Dive Requests · what the research needsfor the expedition

What to bring back to finalize the science.

The models got us to sharp, testable hypotheses on two questions: why Banco Capiro survives heat and pollution that kill its neighbors, and what killed the central bank in June 2023. Turning either into a finished, publishable conclusion needs specific things measured in the water. Each request below closes a named open question. They are in priority order, and most double as footage for the film.

The one measurement that decides the paper

Our corrected analysis says a reef's fate is set by how close it sits to its herbivory tipping point. A grazed reef bleaches and recovers; a reef that lost its urchins gets overgrown and keeps declining. So the single most valuable thing to bring back is where each site sits relative to that threshold: coral cover, seaweed cover, and grazer density, measured together, site by site.

Data & samples, ranked by what they unlock

01

Distance-to-tipping: cover + grazers, site by site

Unlocks: whether the recovery-synergy mechanism applies at Banco Capiro, which turns the model from hypothesis into a fitted attribution. Measure hard-coral cover, macroalgae cover, Diadema density, and herbivorous-fish biomass on the same fixed transects at the collapsed central bank, at Cocalito, and at Punta Sal, so the contrast is quantified.

belt transect + quadratsphoto-quadrats (GPS-tagged)WIN: cover + grazers paired per site
02

Catch the next first-flush: dissolved oxygen + CTD, storm-timed

Unlocks: direct confirmation of the June-2023 kill mechanism. Three airport stations now confirm the June 5-6, 2023 storm was real, what we can't yet see is the oxygen crash it is proposed to have caused, because it was subsurface and cloud-covered. Fix in-situ dissolved-oxygen + CTD (salinity and temperature) loggers on the bank and leave them through the next dry-season-break storm. This is the concrete, fundable test of the whole hypothesis.

DO + CTD loggersdeploy before the first big stormWIN: an oxygen crash caught in the act
03

Symbiont identity (the one thing we cannot model)

Unlocks: whether a heat-tolerant algal partner (Durusdinium) carries the shallow corals. Take small tissue punches from the dominant corals, paired shallow and deep, preserved for ITS2 typing. Coordinate with a coral-symbiont lab (Andrew Baker, U. Miami, already suspects this).

tissue punch + preservativeshallow + deep pairsWIN: heat-tolerant symbiont ID'd
04

Turbidity shading, measured (not assumed)

Unlocks: the shading mechanism, and replaces our coarse 4 km satellite estimate with real in-water light. Log light (PAR) and Secchi depth at 3, 10 and 20 m at Banco Capiro and at a clear reference reef (Cayos Cochinos). Score bleaching by depth during any warm spell.

PAR logger / Secchi diskWIN: shallow bleaches more than deep
05

Temperature at depth, hourly

Unlocks: the daily and tidal temperature swings satellites miss, and any cool pulses that would hint at local mixing. Fix loggers at the bank crest and base and leave them in place.

HOBO loggers ×2+crest + baseWIN: high-frequency record recovered
06

Water chemistry: river mouth and on-reef (and during a storm)

Unlocks: whether the pollution helps or harms growth, plus the first-flush signature, and produces the first water-quality data for Tela. Sample total alkalinity, DIC, nutrients (N and P), aragonite saturation, and oxygen-demanding organic load (BOD) at the Ulua mouth and over the reef, and repeat during and after a storm pulse. The deciding numbers are the river's alkalinity-to-DIC ratio (carbonate subsidy) and the N:P + BOD of the first-flush slug (hypoxia pathway). Add dissolved Mn and Fe, the trace metals behind the black-sand question.

fixed bottle samplesriver + bank + clear refbaseline + storm pulseWIN: high river alkalinity / a first-flush BOD spike
07

Black-sand samples: iron-free lagoon vs bay, plus porewater

Unlocks: whether the black sand's manganese is actually bioavailable, the open question the lab XRF can't answer. The composition is already in hand (a heavy-mineral placer, rich in titanium and manganese; the Los Micos lagoon sand is iron-free while the bay sand carries iron, which can harm coral). Collect both the lagoon and bay sand plus reef porewater for a benchtop leach assay (oxygen-rich vs oxygen-poor) measuring dissolved Mn/Fe release and a full trace-metal profile, and set aside clean lagoon material for any manganese-treatment trial. Lagoon-vs-bay is a natural experiment on the iron effect.

sediment grabs + porewaterlagoon + bay, labeledWIN: measured Mn release, iron effect isolated
08

Permanent plots for the recovery signal

Unlocks: the recovery-versus-overgrowth dynamic in the field, the exact thing the model predicts. Mark permanent plots at a collapsed site and a held site so coral and seaweed can be re-photographed over time.

tagged permanent plotsWIN: repeatable time series started

Visuals the science and the film both need

These are evidence and story at the same time. Shoot them so a scientist can read them and an audience can feel them.

depth-tagged bleaching series (shallow vs deep, same colony type) macroalgae smothering the collapsed central bank vs healthy Cocalito / Punta Sal Diadema urchins grazing at night Secchi disk vanishing into the green Ulua plume from the air or drone clear-reef vs Banco Capiro murk, side by side the layered black sand (and a jar of the milky substance if the die-off ever recurs) elkhorn thickets, shallow divers placing loggers and taking tissue punches

Information to confirm on site

From the Coral Reef Alliance and Operation Wallacea teams, the records that let us fit the model rather than assume it:

Information to confirm on site. Ground-truth records and observations the expedition can gather from local teams to fit the models.
AskWhy it matters
Full Banco Capiro + Utila time seriesBenthic cover, Diadema, fish, macroalgae by year (2011 to 2024). Turns the hypothesis into a fitted attribution.
The June-2023 die-off, first-handAny dated photos, video, or notes of the milky water, odor, or the sequence of death. The storm is now confirmed; an eyewitness record of the die-off itself is the missing piece.
Bleaching history by year and depthGround-truths the satellite heat record and the recovery pattern.
Dive-traffic and fishing-effort numbersTests the human-pressure differential (the busy reefs are the sick ones).
Sediment-plume observationsWhen and where the Ulua plume reaches the bank, by season and after storms.

Logistics notes

permits for tissue, sediment and water sampling fixed, GPS-tagged transects for repeatability same method at every site so contrasts are comparable label and log every sample with site, depth, date

Full methods and the open code these requests come from: Data & Researchers and The Science.