Alor - Sulambali Wall

Setting

A broad, steep upper slope rolls over into a near-vertical wall and drop-off, with open blue water on its seaward side (e.g., Image 1, Image 2, Image 26).

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General benthic features

The deep and mid wall is encrusting rather than framework-building: pink and magenta crustose coralline algae, red, orange, yellow, lilac, and blue encrusting sponges, tunicates, and turf, punctuated by stacked foliose plates (e.g., Image 6, Image 9, Image 21, Image 23).

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Those plate beds are the standout habitat here — meter-scale fields of overlapping whorls, one field carpeted in red Pseudanthias (e.g., Image 5, Image 29, Image 30).

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Large aprons of dead branching-coral rubble, bleached white and bound by coralline algae, run along the upper wall between the live stands, and pale sand chutes cut through repeatedly — live coral is genuinely discontinuous at this site (e.g., Image 27, Image 33).

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Also present: blue-gray finger and tube sponges, orange and brown barrels of Xestospongia form, tan feather-hydroid and gorgonian plumes, black and yellow feather stars, two blue Linckia laevigata, a sea cucumber, and mauve host anemones with anemonefish. The shallow reef top is a different community again: green, tan, and brown table corals, broad staghorn and corymbose coral thickets, bushy branching corals, massive corals, meandering brain corals and fleshy large-polyped corals, free-living mushroom corals, and continuous pulsing xeniid and leather soft-coral meadows (e.g., Image 13, Image 18, Image 24, Image 39, Image 43).

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Sand and rubble channels separated patchy to locally high coral cover, and the shallower frames became increasingly mixed and coral-dense.

Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 22% — a blind Claude computer-vision point count of 208 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

Condition is mixed rather than uniformly good: no basin-wide bleaching, but one large massive colony seen on the dive is bleached over roughly half its surface (stark-white tissue with a few brown, still-pigmented spots) (e.g., Image 55), and several smaller colonies carry white patches, alongside the extensive older rubble.

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A thin white monofilament line or rope is stretched taut across the upper slope in two frames (e.g., Image 56, Image 57).

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

Fish and other fauna

Fish: red anthias in thousands, dark damselfish shoals over the drop-off, yellow-and-blue fusiliers, butterflyfishes, surgeonfishes, and three tight silverside baitballs.

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, 2.14 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.