### BISP95 — Speaker's Bank
**CRD page:** [Speaker's Bank Coral Survey Sites](https://coralreefdiagnostics.com/speakers-bank)

**26 Apr 2015**
**GPS:** 5.04994°S, 72.28725°E
**Setting:** protected submerged lagoonal patch reef, 24.7 m (leeward in the master workbook — see Flag 4)
**Coral cover:** 56.9% (3 formal transects, D2–D4; **algal cover 26.7%**) · **published image bleaching:** 6.5%
**Live hard coral cover across methods:** formal transects 56.9% · CoralNet points 15.1% · Coralscapes masks 15.4% (25 frames). These products have different sampling footprints and denominators and should not be averaged — see Flag 1.
**Temperature:** 29.8 °C · **Salinity:** 34.3
**Photo review:** all 26 frames examined
**Representative photos:** P4260881.jpg, P4260845.jpg, P4260837.jpg, P4260878.jpg, P4260869.jpg

BISP95 is a high-cover lagoonal patch reef whose defining feature is not its coral but its **heterogeneity — and a dense marine macrophyte meadow that no other site in this batch carries.** Coral cover is 56.9%, 12th of the 109 Chagos sites, against 26.7% algae, but the photographic sequence turns over sharply from table-dominated coral habitat through open rubble and pavement into a broad vegetated meadow. Bare substrate is correspondingly high at 15.2%, with coralline algae 9.6%, turf 8.7%, macroalgae 2.9%, non-coral invertebrates 1.2% and erect algae 0.9%.

The assemblage is strongly *Acropora*-led across 15 non-zero genera. ***Acropora* holds 46.67% of the benthos — 82% of all coral recorded** — then *Porites* 3.07%, *Pocillopora* 2.77%, *Stylophora* 0.93%, *Heliopora* 0.67%, *Pavona* 0.60%, and *Cynarina* and *Platygyra* both at 0.53%. Seven further genera fall below 0.5%.

**Cover is flat across the two shallower bands and drops at depth.** D2 carries 64.8% coral across 11 genera with *Acropora* at 53.40%; D3 is essentially identical at 65.4% across seven genera with *Acropora* at 56.60%; **D4 falls to 40.5%** across seven genera with *Acropora* at 30.00%. Algal cover barely moves (25.0%, 25.6%, 29.5%). The genus order is stable throughout — *Acropora*, then *Porites* and *Pocillopora* — so unlike most sites in this batch the site mean is a fair summary of composition, if not of cover.

**The strap-leaved meadow is the site's distinguishing habitat.** P4260845 shows elongated ribbon-like blades rooted among coral and rubble, and P4260879 through P4260883 show a broad meadow occupying much of the bottom. Its form is compatible with seagrass or a seagrass-like marine macrophyte, **but the photographs do not justify a species name and none is assigned.** The meadow provides a habitat wholly different from the table-coral patches and is the main reason the site reads as heterogeneous.

Coral architecture is most developed in the first and middle portions of the sequence. P4260837 and P4260844 show overlapping tables with branching colonies in the gaps; P4260853 and P4260860 retain table and corymbose forms but include more exposed substrate; P4260876 and P4260878 show mixed coral patches reappearing after the open rubble views; and P4260869 and P4260884 show the rubble-dominated ground between them. The habitat is genuinely patchy — locally broad living canopies coexisting with low-relief areas where carbonate debris and old framework dominate.

Bleaching is localised but convincing, consistent with the published **6.5% (56th of 98)**. P4260878 shows several compact branching colonies with broad white tissue patches and white branch ends while retaining brown tissue elsewhere — a partial-bleaching pattern at high confidence. P4260883 shows a table edge beside the vegetation with an extended white margin, but regular edge growth and close illumination are alternative explanations, so it is retained only at medium confidence. Other pale margins were excluded where whitening was narrow and regular. **The vegetation and coral are in close contact in P4260883, but the still does not establish competition, abrasion or causation and no such inference is drawn.** Scattered broken branches on the rubble fields likewise cannot be attributed to a storm, an animal or the survey.

<b>Assemblage composition.</b> Formal surveys give 56.9% coral, 26.7% algae and 1.2% non-coral invertebrates, the coral 82% *Acropora* with a stable genus order across all three depth bands. The photographs document a strongly patchy reef — table canopies, open rubble and pavement, and an extensive strap-leaved macrophyte meadow — plus localised partial bleaching in branching colonies.

**Flags:** (1) **The multi-method spread is about 42 percentage points** (56.9% transect vs 15.1% CoralNet vs 15.4% Coralscapes). The photographic products almost certainly include the rubble fields and the meadow, which the coral transects did not sample equally; this is a plausible explanation but has not been tested. Never publish 56.9% without the method attached. (2) **The strap-leaved vegetation is unidentified.** It may be seagrass or a seagrass-like macrophyte. It is a notable enough occurrence for a Chagos lagoon to be worth a targeted identification from the raw frames. (3) **P4260859 is not benthic evidence** — it looks upward toward the boat or platform silhouette with sun rays and schooling fish. It is counted as a retained still but excluded from condition and cover interpretation. (4) **Exposure differs between sources.** `BIOT-1-MASTER-WkBk.xlsx` records *leeward*; the published `exposure-revised` column records *protected*. The Setting line uses the revised value for corpus consistency; the master value is preserved rather than silently converted. (5) **Frame-count mismatch:** 26 stills in the folder, all reviewed, against `n_photos = 25` in the multi-method CSV. (6) The `Mean(%bleaching)` source column carries at least one known bad value (BITB58 at 22.22% where the corrected figure is 0.77%), so the rank is approximate. (7) No crown-of-thorns starfish, predation flag or diagnostic disease sign was recorded. (8) **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 **6.50%, rank 64 of 110** (1st training: 6.50%, rank 63 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 BISP95 benthic survey data (CSV)](../benthic_data/BISP95_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).