Atauro - Biqueli Wall

Setting

What the four surviving frames document, however, is 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.

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).

1

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).

2

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).

3

The fourth is a coral-rich 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).

4

Coral cover

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

No bleaching, disease lesion, predation scar, transect tape, mooring, or other man-made object appears in any frame.

Comparisons with other data

Also on record for this site: 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. Small reef fishes occur above the coral, while individual bommies support several growth forms within a compact area. 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. A blue sea star compatible with Linckia laevigata is also present in the edited selection. One frame 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, not captured by the otherwise neutral tone of this account.

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, minimum water temperature 27.8°C (lifetime dive 252).