Kenya - Coral Garden (Kisite National Park)

Setting

Across the 161 reviewed frames (179 analyzed; 160 on file) the water is clear, 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).

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At closer range the same carpet is a broad pinkish-mauve knuckled field. 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).

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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 wide set also shows 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

• Reference: Mayfield (2025)
• Data file: (Mayfield, 2025-Supplemental File S1)
• CoralNet submission package (accession #4963)
• This is what 55% cover looks like.
• Coral cover 55% — and 59% 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

Here the healthy-versus-bleached contrast is 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).

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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. 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 59% 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 (not shown) is a close-up of a pigmented brown massive colony crossed by bands of bare skeleton carrying a green algal film. A sharp white advancing margin, where tissue is being lost against otherwise fully colored tissue, marks a tissue-loss lesion; the colony itself had not bleached. Anderson's 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. Typical recent thermal stress: mean annual maximum of 5.1 degree heating weeks (2021-2025, NOAA CRW; Tanzania virtual station, whose polygon covers the Kisite-Mpunguti area). Seawater here was an estimated 31.5°C during the survey (read from the TG7 underwater camera and not validated, per Mayfield 2025, Environments 12:276, Table 1; the Kenya survey-wide mean of 32.0°C matched the 1998 event), and NOAA's Kenya virtual station recorded a peak of 13.5 degree-heating weeks on 18 April 2024, a level not reached there before in records going back to 1985; the Tanzania virtual station that covers this reef peaked at 16.0 on 16 April 2024. For the 2024 Kenya survey as a whole, Mayfield (2025, Environments 12:276) estimated that in situ temperatures ran about 1.3°C above NOAA's, so that "nearly 22 DHWs may actually have transpired"; those in situ readings came from the TG7 underwater camera and have not been validated.

Comparisons with other data

Karisa et al. (2020) surveyed this site (Coral Gardens, Kisite National Park) in 2015, 0.09 km from the pin. Within 5 km, thirteen independent stations recorded hard coral cover between 1998 and 2020: six by benthic survey, station-year means of 0.0–53%, and seven by MERMAID bleaching-protocol quadrats, station-year means of 21–56%; the nearest of these, REEFolution Foundation at Kisite 2, 0.26 km away, read 29–48% between 2017 and 2018.

Dive record

Dived 21 Mar 2024 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.