Alor - Limarahing (Black Sands)

Setting

A pronounced gradient from a dense coral garden down to flat dark volcanic sand, as the site's other name (Black Sands) suggests (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-dense sections, the substrate is essentially wall-to-wall low-relief coral: extensive fields of foliose/cup-shaped colonies with pale growing margins. 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 massive mound of a long-polyp stony coral with tan flanks and a paler crown, 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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A coral-dense 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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Coral cover

• Reference: Claude CV point count (this site's photos)
• 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. Part of this dive was over muck: the photographs pool coral with dark volcanic sand that is not reef, so the value describes that mix, not the cover of a reef.

Stressors

One foliose colony is bleached, with broad cream-white areas across its fronds while every neighbor of the same form is uniformly brown (e.g., Image 55); the pale rims on the surrounding foliose plates are normal growth edges.

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A computer-vision point count called 0.3% of coral points bleached (2 of 162 photos). On the sand flat, a small stark-white branching colony is recently dead, cause unclear (e.g., Image 35). No man-made objects appear in this sample. No crown-of-thorns starfish (COTS) or other corallivores were 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

We found no other surveys at this site as of 2026. Within 5 km, two WWF-US / WWF-Indonesia stations recorded station-year means of 8.0–24% hard coral cover in 2014; the nearest, WWF-US / WWF-Indonesia at station 5003, 3.07 km away, read 24% in 2014.

Regional context, not a survey of this site: Razak et al. (2026) found no significant trend in hard coral cover around Alor (a decline of 0.6% per year at 23 sites, surveyed by point-intercept transect at about 8–10 m in 2014, 2017, 2021, and 2023 by Yayasan WWF Indonesia); this is a trend for that location, not this site’s cover. Cover at those sites fell by 3% between the 2014 and 2017 surveys, which bracket 75 days of NOAA Bleaching Alert Level 1 from December 2016 to February 2017.

Dive record

This afternoon dive on 31 July 2026 is not in Anderson's dive log, so no depth, bottom time, or water temperature is given. The camera clock places it at about 15:18–16:12 local time (about 54 minutes of photographs), between the logged Apuri Bay (12:00) and Ampera night (18:18) dives.