A compiled field report on the reef-flat ecosystems fringing the Calamian group — where bleaching events, coral recruitment, and small-boat tourism all meet, above a sandbar less than two metres deep.
Each point below is supported by a cluster of transect readings, photo-quadrats, and published regional studies. None of these are surprises on their own — it is the pattern they form together that is worth the paper.
Thermal stress events that, before 2016, were confined to late dry season now appear in October and again in February — compressing the window in which recruitment and regrowth can occur without heat load.
Branching species previously dominant on shallow flats are ceding cover to encrusting forms and soft coral. Total live cover holds roughly steady at 34–38%; the species mix behind that number is not.
Parrotfish and surgeonfish biomass remains within the range reported in the 2018 baseline, with local dips near high-traffic snorkel sites. The algal turf-to-coral conversion is not yet runaway.
At ten of eleven day-trip sites, physical damage from anchors, fin-kicks, and hull contact outweighs temperature-attributable loss on this year’s readings. Mooring buoys would move the needle more than carbon talks will, this decade.
Aggregated across 142 transects and six partner dive operations. Figures rounded; full workings in the appendix.
Refining a repeatable quadrat-capture routine that a pair of snorkellers can run from a bangka in under forty minutes, without GPS drift swallowing the point data.
Counting juveniles under 5 cm on tile arrays and natural rubble, to read the pipeline of recovery rather than the standing stock that photographs well.
Sixteen HOBO loggers deployed at paired shallow and reef-slope stations, sampling every fifteen minutes. Funded by a modest grant from the provincial board.
Co-designed with three dive operators. If year-one data holds, the trial moves to a broader memorandum covering all inner-lagoon day-trip sites.
Comparing our transect readings against volunteer-logger data from Reef Check cycles, to understand where amateur observations can substitute and where they cannot.
A smaller study on the soft-bottom margin where the reef flat meets sandbar, including juvenile fish use and a surprising density of feeding green turtles at dawn.
The best hours for this kind of work are never the postcard hours. Noon light flattens everything into a single glare, and the water, which looks opal in the brochures, goes blank under a mask. We learned to favour the two hours after dawn, when the sandbar still holds a little of the night’s cool and the coral heads throw long, legible shadows across the quadrat frame.
Reef surveys are, in the end, a form of reading. You are looking for sentences in the arrangement of polyps and grazing scars, in the species list from a ten-minute point count, in the way a parrotfish ignores you because there are more interesting things on the turf. The numbers in this ledger are attempts to transcribe that reading into something another reef biologist in another country can check against her own.
We publish it as a ledger, rather than a report, for a reason — the figures inside are provisional, the kind of working totals that want to be amended by better eyes. If you have any, please write in.