algae

Some of these animals can photosynthesize like plants; some harvest algae and seawater to make calcium carbonate for their underwater castles; some produce their own light or glow in the dark.

During the summer, these floating mats of brown algae collect in large amounts on beaches where they decay and release an unpleasant smell.

People of all different ages play and splash in the pool, as if this is normal—as if the pool isn’t as big as a baseball field and holding water the color of algae.

"We need to keep the pipes clean, and they eat the algae," Mr Richardson tells the BBC.

It has suffered four significant marine heatwaves between 2016 and 2022, causing much of its coral to expel the algae which gives them life and colour - a process called bleaching, which is often fatal.