Mangrove Forests: Unsung Heroes of the Tropics
Mangroves provide a good living if they are preserved.
Mangrove forests line the edge of the shores in many tropical and semi-tropical places around the world. Increasingly they are being bulldozed to make way for commercial shrimp farming and resort building. The removal of the mangroves gives the tropical resort an unimpeded view of the ocean and a fabulous sandy beach for the well heeled tourist to walk on.
As part of the sun-starved vacation many tourists hire boats to take them snorkeling or diving on the offshore coral reefs which are a wonderland of vibrant, teeming life. Most tourists would be shocked and dismayed to think that they are, in fact, party to killing off these reefs.
It wasn’t until I witnessed an intact mangrove forest that I started to understand the importance of these trees that walk out into the ocean.
The mangroves slow run off from the land, trapping the silt that would be lost to the ocean, gradually building and protecting the edges of the islands and continents. They also serve as breakwaters when the sea surges during a storm, cutting down the amount of damage and flooding inland. As the ocean levels climb, this becomes increasingly important. Storm surges and extreme weather events are becoming more common globally and this includes hurricanes that batter the coastlines.
Mangroves provide shelter and food for a myriad of juvenile fish that eventually move out to the reefs. Remove the nursery and you eventually choke off the flow of fish that help to keep the reefs healthy. Their great diversity of life provides many animals and humans with abundant food.
This tangled, brackish forest is a major carbon sink, calculated at four times what a land based tropical forest can store(ref. Science Daily). When our industrialized world is talking about reducing greenhouse gasses, these forests sequester significant amount of carbon. They also can absorb pollutants such as sewage and pesticides, helping to clean the water. They cannot cope with oil spills very well as the specialized breathing pores(lenticles) become clogged and they die.
While the trees cover nearly 40 million acres of tropical lowlands, they are rapidly being removed. Over the past 50 years nearly half the world’s mangrove forest have succumbed to human activity. They have been exploited for their lumber, making of charcoal, food and medicines. While the use of the forest can be sustainable, the overexploitation by industries – aquaculture, clear cutting and overfishing as well as pollution threaten their survival.
Fortunately people are starting to wake up to the value of these ecosystems and what they provide for free, to all. There are rehabilitation projects now ongoing around the world for example Peace Corps workers are coordinating with local people in Senegal to plant 60 000 seedlings in just three years(ref. IIP Digital).