Atlantic and Gulf Rapid Reef Assessment
Coral Reef Diagnostics

SVG - Mayreau Gardens (second vent)

Reef Check Foundation
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Part of the regional summary: Saint Vincent and the Grenadines

05
Coral Health Index: TBD
Country
Saint Vincent and the Grenadines
Survey date(s)
2019-09-26
Coordinates
12.6245, -61.3822
Approximate position.
Coral cover
30%
Claude computer vision (21 edited photos) · details below · median 25%
Observations
not yet tagged for this site
Heat stress
Today’s heat load
29.6°C5.0°C-weeks
3 Oct 2026 · Alert Level 1
5-year thermal stress load
5-year mean max. degree heating weeks (DHW)
14.3°C-weeksi
2021–2025
NOAA Coral Reef Watch — Windward Caribbean Islands virtual station
i 5-year mean max. DHW is the mean of the annual maximum DHWs over the five complete years named above, not conditions today.
More infoWindward Caribbean Islands (NOAA CRW virtual station) · Eastern Caribbean ecoregion mean: 13.1 degree heating weeks
Dive setting
reef

22 independent survey stations shown with the program’s logo — click one to see how far it is from this site.

Four other CRD dive sites within 5 km shown in orange — click a marker to open its page.

Site description

Setting

A second gas vent on the Mayreau reef system, about 600 m south-southwest of the main CO2 vent studied by Enochs et al. (2020), found on the first dive of the 2019 trip (26 September 2019, about nine minutes of photographs). A fine stream of bubbles rose from sand between boulders beside a white, bacterial-looking film.

Coral cover

Comparisons with other data

No other surveys have been conducted at this site to date. Within 5 km, 22 independent stations recorded 1.2–44% hard coral cover between 1999 and 2019; the nearest, XL Catlin Seaview Survey at transect 22017, 0.68 km away, read 8.5% in 2013.

Other notes

The position is approximate (from Anderson's recollection; the dive was not logged).

CV model comparison

Mean 30%, median 25% across 21 photos.
More infoThe mean is above the median because several frames are portraits of single colonies. No computer-vision method yet estimates coral cover accurately on new images, so treat this as indicative rather than a measurement; it is revised as the methods improve.
Headline: Claude computer vision, a blind point count of this site's own edited photographs; no other computer-vision method has been run on them yet.
More infoNo diver transect exists for this trip, so treat the value as indicative.
MethodHard-coral cover (%)
Claude (edited photos)29.8

See a more detailed, stand-alone version of this table.

Independent surveys nearby

Data availability near this site
Agency / programYear(s)Stations / distanceLink
AGRRA2015–20199 stations, 2.93–4.80 kmRecords ↓
Literature: Deschamps et al. 200319992 stations, 4.13 kmRecords ↓
Reef Check2005–20074 stations, 2.68–4.00 kmRecords ↓
XL Catlin Seaview Survey20137 stations, 0.68–4.73 kmRecords ↓
Hard coral cover over time — this site and every independent station within 5 km. Programs are shown separately because they use different methods at different stations; the lines are not one comparable series.
0%12%24%36%48%199920092019Literature: Deschamps et al. 2003 1999: 30%Literature: Deschamps et al. 2003 1999: 40%Reef Check 2005: 10%Reef Check 2005: 14%Reef Check 2005: 24%Reef Check 2007: 11%Reef Check 2007: 16%Reef Check 2007: 19%Reef Check 2007: 31%XL Catlin Seaview Survey 2013: 1.2%XL Catlin Seaview Survey 2013: 3.0%XL Catlin Seaview Survey 2013: 5.4%XL Catlin Seaview Survey 2013: 6.1%XL Catlin Seaview Survey 2013: 7.5%XL Catlin Seaview Survey 2013: 8.5%XL Catlin Seaview Survey 2013: 11%AGRRA 2015: 1.5%AGRRA 2015: 3.0%AGRRA 2015: 5.2%AGRRA 2015: 5.6%AGRRA 2015: 12%AGRRA 2015: 34%AGRRA 2018: 8.3%AGRRA 2018: 9.2%AGRRA 2018: 11%AGRRA 2018: 12%AGRRA 2018: 44%AGRRA 2019: 11%AGRRA 2019: 13%Coral Reef Diagnostics 2019: 30%Year-averaged across all programs: no detectable trend (-0.79 pp per year, not separable from zero; 7 years)
Literature: Deschamps et al. 2003 Reef Check XL Catlin Seaview Survey AGRRA Coral Reef DiagnosticsYear-average (no detectable trend)

Within 5 km, 22 independent survey stations recorded hard coral cover in 29 records between 1999 and 2019. Of the 7 stations surveyed in more than one year, 5 increased and 2 changed by less than 5 percentage points between their first and latest surveys. The longest record, Petit Rameau (AGRRA, 2.93 km away), went from 34% in 2015 to 44% in 2018. The most recent nearby survey is from 2019, so these values predate recent heat stress. This site's own estimate (30%) sits within the range of these surveys (1.2–44%); 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; AGRRA uses benthic point-intercept transects, reported here as live coral cover; 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.

Show all 22 independent survey records
Independent survey data near this site
AgencySite / locationDateHard coral cover (%)DistanceLink
Literature: Deschamps et al. 2003Horseshoe Reef fore reef, Tobago Cays Marine Park [3-4 m]199930%4.13 km—
Literature: Deschamps et al. 2003Horseshoe Reef fore reef, Tobago Cays Marine Park [9-11 m]199940%4.13 km—
Reef CheckPetit Bateau2005–200714–19% (2 surveys)2.68 km—
Reef CheckPetit Tabac2005–200710–11% (2 surveys)3.44 km—
Reef CheckHorseshoe Reef Back Reef2005–200724–31% (2 surveys)3.69 km—
Reef CheckHorseshoe (outside)200716%4.00 km—
XL Catlin Seaview Surveytransect 2201720138.5%0.68 kmdoi:10.14264/uql.2019.930
XL Catlin Seaview Surveytransect 2201820136.1%0.70 kmdoi:10.14264/uql.2019.930
XL Catlin Seaview Surveytransect 22019201311%0.70 kmdoi:10.14264/uql.2019.930
XL Catlin Seaview Surveytransect 2201620137.5%3.20 kmdoi:10.14264/uql.2019.930
XL Catlin Seaview Surveytransect 2201420135.4%3.50 kmdoi:10.14264/uql.2019.930
XL Catlin Seaview Surveytransect 2201520131.2%4.51 kmdoi:10.14264/uql.2019.930
XL Catlin Seaview Surveytransect 2201120133.0%4.73 kmdoi:10.14264/uql.2019.930
AGRRAPetit Rameau2015–201834–44% (2 surveys)2.93 km—
AGRRAHorseshoe REEF-SE2015–20185.6–11% (2 surveys)3.41 km—
AGRRAHorseshoe Reef MPA Site201512%3.83 km—
AGRRANE Palm Island20151.5%4.31 km—
AGRRARoundabout Reef2015–20185.2–9.2% (2 surveys)4.79 km—
AGRRAWorld's End Reef-S2015–20183.0–8.3% (2 surveys)4.80 km—
AGRRAHorseshoe Reef MPA site201812%3.83 km—
AGRRATaiChi Reef201913%3.70 km—
AGRRAHorse Shoe Reef201911%3.86 km—

Data & links

Data are from Coral Reef Diagnostics and the organizations named in the data sources above.

© Coral Reef Diagnostics.

References

  1. Deschamps A, Desrochers A, Klomp KD (2003). St. Vincent. A Rapid Assessment of the Horseshoe Reef, Tobago Cays Marine Park, St. Vincent, West Indies (Stony Corals, Algae and Fishes). Atoll Research Bulletin 496:438-459. DOI
  2. Enochs IC, Formel N, Manzello D, Morris J, Mayfield AB, Boyd A, et al. (2020). Coral persistence despite extreme periodic pH fluctuations at a volcanically acidified Caribbean reef. Coral Reefs 39:523-528. DOI
  3. Gonzalez-Rivero M, et al. (2019). Seaview Survey photo-quadrat and image classification dataset. The University of Queensland (UQ eSpace) data collection. DOI