Studies on the effect of toxic heavy metal mercury on the physiology and biochemistry of an estuarine crab Scylla serrata (Forskal)

This thesis Entitled studies on the effect of toxic heavy metal mercury on the physiology and biochemistry of an estuarine crab scylla serrata (Forskal). Evaluate the toxicity of three sub lethal concentrations of mercury, viz., 0.009 mg/l, 0.02 mg/1, and 0.04 mg/l on the mud crab, Scylla serrata through bioaccumulation, and depuration studies. To characterize the biochemical responses to the sub-lethal stress of mercury in chelate muscles, abdominal muscles, hepatopancreas and gills. To study the activity pattern of acid and alkaline phosphatases in mercury-exposed crabs. To evaluate the induced changes in these tissues through histopathological studies,The Cochin backwaters is one of the most productive and biologically active backwater systems, and is the habitat of varieties of fishes, mollusks, and crustaceans, though this water body also receives tons of effluents from factories located on the banks of the river, Periyar.To study the activity levels of acid and alkaline phosphatases in crabs, at three time periods, exposed to three sub lethal concentration of mercury,

A Comparative Study Of The Organisation And Management Of Notihed Markets In Bangladesh With The Organisation And Management Of Regulated Markets In West Bengal India

For improving agricultural marketing, which has been discussed in the previous chapter, the Government has intervened in different ways. The direct regulatory role through the regulation of markets and market practices is one of the ways in which governmental intervention can improve agricultural marketing. This study is an enquiry of the direct regulatory role of the government through regulation of markets and market practices. By restructuring the operational methods and redesigning the existing physical markets, this system gives direct benefit to the cultivating class and protects them from the market manipulations of organised and powerful private traders. If traders do not continue their trade for the time being they will not be affected financially, because they are resourceful or financially solvent. On the other hand, Cultivators must sell their produce immediately after harvesting for the lack of additional facilities or to satisfy other needs for which finance is required. Another important reason is that Cultivators/farmers are not organised and because of lack of their organisation, they sell their produces individually. In this situation, a farmer is helpless when astute traders indulge in manipulations at the time of purchase of the produces. So it is the government's obligation to protect the interest of the farmers. Protection of the farmer/cultivator is necessary not only from the point of social justice but also from that of economic growth. If the farmers are assured of a remunerative or incentive price for their produce, they will get the inspiration to produce more and through more production, economy will be developed and the nation as a whole will be benefitted. This study will examine the management system of the markets through the direct regulatory role played by the governments to control markets and market practices in West Bengal and Bangladesh.

Application of ocean colour data to study the oceanographic and atmospheric features off the southwest coast of India with special reference to upwelling

Satellite remote sensing is being effectively used in monitoring the ocean surface and its overlying atmosphere. Technical growth in the field of satellite sensors has made satellite measurement an inevitable part of oceanographic and atmospheric research. Among the ocean observing sensors, ocean colour sensors make use of visible band of electromagnetic spectrum (shorter wavelength). The use of shorter wavelength ensures fine spatial resolution of these parameters to depict oceanographic and atmospheric characteristics of any region having significant spaio-temporal variability. Off the southwest coast of India is such an area showing very significant spatio-temporal oceanographic and atmospheric variability due to the seasonally reversing surface winds and currents. Consequently, the region is enriched with features like upwelling, sinking, eddies, fronts, etc. Among them, upwelling brings nutrient-rich waters from subsurface layers to surface layers. During this process primary production enhances, which is measured in ocean colour sensors as high values of Chl a. Vertical attenuation depth of incident solar radiation (Kd) and Aerosol Optical Depth (AOD) are another two parameters provided by ocean colour sensors. Kd is also susceptible to undergo significant seasonal variability due to the changes in the content of Chl a in the water column. Moreover, Kd is affected by sediment transport in the upper layers as the region experiences land drainage resulting from copious rainfall. The wide range of variability of wind speed and direction may also influence the aerosol source / transport and consequently AOD. The present doctoral thesis concentrates on the utility of Chl a, Kd and AODprovided by satellite ocean colour sensors to understand oceanographic and atmospheric variability off the southwest coast of India. The thesis is divided into six Chapters with further subdivisions

STUDIES ON THE QUALITY AND PROCESS CONTROL FACTORS DURING THE PRODUCTION AND STORAGE OF SALTED DRIED FISH PRODUCTS

In this study the quality and process control factors during the production and storage of salted dried fish products. The study reveals that quantity of dry fish production in the state is decreasing and dry fish processing industry should be encouraged by central and state governments. The dry and wet salting may be carried out to a period of 4 to 8 hours respectively and time may depend on temperature, size, and concentration of medium. Demand is an unavoidable factor for sale of fish. The packed dry salted lots kept at room temperature are useful only for 20 days. The refrigerator- stored lots had more storage life and nutritional content are good up to 3 months. The cold storage stored dry salted lot had more storage life than the wet salted lot. The use of preservatives in salting is encouraged to reduce pH. The low temperature preservation maintains the nutritional value and quality for long period. It further encourages the labeling of nutritional value of dry fish as in tinned products.

Studies On The Biology And Fishery Of The Fishes Of The Family Priacanthidae (Pisces : Perciformes) Of Indian Waters

Preliminary investigations revealed that 3. hamrur is the predominant species along the east and west coasts of India while other species are sparsely distributed and occur sporadically. In the present investigation, aspects such as population parameters, breeding and feeding biology, fishery etc. of _l:. hamrur of the north east coast of India (Fig.1) are dealt with. Studies on the distribution, abundance and stock size of priacanthids all along the Indian waters were undertaken. Taxonomic studies of the priacanthid species encountered during the study from the Indian waters is also attempted