Alor - Clown Valley

Setting

A reef slope with a strong gradient from encrusted rock and rubble near the entry to extensive, dense branching-coral thickets further along. Visibility is good throughout with strong ambient light (e.g., Image 2).

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General benthic features

Early frames show a mixed substrate of purple/maroon encrusting sponge or coralline patches over rubble and dead coral fragments, with a low mound of small-polyp branching coral (gray-green) at the margin (e.g., Image 3).

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Mid-dive frames are dominated by foliose/cup-shaped coral colonies with pale rims forming an almost continuous low canopy interspersed with red and maroon foliose algae (cf. Halymenia), a heart-shaped salmon-pink encrusting sponge, and scattered massive brain/faviid coral (e.g., Image 14, Image 17, Image 42).

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A striking green encrusting/plating colony (possibly stressed or naturally pigmented) sits beside gray encrusting sponge and red algae, with a diver's exhaust bubbles visible in the background (e.g., Image 6, Image 19).

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Multiple wide frames further into the dive show dense, low-relief staghorn/digitate Acropora-type thickets stretching wall-to-wall across the frame, hosting anthias and small reef fish, with massive coral boulders and brain corals as occasional structural breaks; two divers are visible swimming over one such thicket (e.g., Image 5, Image 12, Image 41).

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A broad slope with pronounced variation in coral cover. Apparently shallower sections later in the dive supported dense branching thickets that greatly increased structural complexity, separated elsewhere by rubble, hardground, and older dead framework (e.g., Image 46).

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Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 41% — a blind Claude computer-vision point count of 209 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

The photo review saw no bleaching or disease, and colonies show normal pigmentation (browns, grays, greens, and the one notably green plating colony); however, a computer-vision point count called 0.1% of coral points bleached (2 of 209 photos). Fishing gear: a woven-bamboo fish trap (bubu) lies on the reef slope among branching and massive colonies, a wooden pole with a thin line lies across a staghorn thicket as a trap marker, and a taut yellow rope crosses the branching-coral slope (e.g., Image 51, Image 52, Image 53).

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One brown plating-massive colony carries about ten small white spots of bare skeleton, several beside small borer holes: small recent-mortality or bite spots, cause not visible (e.g., Image 54).

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No crown-of-thorns starfish (COTS) or other corallivores were evident.

Fish and other fauna

A mid-water frame records a school of unicornfish/surgeonfish silhouetted in blue water above the reef. Host anemones, leather and other soft corals, sponges, crinoids, and red encrusting growth were frequent, and anthias, chromis, other damselfishes, butterflyfishes, and surgeonfishes occupied the slope (e.g., Image 7, Image 26, Image 47).

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Comparisons with other data

We found no other surveys at this site as of 2026. Within 5 km, one independent station, WWF-US / WWF-Indonesia at station 5002, 0.75 km away, read 8.0% 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.