### BISA103 — Salomon
**CRD page:** [Salomon Islands Coral Survey Sites (Apr 26–30, 2015)](https://coralreefdiagnostics.com/salomon-20150426-to-0430)

**29 Apr 2015**
**GPS:** 5.34896°S, 72.26869°E
**Setting:** exposed emergent forereef, 32.4 m
**Coral cover:** 32.5% (3 formal transects, D2–D4; **algal cover 41.2%**) · **published image bleaching:** 24.1% — **4th-highest of the 98 Chagos sites carrying a bleaching value**
**Live hard coral cover across methods:** formal transects 32.5% · CoralNet points 18.6% · Coralscapes masks 18.0% (19 frames). These products have different sampling footprints and denominators and should not be averaged.
**Temperature:** 29.8 °C · **Salinity:** 34.3
**Photo review:** all 19 frames examined (one is a blue-light/fluorescence frame — see Flag 2)
**Representative photos:** P4290873.jpg, P4290853.jpg, P4290869.jpg, P4290885.jpg, P4290837.jpg

BISA103 is the deepest site in this batch at 32.4 m and, with BISA104 a kilometre to the north, one of the two most heavily bleached reefs in Salomon. Coral cover is 32.5%, 70th of the 109 Chagos sites, against 41.2% algae — but **published image bleaching is 24.1%, ranking 4th of 98**. The assemblage is broad, with **28 non-zero coral genera**. ***Porites* leads at 13.23% of the benthos** — 41% of all coral recorded — with the branching component carried by ***Stylophora* at 4.84% and *Pocillopora* at 3.59%**, an unusual pairing for Chagos. *Pavona* follows at 1.92%, *Goniastrea* 1.16%, *Acropora* only sixth at 1.11%, *Montipora* 1.09%, and *Gardineroseris* and *Favia* both at 0.82%. Sixteen further genera fall below 0.5%, including *Physogyra*, *Oulophyllia*, *Cantharellus*, *Oxypora* and *Hydnophora*. Non-coral invertebrates hold 21.1% of the benthos, crustose coralline algae 16.4%, turf 15.3% and bare substrate 5.3%.

**Coral cover falls by more than half from the shallowest band to the deepest.** D2 carries **47.4%** — a genuinely coral-abundant shallow reef, with *Porites* at **25.23%** and *Stylophora* at 7.73%, across 24 genera. D3 drops to 28.6% and *Porites* collapses to 6.60%, leaving *Stylophora* (5.88%) and *Pocillopora* (5.25%) nearly level with it. D4 falls again to **21.4%**, with *Porites* at 7.85% and algal cover at 39.8%. Genus richness declines with cover, from 24 to 22 to 19 codes. The 13.23% site-level *Porites* figure is therefore dominated by a single shallow transect and should never be quoted as a uniform value.

Reef architecture is moderate, with colonies set into older consolidated framework and separated by small sand or rubble pockets. Broad views show rounded massive colonies, compact branching clusters, low plates and encrusted surfaces rather than one continuous canopy. P4290868 and P4290869 are useful for the juxtaposition of branching and massive forms around open substrate, and P4290880 through P4290884 show repeated changes in colony scale and relief over a short route. The result is a heterogeneous habitat with many edges and crevices but markedly less vertical layering than the dense channel reef at BIPB110.

**Bleaching is visually prominent and matches the high published figure.** P4290853 contains several colonies at different degrees of pallor: one central branching colony has white branch ends and light tissue farther inward, while neighbours range from darkly pigmented to nearly white. P4290873 shows a large table- or foliose-like colony whose upper surface is coherently white, with intact corallite and plate structure still visible. Additional pale colonies occur in P4290883 through P4290888. The recurrence across both wide and close views makes bleaching the most parsimonious reading.

Not every pale feature is classified as bleaching. White branch tips can reflect active growth, bright illumination or normal interspecific colour, and some exposed skeleton is already dulled by sediment or overgrowth. The flagged examples were selected because pallor extends broadly across intact tissue and contrasts with nearby pigmented colonies. Small dark points on the large pale colony in P4290873 could be attached organisms, sediment or localised mortality, but they do not justify a disease diagnosis.

Several frames show fish close to the substrate, including small damselfish-like and surgeonfish-like silhouettes, but the sequence is not a fish census. The photographed benthos includes purple and red encrusting surfaces, brown algal growth and small mound-forming colonies, all adding texture and microhabitat diversity — the visible counterpart to a 21.1% non-coral invertebrate figure.

<b>Assemblage composition.</b> Formal surveys give 32.5% coral, 41.2% algae and 21.1% non-coral invertebrates, the coral *Porites*-led with a *Stylophora*–*Pocillopora* branching component and *Acropora* only sixth. The photographs show massive, compact branching and plating forms embedded in encrusted framework with small sand and rubble openings, and bleaching common and conspicuous across multiple frames.

**Flags:** (1) **Bleaching at 24.1% ranks 4th of 98.** The rank is computed from the published `Mean(%bleaching)` column, which carries at least one known bad value (BITB58 appears as 22.22% where the corrected figure is 0.77%), so the rank is approximate; the 24.1% is taken as published and is well corroborated photographically. (2) **P4290870 was made under fluorescence or blue-light illumination.** Its altered blue-green palette is not comparable with the white balance of the standard-light frames and **must be excluded from any colour-based condition scoring**, automated or manual. (3) **Cover halves with depth** — 47.4% at D2 against 21.4% at D4 — and the *Porites* signal rests overwhelmingly on the shallow transect. Do not quote the site mean without the depth breakdown. (4) **Photographic selection probably emphasises visually unusual white colonies**, especially in the close-ups, so image frequency is not unbiased prevalence; it is the pale colonies in the *broad* views that establish the signal is ecologically meaningful. (5) **The three cover methods differ by up to 14 percentage points** (32.5% / 18.6% / 18.0%). (6) No crown-of-thorns starfish was identified in any of the 19 stills; no disease band, advancing lesion edge or tissue sloughing was evident; no focal feeding scar had clear enough geometry or a visible predator to support a predation record. (7) **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 **24.05%, rank 9 of 110** (1st training: 24.05%, rank 7 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 BISA103 benthic survey data (CSV)](../benthic_data/BISA103_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).