Effects of the 26 December 2004 tsunami on littorinid molluscs near Phuket, Thailand.

Abstract

A major effort is being undertaken to understand the effects of the December 2004 Indian Ocean tsunami on the marine environment. The emphasis has been on coral reefs, which are subtidal and offshore of the areas that were most heavily affected by the tsunami. The greatest losses of human life and destruction of human infrastructure occurred in the intertidal and supratidal regions where the waves had the greatest destructive force after they broke. We seek to determine the effects of the tsunami in the upper intertidal region, where the effects might be greatest, by using littorinid molluscs as an indicator group.

An extensive 2002 survey of the distribution of littorinid molluscs at 50 sites in mangroves and on rocky shores in Thailand was recently published. Six of the study sites were on the Andaman Sea coast in the area of Phuket, Thailand, one of the regions most heavily hit by the tsunami. These sites (Fig. 1) were resurveyed between 13 and 18 April 2005, 3.5 months after the tsunami, to determine qualitatively what damage had occurred.