01 — Fever log
Twenty-three summers at Buoy 07.
Each stripe is one August peak at Maré Funda, measured against the 1991–2020 mean. Teal ran cooler. Ember ran hotter. The last nine have all burned.
12.4DHW
degree heating weeks on Maré Funda this September. Above eight, coral bleaches. Above twelve, it starts to die.
41refuges
cold refuges kept open this summer, on reefs in Portugal's Atlantic islands, Cabo Verde and São Tomé.
68%
of nursery fragments that came through the 2025 fever alive, against 19 % on the open reef beside them.
02 — Cold refuges
Three ways to buy a reef one more summer.
01Shade
Sails over the nursery
Woven sails rigged two metres above the nursery tables for the six hottest weeks. They cut the midday light by a third, and the bleaching with it.
−31 % light
02Cool
Night water from forty metres
Solar-charged pumps lift water from below the thermocline after dark and wash it over the frames. One pump keeps 400 fragments under the threshold.
−1.4 °C at the frame
03Reseed
Survivors go back out
Fragments that came through a fever are grown on and replanted each autumn, so every heatwave leaves the reef a little harder to cook.
68 % survived 2025
“We stopped calling it a bleaching season. It is a fire season now — it comes every year, and you get ready for it the way a forest does.”
03 — How this page loaded
The ring never froze. Here is why.
The burning ring you watched was drawn by a Web Worker on an OffscreenCanvas, started from the page's <head> before anything below existed. While the page then held its own thread for up to 260 ms at a time — compiling the porthole's shaders, decoding the reef, and a deliberate stand-in build — the fire went on burning on another thread.
When the count reached 100, the ring ran into the hand-off at an even pace, and this hero took over the same rim, on the same clock, with the hole burnt clear down to the water.