Date: Fri, 23 Oct 1998 11:06:27 +0800
From: Gregor Hodgson <rcgregor@ust.hk>
Subject: Bleaching/Mortality in VIETNAM

Report on bleaching in Vietnam.

(This updates a previous report on bleaching by Sue Wells in August.)

Coral bleaching in Vietnam has been extensive beginning in late summer 
1998. In the areas off of Nha Trang (south-central Vietnam), the reefs 
have experienced moderate levels of mortality in shallow water, with 
Acropora being hardest hit according to Dr. Vo Si Tuan.

The conditions in the south were far worse. We re-surveyed the reefs at 
Con Dao National Park from 14-21 Oct. Bleaching typically affected 70% 
of corals at most reefs. At most sites, 90% of the dominant table-Acropora 
had been killed by mid-September and many other corals for total losses of 
about 70-80% of the previous coral cover in shallow water (1-2 m). In 
deeper water, the situation was equally bad in most locations with 90% 
mortality of the dominant massive Porites in late September and many other 
large colonies e.g. Lobophyllia. Overall coral cover loss in deeper water was 
60-70%. Hundreds of (2-3 m diameter) massive Porites were killed including 
colonies as large as 9 m diameter which are likely to be several hundred years 
old.

This event was a catastrophe for the national park which had been hit by a major 
typhoon the previous November. Quantitative data, slides and video will be 
available at ITMEMS.
-- 
Gregor Hodgson, PhD
Institute for Environment and Sustainable Development
Hong Kong University of Science and Technology
Clearwater Bay, Hong Kong
Email: <rcgregor@ust.hk>
Reef Check: http://www.ust.hk/~webrc/ReefCheck/reef.html