Tsunaminegic events have several origins: tectonic, volcanic, submarine landslides, meteorological and others, including possible comet impacts. In the east coast of Sumatra and the Bay of Bengal, all these risks seem to be exacerbated and the occurrence of destructive giant waves seem to increase. Some recent examples are briefly analysed and the known impacts are briefly compared with the present ecological status of local mangroves. They include the November 1970, April 1991 and November 1999 cyclonic storms of Bangladesh. The causes and impacts of the recent December 2004 Asian Tsunami that occurred offshore of Aceh in the north-western Sumatra were discussed. Finally, geophysical and ecological and social issues are linked, with proposed fields of research.