora (2.0%); bare substrate covered 44%, the largest non-coral class. Among the algal classes on this station's transects, turf (17%) led, followed by crustose coralline algae (12%) and erect coralline algae (5.0%).

Coral cover

• Reference: Khaled bin Sultan Living Oceans Foundation, Global Reef Expedition (in situ transect)
• The expedition's in situ point-count transects at this station recorded 18% live coral cover against 36% total algal cover.
• One transect was scored at this station (18%; n = 1, so no SE; Living Oceans Foundation per-transect benthic data); it is the expedition's station value printed above.

Stressors

Anderson's notes record bleached Seriatopora hystrix and S. caliendrum among the corals at 6-7 m and bleached S. caliendrum on the 10.5 m bommie transect, and many Pocillopora damicornis and P. acuta colonies he called "extremely pale" (much like the Seriatopora). Three gallery frames show bleached or very pale branching colonies beside pigmented neighbors (e.g., Image 7, Image 28, Image 36).

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He also noted signs of crown-of-thorns starfish damage at 5 m. The reef lies in a Habitat Protection (Blue) Zone, where line fishing is permitted.

Fish and other fauna

A turtle, only the second of the entire expedition, and a lobster rounded out the sightings.

Comparisons with other data

No prior survey data from this site. If you would like to share yours, please email us.