The worst coral bleaching event on record has caused havoc to the world's reef systems, with scientists calling for urgent action against climate change to reverse the damage caused to the underwater ecosystems.
Pictures from the XL Catlin Seaview Survey show the devastating impact of unusually warm water on corals around the Japanese islands of Okinawa. Corals are seen "fluorescing" in bright colours – an indicator that they are stressed and losing their vitality.
"If ever there was a wake-up call to the threat of climate change, this is it," the not-for-profit Ocean Agency says. "We are seeing an entire ecosystem in a rapid state of collapse. It is a dire warning we can't afford to ignore."
Coral reefs around the Japanese islands of Okinawa are being devastated by bleachingXL Catlin Seaview SurveyBleaching occurs when corals expel algae called zooxanthellaeXL Catlin Seaview SurveyCorals with a blueish tinge are 'fluorescing' – i.e. using fluorescent pigments as a sunscreen to ward off bleachingXL Catlin Seaview SurveyA mixture of bleached and dead corals around Okinawa – corals are known to recover from bleaching but if the stress continues they eventually dieXL Catlin Seaview SurveyScientists say coral bleaching is a visible indicator of climate change – over 90% of global warming heat is absorbed by the world's oceansXL Catlin Seaview SurveyThe current global coral bleaching event – the third since 1998 – is the longest in recorded historyXL Catlin Seaview SurveyCoral bleaching has also devastated large sections of the Great Barrier Reef in Australia. Here fluorescing corals are pictured up close in New CaledoniaXL Catlin Seaview SurveyScientists have called for urgent action against climate change to save the world's reefsXL Catlin Seaview SurveyReefs represent less than 0.1% of the world's ocean floor but support one-fourth of all marine speciesXL Catlin Seaview SurveyAerial image of bleached corals in New CaledoniaXL Catlin Seaview SurveyCoral reefs are built by colonies of tiny animals living in shallow waterXL Catlin Seaview Survey
