Tan, C. H., Heron, S. F.

First observed severe mass bleaching in Malaysia, Greater Coral Triangle, Galaxea

2011

Journal of Coral Reef Studies

13

27-28

In 2010, bleaching began in mid-May along the northwestern coast of Peninsular Malaysia; within three weeks, reefs around the major islands along the east coast were bleached. This event followed the peak of the third strongest El Nino event in the past 50 years. Around 50% of hard corals at Tioman, Redang, and Perhentian Islands were bleached, with two-thirds of those colonies completely white. During the underwater visual surveys bleached corals were observed down to 20 meters depth; at Redang Islands bleaching was found as deep as 25 meters. The severity and extent of the bleaching was consistent with the observed level of satellite-derived thermal stress, exceeding 8 degrees C-weeks. In addition, outbreaks of an unidentified disease increased the mortality rate of corals. In contrast, minimal bleaching was observed in East Malaysia (Sabah and Sarawak) at this time (less than 10%), again consistent with the thermal stress patterns. These observations suggest that the scale of bleaching events in this region may be increasing, underlying the need to undertake effective management strategies to conserve and protect reefs from natural and anthropogenic threats.?

reefs; mass coral bleaching; Malaysia; Coral Triangle