Alor - Limarahing (Black Sands)

Setting

A pronounced gradient from a dense coral garden down to flat dark volcanic sand, exactly matching the existing site name (e.g., Image 18, Image 39).

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Visibility is good throughout with strong ambient light in the shallower coral-garden frames and murkier/greener tones over the open sand.

General benthic features

In the coral-rich sections, the substrate is essentially wall-to-wall low-relief coral: extensive fields of foliose/cup-shaped colonies with pale growing margins (cf. Pachyseris/Echinopora), dense mounds of digitate/knobby coral, and several large mounding faviid/brain corals (one with a sharply defined maze pattern) sit alongside massive Porites-type boulders (e.g., Image 2, Image 5, Image 17, Image 33, Image 44).

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One wide frame shows near-total coral cover from foreground to the reef crest with schooling anthias and damselfish overhead; another shows a comparably dense, slightly different-colored (browner) coral carpet with butterflyfish and a diver's exhaust bubbles visible top-right (e.g., Image 24, Image 27, Image 43).

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As the reef grades onto open sand, colonies become scattered and isolated: individual coral heads, a soft white lettuce/cauliflower-form colony, sponges (an orange branching sponge, a red encrusting patch, a green barrel form), and small gorgonian sea-fan fragments dot an otherwise bare gray-black sand plain (e.g., Image 20, Image 22, Image 32, Image 38).

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On the sand flat itself, isolated coral clusters (staghorn-type branching, encrusting patches) persist alongside more sponges and soft corals, with a garden-eel-style burrow field implied by scattered holes in one lower-relief frame (e.g., Image 34, Image 35).

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Coral cover

Coral cover: 29% — a blind Claude computer-vision point count of 162 of Anderson's unedited photographs (20 points per photo; water, fish, and obstructions excluded). Other computer-vision methods are listed in the method table.

Stressors

No bleaching or disease is visible on any photographed coral; all colonies show normal brown/tan/olive pigmentation. No man-made objects appear in this sample. No crown-of-thorns starfish (COTS) or other corallivores evident.

Fish and other fauna

Reef fauna include a red-and-white basket/brittle star draped across dead coral rubble, a blue Linckia-type sea star on sand, small pink and purple encrusting sponges, and an anemone with a pair of small clownfish.

Comparisons with other data

Also on record for this site: A coral-rich slope grading into flatter dark volcanic sand (e.g., Image 36, Image 41).

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This reef-to-sand gradient accommodates both coral-associated fishes and cryptic volcanic-sand macrofauna; coral cover was locally high but not continuous (e.g., Image 10).

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