Chagos Archipelago - Peros Banhos (BIPB69)

Setting

BIPB69 is a leeward lagoonal pinnacle reef inside Peros Banhos (branching coral dominated on the LOF habitat map), with three dives here on 16 April 2015 (to 28.1 m), 17 April (26.2 m), and 2 May (28.7 m) (e.g., Image 1, Image 4).

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General benthic features

Across 25 genera, Acropora holds 84% of all coral and Echinopora is a distant second at 4.1% (e.g., Image 2, Image 8).

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Coral cover

• Reference: Mayfield & Dempsey (2026)
• CoralNet submission package
• It recorded 73% living coral against 20% algae (e.g., Image 3).
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• Transect mean 73 ± 3.3% SE (n = 22 transects; Living Oceans Foundation per-transect benthic data); the headline above is this all-transect mean, and the published station value, which weights each depth equally, is 65% (Mayfield & Dempsey 2026, Oceans, suppl. S1).
• The depth profile is a clean handover: a near-monospecific tabular Acropora stand at the two shallow strata, 75% and 78% cover with Acropora at 96% and 86% of their coral, giving way to a deepest stratum at 45% cover where Echinopora takes over outright at 60% of the coral and Acropora falls to 10% of the benthos — though that stratum rests on a single transect (e.g., Image 7, Image 9).
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Stressors

The site was dived three times, and the bleaching record tracks the event: 0% on 16 April, 12.1% on 17 April, and 36.5% on 2 May (CoralNet analysis of the survey images; Mayfield & Dempsey 2026, suppl. S1). The May photographs show a mosaic sorted by growth form rather than a uniform whitening, with white tables, massive colonies, and some branching colonies beside vast branching stands still in full dark pigment (e.g., Image 5).

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No crown-of-thorns or predation was seen and no disease was evident in the photographs, though Anderson's sampling sheet notes two colonies on the 2 May dive as possibly diseased. Anderson's sampling sheet records 29 colonies sampled here at 6.2–28.5 m: eight Pocillopora acuta and five P. damicornis by RFLP; 15 Seriatopora hystrix by field call; one Pocillopora sp. sampled for a collaborator (field calls); the condition notes run from healthy to >90% bleached, with some possibly diseased or partly dead colonies. Pocillopora acuta colonies from this archipelago were analyzed in Thomas et al. (2026, Global Ecology and Biogeography 35:e70305, https://doi.org/10.1111/geb.70305). The Living Oceans Foundation transects here recorded 0.1% cyanobacteria and 0.2% recently dead coral.

Comparisons with other data

Apart from the Living Oceans Foundation survey shown here, we found no other surveys at this site as of 2026. If you would like to share yours, please email us.

Other notes

Reef type follows the LOF habitat map: the pin sits inside 'lagoonal pinnacle reefs - branching coral dominated'; a lagoon pin has no rim facing. Anderson's field sheet (LOF fellowship 2016 workbook) records 'lagoonal patch reef', 'leeward'; the expedition's 933-site table classes the station as 'protected' (patch reef).