The New Nation - Internet Edition

Md Tareq Mahmud

Bangladesh is a country with a small territory of 14 million hectares (mn ha), where the cultivable land area is only 9 mn ha. But it is blessed by 3 mn ha of coastal area, of which 1 mn ha is specially characterized by rich and diverse fauna and flora. The coastal area starts from the Indian border in the west and extends some 480 km up to the Burma (Myanmar) border in the southeast and the Bay of Bengal in the south. It includes the numerous low-lying islands and vast mangrove swamps (the Sundarbans) in the southern part of the Ganges-Brahmaputra delta, the similar but much smaller estuarine systems along the Chittagong coast (Chokoria Sundarbans and Naaf Estuary), and a single coral island of the extreme southern tip of the country (St. Martin's Island).The estuaries are also very rich in prawns and shrimps, such as Parapenaeosis, Penaeus, Palaeomon, etc., including estuarine crocodiles, 25 species of turtles and tortoises, three species of monitor lizards and numerous snakes. In fact, the coastal resources are rich with a wide diversity of plants and animals, including significant wild life species. The western part of the Sundarbans lies in India and the rest, almost 60 per cent, is in Bangladesh. This is dominated by two plant species, Heriteria fomes and Excoecaria agallocha. It is characterized by tidal inundation with the pattern of semidiurnal type and the maximum amplitude of 3 m at spring tides. The climate is humid tropical, with an annual rainfall of about 1600 mm to 2500 mm in the central and outer coasts, respectively. Violent storms are frequent during the pre-monsoon period, and again in September, October and November.

Fishermen commonly catch over 120 species of fishes, including 95 species of water fowl, more than 270 species of local and migratory birds, along with very rich species of birds of prey in mangrove swamps. About 42 species of mammals are still seen in the Sundarbans, including the rare Royal Bengal Tiger, Panthera tigris. A recent study estimates the principal mammalian populations as: 350 tigers; 40,000- 70,000 rhesus macaques; 50,000- 80,000 spotted deer; 20,000 wild boars; and 20,000 smooth-coated otters. Crustaceans are also important for the biomes of the system. Crabs, prawns and shrimps are the main groups.

About 20 million people live in the coastal region of Bangladesh, 20 per cent of whom directly depend on the coastal and marine resources for their livelihood. They live exclusively on fishing of wild fish, along with crabs, prawns and shrimps. In addition, the mangrove ecosystem provides living support to nearly 300,000 coastal people through fishing, collecting honey, wax and timber, hunting, and soon. Fishery production in mangroves increased significantly to 14,000 tonnes in 1982-83, compared to 640 tonnes in 1972-73. Many thousands are engaged in collection of honey and wax. It was estimated that about 232 tonnes of honey and wax were harvested in1983. In addition, collection of shrimp fry is an important source of livelihood. The mangrove forest also has a buffer function, protecting the densely settled agricultural areas to the north from the full force of cyclonic storms and tidal waves.

The marine resource of Bangladesh is also of great importance, geographically provided by a relatively shallow embayment of the northeastern Indian Ocean and the Bay of Bengal in the southern part. The Bay of Bengal occupies an area of

2,173,000 sq km, with an average depth of 2,600 meters and a width of 1600 km. In 1974, the special economic zone provision allowed Bangladesh the right of enjoying up to 200 nautical miles (370 km) from the seashore, which comprises an area of 166,000 sq. km, larger than the land mass.

The ecosystem in this region is quite distinct and tropical in nature. The huge river drainage and the profusion of wetlands, marshes, and mangroves increase productivity of near-shore fish species. About 475 species of fishes are found in this renewable habitat, along with 16 species of marine shrimps. In addition, several species of crabs and 31 species of turtles and tortoises, of which 24 live in coastal fresh-water environment, are also found (P. Gain, 1998). The marine fishery is totally open and contributes to 23 per cent of the total fish catch. The marine fisheries are of two types: industrial (trawling) and artisanal, the former contributing about 6 per cent and the later 17 per cent of the total catch. Another aspect is the discovery of petroleum and gas reserves in the marine zone. It was recently estimated that about 20 trillion cubic feet of gases can be extracted from the bottom of the Bay of Bengal. The most recent World Bank estimate shows that Bangladesh is expected to receive US$ 1049 million by 2004, most of which would go to the oil and gas sectors. Regarding ocean transportation facilities, the

Bay of Bengal is of great significance to Bangladesh and neighboring countries like Sri Lanka, India and Myanmar. Carriage of cargoes to and from these countries is of immense importance. The oceanic transport route directly supports the principal seaports of Bangladesh, Chittagong and Mongla.

Degradation of the Marine Environment: Industrial effluents and urban sewage, along with agrochemicals used in the coastal crop fields, are the main threats to the coastal-marine water resource. The two seaports, Chittagong and Mongla, along with the industrial cities of Khulna and Chittagong are of highest concern. In Chittagong, out of the 720 industrial units, only 20 per cent treat their liquid effluents before disposal. These effluents contain hazardous chemicals like chromium, salt, sulphur, costic soda, butanol and so on, finally carried to the Bay of Bengal through the river Karnafuli.

Khulna possesses 300 large industrial units, which discharge about 10 million gallons of liquid waste that finally reach the Bay of Bengal through the Sundarbans. Oil spills on the seaports and ships navigating the area are other sources of pollution. Shipbreaking on the beach add to the pollution. All these pollutants seriously affect the aquatic fauna and the mangrove vegetations. Uncontrolled, illegal fishing and overfishing of marine fishes and aquatic turtles, molluscs and crustaceans threaten marine fish resources. Excess navigation also disturbs the natural habitat of the aquatic flora and fauna.

The Sundarbans have been exploited from time immemorial, when human settlement started in the basin by cutting and clearing the vegetation for homestead and cultivation. Hardly 100 years ago, the area came under the maintenance of the government's department of forest. Agricultural encroachment, a common and indigenous phenomenon to this important ecosystem, threatens its existence. Population explosion and dense settlement in the coast surrounding the Sundarbans could reach a disastrous position, unless checked. Fishermen's camps are also a cause of serious disturbance, with their illegal trapping and hunting. This illegal activity is also done by the woodcutters and a reasonable number of civil and defence officers. Along with agricultural encroachment, the recent aquaculture missions, especially shrimp farms and their intensive cultivation, have added serious damage to the mangrove forests, including the fries of all wild fish.

The ecological disturbances of mangrove forests have been caused by many anthropogenic activities that go against the natural course of development. The first one is the diversion of Ganges water streams. About 40 per cent of the dry season flow of the Ganges has been diverted upstream, following the Farrakhan Barrage in India in 1974. This accelerates the decrease of fresh-water flushing and increases the saline water intrusion, particularly in the dry season, which damages the vegetation and finally degrades the environment. Oil spills cause immense damage, especially to the aquatic fauna and sea birds. The seaport Mongla is the main source of oil spills, with pollution also coming from the large and numerous shipping vessels that pass through the Sundarbans every day via the northeast shipping route. The most significant and immediate threat is the illegal overextraction of the timber and fauna. In the 1980s, an assessment showed that the stock of Heriteria fomes, the principal variety of mangrove locally known as Sundari, has declined by 40 per cent since the forest inventory of 1959. At the same time, another dominant species, Excoecaria agallocha, has fallen by 45 per cent. For any Bangladeshi, it would be shocking to know that, in the near future, the Sunderbans will be a misnomer due to the possible extinction of Sundari if the trend of exploitation continues, instead of conservation and management.