Saudi Red Sea - Bhadur Reef (Jeddah)
Part of the regional summaries: Saudi Arabia - Jeddah / KAUST (Thuwal) / Rabigh, Saudi Arabia, and Red Sea
More info
Al Madinah and Makkah (NOAA CRW virtual station)Bhadur Reef sits directly off the Jeddah waterfront and was surveyed at an accumulated heat stress of 22.3 DHW. The bleaching here hit the whole community at once, not just hard corals: massive Porites, soft corals, and anemones were all found bleached together, with 62% of coral tissue bleached and many branching colonies showing colorful (fluorescent) bleaching, even as the reef kept functioning as habitat for nudibranchs, a blue-spotted ray, and anemonefish.
تقع شعاب بهادر مباشرة قبالة واجهة جدة البحرية، ومُسحت عند إجهاد حراري متراكم قدره 22.3 DHW. وضرب الابيضاض هنا المجتمع كله دفعة واحدة، لا المرجان الصلب وحده: وُجدت Porites الكتلية والمرجانيات اللينة وشقائق النعمان جميعها مبيضّة معًا، مع ابيضاض 62% من نسيج المرجان وظهور الابيضاض الملوّن (الفلوري) على كثير من المستعمرات المتفرعة، بينما ظلت الشعاب تؤدي دورها موئلًا للبزاقات البحرية العارية واللخمة ذات البقع الزرقاء وأسماك المهرج.
ترجمة هذا الملخص بالذكاء الاصطناعي؛ النص الإنجليزي هو المعتمد.
One independent survey station shown with the program’s logo — click one to see how far it is from this site.
7 of the 23 photographs on this page are shown beside the text that discusses them under "Site description" below.
Site description
General benthic features
Structurally the reef is a moderate-relief slope of large massive bommies over rubble and coralline pavement, with pocilloporids, corymbose and staghorn Acropora, faviids, soft corals, and free-living fungiids scattered across it, dropping into hazy inshore blue (e.g., Image 2).
A steel dive-training structure stands on mesh-paved sand at the reef base, and a smaller rusted frame nearby, now colonized by soft corals, is presumably part of the same training area (photos not shown).
Coral cover
- Reference: Mayfield (2025)
- Data file: (Mayfield, 2025-appendix A)
- CoralNet submission package (accession #5546)
- 21% across 222 photographs (± 17% per-photo standard deviation).
- The visit recorded 21% cover with 62% of coral tissue bleached at about 22.3°C-weeks DHW on the survey date (7 September 2024; NOAA Coral Reef Watch, Madinah-Makkah (Saudi Arabia) virtual station).
Stressors
Anderson's field notes inventory the damage: total bleaching, fully bleached Porites, a stark-white pocilloporid, bleaching mushroom corals, dead acroporids, and dying pocilloporids, some already dead (e.g., Image 3, Image 4).
What the frames record is a whole community bleaching at once: white and pink-lavender branching corals and white massive colonies (e.g., Image 1), as well as bleached soft corals (e.g., Image 21, Image 22) and white anemones with anemonefish (e.g., Image 23, Image 21).
Many branching colonies are vivid lavender, pink, electric-blue, or lime rather than white: colorful (fluorescent) bleaching.
Fish and other fauna
Two brightly pigmented nudibranchs and a blue-spotted ray were seen on the same dives — the reef was still functioning as habitat while its corals were white.
Comparisons with other data
Apart from our own published survey shown here, we found no other surveys at this site as of 2026. Within 5 km, one independent station, Reef Check at Sheraton, KSA, 3.16 km away, read 11–12% between 2024 and 2025.
Dive record
Two dives on 7 September 2024 with Saudia SCUBA on a reef in front of the Jeddah waterfront at the peak of the 2024 Red Sea bleaching event.
CV model comparison
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, 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) | 21.3 | |
| CoralSCOP edited | 27.3 | n = 167 |
| Claude (edited photos) | 18.4 | n = 174 · SE 1.2 |
The two computer-vision methods differ by 8.9 pp (18.4–27.3%) and read within 6.0 pp of the published point count (21.3%); 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.
Independent surveys nearby
Within 5 km, 1 independent survey station recorded hard coral cover in 4 surveys between 2024 and 2025. The one station surveyed in more than one year declined by 1.0 points between its first and latest surveys. The longest record, Sheraton, KSA (Reef Check, 3.16 km away), went from 12% in 2024 (mean of 2 surveys) to 11% in 2025 (mean of 2 surveys). Since 2021, station-year means average 12% (range 11–12%; n = 2 station-years from 4 surveys). This site's own estimate (21%) is not compared with these surveys: none lies within 2 km.
Collected by other programs using different methods (Reef Check uses point-intercept transects), so these are context for the figures above, not a like-for-like comparison. Where a station was surveyed more than once, the cell shows either the range of its values or, as a single value, the mean of surveys made in one year. Station names are not dive-site names.
| Agency | Site / location | Date | Hard coral cover (%) | Distance |
|---|---|---|---|---|
| Reef Check | Sheraton, KSA | 2024–2025 | 11–12% (range of yearly means; 4 surveys) | 3.16 km |
Data & links
All images from Coral Reef Diagnostics. Data are from Coral Reef Diagnostics and the organizations named in the data sources above.
© Coral Reef Diagnostics.