How did half of the great Florida coral reef system disappear?

Overfishing, development and pollution have all contributed to the reef’s decline, but climate change is its biggest threat. UN targets must be met to stop ocean acidification

The great Florida coral reef system stretches hundreds of miles down the eastern seaboard of the US. It is the world’s third largest, and nearly 1,400 species of plants and animals and 500 species of fish have been recorded there.

But last year marine scientists found nearly half the reef was missing. They took the latest satellite images, compared them with precisely drawn 250-year-old British admiralty charts and found them nearly identical.

Related: More coral bleaching feared for Great Barrier Reef in coming months

Fishing gear dragged along the ocean floor has crushed corals, dynamite has shattered colonies and cyanide has killed hosts of living creatures

Related: Scientists warn US coral reefs are on course to disappear within decades