Life History and Population Dynamics of Tenualosa ilisha of Sundarban Estuary in Bay of Bengal, India for Sustainable Fishery Management

1870-1880The population structure of Hilsa Shad (Tenualosa ilisha), a choicest table fish, in the estuaries of India, Bangladesh and Myanmar of Bay of Bengal has been studied by different methods and each provided complementary data on population structure. Considering the present scenario of climate change, increasing pollutant load in Indo–Bangladesh and its effect on reproduction and maturation a thorough and detailed understanding of the life cycle of Hilsa is a pre requisite criteria. However, understanding of the life history of anadromous Hilsa Shad, considering the widespread climatic changes, would be immensely important. Further, in view of increasing pollutant loads in the Indo-Bangladesh estuary region, the important area of Hilsa reproduction and maturation, a detailed work on the life history strategies of Hilsa is also need of the hour. Results of such studies would be important for sustainable management of this highly economic biological resource. The present paper deals with the aspects of life history and population dynamics of Hilsa Shad in Sundarban estuaries. The data collection was done during the period of June 2011 to March 2012 at Frasergunje Fishing Harbour and offshore, northern Bay of Bengal. The length and weight of total 617 Hilsa fish were measured under this study. Monthly variations of length and weight, length frequency distribution, monthly variation of the allometry coefficient, movement pattern, and catch per unit effort were estimated. The exploitation rate of Hilsa species was found to be 0.78 and the maximum sustainable yield was 11700.18 tonnes whereas the annual catch was 18126.00 tonnes. Highest weight of adult Hilsa was recorded during the monsoon i.e. the months of June, July and August. The result of relative yield per recruitment indicated that the mortality due to current fishing period and pressure were high. Widespread fishing of juvenile and growing Hilsa (. In our study we have observed over harvest of Hilsa fish, especially Jatka (<500 gms and <230 mm) from West Bengal coastal areas

Protonibea diacanthus (Lacepède, 1802): NOVA DIMENZIJA RIBOLOVA U ZAPADNOM BENGALU, INDIJA

Blackspotted Croaker (Protonibea diacanthus) is one of the most commercially important croakers which migrate along West Bengal coast during winter season. This paper deals with the importance of the species along with its market value and the cause of its popularity in West Bengal. This species is gaining prime importance among the fishermen due to the highmarket price of its swim bladder. The dried swim bladders are sold in local markets for Rs. 40,000-50,000 per kg. There is a risk factor involved as the fishermen do not get the catch at a time and, moreover, they often lose common pelagic fishes due to the usage of larger mesh nets. In spite of this risk, a shift from pelagic to demersal fishing across the northern Bay of Bengal marks an important emerging trend of winter fishing in this area.Protonibea diacanthus jedna je od gospodarski najvažnijih vrsta ribe na obali zapadnog Bengala u posljednjih nekoliko godina. Provedeno istraživanje u ovom radu bavi seispitivanjem tržišta i uzrocima popularnosti ove vrste u zapadnom Bengalu. Ova riba jako je važna za ribare zbog visoke tržišne cijene njezinog plivaćeg mjehura. Cijenaosušenih plivaćih mjehura na lokalnim tržnicama iznosi 40 000 – 50 000 indijskih rupija po kilogramu. Međutim, postoji velik rizik jer nemaju svi ribari dobar ulov u određenom vremenskom periodu i k tome često gube uobičajene pelagične ribe zbog uporabe prevelikih mreža.Unatoč riziku, postoji pomak od pelagičkog ka pridnenom ribolovu na sjeveru Bengalskog zaljeva, što pridonosi razvitku trenda zimskog ribolova u tim krajevima

Atrapadas o reasentadas: las comunidades costeras del delta de Sundarbans, India

Cuando las comunidades locales se llevan la peor parte de los efectos del cambio climático, ¿qué capacidad tienen de decidir sobre su respuesta? ¿Y de quién es la responsabilidad de ayudarles

Environmental change and migration from Indian Sundarban : the need for an adaptation policy

PowerPoint presentationThe presentation focuses on climate change and forced migration patterns in vulnerable areas of Bangladesh, factoring in changes in sea surface temperature (SST), sea level rise, monsoon rainfall and events such as cyclones. Thousands of island residents have been displaced due to disappearance of land and coastal erosion. Environmental degradation has led to population migrations of 60,000 people - with women, infirm people and children often left behind

Migration in the Indian Bengal Delta and the Mahanadi Delta `a review of the literature

This series is based on the work of the Deltas, Vulnerability and Climate Change: Migration and Adaptation (DECCMA) project, funded by Canada’s International Development Research Centre (IDRC) and the UK’s Department for International Development (DFID) through the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA).Like anywhere else in India, Migration over past several decades from ISD have occurred for better livelihood opportunities and earning better income, acquiring higher education or skills.Such migration can be seen as seasonal in nature (CRS, 2010; CSE, 2012). But over the years, studies in Indian Bengal Delta are largely concentrating on migration resulting from natural disasters like cyclones, storm surges, erosion of land, breaching of embankments or submergence of islands. (Hazra Sugata et.al., 2002; CRS, 2010; CSE, 2012; Bera M., 2013; Ghosh A.K., 2014; GhoshTuhin, et.al., 2014; Mukherjee, 2014

Protonibea diacanthus (Lacepède, 1802): NOVA DIMENZIJA RIBOLOVA U ZAPADNOM BENGALU, INDIJA

Blackspotted Croaker (Protonibea diacanthus) is one of the most commercially important croakers which migrate along West Bengal coast during winter season. This paper deals with the importance of the species along with its market value and the cause of its popularity in West Bengal. This species is gaining prime importance among the fishermen due to the highmarket price of its swim bladder. The dried swim bladders are sold in local markets for Rs. 40,000-50,000 per kg. There is a risk factor involved as the fishermen do not get the catch at a time and, moreover, they often lose common pelagic fishes due to the usage of larger mesh nets. In spite of this risk, a shift from pelagic to demersal fishing across the northern Bay of Bengal marks an important emerging trend of winter fishing in this area.Protonibea diacanthus jedna je od gospodarski najvažnijih vrsta ribe na obali zapadnog Bengala u posljednjih nekoliko godina. Provedeno istraživanje u ovom radu bavi seispitivanjem tržišta i uzrocima popularnosti ove vrste u zapadnom Bengalu. Ova riba jako je važna za ribare zbog visoke tržišne cijene njezinog plivaćeg mjehura. Cijenaosušenih plivaćih mjehura na lokalnim tržnicama iznosi 40 000 – 50 000 indijskih rupija po kilogramu. Međutim, postoji velik rizik jer nemaju svi ribari dobar ulov u određenom vremenskom periodu i k tome često gube uobičajene pelagične ribe zbog uporabe prevelikih mreža.Unatoč riziku, postoji pomak od pelagičkog ka pridnenom ribolovu na sjeveru Bengalskog zaljeva, što pridonosi razvitku trenda zimskog ribolova u tim krajevima

Resettlement and rehabilitation : Indian scenario

This work was funded by Canada’s International Development Research Centre (IDRC) and the UK’s Department for International Development (DFID) through the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA).Displacement of people in India, is largely triggered by factors such as, development projects, political conflict, setting up Protected Area Networks and Conservation areas and natural disasters, amongst others. The International Displacement Monitoring Centre in 2007 reveal that about 50 million people in India had been displaced due to development projects in over 50 years. A study conducted in six states estimated the figure at around 60 million between 1947-2000 (Fernandes, 2007; Negi &Ganguly, 2011). ...Although, these approximate figures for displacement in India may be staggering, there remains no reliable data on the total number of people actually displaced nor the number of people that have been resettled and rehabilitated. This review highlights issues relating to resettlement and rehabilitation, majorly focusing on the following causes, political/ethnic conflict, and developmental projects

Linking IPCC AR4 & AR5 frameworks for assessing vulnerability and risk to climate change in the Indian Bengal Delta

The International Panel on Climate Change (IPCC) AR5 (Fifth Assessment Report, 2014) conceptual approach and terminology is aligned with a concept of risk which differs from the previous framework (AR4). This study draws links between the AR5 concept of risk with the previous concept of vulnerability (AR4). The most significant difference between the results of the AR4 and AR5 approaches is the change in sub-district level relative rankings. Findings show that Basanti, in the Bengal Delta, is the most vulnerable sub-district using the AR4 approach, whereas Gosaba is found to be highly exposed to risk using the AR5 approach.UK Government's Department for International Development (DFID

Assessment and attribution of mangrove forest changes in the Indian Sundarbans from 2000 to 2020

The Indian Sundarbans, together with Bangladesh, comprise the largest mangrove forest in the world. Reclamation of the mangroves in this region ceased in the 1930s. However, they are still subject to adverse environmental influences, such as sediment starvation due to migration of the main river channels in the Ganges–Brahmaputra delta over the last few centuries, cyclone landfall, wave action from the Bay of Bengal—changing hydrology due to upstream water diversion—and the pervasive effects of relative sea-level rise. This study builds on earlier work to assess changes from 2000 to 2020 in mangrove extent, genus composition, and mangrove ‘health’ indicators, using various vegetation indices derived from Landsat and MODIS satellite imagery by performing maximum likelihood supervised classification. We show that about 110 km 2 of mangroves disappeared within the reserve forest due to erosion, and 81 km 2 were gained within the inhabited part of Sundarbans Biosphere Reserve (SBR) through plantation and regeneration. The gains are all outside the contiguous mangroves. However, they partially compensate for the losses of the contiguous mangroves in terms of carbon. Genus composition, analyzed by amalgamating data from published literature and ground-truthing surveys, shows change towards more salt-tolerant genus accompanied by a reduction in the prevalence of freshwater-loving Heiritiera, Nypa, and Sonneratia assemblages. Health indicators, such as the enhanced vegetation index (EVI) and normalized differential vegetation index (NDVI), show a monotonic trend of deterioration over the last two decades, which is more pronounced in the sea-facing parts of the mangrove forests. An increase in salinity, a temperature rise, and rainfall reduction in the pre-monsoon and the post-monsoon periods appear to have led to such degradation. Collectively, these results show a decline in mangrove area and health, which poses an existential threat to the Indian Sundarbans in the long term, especially under scenarios of climate change and sea-level rise. Given its unique values, the policy process should acknowledge and address these threats

Projected changes in area of the Sundarban mangrove forest in Bangladesh due to SLR by 2100

The Sundarbans mangrove ecosystem, located in India and Bangladesh, is recognized as a global priority for biodiversity conservation and is an important provider of ecosystem services such as numerous goods and protection against storm surges. With global mean sea-level rise projected as up to 0.98m or greater by 2100 relative to the baseline period (1985-2005), the Sundarbans – mean elevation presently approximately 2 m above mean sea-level – is under threat from inundation and subsequent wetland loss; however the magnitude of loss remains unclear. We used remote and field measurements, geographic information systems and simulation modelling to investigate the potential effects of three sea-level rise scenarios on the Sundarbans within coastal Bangladesh. We illustrate how the Sea Level Affecting Marshes Model (SLAMM) is able to reproduce the observed area losses for the period 2000-2010. Using this calibrated model and assuming that mean sea-level is a better proxy than the SLAMM assumed mean lower low water for Mangrove area delineation, the estimated mangrove area net losses (relative to year 2000) are 81-178 km2, 111-376 km2 and 583-1393 km2 for relative sea-level rise scenarios to 2100 of 0.46m, 0.75m and 1.48m, respectively and net subsidence of ±2.5 mm/year. These area losses are very small (<10 percent of present day area) and significantly smaller than previous research has suggested. Our simulations also suggest that erosion rather than inundation may remain the dominant loss driver to 2100 under certain scenarios of sea-level rise and net subsidence. Only under the highest scenarios does inundation due to sea-level rise become the dominant loss process