TSUNAMI DAMAGE ON MANGROVES
IN PENINSULAR MALAYSIA

Mangroves were alleged to have significantly prevented or reduced damage caused by the Boxing Day 2004 Indian Ocean Tsunami. The veracity of this is not only unknown but also very difficult to scientifically verify. The extent of that tsunami damage to mangroves in Malaysia is also not well documented. Post-tsunami surveys of mangroves in Kedah and Penang (the two states with major human fatalities and property losses) showed that direct damage to mangroves by the tsunami was virtually negligible. Indeed, the extent of damage is less than that caused by bow waves. In fact, there appears to be more damage to mangroves from post-tsunami rehabilitation works. Of course, any physical barrier (be it coastal vegetation or man-made structures) will offer some degree of protection. On the other hand, physical barriers may also channel or funnel (i.e. amplify) the waves ('tsunami' translates as 'harbour waves'), causing greater damage. There are also indications that tsunami-deposited sands/shells may hasten subsequent storm wave erosion of mangrove mudflats through increased abrasion. Whilst it is gratifying (especially to the conservation-minded) that the Government is spending tens of millions of Ringgit Malaysia to plant mangroves and other coastal vegetation to mitigate future tsunami damage, it is even more important to ensure that all such projects have strong scientific bases. It is suggested that scientific studies on the functional physical and ecological processes involved be carried out before more good money is poured into very badly thought out so-called mitigation projects.