N. GBR - Blue (AUR515)

Setting

This site sits in a Habitat Protection (Blue) Zone, where line fishing is permitted.

General benthic features

Twelve frames survive of this dive and they show a colorful, structurally low reef with an unusually strong soft-coral component. The wide frames (e.g., Image 1, Image 2, Image 3, Image 4, Image 8, Image 9, Image 10) all look across a broken, close-packed mosaic rather than any single dominant form.

12348910

Smooth mounding domes — brown, tan, and gray, consistent with Porites, and mounding faviids — recur in nearly every frame (e.g., Image 8, Image 9, Image 10), and around and between them sit cream, tan, and orange corymbose and branching colonies, pale plating colonies, purple, and blue-tipped branching colonies (e.g., Image 1, Image 10), and small pink and mauve clumps. Image 2 and Image 1 carry a vivid orange fleshy colony each, the brightest hard-substrate color in the set. Soft corals are conspicuous: dusty-pink and mauve bushy soft corals crowd the reef in Image 4, Image 9, and Image 8 — Image 9 has them massed a meter deep between the mounding heads — and Image 7 has a dark branching gorgonian or black-coral bush standing on the top of a bommie against blue water.

7

Image 4 and Image 3 show the reef edge falling away into darker blue. Two frames are close-ups. Image 6 is a macro of a lavender-purple colony with large, ruffled, radially fringed polyps fully expanded — a corallimorph or a fleshy-polyped coral; at this resolution the frame does not settle which.

6

Image 11 is a close view of pale branching and encrusting growth with crimson-red encrusting patches and a gray-green algal-turf patch through the middle.

11

Coral cover

• Reference: Khaled bin Sultan Living Oceans Foundation, Global Reef Expedition (in situ transect)
• The point-count survey read 45% live coral.
• Transect mean 45 ± 4.0% SE (n = 5 transects; Living Oceans Foundation per-transect benthic data); the headline above is the expedition's station value.

Stressors

Condition, qualitatively: pigmentation looks normal in the wide frames — the mauve and pink colonies here read as pigmented rather than pale. No stark-white colonies, disease lesions, or crown-of-thorns appear in the twelve frames. Anderson's own record for this dive notes that most of the reef's Seriatopora had bleached along with some Pocillopora damicornis, and that a cluster of toppled Acropora colonies at 5-8 m suggested fairly recent storm damage, much of it still alive; neither the bleached fine-branched material nor the toppled colonies are identifiable in this reduced photo set, so his field record stands on its own and no percentage is estimated from the photographs.

Fish and other fauna

Image 12 is a giant clam (Tridacna) wedged into the reef with its mantle in mottled cream, brown, and dark stripes, fringed by tan branching Acropora and encrusting Montipora-type sheets.

12

Image 5 records the sea snake Anderson logged: an olive-and-cream banded snake, thin-necked and paddle-tailed, crossing a patch of white sand and rubble with mauve branching corals at the edge.

5

It is a single-subject frame with little usable substrate. An aggressive 2 m olive sea snake patrolled the site.

Comparisons with other data

No other surveys have been conducted at this site to date. Within 5 km, four independent stations (AIMS manta tow and XL Catlin Seaview Survey) recorded 8.0–36% hard coral cover between 1996 and 2021; the nearest, XL Catlin Seaview Survey at transect 12038, 1.24 km away, read 8.0–27% between 2012 and 2017.

Dive record

Ribbon Reef No. 5, sheltered side, dived 5 September 2014.

Other notes

What the frames cannot settle: the depth-related shift from soft-coral-dominated deeper ground to hard coral mosaic higher up that Anderson describes cannot be verified frame by frame, since no frame carries a depth; and at this image size most colonies here cannot be taken past growth form and genus.