The importance of mangrove forests

Importance of mangrove forests

What mangroves are. Mangroves are salt-tolerant trees and shrubs of sheltered tidal shores, at their richest in river deltas, where the water is brackish because river and sea mix; Bharucha places the largest mangrove swamps in the Sunderbans, in the Ganges delta.

Their ecological role

• Keeping silt near the shore. Standing mangroves keep river silt from being swept out to sea. Bharucha notes that when mangroves beside a reef are cut down, the silt is carried offshore, settles on the coral and kills it, so a healthy mangrove belt also protects the reefs next to it.
• A living sea wall. Their dense stems and tangled roots take the force out of waves and storm surges and hold the shoreline against erosion, so coastal villages behind an intact belt suffer less when a cyclone strikes.
• Breeding ground for sea fish. Mangroves provide habitat that marine fish need in order to breed; the young fish shelter among the roots before moving out to open water.
• A base for coastal food webs. In biomass produced, the brackish deltas that mangroves cover rank among the most productive ecosystems in the world. Fallen leaves feed crabs and small fish, which in turn feed larger fish and wading birds.
• Support for fishing villages. Because these waters stock the coastal fishery, the loss of a mangrove belt is felt in the catch of nearby fishing families as well.

Conclusion

A mangrove belt is worth far more to the coast left standing than cleared. The pressures on it are felling for firewood and the digging of prawn ponds; guarding the belts that remain and replanting bare mudflats secure both the shoreline and the fishery.