Mangroves are salt tolerant plants growing on the coastal zone in intertidal areas, and in estuaries of rivers. These plants occur in the world in tropical and subtropical areas in many countries. Whether it be checking shoreline erosion or stabilizing land elevation by reducing sediment loss, one cannot think of better keepers of a coastline other than mangroves. With immense ecological and socio-economic value, these wonders of the sea have become an indispensible part of coastal ecosystems – nurturing & replenishing marine & aquatic life while adding to the element of beauty and serenity. Mangroves form a fragile ecosystem that provides livelihood opportunities for local coastal communities.

In India, the total mangrove cover is estimated to be around 4693 sq. km. and caters to a huge marine biodiversity. In India, mangroves are found in the states of West Bengal, Orissa, Andhra Pradesh, Tamil Nadu, Andaman and Nicobar Islands, Kerala, Goa, Maharashtra, and Gujarat. Bhitarkanika Mangrove Biosphere Reserve situated in the State of Orissa along the east coast of India has been identified as one of the major mangrove biodiversity hotspots with more than 65 different species of mangroves. Gujarat, being highly saline in terms of water and soil salinity has very less biodiversity of mangroves along the coast. However, recently over 14 previously extinct species of mangroves have been found to be proliferating in South Gujarat in the districts of Valsad and Navsari by GEER foundation.

In Gujarat, mangroves form a unique ecosystem that harbours more than 34 major and 20 minor mangrove species belonging to about 20 genera in over 11 families. The Mangroves in Gujarat are second only to the Mangroves in the West Bengal on the East Coast in terms of area, found in about 911 sq. km. area in Gujarat. There has been considerable degradation of the mangroves in Gujarat over the years. The reasons for this are many, like the dependency of the local and nomadic pastoralist communities on the mangroves for fodder and fuel, diversion of mangrove areas to industries, salt pans, and construction of ports, jetties, reduction in natural regeneration and death of the rich mangroves because of decreased influx of fresh water into the mangrove areas, due to construction of dams, both small and big in upstream areas.

The 1600 km. long coastline of Gujarat was once dotted with mangroves, along the Gulfs of Kachchh and Khambhat and along the south Gujarat coastline. These Mangroves were not only protecting the coastal areas from vagaries of cyclones and erosion, but were also acting as green barriers against saline breeze. In addition, they were providing rich breeding grounds for the marine fisheries. Unfortunately most of these Mangroves, except in the marine national park and Kori creek areas in Gulf of Kachchh have been severely degraded with disastrous consequences. Most of these Mangrove forests have largely been degraded over the years. The degradation has been both in terms of loss of Mangroves and also loss of species, with Avicennia marina virtually replacing all other species of Mangroves. The total Mangrove cover in the State at present is about 938 sq. kms, which on the face of it is quite impressive. But most of these Mangroves are located only in Kachchh and Jamnagar districts, 727 and 141 sq. km respectively, which account for more than 90% of the State's Mangroves. And here too, only one place - Kori creek - situated at the northwestern tip of the Gulf, accounts for 68% (643.3 sq. km) of the State's mangrove cover. This is an isolated patch of natural mangroves, which has survived all these years as it is very far from any human habitation and directly influenced by the Indus delta. Recently, there have been reports of degradation in these mangroves as well due to biological reasons. The 1999 cyclone too had its effect, by uprooting many mangrove trees in this area.

In the past, the entire coastline from Okha to Navalakhi and Surajbari, i.e. the southern coast of Gulf of Kachchh in the Jamnagar and Rajkot districts was covered with thick mangrove forests. Now one finds only isolated patches of sparse mangroves, restricted mainly to the various bets (islands) which form the Marine National Park and Sanctuary. Most of the coastal mudflats in this region are devoid of any vegetation. In the Gulf of Khambhat, the area has suffered severe degradation in a short span of 25-30 years, with a rapid rate of 32.3 sq. km per decade at places (Ashwini Kumar, 1996). Mangroves were present even 30 years ago near villages Sigam, Zamdi, Malpore and Nada. Presently, only Nada has some sparse and scrubby mangroves. The patchy records of mangrove cover by various agencies during the period from 1875 to 1983 show that there was a marked decline in the mangrove cover from 438 sq. km. in 1970 to 13 sq. km. in 1983 in most parts of the Gulf of Khambhat. In Kachchh district rainfall is low, averaging 360 mm. per year with very high variation in annual pattern. Intense rains lasting for short duration triggering erosion in the adjacent upland areas are common. Drought is a recurring phenomenon and the region falls under arid zone with aridity index reaching above 40 in the western parts of Kachchh. Desertification, seawater intrusion and extent of saline soils are also on the increase every year. There has been a progressive decrease in the net cropped area registering a negative growth of around -1% between 1990 and 1995 which is solely attributable to increase in saline soils and recurrent drought. Similarly, ground water situation is grim with many coastal talukas of Kachchh district falling in grey and dark categories. However ground water accounts for 67% of the source of irrigation. There are no perennial rivers in Kachchh district. Low annual rainfall, high velocity winds and extreme temperatures result in high rates of evapotranspiration. Although the population density is less, many of the coastal communities, particularly the fishermen & Maldharis, are directly or indirectly dependent on the mangroves for the sustenance of their livelihood. However, large mangrove areas in this region have been affected by port development activities, notably at Kandla and Mundra.

Mangroves play a very significant role in maintaining the coastal environment, reducing the impact of wave action and erosion in the coastal areas, preventing salinity and seawater ingress into the inland agricultural areas, and also providing protection to the coastline from the impact of cyclones. Apart from these ecological functions, mangroves play a very significant economic role in the lives of the coastal village communities. The villagers are dependent on mangroves mainly for fodder, fuel-wood and fishing activities.

Natural and anthropogenic factors pose severe threats to the marine ecosystems on the coast. However, the damage caused by human activities is much higher than the damage caused by natural calamities like cyclones, storms and earthquakes. Varied human activities like run offs and sedimentation from development activities, eutrophication from sewage and agriculture, physical impact of maritime activities, dredging, destructive fishing practices, pollution from industrial sources, and oil refineries etc. are some of the major threats to the fragile marine environment. Gujarat is one of the most industrialized states in India. The major industries located around Gulf of Kachchh include cement, chemicals, petroleum and oil refineries, shipping, power plants, fertilizers, fishing, etc. The increasing untreated effluents waste discharged into the marine environment severely hamper the marine flora and fauna. Due to major refineries established on the coastline along the Gulf of Kachchh, ship and heavy vessel traffic has also increased in the area. Accidental oil spills from various vessels ferrying in Gulf of Kachchh is a matter of serious concern as it may also be a potential threat to the coastal flora and fauna. Destructive agricultural practices using chemicals and pesticides like DDT have caused a lot of damage to the marine ecosystem. Many of the state’s rich fishing grounds, especially in the Gulf of Kachchh, are directly or indirectly dependent on mangroves for their sustained yield. Degradation of mangroves poses a serious threat to this resource and to the dependent fishing community. It also leads to increased soil erosion in the coastal areas, as the protective barrier between the sea and the land is lost. The natural barrier to the salt laden winds is also lost due to destruction of mangroves leading to increased spread of soil salinity adversely affecting agricultural production. This leads to declining employment opportunities among agricultural laborers and marginal workers of villages.

The broad causes of degradation of mangroves can be described as below:

Natural Hazards

Natural calamities like cyclones, droughts, higher intertidal currents, and low rainfall affect mangroves. The younger growth is affected by algae during certain periods of the year. Higher currents cause phenomena such as shifting sand and erosion which uproot older trees. There is also degradation of mangroves in the Gulf of Khambhat by erosion of the shoreline due to violent sea actions.

Over exploitation of mangroves for fodder and fuel-wood by local communities

Over exploitation of mangroves for fodder and fuel wood by local communities and Maldharis is a complex problem with a variety of inter-related causes. Unproductive village commons with frequent droughts due to arid and semi arid character of the area accentuates the problem by increasing the pressures on mangroves for fodder and fuel-wood. Mangrove leaves are rich in protein and are usually preferred over other grasses as fodder and are collected and carried by the local people to feed their cattle. Migrating populations of Maldharis, with large hordes of cattle, including camels, also cause severe damage to the mangroves. At present the local communities are often helpless in regulating their access to the mangroves, as they have no control on these areas. Free grazing by camels in the mangrove areas causing trampling of seedlings and over-exploitation of seeds and twigs by the local communities also lead to the reduced natural regeneration of mangroves. The problem is aggravated by the repeated droughts. Lack of knowledge and awareness of the ecological functions of mangroves in the local communities is also often responsible for the indiscriminate exploitation of mangroves by these communities.

Reduced Natural Regeneration

One of the factors for reduced natural regeneration of mangroves has been the reduction in fresh water inflow, which has led to increased salinity. No major rivers, except Indus with its reduced annual flows, pour fresh water in the Gulf of Kachchh. As a result, only hardy species like Avicennia Marina, with high salt tolerance, have survived. Similarly, in the Gulf of Khambhat, fresh water inflows from some of the major rivers like Sabarmati and Mahi have reduced due to construction of dams for irrigation in the upstream areas.

Diversion of mangrove lands for other uses like salt-pans, industries etc.

Another important reason for the degradation of mangroves in the state is the diversion of mangrove lands for uses like salt-pans, industries, ports, etc. This is particularly true for Kachchh and Jamnagar districts where large mangrove areas have been diverted for industrialization purposes. Insufficient understanding of the ecological functions of the mangroves is largely responsible for such diversions. Location of ports and industries in the vicinity of mangrove areas also cause damage to the mangroves due to dredging and bunding activities as well as construction of roads and other infrastructure. Often, it also brings in a large population of migrant laborers, increasing the anthropogenic pressures on the existing mangroves. The loss of mangroves in the state has a direct negative consequence for the marine fisheries, as they provide nutrients and breeding grounds to many fish species.

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