Turks and Caicos - Rock and Roll

Setting

Two settings recur. Second, the wall lip and the near-vertical drop-off beyond it.

General benthic features

First, a broad low-relief pavement-and-sand plateau at roughly 12-20 m, octocoral country: dense sea plumes and sea rods (Antillogorgia / Pseudopterogorgia, lilac, cream, and golden-brown), purple sea fans, and black wire-coral (Stichopathes) whips over pale turf- and coralline-crusted dead framework, white sand channels between (e.g., Image 17, Image 40, Image 42).

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Stony coral here is small and scattered, not structural: mustard Porites astreoides knobs, lavender branching Porites porites, small Siderastrea discs, dark Montastraea cavernosa domes, tan Pseudodiploria / Diploria labyrinthiformis brains (e.g., Image 4, Image 20, Image 54).

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Sponges carry the relief: yellow tubes (Aplysina fistularis), brown multi-osculum tubes (Agelas conifera), orange lobate elephant-ear (Agelas clathrodes), maroon rope sponges, gray vase and barrel sponges, and lilac encrusting sheets overgrowing coral in one frame (e.g., Image 15, Image 38, Image 41).

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Coral improves markedly at the edge: tiered plating and encrusting Orbicella- and Agaricia-type colonies, some with vivid yellow growing margins, plus knobby Orbicella annularis mounds (e.g., Image 2, Image 3, Image 21).

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The vertical face is mostly bare framework, white feathery gorgonians, red encrusting sponges, and turf (e.g., Image 5, Image 53).

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Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 5.9% — a blind Claude computer-vision point count of 90 of Anderson's edited photographs (the mean of the two dives' means; 20 points per photo; water, fish, and obstructions excluded). Other computer-vision methods are listed in the method table.

Stressors

But eight close-ups show sharply bounded bands of freshly exposed white skeleton at colony margins, older dead area claimed by violet crustose coralline algae - active tissue loss rather than bleaching (e.g., Image 29, Image 33, Image 34, Image 51).

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No corallivores evident.

Fish and other fauna

Fauna is the site's signature: Caribbean reef sharks (Carcharhinus perezi) work the drop-off in a dozen frames, and nurse sharks (Ginglymostoma cirratum) rest on sand beneath isolated bommies wrapped in French and bluestriped grunt schools - the defining Rock and Roll image, and what separates this site from G Spot's V-shaped wall notch just east (e.g., Image 27, Image 36, Image 49).

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Horse-eye jacks, creole wrasse, barracuda, hogfish, spiny lobster, an arrow crab, and Christmas-tree worms also appear; visibility read 20-30 m on dive 1, hazier on dive 2 (e.g., Image 16, Image 18, Image 26).

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Comparisons with other data

Rock and Roll (French Cay) was dived from the Turks & Caicos Explorer II liveaboard on 3 August 2022 (dives 16-17). Squirrelfish and cardinalfish peer from sponge cavities while schooling horse-eye jacks and barracuda move overhead (e.g., Image 10, Image 25).

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Dive record

Rock and Roll, French Cay - described from both dives on 3 August 2022 (entries 08:31 and 11:01; 32.3 m and 29.6 m max).

Other notes

Stony coral here is small and scattered, not structural: mustard Porites astreoides knobs, lavender branching Porites, small Siderastrea discs, dark Montastraea cavernosa domes, tan Pseudodiploria / Diploria labyrinthiformis brains (e.g., Image 4, Image 20, Image 54).