Production potential of blood clam (Anadara granosa) in Bang-tabun Bay was examined by integrating data for size distribution, growth rate, and aquatic environmental factors. Collection of data was conducted from December 2011 to May 2012. Blood clam culture areas from three muddy tidal flats; Don Bon flat, Don Klang flat, and Don Tuen flat located from the north to the south of the bay, respectively, were studied. Length and weight of clams at each station varied each month depending on the growth potential of the clam and culture management practices of farmers. The growth rate of blood clam throughout this study period ranged from 0.1-0.8 g/month. The results revealed significant correlations between blood clam growth rate, chlorophyll a and salinity. Blood clam growth rate was most rapid at the station on Don Tuen flat, which exhibited the highest overall salinity and chlorophyll a. Don Klang flat and Don Bon flat can be adversely affected by freshwater runoff and food availability limiting the utility of these areas. Overall results indicate that among the three muddy tidal flats selected for this study, Don Tuen flat is the most suitable area for blood clam culture.

Production potential of blood clam (Anadara granosa) in Bang-tabun Bay was examined by integrating data for size distribution, growth rate, and aquatic environmental factors. Collection of data was conducted from December 2011 to May 2012. Blood clam culture areas from three muddy tidal flats; Don Bon flat, Don Klang flat, and Don Tuen flat located from the north to the south of the bay, respectively, were studied. Length and weight of clams at each station varied each month depending on the growth potential of the clam and culture management practices of farmers. The growth rate of blood clam throughout this study period ranged from 0.1-0.8 g/month. The results revealed significant correlations between blood clam growth rate, chlorophyll a and salinity. Blood clam growth rate was most rapid at the station on Don Tuen flat, which exhibited the highest overall salinity and chlorophyll a. Don Klang flat and Don Bon flat can be adversely affected by freshwater runoff and food availability limiting the utility of these areas. Overall results indicate that among the three muddy tidal flats selected for this study, Don Tuen flat is the most suitable area for blood clam culture.

ABSTRACT:The coral reef ecosystem in the Andaman sea was studied by monitoring aquatic environmental conditions and reef condition from years [2005][2006][2007][2008][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 30.6 ± 0.4°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.

Domoic acid (DA), a toxin produced by diatoms Pseudo-nitzschia and Nitzschia, causes amnesic shellfish poisoning. DA accumulated in marine organisms from Sriracha bay, Chonburi province, Thailand was determined from May 2012 to July 2013. Field surveys and sample collections were conducted every two months. DA content was determined using the enzyme linked immunosorbent assay (ELISA) method and ranged between not detectable and 110 ng/l for plankton. DA content in zooplankton ranged between 0.04 and 0.21 ng/l and in Perna viridis, Crassostrea lugubris, and Pinctada fucata it ranged between 214 and 454, 171 and 371, and 117 and 282 ng/g, respectively. DA content in Secutor megalolepis ranged between not detectable and 44.2 ng/g. DA was found in zooplankton, shellfish, and fish from Sriracha bay throughout the year. The amount of DA accumulation in marine organisms was lower than the regulation level (20 µg/g). Average DA content in zooplankton, shellfish, and fish throughout the year were 42%, 44%, and 5% of the DA content in phytoplankton, respectively. DA transfers from phytoplankton to zooplankton and shellfish were 7% and 8%, respectively, while transfer from zooplankton to fish was 2%.