Saudi Red Sea - Shark Reef (Thuwal)

General benthic features

The reef is a steep buttressed slope of large massive corals — knobby and columnar Porites and other domed and encrusting massives — over consolidated pavement, with pocilloporids and branching Acropora in the shallows and undercuts holding bluestripe snapper and moray eels (e.g., Image 2, Image 5).

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Coral cover

• Reference: Mayfield (2025)
• Data file: (Mayfield, 2025-appendix A)
• CoralNet submission package (accession #5546)
• 16% ± 16% SD across 421 photographs.
• The site record carries the two visits separately: 16% cover with 73% of coral tissue bleached on 31 August 2024 at 20.6°C-weeks DHW on the survey date (31 August 2024; NOAA Coral Reef Watch, Madinah-Makkah (Saudi Arabia) virtual station) and 33°C, and 16% cover with 71% bleached on 14 September 2024 at 21.8°C-weeks and 31°C.
• Cover barely moved between visits; the tissue underneath it was in crisis on both.

Stressors

The photographs leave no room for interpretation. In wide-angle frame after wide-angle frame the dominant color is white: whole slopes where the majority of visible colonies are stark, uniform, glowing white from top to bottom, running out of the frame in both directions (e.g., Image 3, Image 8, Image 9).

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Anderson's field notes for this dive record severe bleaching; bleached pocilloporids, corals, and anemones; bleaching Porites; and dead and dying coral, among it dead Acropora, a mostly dead acroporid, pocilloporids that were nearly dead or dead, and dead coral covered in algae. And there are crown-of-thorns here: three separate Acanthaster individuals photographed amid bleached and dying coral, one on 31 August and two different ones on 14 September, a gray-green one on open rubble (e.g., Image 1) and a reddish-brown one in a crevice among bleached massives.

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Pink-lavender colonies in Anderson's frames from both days (e.g., Image 21, Image 18), including one noted as a nearly dead pocilloporid (e.g., Image 22), are fluorescent (colorful) bleaching.

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In one 14 September frame a rust-orange cyanobacterial mat is overgrowing dead coral framework (e.g., Image 23).

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Fish and other fauna

Two giant clams sit among bleached colonies (e.g., Image 5), and a blue-spotted stingray was photographed on the 14 September dives (e.g., Image 24).

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Comparisons with other data

Aeby et al. (2021) surveyed a nearby station (Qita al Kirsh) in 2015, 0.36 km from the pin. Within 5 km, three independent stations recorded station-year means of 23–60% hard coral cover between 2010 and 2015; the nearest, Monroe et al. (2018) at Midshelf reef 2, 0.36 km away, read 37% in 2015.

Dive record

Two logged dives on 14 September 2024 (the 31 August visit is not in the log) at the peak of the 2024 Red Sea bleaching event, worked with Coastline (KAUST).