Coral Reef Diagnostics

Kenya - Coral Garden (Kisite National Park)

REEFolution Foundation
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05
Photo: Anderson Mayfield/Coral Reef Diagnostics
Country
Survey date(s)
2024-03-21
Coordinates
-4.7163, 39.3658
Coral cover
55%
Manual point count (178 photos) · other methods below
Observations
Heat stress
Today’s heat load
16 Sep 2026 · No heat stress
5-year thermal stress load
5-year mean max. degree heating weeks (DHW)
2021–2025
NOAA Coral Reef Watch — Tanzania 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 infoTanzania (NOAA CRW virtual station) · East African Coral Coast ecoregion mean=4.1°C-heating weeks
Photographs
4
Site summary
Read this summary in:

Coral Garden, in Kisite Marine National Park, was both the richest reef in the entire 20-site Kenya survey (55% cover, wall-to-wall coral in many frames) and among the least bleached (58.9% of tissue, versus a 77.1% Kenya-wide average) - an enormous carpet of knobby Galaxea coral held its color well, while the acroporid thickets growing on and around it took most of the damage, producing some of the clearest side-by-side healthy-versus-bleached imagery in the whole study. A green turtle, batfish, and streaming anthias rounded out the site, and no crown-of-thorns starfish were seen, a contrast with reefs further north.

Max. depth dived
6 m
Water temp. during survey
31.5°C
+3.3°C vs the 2024 mean sea temperature (28.2°C)

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

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

Photo credit & attribution

Site description

Setting

The full 161-frame set confirms what the four published frames suggested and then some: this is the clearest water of the Kenya survey, deep open blue above the reef in almost every wide frame, and it is genuinely rail-to-rail coral.

General benthic features

Frame after frame is wall-to-wall living colony with no bare substrate in view at all. The feature the site is named for is real and it is enormous. Two of Anderson's own frames are both wide views of a single unbroken hillside of knobby, nodular columnar Galaxea running out of frame in every direction -- hundreds of square meters of one growth form, gray-mauve on the high ground grading to tan and chocolate-brown in the hollows, with only a handful of small white colonies dotted across it (e.g., Image 1, Image 3).

Another frame is a third view of the same carpet at closer range, a broad pinkish-mauve knuckled field filling the frame. Around and above it the reef is acroporid: multi-tiered stacked Acropora tables, corymbose bushes, digitate stands, and dense staghorn thickets that run for whole frames at a time (e.g., Image 2).

Other taxa and fauna across the set: broad yellow-green foliose Turbinaria stands; cream and tan lobed Sarcophyton leathers; a large tan-orange Dendronephthya-type soft coral bush standing clear of the reef; orange encrusting sponges; a green turtle resting in the shade of a boulder overhang draped in pink soft corals; a batfish (Platax) over a maroon thicket; a ray on the reef top; yellow-and-blue snappers; anthias and fusiliers streaming over the crest; and clouds of chromis in most wide frames. The one thing the wide set adds against the earlier text is that the reef is not gapless everywhere. The carpet and the thickets are continuous across the reef top, but the base of the structure meets clean sand and coral-rubble aprons in six frames, and two large rock outcrops rise clear of the coral into open blue in two more frames.

Coral cover

This is what 55% cover looks like, and it is the richest site in the whole Kenya set. Coral cover 55% -- and 58.9% of hard coral tissue bleached (March-April 2024). Measured from 178 white-balanced photographs taken at this site during the 2024 Western Indian Ocean mass bleaching event and point-annotated in CoralNet, published in Mayfield, A.B. (2025) A Citizen Science Approach for Documenting Mass Coral Bleaching in the Western Indian Ocean. Environments 12(8):276. doi:10.3390/environments12080276. This is a published diver-photograph point-annotation value, not a computer vision estimate.

Stressors

This is the site where the healthy-versus-bleached contrast is most legible, because both states sit side by side in the same frame over and over. One frame has a brilliant white corymbose Acropora at center with a chocolate-tan digitate colony directly above it and a pastel lavender massive colony immediately right (e.g., Image 4).

Two frames put one large bone-white corymbose bush in the middle of an otherwise pigmented tan-brown field. The starkest single image in the set shows a meter-scale massive dome bleached to flat porcelain white, ringed on all sides by fully pigmented brown fine-branched acroporid, with two white meandroid brains beside it. The same within-frame split runs through five more frames -- white branching colonies pressed against olive, gold, and maroon neighbors. On which groups held pigment, the full set corrects the earlier reading. Massive Porites and the brains did NOT largely keep their color here. Several of the most completely white colonies in the set are massives: the porcelain dome described above, a row of massive domes bleached white on rubble, a large lobate Porites gone cream-white across its whole surface, more white domes in another frame, and a large Platygyra brain bleached to pale cream. A pale cream massive Porites also anchors the left of one frame. A minority of massives did hold pigment and are worth naming as the exception: a mauve-brown brain and a green massive colony together in one frame, a tan-brown dome, and the brown lobate colonies of two more frames. The group that most conspicuously retained pigment at Coral Garden is the Galaxea carpet itself, together with the dark maroon and red-brown branching fields -- one is an entire frame of deep maroon branching coral with barely a pale tip in it, and three more frames are the same story. Because that carpet is also the single largest area of coral at the site, the reef reads far healthier in wide shot than the 58.9% bleached figure implies; the bleaching is concentrated in the acroporids on top of and around it. The acroporid tier took the damage: two frames are close-ups of branching Acropora bleached to bare white with only a faint pink blush left at the tips, and a consecutive run of frames shows whole staghorn fields gone gray-white above still-brown columnar coral beneath. A third condition state is present and should not be read as bleaching. One of Anderson's frames is a close-up of a pigmented brown massive colony crossed by bands of bare skeleton carrying a green algal film, with a sharp white advancing margin where tissue is being lost against otherwise fully colored tissue -- a tissue-loss lesion on a colony that never bleached. His frame of an acroporid with partial mortality shows a discrete white patch set inside a continuous brown pigmented acroporid thicket. Three frames show broader gray-white areas that read as recently dead skeleton under a fine algal film rather than as live bleached tissue. Stress coloration is well represented: a vivid lavender-blue verrucose Pocillopora beside a brown-mantled Tridacna, and lilac and violet colonies in three more frames. These are pastel rather than white and, given the color-adjusted frames, are called as probable stress coloration rather than asserted. No crown-of-thorns seastar appears anywhere in the 161 frames reviewed -- a real contrast with the Kilifi sites. Typical recent thermal stress: mean annual maximum of 4.1 degree heating weeks (2021-2025, NOAA CRW; East African Coral Coast ecoregion). Seawater here measured 31.5°C during the survey (the Kenya survey-wide mean of 32.0°C matched the 1998 event), and NOAA recorded a peak of 13.5 degree-heating weeks on 18 April 2024, the highest for Kenya since records began in 1985. In situ temperatures ran 1.3 degrees C above NOAA's estimates, so the true heat stress was likely nearer 22 DHWs.

Comparisons with other data

This site publishes 55.0%.

Dive record

Dived 21 Mar 2024 at about 6 m in Kisite Marine National Park during the 2024 Western Indian Ocean mass bleaching event. Surveys were run with REEFolution.

Other notes

REEFolution divers appear in three frames, one of which shows two divers above a bank of stacked acroporid tables.

CV model comparison

Computer vision on this site's own photographs gives Manual point count, recomputed on the CV frames only 45%; In-house DINOv3 point classifier 46%; CoralSCOP 21% — reported alongside rather than merged, because as of September 2026 no computer-vision method estimates coral cover accurately on new images.
Headline is the reference value; every other row is listed beside it for comparison and none is averaged in. ⚠ The published manual column and the four CV columns are on DIFFERENT FRAME SETS: the manual covers the site's full photo set (21–375 frames), the CV arms ran only on the 50-frame blind batch, which supplies 1–24 frames per site.
More infoThe like-for-like row is the recomputed manual, not the published one. ⚠ The CV columns are on the OLD all-30 denominator while the published manual is on the settled rule; on these frames that understates cover by ~3.0 pp. The 50-frame batch is 6.3 pp poorer in cover than the survey average, so the CV columns are subset-distorted as well as denominator-shifted. Round Reef and Uyombo roll up 15 and 16 quadrat codes respectively. CoralSCOP (SAM-based mask-sum), edited photos: n/a — CoralSCOP was never run on Kenya edited copies; owner's ruling 2026-09-17: 'for kenya, it's only on unedited'
MethodHard-coral cover (%)
Manual (published)55.0
CoralNet46.4
In-house DINOv346.0
CoralSCOP unedited20.9
Claude40.0

Independent surveys nearby

Data availability near this site
Agency / programYear(s)Stations / distanceLink
Global bleaching + environmental database20161 station, 0.72 kmRecords ↓
Kenyan reef survey compilation (source not identified)—3 stations, 0.09–1.34 kmRecords ↓
McClanahan et al. (1996)19961 station, 0.62 kmRecords ↓
McClanahan et al. (2007)19981 station, 0.95 kmRecords ↓
REEFolution Foundation2013–20195 stations, 0.26–4.57 kmRecords ↓
WCS Kenya / WCS Tanzania via MERMAID20201 station, 4.19 kmRecords ↓
WCS Kenya via MERMAID2009–20166 stations, 0.26–1.73 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%15%30%45%60%199620102024McClanahan et al. (1996) 1996: 19%McClanahan et al. (1996) 1996: 24%McClanahan et al. (1996) 1996: 27%WCS Kenya via MERMAID 2009: 42%WCS Kenya via MERMAID 2010: 56%WCS Kenya via MERMAID 2013: 42%WCS Kenya via MERMAID 2015: 48%WCS Kenya via MERMAID 2016: 46%WCS Kenya via MERMAID 2016: 50%REEFolution Foundation 2013: 21%REEFolution Foundation 2017: 2.4%REEFolution Foundation 2017: 15%REEFolution Foundation 2017: 29%REEFolution Foundation 2017: 39%REEFolution Foundation 2018: 8.0%REEFolution Foundation 2018: 48%REEFolution Foundation 2018: 53%REEFolution Foundation 2019: 0.0%REEFolution Foundation 2019: 7.1%REEFolution Foundation 2019: 40%WCS Kenya / WCS Tanzania via MERMAID 2020: 29%Global bleaching + environmental database 2016: 47%McClanahan et al. (2007) 1998: 10%McClanahan et al. (2007) 1998: 22%Dr. Coral (CRD) 2024: 55%Year-averaged across all programs: no detectable trend (+0.59 pp per year, not separable from zero; 12 years)
McClanahan et al. (1996) WCS Kenya via MERMAID REEFolution Foundation WCS Kenya / WCS Tanzania via MERMAID Global bleaching + environmental database McClanahan et al. (2007) Dr. Coral (CRD)Year-average (no detectable trend)

Within 5 km, 15 independent survey stations recorded hard coral cover in 77 records between 1996 and 2020. Of the 4 stations surveyed in more than one year, 1 declined, 1 increased, and 2 changed by less than 5 percentage points between their first and latest surveys. The longest record, Kisite Edge 2 (REEFolution Foundation, 0.69 km away), went from 21% in 2013 to 15% in 2017. The most recent nearby survey is from 2020, so these values predate recent heat stress. This site's own estimate (55%) sits within the range of these surveys (0.0–56%); the methods differ, so the comparison is context, not a like-for-like test. 3 further rows in the table have no survey date, so they are listed but not part of this summary.

Collected by other programs using different methods (MERMAID is a data platform: each MERMAID row names the organization that did the survey, and its method is in the row's hover text), 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 19 independent survey records
Independent survey data near this site
AgencySite / locationDateHard coral cover (%)DistanceLink
McClanahan et al. (1996)Kisite Island199624% (3 surveys)0.62 kmHeatCRD database
McClanahan et al. (2007)Kisite, Kenya (KN)post-199810%0.95 km—
McClanahan et al. (2007)Kisite, Kenya (KN)pre-199822%0.95 km—
WCS Kenya via MERMAIDKisite (mean of 2 surveys, 2008–2009)200942% (4 images)0.85 kmDarling E. 2018. Kenya CRCP legacy. MERMAID
WCS Kenya via MERMAIDKisite South of Site 1201056% (2 images)0.95 kmDarling E. 2018. Kenya CRCP legacy. MERMAID
REEFolution FoundationKisite Edge 22013–201715–21% (2 surveys)0.69 km2023. REEFolution Kenya. MERMAID
WCS Kenya via MERMAIDKisite Edge 1201342% (2 images)1.73 kmDarling E. 2018. Kenya CRCP legacy. MERMAID
WCS Kenya via MERMAIDKisite 2 (mean of 2 surveys, 2012–2015)201548% (4 images)0.26 kmDarling E. 2018. Kenya CRCP legacy. MERMAID
WCS Kenya via MERMAIDKisite 1 (mean of 3 surveys, 2012–2016)201646% (6 images)0.85 kmDarling E. 2018. Kenya CRCP legacy. MERMAID
WCS Kenya via MERMAIDKisite corner201650% (2 images)1.73 kmDarling E. 2018. Kenya CRCP legacy. MERMAID
Global bleaching + environmental databaseKisite 1 Tempgauge2016-05-2347%0.72 km—
REEFolution FoundationKisite 22017–201829–48% (3 surveys)0.26 km2023. REEFolution Kenya. MERMAID
REEFolution FoundationOuter Kisite2017–201939–53% (13 surveys)1.48 km2023. REEFolution Kenya. MERMAID
REEFolution FoundationLower Mpunguti2017–20190.0–8.0% (15 surveys)4.57 km2023. REEFolution Kenya. MERMAID
REEFolution FoundationLower Mpunguti (mean of 15 surveys, 2017–2019)20197.1% (15 surveys)4.57 km2023. REEFolution Kenya. MERMAID
WCS Kenya / WCS Tanzania via MERMAIDMkwiro202029% (3 surveys)4.19 kmDarling E, Mensa J, O'Leary J, Schwarz A. 2020. BAF 1 - 2020. MERMAID
Kenyan reef survey compilation (source not identified)Kisite Leeward (site code S_KL’14), South zone—12%0.09 km—
Kenyan reef survey compilation (source not identified)Kisite Deep (site code S_KD’14), South zone—12%0.91 km—
Kenyan reef survey compilation (source not identified)Kisite Seaward (site code S_KS’14), South zone—16%1.34 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.

References

  1. McClanahan TR, Kamukuru AT, Muthiga NA, Yebio MG, Obura D (1996). Effect of Sea Urchin Reductions on Algae, Coral, and Fish Populations. Conservation Biology 10:136-154. DOI
  2. Mayfield AB (2025). A Citizen Science Approach for Documenting Mass Coral Bleaching in the Western Indian Ocean. Environments 12:276. PDF
  3. McClanahan TR, Ateweberhan M, Muhando CA, Maina J, Mohammed MS (2007). EFFECTS OF CLIMATE AND SEAWATER TEMPERATURE VARIATION ON CORAL BLEACHING AND MORTALITY. Ecological Monographs 77:503-525. DOI