### BISA106 — Salomon
**CRD page:** [Salomon Islands Coral Survey Sites (Apr 26–30, 2015)](https://coralreefdiagnostics.com/salomon-20150426-to-0430)

**29 Apr 2015**
**GPS:** 5.34425°S, 72.20390°E
**Setting:** protected submerged forereef, outside the lagoon, 20.5 m — **the published reef-type cell is blank for this site** (see Flags); the CRD Salomon page calls it a barrier forereef
**Coral cover:** 46.0% (10 formal transects, D1–D5; **algal cover 38.1%**) · **published image bleaching:** the `Mean(%bleaching)` cell is blank for this site — no value exists, and none may be inferred
**Live hard coral cover across methods:** formal transects 46.0% · CoralNet points — none · Coralscapes masks — none. **No imagery exists for BISA106, so neither computer-vision product was ever generated and no multi-method comparison is possible here.** Where those products do exist elsewhere in Chagos they carry different sampling footprints and denominators from the transects and should not be averaged with them; at this site the transect figure stands alone — and it is the best-supported transect figure of the seven photo-less Chagos sites.
**Temperature:** 30.5 °C · **Salinity:** 34.3
**Photo review:** **none — no photographs exist for this site anywhere.** **Anderson did not dive here**; the CRD Salomon page states "I did not dive at this barrier forereef", the published site table's `submitted to CoralNet?` column reads **"no photos"**, and the supplement's `formal vs. informal comparison` sheet flags it **"did not dive"**. No folder resolves to site number 106 under any prefix or casing; the site returns zero photo directories and zero frames. **Everything below therefore rests on transect point counts alone, and reef condition at BISA106 cannot be assessed** — bleaching, tissue loss, disease, predation scarring, COTS, fish and macrofauna are all simply *unavailable*, and must never be read as zero or inferred from neighbouring Salomon sites.

BISA106 sits about two kilometres from BISA98 and three days later in the survey, and the two are near-opposites in what they can support. Ten formal transects across **all five depth strata, 4,200 points** — top-effort-quartile sampling — give **46.0% live coral against 38.1% algae: 33rd of 109 Chagos sites for coral cover and 60th of 109 for algal cover**, above the archipelago's coral mean of 37.9% and seventh of the fourteen Salomon sites (atoll mean 43.4%). Bare substrate is 5.78% and non-coral invertebrates 10.1%. The raw ten-transect mean is 46.90% ± 7.99 SD over a **36–60% range — the tightest relative spread of the seven photo-less sites** (SD is 17% of the mean, against 42–48% at BITB48, BITB49 and BIEA17). **BISA106's value to the archive is not its cover but its reliability:** BISA98 offers an extreme number on one transect, BISA106 a mid-pack number on 4,200 points. The site is marked **`Validation`** in the published table (Validation = 1), one of 37 so assigned.

It is also the most genus-rich site in this group, and the two facts are related. Transects record **28 nonzero genera — 35th of 109 sites for genus count** — with H′ = 2.16, Simpson = 0.80 and evenness J′ = 0.65. All values below are **percent of total benthos, not percent of coral**, and the 28 genus columns sum to 45.99%, matching the published cover figure exactly. ***Porites* leads at 18.26% of the benthos (39.7% of live coral)**, then ***Acropora* 7.37% (16.0%)**, ***Lobophyllia* 4.41% (9.6%)**, ***Goniopora* 2.85%**, *Pachyseris* 2.45%, *Favia* 1.87%, *Montipora* 1.59% and *Herpolitha* 1.44%, followed by a twenty-genus tail at 0.83% or less: *Favites*, *Fungia*, *Pavona*, *Goniastrea*, *Pocillopora*, *Heliopora*, *Turbinaria*, *Millepora*, *Leptastrea*, *Platygyra*, *Seriatopora*, *Merulina*, *Cyphastrea*, *Symphyllia*, *Alveopora*, *Physogyra*, *Astreopora*, *Galaxea*, *Coscinaraea* and *Blastomussa*. **The free-living fungiids are the distinctive element — *Herpolitha* and *Fungia* together at 2.20% of the benthos — alongside *Goniopora* and *Alveopora***, a suite more typical of sheltered soft-bottom settings than of an exposed forereef. That sits oddly against the "barrier forereef" label, and should be weighed with Flags 1 and 2 rather than resolved here.

**The depth profile shows almost no gradient in total cover and a very large one in composition — and it ends on a single transect that changes the reef entirely.** Coral cover runs D1 44.4%, D2 51.9%, D3 45.1%, D4 52.6%, D5 36.0%, with algae 48.6 / 38.7 / 38.9 / 38.4 / 26.0% — a flat, well-mixed profile with no systematic shallow-to-deep trend. Underneath that flatness the assemblage turns over completely. **D1 is the only *Acropora*-led stratum in the upper reef** (*Acropora* 16.00% of benthos, *Porites* 9.10%, *Lobophyllia* 7.10%, *Favia* 4.20%, 16 genera) over zero bare substrate and the site's heaviest CCA reading, 32.9%. From D2 down, *Porites* takes over and does not let go: **D2 *Porites* 23.10% with *Lobophyllia* 8.10%, *Goniopora* 5.50% and *Acropora* fallen to 5.00%** (18 genera); **D3 *Porites* 14.40%, *Goniopora* 6.87%, *Lobophyllia* 5.07%, *Herpolitha* 2.60%, *Acropora* down to 1.73%** — 22 genera, the site's most diverse stratum, and the one where *Heliopora* and *Millepora* appear at 1.33% each. **D4 is the extreme: *Porites* alone at 41.70% of the benthos — 79% of all the coral on that stratum — with nothing else above 2.80%** (17 genera). Then **D5 inverts the whole reef: *Acropora* returns at 13.00% and *Pachyseris* jumps from 0.10% to 12.00%, with *Montipora* 6.00% and *Porites* collapsed to 3.00%, on just six genera** and the lowest algal cover of the profile (26.0%). **The site-level order — *Porites* first at 18.26%, *Acropora* second at 7.37% — describes no single stratum**: it averages a shallow *Acropora* fringe, a three-stratum *Porites* core that peaks at near-monodominance, and a deep *Acropora*/*Pachyseris* plate zone. **D5 is one 100-point transect** (see Flag 3), so that final inversion — the most striking feature of the profile — is the least supported part of it.

The algal budget is CCA-dominated and almost sediment-free. Of 38.1% total algae, **crustose coralline algae is 21.13% — 55% of all algae, and 15th of 109 sites**, well above the archipelago's middle. Plain turf follows at 8.45% (66th of 109), macroalgae 4.88%, cyanobacteria 1.65%, erect algae 1.46%, and **sediment-laden turf just 0.56%**, a fraction of the archipelago's typical value and reading exactly zero at D1, D2 and D5. A CCA-dominated, sediment-free floor under 46% coral is a well-grazed signature. Across the ten transects pavement averages 46.2%, sand 2.22%, rubble 2.06%; **dead coral averages 2.46% (range 0.2–11%) and recently dead 0.16% (maximum 0.8%) — among the lowest mortality readings of the seven photo-less sites.** With no imagery, none of this can be checked visually.

<b>Assemblage composition.</b> Ten transects across five strata and 4,200 points give 46.0% coral against 38.1% algae on 28 nonzero genera, led by *Porites* (18.26% of benthos, 39.7% of coral), *Acropora* (7.37%, 16.0%) and *Lobophyllia* (4.41%, 9.6%), over a CCA-dominated floor with almost no sediment-laden turf. Total cover is nearly flat across D1–D5 while the assemblage turns over completely — an *Acropora* fringe at D1, a *Porites* core through D2–D4 peaking at 79% of stratum coral at D4, and an *Acropora*/*Pachyseris* plate zone on six genera at D5. The presence of *Herpolitha*, *Fungia*, *Goniopora* and *Alveopora* reads more sheltered than the "barrier forereef" label implies, and the published reef-type cell is blank. **There is no photographic record whatsoever, so none of this can be corroborated visually and no statement about the reef's condition — bleaching, mortality, disease, predation or fauna — is possible at BISA106.**

**Flags:** (1) **THE PUBLISHED REEF-TYPE CELL IS BLANK.** Both `reef type` and `reef type-simplied` are empty in `Chagos benthic data by site (n=109).csv` — **the only one of the seven photo-less sites with a missing reef type.** The CRD page's "barrier forereef" is used above and is consistent with the sheet's `reef location` = forereef, `lagoon` = outside and `reef emergence` = submerged, but **no reef class may be invented for the blank cell.** Recommend backfilling. (2) **THE ASSEMBLAGE DOES NOT READ LIKE A FOREREEF.** Free-living fungiids (*Herpolitha* + *Fungia*, 2.20% of benthos combined) plus *Goniopora* and *Alveopora*, on a `protected` exposure with no depth gradient in total cover across D1–D5, suit a sheltered or back-reef setting better than a barrier forereef. This may be why the cell was left blank. **Anderson's judgement needed** — do not assert a reef type beyond what the CRD page states. (3) **D5 RESTS ON A SINGLE 100-POINT TRANSECT.** Site cover is the unweighted mean of the five stratum means, so **that one transect carries a full 20% of the 46.0% headline**, and it is also the only evidence for the site's most striking compositional feature — the deep *Acropora*/*Pachyseris* inversion and the six-genus collapse. Transect counts by stratum are D1 = 2, D2 = 2, D3 = 3, D4 = 2, D5 = 1. Treat the D5 result as indicative only. (4) **NO PHOTOGRAPHS EXIST AND ANDERSON DID NOT DIVE HERE.** Zero photo directories resolve to site number 106; `submitted to CoralNet?` reads "no photos"; the comparison sheet reads "did not dive". There are therefore no CoralNet points, no Coralscapes masks, no multi-method comparison, and **no basis for any condition assessment** — bleaching, disease, predation, COTS and fauna are unavailable, not zero. (5) **THE PUBLISHED `Mean(%bleaching)` CELL IS BLANK.** BISA106 appears in `formal vs. informal comparison` only as a placeholder row keyed under `site code 2`, with no cover, bleaching or image count. **% bleached is unavailable and must not be computed from anything else.** Corpus-wide the published bleaching figure is a **computer-vision product** rather than an in-situ observation, with per-image human-vs-model agreement of r = 0.40 for bleached against r = 0.72 for live hard coral (`CHAGOS_MULTIMETHOD_README.md`) — but here there is no figure at all to caveat. (6) **POINT-COUNTS ARE MIXED AND UNWEIGHTED** — eight 500-point and two 100-point transects, 4,200 points total, pooled without effort weighting. The two 100-point transects are `BISA106_d3_T3` and `BISA106_d5_T1`, and the latter is the sole D5 transect, compounding Flag 3. (7) **Integrity checks pass:** the 28 genus columns sum to 45.99% against a published 45.9933%; the six algal categories sum to 38.13% against a published 38.1267%. Both reconcile within rounding, with no unexplained shortfall. (8) **Depth is published as 20.5 m at site level but only as strata D1–D5 in the depth table — no per-stratum metre values exist**, so the D1→D5 turnover described above cannot be tied to absolute depths. (9) **This is the strongest evidence base of the seven photo-less sites** (4,200 points, five strata, SD 17% of the mean, marked `Validation`); where a single trustworthy transect-derived cover figure is needed from this group, it is this one.

**Benthic data:** [Download BISA106 benthic survey data (CSV)](../benthic_data/BISA106_benthic.csv) — scleractinian cover by genus with full names, plus substrate and algal categories (bare substrate, CCA, turf, sediment-laden turf, macroalgae, erect algae, non-coral invertebrates), from the LOF BIOT-1 survey (Mayfield & Dempsey 2026, *Oceans*, supplemental file S1).