Estou a fazer um trabalho sobre o sismo e tsunami de Sumatra. Deixo um dos textos sobre protecção natural (com mangais) e sua respectiva destruição (pelo Homem).

"The Indian Ocean tsunami destroyed thousands of miles of coastline and even submerged entire islands permanently. The island country Maldives rise only a few feet above sea level, but it is largely protected by outlying coral reefs. Even so, the tsunami swept across the reefs and was reported to have washed over some islands entirely. The capital and many tourist resorts in the Maldives were flooded. Astonishingly, relatively few people were killed. The country was likely protected from the full force of the tsunami by its reefs.
Some mangrove forests play an important role in protecting coastal zones. Surveys developed in 24 mangrove lagoons and estuaries Sri Lanka coastal zone show that, where mangroves occur in the districts visited, they did in fact offer protection. Mangroves play a important role in storm and tsunami protection, but with the subtle point that this all depends on the quality of the mangrove forest. The conversion of mangrove land into shrimp farms, tourist resorts, agricultural or urban land over the past decades, as well as destruction of coral reefs off the coast, have likely contributed significantly to the catastrophic loss of human lives and settlements during the recent tsunami event. It is not only important to establish early warning systems for the next tsunami, but also restore and protect mangrove forests and other natural defences in parallel."