Mangroves are highly specialized ecosystem, which are characterized by salt resistant plants growing in the inter tidal areas along sheltered seacoasts and estuaries in the tropical and subtropical regions. India has approximately 31,5000 ha of mangrove out of which about 65000 ha are along the west coast. Gujarat and Kerala coasts have the most degraded mangroves, while Maharashtra, Goa and Karnataka have occasional luxuriant pockets. They form extensive and highly productive forests characterized by the accumulation of clayish mud and fine silt deposits. Various biotic communities associated with mangroves form a complex food web in these areas. They provide wide services to the livelihood of coastal people and are of immense ecological and economic significance thereby forming a significant component of any bioregion.
Distribution of Mangroves in Goa
Goa is drained by seven major rivers of which the Mandovi and Zuari with the Cumbarjua Canal form the largest estuarine complex.
Along the entire course of Goan rivers, there exists an intricate network of creeks and backwaters. A luxuriant growth of mangroves (some of which are degraded) and associated swamps can be observed along most of the water bodies within the estuarine reaches. The most prominent and extensive backwaters with mangroves are located along the East of the capital city of Panaji.
The total area covered by the estuaries in Goa including the major Mandovi Zuari estuarine complex is approximately 12,000 ha of which the mangrove forest occupy 2000 ha. About 900 ha of mangroves are found along the Zuari estuary, 700 ha along the Mandovi estuary and 200 ha along the Cumbarjua canal.
Mangrove Diversity in Goa
More than 59 species of mangroves have been recorded all over the world, out of which, 45 species are found in India. 12 of these species find their home in the saline waters of Goa.
Flora Associated with mangrove
The Flora associated with the mangroves, are:
- Derris heterophylla
- Clerodendron inermi
- Acrostichum aureum
- Cyperus spp.
- Porteresia coaretata
- Ceasalpinia crista
- Salvadora persica
- Halophila beccarii
- Lannea grandis
- Abrus precatorius
- Thespesia populne
Fauna Associated with mangroves
The fauna associated with mangroves are as follows:
Pin tailed duck Small blue kingfisher Lesser wood shrike Coots Blue eared Kingfisher Large cuckoo shrike Purple moor hen White breasted kingfisher Flying Foxes (bats) Cormorants Roller or Blue jay Crocodiles Shovellor Night Heron Turtles Terns Reef Heron Otters Pond Heron Common Sandpiper Jackls Cattle Egret Green bee eater Snakes Little Egret Black Drongo Crabs Large Egret Grey Drongo Oysters Blackwinged Kite Grey headed Myna Fish Brahminy Kite Tree pie
Uses of Mangroves
Mangroves provide a vide range of services and benefits to the mankind. They are instrumental in providing ecological and livelihood security to the people of coastal regions. The services provided by the mangroves are as follows-
- Prevention from soil erosion and stabilization of coasts and beaches.
- Protection of land from tidal surges and cyclonic storms.
- Aqua culture.
- Provides fuel wood, fodder, green manure, charcoal, timber etc.
- Used for boat/canoe making.
- Provides tannin.
- Used for thatching craft material, cordage and rope material.
- Used for art and craft, bow making.
- Used as food and beverage.
- Widely used for medicinal purposes.
- Useful for bee hives and provides wax and honey.
- Useful for recreational purposes as eco-tourism.
- Provides an excellent home to birds and animals.
Problems Faced by mangroves in Goa
Increasing pressure on natural resources has lead the mangroves being exploited beyond their sustainable potential. Reclamation and exploitation of mangroves for human settlements and agriculture have threatened a number of species. Some species like Kandelia Rheedii are already on the verge of extinction. Some of the problems faced by the mangroves of Goa are:
1. Conversion for agriculture, human habitation, aqua - culture, other developmental activities.
2. Felling for firewood, timber etc.
3. Fishing using dragnets, which damages the younger regenerated crop.
4. Lack of adequate and proper infrastructure for protection.
5. Movement of barges carrying ores causing uprooting of seedlings and erosion.
6. Pollution by way of oil leakage, deposition of solid wastes e.g. Polybags.