Saudi Red Sea - north Rabigh (shore) (Rabigh)

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Part of the regional summaries: Saudi Arabia - Jeddah / KAUST (Thuwal) / Rabigh, Saudi Arabia, and Red Sea

Photo: Anderson Mayfield/Coral Reef Diagnostics

Country

Saudi Arabia

Survey date(s)

2024-08-16

Coordinates

22.9325, 38.8442

Approximate position.

Coral cover

24%

Published point count (Mayfield 2025; CoralNet-assisted, 173 photos) · details below

Coral bleached

65%

of coral tissue · Mayfield (2025), Environments 12:248

Observations

bleaching

Heat stress

Most recent heat load record

33.0°C 12.9°C-weeks

26 Oct 2026 · Alert Level 2

5-year thermal stress load

5-year mean max. degree heating weeks (DHW)

14.3°C-weeksⁱ

2021–2025

NOAA Coral Reef Watch — Al Madinah and Makkah 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 info

Al Madinah and Makkah (NOAA CRW virtual station)

Photographs

168

24 shown on this page; 175 analyzed

Site summary

Read this summary in:

This shore-entry reef north of Rabigh was surveyed at the height of the 2023-24 Red Sea bleaching event: much of the shallow branching and plate coral is stark bone-white, standing over darker, still-pigmented massive colonies, while some massive domes show blotchy partial bleaching with algae already creeping into dead margins. Published cover is 24% with 65% of coral tissue bleached.

Water temp. during survey

35.0°Cⁱⁱ

+5.9°C vs the 2024 mean sea temperature (29.1°C)

ii Published dive temperature (Mayfield 2025, Environments 12:248, Appendix A).

More info

Note: NOAA's regional station series averages 2.1°C warmer than the satellite pixel nearest this site (2.1 km away), which is used here instead.

8 of the 24 photographs on this page are shown beside the text that discusses them under "Site description" below.

Photo credit & attribution

Site description

Setting

A shore-entry reef north of Rabigh on the central Saudi Red Sea coast, surveyed 16 August 2024 during the 2023-24 Red Sea bleaching event.

General benthic features

Away from the crest, isolated colonies sit on open carbonate sand, and turf-covered rubble separates surviving heads (e.g., Image 4).

Coral cover

Reference: Mayfield (2025)
Data file: (Mayfield, 2025-appendix A)
CoralNet submission package (accession #5546)
Published CoralNet point counts put total coral cover here (bleached corals included) at 24% with 6% algae, and 65% of coral tissue bleached at about 16.9 degree-heating-weeks.
That figure is the published CoralNet point count from Anderson's own paper (most frames annotated by CoralNet's AI, trained and checked by the author).
This figure carries the provenance of the paper it appears in and is not subject to the CoralSCOP/DINOv3 caveats applied elsewhere on this map.

Stressors

The photographs are a bleaching record first and a habitat record second. The crest is a shallow, wave-washed pavement almost at the surface, and much of the branching framework in the frame is stark bone-white — fully bleached branching and plate colonies standing over darker, still-pigmented massives (e.g., Image 1).

Massive colonies tell the same story more slowly: one dome is uniformly lilac-pale with two large patches of freshly exposed skeleton already fouling brown, another green-tinged massive is bleaching in blotches with algal turf creeping into the dead margins (e.g., Image 2, Image 3).

Vivid blue, pink, and yellow colonies in Anderson's 16 August frames are fluorescent (colorful) bleaching (e.g., Image 2, Image 3, Image 21).

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

Fish and other fauna

Anderson's photographs also record stingrays (e.g., Image 22, Image 23) and a turtle (e.g., Image 24).

Comparisons with other data

Al-Sofyani et al. (2014) surveyed Rabigh Reef; we could not confirm that it is the same reef. If you have survey data from this site to share, please email us.

CV model comparison

Computer-vision estimates from this site's own photographs are listed in the comparison table below, alongside the headline rather than merged into it.

Headline is the reference value; every other row is listed beside it for comparison and none is averaged in.

More info

The reference is this dive site's own published CoralNet point count by the author (Mayfield 2025, Environments 12:248, Appendix A; most frames annotated by CoralNet's AI, trained and checked by the author). The computer-vision rows are this site's own values: Claude is a blind point count of all of the site's edited photographs, DINOv3 ran on the site's benchmark frames (the photographs the author annotated point by point), and CoralSCOP is the site's finished survey of its edited photographs. They are on different frame sets from the published count, a row under 30 frames is indicative only, and no computer-vision method yet estimates coral cover accurately on new images.

Method	Hard coral cover (%)	Photos (n) ± SE
Published point count (CoralNet-assisted)	23.6
In-house DINOv3	56.5	n = 175
CoralSCOP edited	29.9	n = 122
Claude (edited photos)	22.6	n = 158 · SE 1.2

The three computer-vision methods disagree by 33.9 pp (22.6–56.5%) and read on both sides of the published point count (23.6%); the headline is the published point count because it is the site's published value (CoralNet-assisted: most frames were annotated by CoralNet's AI, trained and checked by the author).

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

Data & links

All images from Coral Reef Diagnostics. Data are from Coral Reef Diagnostics.

References

Mayfield AB (2025). Using Tourist Diver Photos to Assess the Effects of Marine Heatwaves on Central Red Sea Coral Reefs. Environments 12:248. PDF
Al-Sofyani AA, Marimuthu N, Wilson JJ (2014). A rapid assessment of scleractinian and non-scleractinian coral growth forms along the Saudi Arabian coast, Red Sea. Journal of Ocean University of China 13:243-248. DOI