The Phuket and Similan Islands Trip (Thailand)

Between the years 1999 and 2000, a strong el Niño caused vast coral bleaching in the northern Indian Ocean, affecting the Maldives, Seychelles, Sri Lanka, and the western coast of Thailand. In 2004, the tsunami following the earthquake offshore Banda Aceh, Western Sumatra, damaged the coral reefs of that region even further.  This was especially desastrous because by washing out polluted soil into coastal environments, it multiplied the concentrations of phosphates and nitrates, which is fatal to stone corals.  In 2012, a group of divers, now associated with the Foundation, visited Sri Lanka to collect shells from the intertidal to 45 m, and returned empty-handed (Kahlbrock, personal communication).  

 

In 1999, the areas visited had a wealth of gastropods, especially the family of cowries (Cypraeidae). Earlier this year, we visited Phuket in Western Thailand and did an exploration to 25 Stations along the coast, covering the area between Richelieu Rock off Surin Island in the north, across the Similar Islands, to Hin Daeng Island in the south (see inset map). We collected 12 different species of cowries along this route, but only five in abundance, while others were represented only by apparently old, eroded shells.

 

In Phuket, we were supported by our friends Jom and Somnuk Patamakanthin, owners of the Phuket Shell Museum.  They assisted in hiring local compressor divers, to search for five particular species of cowries for DNA analysis, in the vicinity of Rawai Beach: Erronea caurica, Pustularia globulus, Ransoniella punctata, Bistolida ursellus (see photo below), and Palmadusta ziczac. In former years, these fishermen had worked as professional shell divers for the collector's market, but more recently, this activity was no longer feasible due to the disappearance of most of their target shells. In the years before the el Niño of 1999, the species we were looking for were abundant in the shallow water on reefs facing the town of Rawai, according to Jom Patamakanthin.

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