Informatics Publishing Limited

Ashis Kumar Panigrahi ¹

Affiliations
1 Fisheries and Aquaculture Ext. Laboratory, Dept. of Zoology, University of Kalyani, Kalyani-741235, Nadia, West Bengal, IN

Abstract

River Churni is a very important river of Nadia district, West Bengal. It performs important role in geo-morphological, environmental, sociological and economic status of the district. Studies have revealed that due to huge pollution load from diffused sources, ecological condition of the river is in critical state. The degrading ecological condition casts some adverse impacts upon socio-economic condition of the river-side villages. As such the present study was undertaken to estimate the whole scenario of the Churni river pollution. The river loses its natural productivity especially in its upstream. Rest of the part of the total stretch is facing serious threat of ecodegradation. Some fishes have been found to be eliminated completely from the stretch. Huge variations in the limnological parameters and presence of only 33 fish species (mostly present in middle and lower stretch) in the river have been evident during the total stretch of the study. The fishermen from the said arena have compelled to quit their occupation owing to the aforesaid degrading condition of the river. In this study, seasonal variation of limnological parameters, present status of fish fauna and socio-economic structure of the riverside fishermen community have been beaconed to compare the previous and recent conditions. Comparing the result with the previous reports, about 61.35% fishermen are found to switch over their occupation since last 2 decades. About 72.73% in upstream, 65% in mid-stream and 25% in downstream have been recorded as elimination rate of fish since the period. Decreasing rate of dissolved oxygen (DO) and increasing Biochemical Oxygen Demand (BOD) indicate the deterioration of water quality. To cope up with this problem, suggestions have been discussed in several awareness programmes, seminars at grass ischolar_main level in the river side areas, conducted by the research team. It is also found that the actual development of the riverine ecosystem and socio-economic condition of the riverside communities can be improved only by the proper interference of Governmental actions.

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Avijit Bakshi ¹, Ashis Kumar Panigrahi ¹

Affiliations
1 Fisheries and Aquaculture Ext. Laboratory, Department of Zoology, University of Kalyani, Kalyani-741235, Nadia, West Bengal, IN

Abstract

Sundarban is the largest chunk of mangrove forest and only tiger inhabiting mangrove land in the world. It is one of the most beautiful biospheres in the world, which happen to safeguard one of the most densely populated areas of the country from several catastrophes. This mangrove ecosystem of Indian subcontinent is well known not only for the aerial extent, but also for the species diversity. The biodiversity of Sundarban includes numerous species of phytoplankton, zooplankton, micro-organisms, invertebrates and vertebrates. But the biodiversity scenario has changed during past few decades. As for residents of Sundarban, climate change is becoming a part of their survival battle. Recorded data shows that a huge number of flora and fauna were eliminated due to the consequences of climate change during the last century. Climate change components that affect mangroves and its inhabitants include changes in sea-level, high water events, storminess, precipitation, temperature, atmospheric CO2 concentration and ocean circulation patterns. This study was conducted to identify the threats on the diversity and its effect on the socio-economic condition of the local community.

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Santanu Debnath ¹, Ashis Kumar Panigrahi ¹

Affiliations
1 Fisheries and Aquaculture Extn. Laboratory, Dept. of Zoology, University of Kalyani, Kalyani-741235, West Bengal, IN

Abstract

Zooplankton communities are the primary consumers of the aquatic ecosystem and they constitute important food source of many carnivorous and as well as omnivorous fishes. They also support necessary amount of proteins for the growth of larval carps. Distribution and diversity of zooplankton in aquatic ecosystem depend on various physico-chemical characteristics of water. Keeping in view the importance of such zooplankton community in the wetlands, a year long study was carried out in Purbasthali beel, an ox-bow lake, situated in the Burdwan district of West Bengal. Studies were undertaken to assess the physico-chemical parameters of water in each month of the study year. Zooplankton species diversity of this wetland was found to be quite high. Among the zooplankton community Copepoda showed the highest percentage (47.40%), followed by Cladocera (31.38%) and Rotifera (16.27%), while Ostracoda showed the lowest percentage of population (4.95%).

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