The coral reef ecosystem in the Andaman sea was studied by monitoring aquatic environmental conditions
and reef condition from years 2005–2009. Following the Asian tsunami in December 2004, the ammonium-nitrogen
concentration in the surface water in Ranong province ranged from 8.45–14.08 µM, while in Phang Nga area, it was
between 9.99 and 25.11 µM. Mean sea surface temperatures in Ranong and Phang Nga were 30.60.4 °C during
the dry season. The growth rate of Acropora spp. in Chong Khat bay, Surin Marine National Park, was 1.0 cm/month
during the first 5 months after the tsunami. After this five-month period, corals, especially Acropora spp., showed signs
of recovery but then faced extensive bleaching in May 2005. Three years after the tsunami, the coral reefs in deep water
areas could grow and recover rapidly although they faced serious bleaching while coral reefs in the shallower waters
were in a poor condition after serious bleaching in May 2005. This phenomenon revealed that the mass mortality of
corals in shallow waters was enhanced by high seawater temperature and high turbidity due to phytoplankton blooms.
Overall results indicate that the relationships between environmental conditions and coral reef status in the Andaman
sea is an issue of great concern and coastal corals may gradually degrade in the near future unless action is taken to
alleviate coastal environmental problems.