Video Documents Koh Tao, Thailand Bleaching

By Reef Check EcoDiver Trainer Nathan Cook

This year has been a challenging year for the reefs of Koh Tao, Thailand. Marine ecosystems have been under a great deal of stress as a result of the 2009-2010 El Niño causing widespread bleaching across Koh Tao’s reefs.

It started in 2009 when our monsoon season, which usually produces lots of wind and rain and a general lowering of sea water temperatures, didn’t really eventuate. Temperatures stayed 1-2° Celsius higher than normal and 3-4° Celsius higher than the preceding year.

2010 was a special year- the hottest in recorded history on earth. Extreme temperatures, low tides and intense solar radiation for abnormally extended periods of time combined to place enormous pressure on this small island. These conditions led to extensive coral bleaching, with all reefs around the island affected. During the early part of summer, through April and May, there was little respite and large amounts of coral bleached. It was almost as if a blanket of snow had settled on the reef.

In the height of our summer months, with intense sunlight continuing, sea temperatures peaked at around 32° Celsius, almost a full 2 degrees above average. Even surface temperatures of up to 34° were recorded around Koh Tao.

To document the bleaching event, we put together a documentary to highlight the changes as part of an entry for a local film festival, but also to provide an educational tool for local centres like our Crystal Dive Resort to use when teaching about coral bleaching and its effects both globally and locally. Click here to watch the video.