Slide into the Celebes sea which surrounds the sleepy island of Bunaken in North West Sulawesi, and you’ll find a carnival of life. You need not even go as far as the surrounding oceanic walls that bustle with life as they fall away to the murky depths. Just 5 metres from shore lies a refuge, a nursery, a strip of forest that battles two fierce tides a day. Welcome to the Mangroves of Bunaken…
Mangrove trees grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate. Mangrove forests only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperatures.
They produce aerial roots from their trunks that become embedded in the mud and form a tangled network; this serves both as a prop for the tree and as a means of aerating the root system. Such roots also form a base for the deposit of silt and other material carried by the tides, and thus land is built up which is gradually invaded by other vegetation.
White mangrove is the most widespread mangrove in the world, with the scientific name of Avicennia marina.
Indonesia has around 9.36 million hectares of mangrove forests, but 48% is categorized as ‘moderately damaged’ and 23% as ‘badly damaged.
The mangrove forests can protect inland coastal areas by absorbing the effects of storm and some tsunami waves, but too many mangroves have been harvested, causing large scale destruction. The bark is a rich source of tannins, and the wood is used for wharf pilings and other purposes.
One village in Tamil Nadu protected itself from tsunami destruction. The villagers in Naluvedapathy planted 80,244 saplings to get into the Guinness Book of World Records. This created a kilometre-wide belt of trees of various varieties. When the tsunami struck, much of the land around the village was flooded, but the village itself suffered minimal damage.
In conservation terms, adequate data is only available for about half of the global area of mangroves. However, of those areas for which data has been collected, it appears that 35% of the mangroves have been destroyed. The United Nations Environment Program & Hamilton (2013), estimate that shrimp farming causes approximately a quarter of the destruction of mangrove forests. Likewise, the 2010 update of the World Mangrove Atlas indicated that approximately one fifth of the world’s mangrove ecosystems have been lost since 1980, although this rapid loss rate appears to have decreased since 2000 with global losses estimated at between 0.16% and 0.39% annually between 2000 and 2012. Despite global loss rates decreasing since 2000, Southeast Asia remains an area of concern with loss rates between 3.58% and 8.08% between 2000 and 2012.
Grassroots efforts to save mangroves from development are becoming more popular as their benefits become more widely known. In the Bahamas, for example, active efforts to save mangroves are occurring on the islands of Bimini and Great Guana Cay. In Trinidad and Tobago as well, efforts are underway to protect a mangrove threatened by the construction of a steelmill and a port in Thailand, community management has been effective in restoring damaged mangroves. Within northern Ecuador mangrove regrowth is reported in almost all estuaries and stems primarily from local actors responding to earlier periods of deforestation in the Esmeraldas region.
