Maldives - Big Sand Bank

Setting

Big Sand Bank hides a secret beneath its sunny name: a maze of canyons and swim-throughs where sheer walls squeeze the light into pale blue keyholes overhead (e.g., Image 5).

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General benthic features

The passage walls drip with life that loves the shade — blue rope sponges slung like cables, red encrusting sponge, white lacework hydroids, feather stars, and soft corals in lavender and crimson (e.g., Image 2, Image 8, Image 9).

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Then the reef climbs into the light and changes character completely: staghorn thickets boiling with blue-green chromis, tabletop corals stacked along the spurs, and pink cauliflower corals crowding the crests (e.g., Image 14).

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Coral cover

Coral cover: 18% — photo-derived, and the two methods broadly agree (16% vs 20%). This site's figure is the mean of two independent computer vision passes over Anderson's own frames: a DINOv3 calibrated point classifier reads 15.8% and a CoralSCOP computer vision reads 19.6%, a spread of 3.8 percentage points. The map publishes the mean so sites can be sorted against one another, but the honest statement of what is known here is the 16–20% range: the two products have different denominators and should not be treated as one measurement.

Stressors

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

Fish and other fauna

A Clark's anemonefish guards its anemone, a moorish idol works the spur tops, electric-blue fusiliers rip past in formation, and anthias spill over every rim like orange confetti (e.g., Image 4, Image 20).

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Comparisons with other data

No independent survey was made at this exact site; the nearest ones are listed in the table below.

Dive record

Photographed in January 2016, three months before the El Niño bleaching rewrote these reefs — this is the Maldives at full volume. Revisited in May 2017, when the tagged long-term monitoring colonies here were found largely dead — a stark before-and-after bracketing the 2016 El Niño bleaching.