Atolls are ring-shaped islands that form in the tropics and subtropics from the buildup of coral reefs atop an underwater landmass. The shape of the island usually forms a lagoon. The lagoons are often connected to the outside ocean by passes but Taiaro Atoll, located in French Polynesia, is unique. Its lagoon is fully enclosed. With a temperature of around 0.5-1.0°C warmer than the surrounding ocean, this lagoon provides scientists with a natural laboratory to answer questions about climate change and evolution.
Credit: Pascal Kobeh
