When passion meets research, tranquility blossoms

When passion meets research, tranquility blossoms

Abhijit Mitra Abhijit Mitra

Abhijit Mitra

Associate Professor at University of Calcutta

发布日期: 2024年11月6日
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It is now accepted that mangrove ecosystem provides a wide range of ecological and economic products and services, and also supports a variety of other coastal and marine ecosystems, which again provide several economic and ecological benefits. The full value of mangroves is, however, still not recognized in most economies, as most of these benefits have not yet entered the market (e.g., carbon credit from mangrove forest and soil). Consequently, mangroves have been highly undervalued and neglected ecosystems, resulting in their heavy depletion and degradation in most parts of the world. Recently researchers have initiated compiling their value in monetary terms in some parts of the world. Most of this valuation is for developed countries and even when it is for developing countries, the nature of benefits and costs estimated are very much different from the same in India, Indonesia, Sri Lanka, Pakistan or Bangladesh where mangroves play an extremely important role in the life and livelihood of coastal population. It is therefore a need to compute monetary value of mangroves in developing countries to understand its importance in the economic matrix. Today mangroves are observed in about 30 countries in tropical subtropical regions covering an area of about 99,300 Sq.Km. However during the past 50 years, over 50% of the mangrove cover has been lost, mainly because of the increased pressure of human activities like shrimp farming and agriculture, forestry, salt extraction, urban development, tourist development and infrastructure. Also, dam on rivers, contamination of sea waters caused by heavy metals, oil spills, pesticides and other products etc. have been found to be responsible for the decline of mangroves. Shrimp farming is directly linked to the loss of mangrove in tropical countries. About 2000 Sq.Km. in Vietnam, 350 Sq.Km. in India and 90 Sq.Km. in Bangladesh have been lost to shrimp farming.

Climate change and subsequent sea level rise is also a major threat to mangrove ecosystems of the world. Researchers are of the opinion that mangroves may be affected by climate change-related increases in temperature and sea-level rise. Although the temperature effect on growth and species diversity is not known, sea-level rise may pose a serious threat to these ecosystems. In Bangladesh, for instance, there is a threat to mangrove species in the three distinct ecological zones (Hypersaline, mid saline and hyposaline regions) that make up the Sundarbans-the largest continuous mangrove area in the world. If the saline water front moves further inland, Heritiera fomes (the dominant species in the landward freshwater zone of Bangladesh and locally referred to as Sundari) could be threatened. Species in the other two ecological zones Nypa fruticans and Sonneratia apetala also could suffer. These changes could result severe adverse impacts on the socio-economic profile of the coastal zone. A large section of the population-who are directly employed in the industries that use raw materials from the mangrove forests (e.g., woodcutting, collection of thatching materials, honey, beeswax, and shells, fishing) - may lose their sources of income. Sea-level rise also may threaten a wide range of mammals, birds, amphibians, reptiles, and crustaceans living in the mangrove forests.

Some ecologists believe that mangrove communities are more likely to survive the effects of sea-level rise in macrotidal, sediment-rich environments-such as northern Australia, where strong tidal currents redistribute sediment -than in microtidal, sediment-starved environments like those in many small islands (e.g., in the Caribbean). Most small islands fall within the latter classification; therefore, they are expected to suffer reductions in the geographical distribution of mangroves. Furthermore, where the rate of shoreline recession increases, mangrove stands are expected to become compressed and suffer reductions in species diversity in the face of rising sea levels. The present book addresses all these important issues in separate chapters with some interesting case studies whose data may serve as pathfinder for future researches in the sphere of the influence of climate change on mangrove ecosystem. According to me what seems to be needed, at the least is a massive programme of research and development to broaden the choices of alternative livelihood and a firm national and international commitment to mangal conservation instead of few sporadic afforestation programmes of mangrove species that are often taken up by the Government sectors and private organizations. The role of mangroves in the sector of bioremediation is a unique feather in the crown of this coastal and brackish water vegetation that may be taken up by the coastal industries in order to maintain the health of ambient environment.

The present book has critically presented the data bank for biotic and abiotic resources not merely in the form of text description, but also through case studies that are the outcomes of research projects and pilot programmes carried out in different parts of the world. The influence of relevant hydrological parameters on the biotic community has also been critically analyzed through statistical tools. Advanced researches in marine ecology are based on sophisticated instruments, sampling precision, statistical tools etc. Considering these aspects, the present book also attempted to discuss these topics in details so that a road map can be formulated for budding ecologists.
The methodologies for assessing blue carbon stock also need further standardization so that credit from blue carbon reservoir is accepted by the International bodies in the form of a concrete policy. It is a matter of great appreciation that Conservation International (CI), the International Union for Conservation of Natural Resources (IUCN), and the Intergovernmental Oceanic Commission (IOC) of UNESCO is collaborating with governments, research institutions, non-governmental and international organizations, and communities around the world to develop management approaches, financial incentives and policy mechanisms for ensuring conservation and restoration of coastal blue carbon ecosystems and implement projects around the world that demonstrate the feasibility of coastal blue carbon accounting, management, and incentive agreements.
The methodologies for assessing blue carbon stock also need further standardization so that credit from blue carbon reservoir is accepted by the International bodies in the form of a concrete policy. It is a matter of great appreciation that Conservation International (CI), the International Union for Conservation of Natural Resources (IUCN), and the Intergovernmental Oceanic Commission (IOC) of UNESCO is collaborating with governments, research institutions, non-governmental and international organizations, and communities around the world to develop management approaches, financial incentives and policy mechanisms for ensuring conservation and restoration of coastal blue carbon ecosystems and implement projects around the world that demonstrate the feasibility of coastal blue carbon accounting, management, and incentive agreements.
The estuaries of the Indian sub-continent are known for their rich genetic diversity, biological productivity, aesthetic beauty and economic values. However, such ecotones of the World are today facing threats of various categories and magnitudes. Acidification is one stressor expected to have wide spread impacts on the estuaries, which is keenly related to rapid industrialization, urbanization and change of land-use pattern. In addition to these man-made factors, there is growing evidence of tidal and gravitational currents that can deliver low pH and hypoxic marine waters into bays and estuaries. Input of low pH water from the open sea may be impounded by local eutrophication-triggered acidification and hypoxia in nutrient rich aquatic phase of the estuaries. These alterations have high probability to impact many species (preferably the biotic community with calcareous shell) important to functional ecology of the estuaries. Adverse impact on the survival, growth, recruitment of larval and juvenile shellfish is suspected to be amongst the earliest consequences of the phenomenon of estuarine acidification.
The ecosystem services paradigm—the benefits that ecosystems provide to human populations and society are now strongly applied to threatened tropical coastal forest ecosystems preferably to intertidal mangrove forests that exist at the land-sea interface. A huge amount of research is currently focusing on the range of ecosystem services that mangrove forests provide, and their regional distribution. Mangrove forests have commonly been shown to provide multiple provisioning services that increase the economic or food security of local communities such as timber, fuel wood, medicinal, and food resources. Regulating services such as wave attenuation, and more recently carbon and nitrogen sequestration and storage have also become important in the contemporary mangrove forest research agenda. These regulating services are potentially important at very large scales, with carbon storage in Indonesia being so high that mangrove deforestation may account for as much as 10%–31% of all carbon emissions related to national land cover change. Mangrove forests also provide a diverse spectrum of cultural ecosystem services to coastal populations living close to mangrove forests, ranging from the tangible (tourism, recreation, education) to the abstract (cultural heritage, aesthetics, sense of place). While huge challenges to quantifying and valuing ecosystem services remain, mangrove forest ecosystem services have been tentatively estimated at an average of US 4185 per hectare per year, though substantial spatial and temporal variation in this figure exists.
The livelihoods associated with the mangrove ecosystem at the apex of Bay of Bengal are also poorly understood. The mangrove forests in deltaic Sundarbans are areas of complexity, opportunity, and conflict (particularly man-animal conflict). They are rich in natural resources, but also fragile in nature due to impact of climate change that has made the ecosystem highly vulnerable. The deltaic ecosystem is the homeland of about 4.5 million Indian population and the livelihoods of this large percentage of population are mostly oriented around the mangrove forests. Agriculture, pisciculture, aquaculture (preferably shrimp culture), animal husbandry, deep-sea fishing, prawn seed collection from the estuaries are the traditional livelihoods of the people of Indian Sundarbans. However, many of these livelihoods are detrimental to the environment particularly in terms of biodiversity loss. Many other dark chapters are also associated with the present mode of livelihoods in the deltaic complex like loss of stored carbon due to cutting of mangrove flora for timber, fuel, fodder etc., deterioration of the estuarine water quality due to proliferation of unplanned shrimp farming at the cost of mangroves, mass destruction of fish juveniles (ichthyoplankton) during wild collection of prawn seeds, emission of carbon dioxide from the brick kilns and tourist boats etc. All these activities have accelerated the pulse of climate change in the Indian Sundarban deltaic complex. The island dwellers are facing challenges in their livelihood domains as paddy cultivation, pisciculture and animal husbandry cannot withstand the intrusion of saline water in the island villages that frequently occurs during natural disasters like super cyclones, tidal surges etc. To overcome these challenges, it is the need of the hour to bring reformation in the sector of livelihoods. Halophyte farming, polyculture, fish feed preparation from mangrove associate species, mangrove- based snacks preparation for human consumption are some innovative steps to ensure food security as well as economic security to the people of this fragile ecosystem at the apex of Bay of Bengal. The market liberalization phase that has spread wings in India can open up new scopes and opportunities for such carbon-neutral mangrove centric livelihoods. Although many common livelihoods like pisciculture, shrimp farming, apiculture have been discussed in the framework of Indian Sundarbans, but lot of discrepancies were observed between nascent/ practicing entrepreneurs and researchers and entrepreneurs are in line with general criticism that research and practice operate independent of each other. In most of the fundamental resource-based researches, business models are often overlooked, which have been covered for all categories of innovative livelihoods with realistic cost benefit ratio.


Enhancing mangrove-based carbon trading involves standardizing carbon estimation protocols, utilizing drone and satellite data, and promoting alternative livelihoods such as halophyte farming and seaweed culture. These nature-based solutions can boost carbon sequestration and provide sustainable economic opportunities for local communities.
Contact point: [email protected]



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