Cell volumes of phytoplankton collected from 12 different stations distributed in western and central Indian Sundarbans were estimated through calculation of similar type of geometric models. 12 geometric shapes have been assigned to calculate the cell volume of 47 phytoplankton species documented during the study period. The cell volume of the observed species was more in the western sector (112.89-269383.60 urn3) compared to the central sector (108.37-225131.20 urn3). Among 47 species recorded during December 2011, cell volumes of 6 species exhibited significant inverse relationships, and 2 species exhibited significant positive relationships with aquatic salinity. Our results suggest that cell volume of certain phytoplankton species can be used as indicator of aquatic salinity. © The National Academy of Sciences, India 2012.

ABHIJIT MITRA

Marine Science

S ZAMAN

S K RAY

S SINHA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

National Academy Science Letters

The ever increasing emission of carbon dioxide due to rapid industrialization, urbanization, unplanned tourism and alteration of land use pattern is causing unprecedented changes to marine biodiversity. Irrespective of political philosophy, nation, caste, sex and religion, mankind is under the appalling shadow of climate change. Today nature-based approaches for the mitigation of climate change are increasingly accepted as part of the low-cost solution. Thrust has been given by several scientific communities to assess the magnitude and viability of carbon sequestering potential of plants. Coastal producer communities like mangroves, salt marsh grass, seagrass beds, and seaweeds absorb atmospheric carbon dioxide during the process of photosynthesis. This carbon known as the blue carbon is thus associated with the marine and estuarine ecosystems. However, a number of gaps in our scientific knowledge on blue carbon domain still exist. Molluscs, coral reefs, phytoplankton, which are amongst the important storehouses of carbon, have not been addressed. Very few scientific studies on the carbon stored in these valuable natural vaults have been performed, and no data bank is available on their carbon sequestering capacity on global basis. 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 blue carbon ecosystems and implement projects around the world that demonstrate the feasibility of blue carbon accounting, management, and incentive agreements. The present book has critically presented the data bank for each community of blue carbon not merely in the form of text description, but also through case studies that are the outcomes of research projects and pilot programmes." © Springer India 2015.

Blue Carbon Reservoir of the Blue Planet

Blue carbon reservoir of the blue planet

There are no differences of opinion in saying that the climate of the planet Earth is changing with the passage of time. Although several factors beyond our control (like variations in the Earth's orbital characteristics, volcanic eruptions, variations in solar energy output and plate tectonics) do play a major role in this change, the infl uence of human intervention cannot be ignored. The rapid industrialization and urbanization in the recent era has hiked up the concentration of greenhouse gases in the atmosphere, and as the successive events, the temperature has increased, the seawater has expanded, the agricultural productivity has gone down, the existing socio-economic profi le has altered, the vector-borne diseases have proliferated and the biodiversity of the world oceans and estuaries has changed. Question arises whether these chain reactions are irreversible in nature. Question also arises regarding the rate of alteration (acceleration or retardation) of environment around us, and we are uncertain about these answers. All the nations of the world have converged on a common platform to fi ght this invisible demon with irregular and uncertain behaviour. There is no point other than adaptation to minimize the impact of climate change. Adaptation here refers to the ability to respond and adjust to actual or potential impacts of changing conditions of the climate in ways that moderate harm or takes advantage of any positive opportunities that the climate may afford. It is therefore a mode of coping with the surrounding environment through development and alteration/modifi cation of some attitude, habit, habitat, etc. Even changes in the policy level or planning processes or decision-making processes are also the part of adaptation. This manuscript critically focuses on all the events of climate change starting from causes to effects on the matrix of mangrove ecosystem. Sundarbans being the biggest mangrove chunk of the globe has been used as the test bed to distinguish between human factors (effects of dam construction, barrage discharge, industries, etc.) and natural causes of environmental change, which often creates a noise while explaining the issue of climate change. The emphasis has been given on Indian Sundarbans because the subcontinent has been identifi ed as one among 27 countries which are most vulnerable to the impact of global-warming-related accelerated sea-level rise (UNEP 1989). Available literatures state that the sea level is rising at the rate of 3.14 mm/ year in Indian Sundarbans, which is greater than the average sea-level rise in rest part of the globe. The Indian Sundarbans sustains 34 true mangrove species, which not only act as the line of defence against sea-level rise, cyclones and tidal surges, but their role in carbon sequestration and minimization of carbon dioxide at the regional level has been critically analyzed in the present book. Apart from ecological approach in reducing carbon dioxide level of the atmosphere, the existing policies and laws have also been discussed in the matrix of Indian subcontinent. In India, there are no laws, policies, insurance or funds to protect, compensate and rehabilitate the vulnerable communities related to climate change or weather extremes. This creates a situation where the properties and life along the coastline are exposed to extreme risks. Building of cyclone shelters and tidal surge warning system along with a well-orchestrated disaster management plan can ameliorate the adversity of impact to a certain extent. The authors of the present book feel the necessity of introducing some kind of climate insurance policies (like health insurance and car insurance) to cover the risk of climate-change-related disasters. The book has its own individuality not because of the lucidness of language and presentation of relevant case studies but for bringing in frontline the long-term data (30 years) of this biggest mangrove chunk, which have just started to see the light of publication. Criticism and debates are the hallmarks of any climate-change-related books, as a 'noisy zone', always lies in such subjects, where it is diffi cult to segregate the effects of climate change from man-made intervention. In this connection, the Farakka dam issue has been discussed very clearly with its major role in regulating the salinity at the confl uence of the Hooghly-Bhagirathi system and Bay of Bengal. Finally the untapped marine and estuarine living resources (like seaweeds and edible oyster) have also been highlighted with the aim to develop alternative livelihood schemes as steps towards adapting to a new situation of rising salinity. © Springer India 2013. All rights are reserved.

Sensitivity of Mangrove Ecosystem to Changing Climate

Sensitivity of mangrove ecosystem to changing climate

Climate change induced sea level rise (SLR) added with anthropogenically altered environment leads to rapid land dynamics in terms of erosion and accretion; and alteration in species diversity and productivity, more pronouncedly in sensitive ecosystems such as river deltas. Here, we tried to analyze the historical records to understand the SLR with respect to hydrological conditions, sedimentation and morphological processes. We analyzed the land transformation of few islands in Indian Sunderbans using maps and satellite images in increasing order of temporal frequency between 1924 and 2008, which revealed that both the erosion and accretion processes go hand in hand. Increase of downstream salinity due obstruction in upstream has led to decrease in transparency of water causing decrease in phytoplankton and fish, density and diversity in the central sector of Indian Sunderbans. Analysis of the above ground biomass of three dominant mangrove species (Sonneratia apetala, Avicennia alba and Excoecaria agallocha) revealed better growth in the western sector compared to the central sector. The study reveals the cumulative effect of climate change and anthropogenic disturbance on the diversity and productivity in World's largest ecosystem; and advocates mangrove plantation and effective management of freshwater resources for conservation of the most vulnerable and sensitive ecosystem. © 2012 Springer Science+Business Media B.V.

Biodiversity and Conservation

Climate change impacts on Indian Sunderbans: A time series analysis (1924-2008)

Heavy metals are dangerous to aquatic organisms and it can be bioaccumulated in the food chain leading to diseases in human. Cumulative effects of metals or chronic poisoning may occur as a result of long-term exposure even to low concentrations. The accumulation of heavy metals varies depending upon the species, environmental conditions, and inhibitory processes. Concentrations of zinc, copper, lead, and cadmium were determined in finfish and shellfish species in the Gangetic delta using a PerkinElmer Sciex ELAN 5000 ICP mass spectrometer and expressed as milligrams per kilogram of dry weight. In finfish and shellfish species the concentrations of Zn, Cu, Pb, and Cd were comparatively higher at stations 1 and 2 than the permissible level of WHO. The concentration of metals exhibited significant spatial variation and followed the order station 1 > station 2 > station 3 > station 4, which may be related to different degree of contamination in different location. The metal accumulation exhibited species specificity. © Springer Science+Business Media B.V. 2011.

Journal	National Academy Science Letters
Publisher	NATL ACAD SCIENCES INDIA
ISSN	0250-541X
Open Access	No