Coral Bleaching in the Vatu-I-Ra Seascape: How Bad Is It?
By Sangeeta Mangubhai
[This is the fourth in a series of blogs by WCS-Fiji Director Sangeeta Mangubhai assessing the damage to coral reefs caused by Cyclone Winston, a Category 5 storm that hit Fiji on February 20]
Before Cyclone Winston hit Fiji, we were following closely the El Niño cycle, the drought, and reports of coral bleaching from dive operators. The local newspaper, the Fiji Times, ran a number of stories about fish kills and there was a lot of speculation about whether this was caused by the elevated sea surface temperatures we were experiencing across Fiji.
Temperatures on inner reef flats along the Coral Coast recorded temperatures as high as 35°C. A similar story emerged from Vanuatu.
I have been spending part of each dive collecting data on the scale and intensity of bleaching across a range of habitats – including fringing patch and lagoonal reefs, channels, and bommies – using a rapid assessment technique developed by my colleagues Dr. Tim McClanahan and Dr. Emily Darling at the Wildlife Conservation Society.
Over the last four days, I have documented mild levels of bleaching, with common coral genera like Acropora, Pocillopora, Porites (massive forms), Montipora and Pavona mostly affected.
By mild, I mean that corals are either iridescent or slightly pale, rather than fully white (i.e. bleached). The tissue on these corals is still very much alive. A few very large colonies of Porites and Pavona are severely bleached in the shallow —> Read More