### BISA105 — Salomon
**CRD page:** [Salomon Islands Coral Survey Sites (Apr 26–30, 2015)](https://coralreefdiagnostics.com/salomon-20150426-to-0430)

**29 Apr 2015**
**GPS:** 5.33426°S, 72.24311°E
**Setting:** protected submerged lagoonal patch reef, 25 m
**Coral cover:** 50.3% (3 formal transects, D2–D4; **algal cover 26.6%**) · **published image bleaching:** 5.6%
**Live hard coral cover across methods:** formal transects 50.3% · CoralNet points 17.4% · Coralscapes masks 16.2% (19 frames). These products have different sampling footprints and denominators and should not be averaged — see Flag 1, the disagreement here is the largest in the Chagos set.
**Temperature:** 30.5 °C · **Salinity:** 34.2
**Photo review:** all 25 frames examined
**Representative photos:** P4290915.jpg, P4290882.jpg, P4290914.jpg, P4290857.jpg, P4290850.jpg

BISA105 is a high-cover, high-diversity lagoonal patch reef — 50.3% transect coral cover, 23rd of the 109 Chagos sites, carrying **24 non-zero coral genera** — and it is emphatically not an *Acropora* reef. ***Porites* leads at 14.50% of the benthos**, followed by ***Lobophyllia* at 10.83% and *Goniopora* at 8.92%**, an unusual pairing that together with *Porites* accounts for 68% of all coral recorded. *Pavona* follows at 4.25%, *Acropora* only fifth at 3.00%, then *Favia* 1.75%, *Goniastrea* 1.17% and *Hydnophora* 0.83%. A ten-genus tail below 0.5% includes *Echinopora*, *Ctenactis*, *Physogyra*, *Astreopora*, *Turbinaria*, *Alveopora*, *Galaxea*, *Montastrea*, *Montipora* and *Platygyra*. Bare substrate holds 13.8% of the benthos, macroalgae 11.2%, non-coral invertebrates 9.2%, turf 7.7% and crustose coralline algae 7.5%.

**The depth structure is a clean handover between the three lead genera.** D2 carries 55.0% coral and is the *Lobophyllia* band — 16.50%, with *Pavona* 9.75% and *Goniopora* 5.75% — and is also the richest at 19 genera. D3 holds 54.0% and inverts to ***Goniopora* at 21.00%** with *Porites* 13.50% and *Lobophyllia* 9.50%, on the site's lowest algal cover of 10.0%. D4 falls to 42.0% and becomes a *Porites* reef outright at **27.00%**, with algal cover rising sharply to 47.0% and richness dropping to eight genera. The site-level 14.50% *Porites* figure is therefore the average of a band where it is absent from the top three and one where it holds better than a quarter of the benthos.

The characteristic architecture is a sequence of coral-capped blocks and pinnacles separated by narrow sediment pockets. P4290850 and P4290857 show plates projecting from older framework and massive colonies stacked above one another. P4290881 and P4290882 show convoluted surfaces with deep crevices providing shelter and shaded microhabitat. P4290915 emphasises a pinnacle rising into clear blue water, massive heads around the upper relief and branching colonies along exposed edges. The prominence of massive, lobate and mound-forming colonies in these frames is the photographic counterpart to a *Porites*–*Lobophyllia*–*Goniopora* assemblage.

**Water clarity changes appreciably across the sequence.** Suspended material softens contrast in the first several frames, particularly P4290837 and P4290838, and some surfaces appear muted or gray from distance and backscatter; later images use closer illumination and stronger colour balance. Condition calls are therefore based on coherent tissue pallor across intact colonies rather than isolated bright patches. No quantitative turbidity value is supported by the photographs and none is reported.

Bleaching is localised but convincing. P4290914 shows a branching colony tucked beneath a ledge whose tissue is nearly uniformly white, fine branchlets intact, contrasting with surrounding brown macroalgae and pigmented encrusting surfaces. P4290915 shows two bright branching colonies on a pinnacle contrasting sharply with neighbouring brown and tan massive corals, and P4290916 gives another angle on pale branches. Other pale surfaces were deliberately excluded: strobe reflection brightens smooth massive colonies, and exposed skeletal patches and naturally pale growth tips can mimic bleaching. The published site figure of **5.6% ranks 64th of 98** — comparatively low, and consistent with bleaching that is present in several branching colonies without being a site-wide event.

Non-coral colour and texture are conspicuous. Bright magenta, red and orange encrusting patches occur on vertical faces and shaded recesses, and brown foliose or blade-like growth appears around the pale branching colony in P4290914. These are described morphologically because a still photograph cannot securely separate sponge, coralline algae and other encrusting taxa in every case, but they demonstrate that shaded and exposed microhabitats differ strongly across the outcrop. Small planktivorous fishes occur against blue water in P4290915 and darker reef fishes move among the crevices in earlier views; the frames are not standardised for fish abundance and no individual can be assumed unique across adjacent photographs.

<b>Assemblage composition.</b> Formal surveys give 50.3% coral, 26.6% algae and 9.2% non-coral invertebrates, the coral led by *Porites*, *Lobophyllia* and *Goniopora* in a depth-dependent order. The photographs document rugged pinnacles, stacked massive and plating colonies, narrow sediment pockets and colourful encrusted framework under variable visibility, plus localised bleaching in branching colonies.

**Flags:** (1) **This site has the widest multi-method cover disagreement in the Chagos set** — 50.3% by transect against 17.4% by CoralNet points and 16.2% by Coralscapes masks, a spread of 34 percentage points. Publishing "50.3%" alone materially overstates certainty. The likeliest cause is that the transects sampled coral-capped relief while the photographic products include the surrounding sediment pockets and flanks, but this has not been tested and should be before either figure is used in isolation. (2) **Frame-count mismatch:** the folder holds 25 stills and all 25 were reviewed, but `chagos_multimethod_cover_by_site.csv` records `n_photos = 19`. The CoralNet and Coralscapes percentages rest on the smaller set; never present "25 frames" beside those figures. (3) **Variable visibility across the sequence** limits colour-based condition calls in the early frames; only broad coherent pallor was flagged. (4) **The *Goniopora* signal rests largely on one transect** (21.00% at D3 against 5.75% at D2 and none in D4's top four). Treat the 8.92% site mean with caution. (5) No crown-of-thorns starfish was identified; no lesion with an advancing margin, disease band or tissue sloughing was visible; no focal feeding scar was unambiguous enough to record as predation. (6) **NON-CANONICAL BLEACHING RANK — added 2026-08-26.** Any "of 98" bleaching rank above was computed off the site table's `Mean(%bleaching)` column, which equals the **1st** CoralNet training run. Anderson's decision of 2026-08-26 (HOW_TO rule 4e) makes **`% bleaching (2nd training)` canonical**, The file carries TWO pools for it, and they are not interchangeable: a **110-row pool** ranking every dive (revisit dives included, so BIPB70B/72B/69C compete) and a **99-site pool** ranking one value per site. The rank quoted below is on the 110-row dive pool. For this site the canonical value is **5.65%, rank 72 of 110** (1st training: 5.65%, rank 71 of 110). The two runs agree to <0.05 pp on 100 of 110 rows and diverge only on the bleaching-onset dives, so for most sites the distinction changes the rank but not the number.

**Benthic data:** [Download BISA105 benthic survey data (CSV)](../benthic_data/BISA105_benthic.csv) — scleractinian cover by genus with full names, plus substrate and algal categories (bare substrate, CCA, turf, macroalgae, invertebrates), from the LOF BIOT-1 survey (Mayfield & Dempsey 2026, *Oceans*, supplemental file S1).