Chagos Archipelago - Salomons Island (BISA98)

General benthic features

Assemblage composition from transect data. The transect records nine genera, and the reef is Acropora-led but not Acropora-only: Acropora 38.0% of the benthos (53.5% of live coral), Montipora 12.0% (16.9%), Pachyseris 7.0% (9.9%), Favia 4.0%, Porites 3.0%, then Goniastrea, Lobophyllia, and Montastrea at 2.0% each, and Astreopora 1.0%. H′ = 1.52, Simpson = 0.67, J′ = 0.69. The Montipora figure is the distinctive one — 12% of the benthos and 16.9% of live coral is a far larger plating/encrusting component than most Chagos sites carry, and with Pachyseris at 7% nearly a quarter of this reef's coral is plate-forming rather than branching or massive. Richness of 9 is third-lowest in the dataset, but see flag 2 — that number is not trustworthy. Algae and substrate. Total algae is 20.0% — second-lowest of these eight sites — split evenly between CCA 7.0% and erect algae 7.0% (35% each), with plain turf 5.0% and macroalgae 1.0%. Sediment-laden turf and cyanobacteria both read exactly zero, one of a handful of sites in the survey with no sediment-turf at all. Bare substrate 9.0%, pavement 21.0%, and sand, rubble, and non-coral invertebrates (PITS) all read zero. A high-cover, low-algae, CCA-and-erect-algae forereef with essentially no sediment signal.

Coral cover

The 71.0% headline is 71 points out of 100 on one transect. Coral cover: 71%. Live hard coral measured on the in situ benthic transects of the LOF BIOT-1 expedition (Mayfield & Dempsey 2026, Oceans, supplemental S1), against algal cover of 20% of the benthos. The transect figure is this site's authoritative cover value; no image-derived product overrides it.

Stressors

Dead coral is 8.0%, recently dead 0% — above the dataset mean of 4.55% but far below BIPB71's 15.67%. No crown-of-thorns starfish (COTS) or other corallivores evident.

Comparisons with other data

No independent survey was made at this exact site; the nearest ones are listed in the table below.

Other notes

Replication — the site's central weakness, and it is severe. BISA98 rests on one transect, one depth stratum (D4), 100 points, one of only two single-transect sites in the dataset (the other is BIDI11, also in this pass). Every figure above is one 100-point read — hence the whole integers — and no standard deviation, depth profile, range, or confidence interval can be given for any of them. Marked `Training`. Exactly what a single short transect on a high-cover reef would produce. Among its neighbors, BISA98 is the only Salomon forereef above 40% — the other five run 25–39% on 24–34 genera each — making it doubly anomalous: far higher in cover and far poorer in recorded genera than every comparable reef on the atoll.