Saudi Red Sea - Anderson's Reef-I (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)Anderson's Reef-I is a well-built stand of tall coral pinnacles off Jeddah, pocilloporids crowding the flanks in the photographs beneath large corymbose and staghorn Acropora stands with clean white growing tips. This August 2024 visit recorded just 17% of coral tissue bleached.
شعاب أندرسون-I مجموعة متقنة البناء من القمم المرجانية الشاهقة قبالة جدة، تظهر البوسيلوبوريات في الصور مزدحمة على جوانبها تحت تجمعات كبيرة من Acropora العنقودية وقرون الأيل ذات أطراف النمو البيضاء السليمة. وسجّلت هذه الزيارة في أغسطس 2024 ابيضاض 17% فقط من نسيج المرجان.
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.
One other CRD dive site with its own page within 5 km shown in orange — click a marker to open its page.
5 of the 21 photographs on this page are shown beside the text that discusses them under "Site description" below.
Site description
General benthic features
The reef is a set of tall coral pinnacles and buttressed ridges rising from sand into blue water, and the frames read genuinely well-built (e.g., Image 1).
Lavender, dusty-rose, and pale-blue pocilloporids crowd the pinnacle flanks in Anderson's frames; large corymbose and staghorn Acropora stands sit on the shoulders in warm tan and cream with clean white growing tips; golden-brown Millepora-type fire coral fans off the crest against open blue; smooth blue-gray Porites lobes, big gray-green faviid domes, and encrusting Montipora-type sheets fill the gaps; and cream and khaki soft corals with polyps extended soften the edges (e.g., Image 2, Image 3, Image 4).
A giant clam (Anderson's identification) with an olive-green mantle sits recessed into the pavement between pale-blue Acropora colonies.
Coral cover
- Reference: Mayfield (2025)
- Data file: (Mayfield, 2025-appendix A)
- CoralNet submission package (accession #5546)
- 23% ± 15% SD across 146 photographs.
- The visit recorded 23% cover with 17% of coral tissue bleached at about 11.9°C-weeks DHW on the survey date (3 August 2024; NOAA Coral Reef Watch, Madinah-Makkah (Saudi Arabia) virtual station).
Stressors
One of Anderson's frames shows a pale, bleaching table colony beside pigmented ones (e.g., Image 21).
Fish and other fauna
Red anthias hang over the crest in clouds.
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, Khalil et al. (2017), 4.35 km away, read a mean of 31% in 2013.
Dive record
The first of the two 3 August 2024 dives off Jeddah with Al-Haddad SCUBA, on the pair of reefs that carry Anderson's name on this map.
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, 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) | 22.7 | |
| In-house DINOv3 | too few photos (n=1) | |
| CoralSCOP edited | 29.3 | n = 147 |
| Claude (edited photos) | 20.0 | n = 146 · SE 1.1 |
The two computer-vision methods differ by 9.3 pp (20.0–29.3%) and read within 6.6 pp of the published point count (22.7%); 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).
In-house DINOv3: this method was run on 1 of 147 photos, under the 10 needed for a value, so it is not shown and is left out of any mean; every other row rests on its own photo count.
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 2013. The most recent nearby survey is from 2013, so these values predate recent heat stress. This site's own estimate (23%) is not compared with these surveys: none lies within 2 km.
Collected by other programs using different methods, 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 | Link |
|---|---|---|---|---|---|
| Khalil et al. (2017) | — | 2013 | 31% (2 records) | 4.35 km | doi:10.7717/peerj.3410 |
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.
References
- Khalil MT, Bouwmeester J, Berumen ML (2017). Spatial variation in coral reef fish and benthic communities in the central Saudi Arabian Red Sea. PeerJ 5:e3410. DOI
- Mayfield AB (2025). Using Tourist Diver Photos to Assess the Effects of Marine Heatwaves on Central Red Sea Coral Reefs. Environments 12:248. PDF