Maldives - Small Sand Bank
Part of the regional summaries: Maldives - Central (Male Atolls / Ari / Vaavu) and Maldives
2016-01-19
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Maldives (NOAA CRW virtual station) · Maldives ecoregion mean=2.9°C-heating weeksSmall Sand Bank is a coralline-crusted bank reef dropping into blue water, the first quadrat site of a January 2016 research baseline, where tagged coral colonies were healthy and feeding and crown-of-thorns starfish prowled the pavement. By the April 2016 resurvey, at the height of El Nino, four out of five colonies here were bleached.
Two independent survey stations shown with the program’s logo — click one to see how far it is from this site.
Nine other CRD dive sites within 5 km shown in orange — click a marker to open its page.
9 of these 25 photographs are shown beside the text that discusses them under "Site description" below.
Site description
Setting
A hard-pavement bank reef that rolls over into a steep slope of blue water — and the first quadrat site of the January 2016 research baseline (e.g., Image 25).
General benthic features
The reef top is crusted pink with coralline algae and dotted with tagged study colonies: cauliflower-shaped Pocillopora heads and branching, pale-tipped Acropora, each wearing a small numbered cattle-tag beside the transect line (e.g., Image 1, Image 6, Image 10, Image 18).
Macro frames catch their polyps fully extended, healthy and feeding — while feather stars perch on the rubble and vivid purple crown-of-thorns seastars prowl the pavement, one photographed beside the survey hammer (e.g., Image 2, Image 11, Image 17, Image 20).
Coral cover
Coral cover: 20% — photo-derived, and the two methods broadly agree (23% vs 17%). This site's figure is the mean of two independent computer vision passes over Anderson's own frames: a DINOv3 calibrated point classifier reads 23.1% and a CoralSCOP computer vision reads 17.1%, a spread of 6 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 17–23% range: the two products have different denominators and should not be treated as one measurement.
Stressors
It is a portrait of a reef in its last healthy season: when the team returned in April 2016, at the height of the El Niño, four out of five coral colonies here were bleached.
Comparisons with other data
No independent survey was made at this exact site; the nearest ones are listed in the table below.
CV model comparison
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As of September 2026 no computer-vision method estimates coral cover accurately on new images, so treat this as indicative rather than a measurement; it is revised as the methods improve.More info
The published figure is the mean of the two methods.| Method | Hard-coral cover (%) |
|---|---|
| In-house DINOv3 | 23.1 |
| CoralSCOP | 17.1 |
| Mean (± SD) | 20.1 ± 4.2 |
| Range | 17.1–23.1 |
Mean ± SD and range are across the computer-vision methods shown.
Independent surveys nearby
| Agency / program | Year(s) | Stations / distance | Link |
|---|---|---|---|
| Reef Check | 2022 | 1 station, 4.83 km | Records ↓ |
| XL Catlin Seaview Survey | 2015–2017 | 1 station, 4.79 km | Records ↓ |
Dr. Coral (CRD)Within 5 km, 2 independent survey stations recorded hard coral cover in 3 records between 2015 and 2022. Of the 1 station surveyed in more than one year, 1 changed by less than 5 percentage points between their first and latest surveys. The longest record, transect 37035 (XL Catlin Seaview Survey, 4.79 km away), went from 7.1% in 2015 to 5.5% in 2017. One survey since 2021 recorded 19%. This site's own estimate (20%) is indistinguishable from the recent value (19%): the 0.7-point gap is inside the ±7 percentage-point noise between methods; the methods differ, so the comparison is context, not a like-for-like test.
Collected by other programs using different methods (Reef Check uses point-intercept transects; the XL Catlin Seaview Survey uses photo-transects with automated image annotation), so these are context for the figures above, not a like-for-like comparison. Where a station was surveyed more than once the range is shown. Station names are not dive-site names.
| Agency | Site / location | Date | Hard coral cover (%) | Distance | Link |
|---|---|---|---|---|---|
| XL Catlin Seaview Survey | transect 37035 | 2015–2017 | 5.5–7.1% (2 images) | 4.79 km | — |
| Reef Check | Gulhi Island Backreef | 2022 | 19% | 4.83 km | — |
Data & links
All images from Coral Reef Diagnostics. Data are from Coral Reef Diagnostics and the organizations named in the data-sources table above.
© Coral Reef Diagnostics.