Atauro - Biqueli Wall

Setting

Although the site is named for its wall, the first four photographs reviewed document the upper terrace rather than the drop-off. Taken together the frames show excellent visibility, high branching-Acropora cover, and exceptional small-fish abundance in the shallows, alongside at least one substantial coralline-bound rubble field. Because the reviewed images do not document the full drop-off, this is an account of the photographed upper reef at Biqueli Wall, not a complete characterization of the wall itself. In three consecutive frames a taut blue line rises from near the top of one bommie into the water column; what kind of line it is cannot be told from the photographs.

General benthic features

Frame by frame: the first is a broad wide-angle over a near-continuous field of tan corymbose and digitate Acropora, mound after mound of fine branching growth running to a flat horizon, with an enormous aggregation of small planktivorous fishes — damselfishes and fusilier-like schools numbering in the hundreds — filling the entire water column above it; a single block of pale dead skeleton crusted in pink coralline sits in the near foreground (e.g., Image 1).

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The second is the same habitat in better light: wall-to-wall corymbose Acropora with pale branch tips sloping gently into clear blue, again with a dense cloud of dark-green damselfishes hovering over the thicket and hundreds more strung out into the blue (e.g., Image 2).

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The third frame is a close view of the other extreme — a blue sea star consistent with Linckia laevigata lying across a consolidated bed of dead Acropora branch rubble entirely encrusted in pink and mauve crustose coralline algae, with red encrusting growth and a few small green ascidians and sponges, and no living coral in the frame at all (e.g., Image 3).

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The fourth is a coral-dense pavement at mid relief: a large mauve-pink digitate colony with blunt, pale-tipped fingers dominates the center, flanked by dark brown massive lobate Porites, tan honeycomb-textured faviid brain corals, pale branching growth, a black feather star tucked into a crevice, and a few dark damselfishes (e.g., Image 4).

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Sand, pale framework, and rubble channels separate the denser patches. Black feather stars (crinoids) recur constantly on bommie tops throughout the sequence, and barrel, tube, and encrusting sponges are a regular presence, though neither is a dominant visual feature.

Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 27% — a blind Claude computer-vision point count of 147 of Anderson's edited photographs (20 points per photo; water, fish, and obstructions excluded). Other computer-vision methods are listed in the method table.

Stressors

Anderson photographed two bleached branching colonies on this dive: one stark white throughout among pigmented brown colonies, and one with a large stark-white center ringed by pigmented tan branches (e.g., Image 21, Image 22).

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A computer-vision point count called 1.9% of coral points bleached (10 of 147 photos). Image 23 documents a single live table coral isolated within a broad field of dead rubble — a striking contrast that hints at real reef degradation in at least part of the photographed area.

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

Fish and other fauna

Small reef fishes occur above the coral, while individual bommies support several growth forms within a compact area.

Comparisons with other data

We found no other surveys at this site as of 2026. Within 5 km, nine independent stations recorded station-year means of 13–61% hard coral cover between 2004 and 2017; the nearest, Reef Check at North of Tanjung Reta, 0.13 km away, read 44% in 2004.

Dive record

Biqueli Wall was dived on 30 January 2024, in at 08:31 for 59 minutes, 30.8 m maximum and 12.2 m average depth, average water temperature 28.0°C (dive-computer minimum 27.8°C).