Pakistani mangroves rank sixth among the mangroves spread in 92 countries of the world


By Dr. S.M. ALAM NIA, Tandojam
Feb 23 - 29, 2004



The coastal area of the country is an arid sub-tropical desert with the coastline extending to about l000 km. One-third of the coastline is in the Province of Sindh, while the rest is in Balochistan. The average rainfall is 100-200 mm per year, and that too is sporadic. The Indus Delta is spread over 600,000 hectares along the southern Arabian Sea Coast in Sindh. Out of these, 260,000 hectares are covered with mangroves mainly in the Indus Delta Swamps. In addition, small pockets exist also in deltaic swamps of other small rivers namely Basol, Dasht, Piroli, Winder, which meet the Arabian Sea in the Province of Balochistan. Mangroves thrive on a continuous supply of fresh river water, but presently due to the construction of dams, a lot of water is diverted into smaller reservoirs and irrigation canals, before it reaches the delta, thus decreasing the discharge of fresh water.

Pakistani mangroves rank sixth among the mangroves spread in 92 countries of the world. The mangroves thrive at the mouth of the Indus the sixth largest river of the world and the Indus Delta is the fifth largest delta in the world. This delta is an important fly over for migratory birds from Siberia, and thus the mangroves are an important stopover for many winter birds. 'They are the arid coast mangroves (mangroves which grow in high salinity areas with low rainfall) and spread over the largest area among the world's arid coast mangroves.

The mangrove's ecosystem is dominated by a single species called Avicennia marina, which forms 99.9% of the total crop. There are few stands of Ceriops tagal, Bruguiera conjugafa and Aegiceras corniculatum. Perhaps, the most important aspect of these unassuming plants are their ability to act as physical barriers to cyclones and typhoons. The recent cyclone to hit coastal areas of Thatta and Badin districts would not have been so intense, if the previously present mangroves had been wiped out to make room for human development. The roots trap the sediment that is brought into the sea via the flow of the Indus and its tributaries. This helps in keeping the sedimentation level of the harbour under control. With the depletion of these plants sedimentation level is increasing and is a sign of concern for the port authority.

Micro-organisms, plants, animals and people all are part of the mangrove ecosystem. The living things mainly rely on soil and water for sustenance and growth. Microorganism is an invisible, but an essential part of the ecosystem. They digest the dead leaves of the plants and recycle the nutrients for the mangroves and other plants and animals. Fish such as sardines and palla and other sea creatures such as crab and shrimps either live in the surrounding waters or spend a critical part of their lives here. Breeding grounds and nurseries for water fowl, fish, shrimps, snakes and other fauna, they form essential ecosystem with perhaps more bio diversity than the rainforests. Fish and shrimps are not only of importance for the ecology but also boost Pakistan's economy through exports. Shrimps export is the major chunk of fish exports, being 68% of the US$ 100 million transactions. Around 14 species of sea snakes use these mangroves as a breeding ground. During winter many species of water fowls, including pelicans and flamingoes make the Indus Delta their home. Over 60 species of these birds are found in the mangroves.



In 1985, the Government of Pakistan initiated a program for the replanting of the mangroves. More than 9000 hectares were planted around the Indus delta. Another 3000 hectares were restocked by Avicennia marina by assisted natural regeneration. IUCN-Pakistan, UNDP/UNESCO Regional mangrove project and the Sindh Forest Department were involved in this project. Various species were also planted experimentally in different areas of the Indus Delta and the Avicennia marina and Rhizophora mucronata were predominant among them. In 1990, a socio-economic survey was conducted to gauge the dependence of local people on these mangroves. The survey showed that about one hundreds thousand people depended on the mangroves. They lacked many facilities and even did not have proper drinking water. The survey also discovered that a few container plants had survived in the area around their settlements.

Consequently, IUCN-Pakistan initiated a mass plantation programme of Avicennia marina and Rhizophora mucronata in the coastal villages. The purpose of the programme was to establish wood lots and to create an alternative source of fuel and fodder for their animals and reduce their dependence on the inter-tidal mangrove. The villagers were given technical support to grow these plants in their own vicinity. The local villagers maintain these plantations at present. Honey was already available in the forests, but apiculture had never been used as an income generating, activity. In 1992-4, IUCN and the Pak-Beekeepers Society initiated the Mangrove Honey Production Project for the villagers in the northern part of the Indus delta. This was mainly to provide an alternative source of income during the time of the year, when fishing is banned in the harbour. The project has grabbed the attention of many villagers and seems to be on the road to success.

These forests play a vital role in many aspects of animal, plants and human life. Mangroves serve as nurseries for fish, shrimps, crabs and other marine life. Shrimps also use them as a breeding ground. A large proportion of coastal fish and shrimps pass at least a portion of their lives in the mangroves. They are dependent on the food chains for their sustenance and are protected by these shrubs during the fragile early period of their lives. They act as guardians of river banks and coastlines. The areas near the sea are secured from the harmful effects of cyclones, hurricanes and typhoons. Their roots collect the sediment that flows into the sea with the river and slow down the water's flow, helping to protect the coastline and preventing erosion. They are extensively used as fodder and fuelwood. The water surrounding them is rich in different of fish, shellfish and other sea organisms, which are a rich economic source for the country.