2. Significance and importance:
The first and foremost objective of a field study is to specifically analyze the various topics of interest regarding [i.e. behavior, autoecology, flora and fauna diversity etc] and to perform detailed observations and drawing out conclusions. Not to mention that ecology can’t be studied theoretically but also it needs a practical way of approach by which we can frame the exact issue of our interest. This makes studying ecology in a broader sense. Compared to experiment performed in the lab , studying on-field elements and observing them leads to more accurate results since we get a visual outlook on them.
Its important can be mentioned in the following points:-
Understand basic ecological principles as applied to global and local ecosystems.
Understand basic ecological principles as applied to global and local ecosystems.
Be able to apply an understanding of ecological principles to issues of environmental concern.
Have experienced and used a variety of ‘modern experimental’ and ‘traditional’ field studies techniques during practical investigations of a range of natural and managed terrestrial ecosystems.
Be familiar with aspects of preservation and management of natural and semi natural habitants of conservation importance.
Here in our case we have studied the ecological diversity of a coastal ecosystem prevailing in Digha, West Bengal. After stating the importance and significance of the ecological field study. We will now give a brief about West Bengal, its ecological significance, its coastal ecosystem features and characteristics along with conservation strategies.
WEST BENGAL: A Brief Introduction
West Bengal is a state in eastern India and is the nation's fourth-most populous state, with over 91 million inhabitants. Spread over 34,267 sq mi (88,750 km2), it is bordered by the countries of Bangladesh, Nepal and Bhutan, and the Indian states of Orissa, Jharkhand, Bihar, Sikkim, and Assam. The state capital is Kolkata. Together with the neighboring nation of Bangladesh and parts of the state Tripura, it makes up the ethno-linguistic region of Bengal.
West Bengal is on the eastern bottleneck of India, stretching from the Himalayas in the north, to the Bay of Bengal in the south. The state has a total area of 88,752 square kilometres (34,267 sq mi). The Darjeeling Himalayan hill region in the northern extreme of the state belongs to the eastern Himalaya. This region contains Sandakfu (3,636 m or 11,929 ft)—the highest peak of the state. The narrow Terai region separates this region from the plains, which in turn transitions into the Ganges delta towards the south. The Rarh regionintervenes between the Ganges delta in the east and the western plateau and high lands. A small coastal region is on the extreme south, while the Sundarbans mangrove forests form a geographical landmark at the Ganges delta.
The Ganges is the main river, which divides in West Bengal. One branch enters Bangladesh as the Padma or Pôdda, while the other flows through West Bengal as the Bhagirathi River and Hooghly River. The Farakka barrage over Ganges feeds the Hooghly branch of the river by a feeder canal, and its water flow management has been a source of lingering dispute between India and Bangladesh. The Teesta,Torsa, Jaldhaka and Mahananda rivers are in the northern hilly region. The western plateau region has rivers such as the Damodar, Ajayand Kangsabati. The Ganges delta and the Sundarbans area have numerous rivers and creeks. Pollution of the Ganges from indiscriminate waste dumped into the river is a major problem. Damodar, another tributary of the Ganges and once known as the "Sorrow of Bengal" (due to its frequent floods), has several dams under the Damodar Valley Project. At least nine districts in the state suffer from arsenic contamination of groundwater, and an estimated 8.7 million people drink water containing arsenic above the World Health Organisation recommended limit of 10 µg/L.
West Bengal's climate varies from tropical savanna in the southern portions to humid subtropical in the north. The main seasons are summer, rainy season, a short autumn, and winter. While the summer in the delta region is noted for excessive humidity, the western highlands experience a dry summer like northern India, with the highest day temperature ranging from 38 °C (100 °F) to 45 °C (113 °F).At nights, a cool southerly breeze carries moisture from the Bay of Bengal. In early summer brief squalls and thunderstorms known as Kalbaisakhi, or Nor'westers, often occur.[48] West Bengal receives the Bay of Bengal branch of the Indian ocean monsoon that moves in a northwest direction. Monsoons bring rain to the whole state from June to September. Heavy rainfall of above 250 cm is observed in the Darjeeling, Jalpaiguri and Cooch Behar district. During the arrival of the monsoons, low pressure in the Bay of Bengal region often leads to the occurrence of storms in the coastal areas. Winter (December–January) is mild over the plains with average minimum temperatures of 15 °C (59 °F). A cold and dry northern wind blows in the winter, substantially lowering the humidity level. The Darjeeling Himalayan Hill region experiences a harsh winter, with occasional snowfall at places.
As of 2013, recorded forest area in the state is 16,805 km2 (6,488 sq mi) which is 18.93% of the state's geographical area, compared to the national average of 21.23%.Reserves, protected and unclassed forests constitute 59.4%, 31.8% and 8.9%, respectively, of the forest area, as of 2009. Part of the world's largest mangrove forest, the Sundarbans, is located in southern West Bengal.
From a phytogeographic viewpoint, the southern part of West Bengal can be divided into two regions: the Gangetic plain and the littoral mangrove forests of the Sundarbans. The alluvial soil of the Gangetic plain, compounded with favourable rainfall, make this region especially fertile. Much of the vegetation of the western part of the state shares floristic similarities with the plants of the Chota Nagpur plateau in the adjoining state of Jharkhand. The predominant commercial tree species is Shorea robusta, commonly known as the Sal tree. The coastal region of Purba Medinipur exhibits coastal vegetation; the predominant tree is the Casuarina. A notable tree from the Sundarbans is the ubiquitous sundari (Heritiera fomes), from which the forest gets its name.
The distribution of vegetation in northern West Bengal is dictated by elevation and precipitation. For example, the foothills of the Himalayas, the Dooars, are densely wooded with Sal and other tropical evergreen trees. However, above an elevation of 1,000 metres (3,300 ft), the forest becomes predominantly subtropical. In Darjeeling, which is above 1,500 metres (4,900 ft), temperate-forest trees such as oaks, conifers, and rhododendrons predominate.
West Bengal has 3.26% of its geographical area under protected areas comprising 15 wildlife sanctuaries and 5 national parks— Sundarbans National Park, Buxa Tiger Reserve, Gorumara National Park, Neora Valley National Park and Singalila National Park. Extant wildlife include Indian rhinoceros, Indian elephant, deer, leopard, gaur, tiger, and crocodiles, as well as many bird species. Migratory birds come to the state during the winter. The high-altitude forests of Singalila National Park shelter barking deer, red panda, chinkara, takin, serow, pangolin, minivet and Kalij pheasants. The Sundarbans are noted for a reserve project conserving the endangered Bengal tiger, although the forest hosts many other endangered species, such as the Gangetic dolphin, river terrapin and estuarine crocodile. The mangrove forest also acts as a natural fish nursery, supporting coastal fishes along the Bay of Bengal. Recognizing its special conservation value, Sundarban area has been declared as a Biosphere Reserve.
MAPS
PRESENCE OF WEST BENGAL IN INDIA
COASTAL PLAIN OF WEST BENGAL
A small coastal region is on the extreme south of the state. A part of the district of Purba Medinipur along the Bay of Bengal constitutes the coastal plain. This emergent coastal plain is made up of sand and mud deposited by rivers and by wind. Parallel to the coast are colonies of sand dunes and marshy areas. The Digha dune lies nearest to the Bay of Bengal while the Kanthi dune is the farthest from it. In some areas dunes occur at a distance of 15–16 km from the coast and are 11–12 m high.
India has a coastline of 7517km of which the mainland accounts for 5422km. Lakshadeep coast extends 132km and Andaman and Nicobar Islands have a coastline of 1962km. Nearly 250 million people live within a distance of 50km from the coast (Qasim et al., 1988). Coastal habitats across the world have been under multi-dimensional threats during last few decades because of high population and development pressures. Mangroves have been particularly vulnerable to exploitation because they contain valuable bioresources and provide significant ecological services. Mangrove ecosystem, a unique, fragile, highly productive ecosystem in the sealand interphase, is the conglomerations of plants, animals and microorganisms acclimatized in the fluctuating environment of tropical intertidal zone. Mangrove forests cover wide tropical and subtropical intertidal areas of coastal environment, and they are very important for their role in maintaining biodiversity, for sustainable livelihood (e.g., wood and food resources) and for coastal protection (Robertson and Alongi, 1992; Wolanski, 2006a). The coastal area of West Bengal extends over 0.82 million hectors and 220km of coastal line. Muddy coast accounts for 180km, of which 90% are treated as marshy zone having halophytic vegetation and their associated flora and fauna; only around 40km is considered as sandy belts. It includes two coastal districts – The South 24 Parganas, supported by Sundarban Mangrove Ecosystem and Midnapore Coast having sand flats and degraded mangrove patch. Indian part of Sundarbans occupies mangrove area (4262km2 ) slightly more than that (4109km2 ) of highly reclaimed counterpart in Bangladesh (Chaakraborty, 2011). The coastal belt of Midnapore district represents 27% of West Bengal of coastal tract (60km) extending along the west bank of Hooghly estuary from New Digha and then curving around Junput, Dadanpatrabarh, Khejuri and Haldia on the east to the further north east upto Tamluk or even on the bank of Rupnarayan (Fig. 1). In West Bengal, three seasons are very much pronounced (premonsoon, monsoon and postmonsoon), each with four months duration and are mainly governed by rainfall and temperature.
Deltaic regions are mostly clayey due to high deposit of sediments [ 8 million tones/yr]through the Hooghly system. A clayey blanket covering gravels of sandstone , siltstone and quartz indicate quaternary age of the area. A neotectonic and morphological tilt between 12th and 16th century resulted in an uplift of the western part of the Ganga towards the Padma and hastened the deltaic formation. Consequently, West Bengal does not receive the fertile alluvium as before and the terrain is not de-salinated by river floods. The beaches and inlets, creeks, and mangroves swamps, mudflats, coastal dunes and sand flats are the characteristics of the area.