A global coral map

When I last wrote about the Allen Coral Atlas, I was new on the team and we had just launched a site mapping a handful of test reefs. A lot has changed since then:

A dark map centred on micronesia and spanning as far W as myanmar and as far E as French Polynesia, with areas of coral, sand and seagrass in bright colours

As of today, we have completed mapping the world’s shallow tropical coral reefs. A few small sections are still in final QA, but the enormous satellite image analysis task is done and we can truly say we have global coverage now. Along the way, we also added some major features, such as monitoring for coral bleaching:

A screenshot with satellite imagery of a part of New Caledonia, with areas of probable bleaching highlighted in yellow and orange

And overlaying marine protected areas on the map so we can see how much coral is covered by some level of conservation measures:

A screenshot showing 3 protected areas as blue outlines, encompassing a lot of coral areas shown as pink

Along with downloadable data, integrating the NOAA Coral Reef Watch alert areas, and a huge amount of coalition-building work to both get the data validated by researchers with local knowledge in each area we cover and get it out into the hands of people who will use it. I get absorbed in the scale challenge—I’ve learned so much from this project about details of PostGIS performance that hopefully no Atlas user will ever have to think about—but the real achievement is that it’s already being used to inform several countries’ conservation planning.

There is something deeply elegiac about mapping coral in the 2020s. If the world doesn’t collectively decide to take global warming seriously, this will become an entirely historical document before I am old. But the whole project is also a reminder of the number of people who are working to prevent that fate, and I want to give the last word to some of those people: Hopeful thoughts from our Coral Reef Conservation Heroes.