| Abstract: | Fishes are one of the most important members of the aquatic food chain, and through them some toxicants may reach human beings as well. The selection of organisms for toxicity test is mainly based on certain criteria like its ecological status, position within the food chain, suitability for laboratory studies, genetically stable, uniform populations and adequate background data on the organism (Buikema et al., 1982). The species selected for the present study Etroplus maculatus satisfy most of the above protocols. Rechten (1980) opined it as a laboratory favorite of fish researchers. However, there are difficulties in the rise of fishes for pollution assessment impact. Most important of these is our limited understanding of the mechanism of toxicity. The interpretation of the significance or specificity of a measured biological response could there for become difficult. Not withstanding these limitations, attempts have been made to the normal haematology and to analyze the impact of heavy metal at realistic levels to the experimental media, on the haematology, and enzymatic activity and histology of Etroplus maculatus |
| Description: | Dept. of Marine Biology, Microbiology and Biochemistry Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3670 |
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| Dyuthi-T1627.pdf | (9.669Mb) |
| Description: | Department of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/xmlui/purl/1961 |
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| Dyuthi-T0413.pdf | (2.588Mb) |
| Abstract: | This thesis Entitled Haematological responses of penaeus monodon to environmental alterations and pathogenic invasion. Thesis concluded from the present study that stress is accompanied by alterations in haemolymph metabolic variables and immune responses that influences the susceptibility of P. monodon to infection. Acute salinity variations were proved to be a stress condition that enhances the susceptibility of P. monodon to V. harveyi and WSSV infection. Ambient Cu at 0.1 mg 1" and ambient Zn at 1.0 mg 1" proved immunostimulatory in increasing the immunocompetence of P. monodon to WSSV infection and higher concentrations of Cu and Zn proved immunosuppressive. Haemolymph total protein, total carbohydrates and total lipids showed the highest relation with immune responses. THC, PO, ACP and ALP that greatly correlated with the survival rate proposed as reliable biomarkers of health in P. monodon. The study highlights the need for proper management practices and regular health monitoring to be adopted to avoid mass mortality in shrimp culture ponds. |
| Description: | Department of Marine Biology, Microbiology and Biochemistry, School of Ocean Science and T echnology, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3033 |
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| Dyuthi-T1007.pdf | (6.565Mb) |
| Abstract: | Aquaculture has developed to become one of the fastest growing food producing sectors in the world.Today India is one among the major shrimp producing countries in the world.There are extensive and intensive shrimp culture practices. In extensive shrimp culture, shrimps are stocked at low densities (< 25 PLs m'2)in large ponds or tidal enclosures in which little or no management is exercised or possible. Farmers depend almost entirely on natural conditions in extensive cultures. Intensive shrimp culture is carried out in high densities (>200 PLs m'2). Much of the world shrimp production still comes from extensive culture.There is a growing demand for fish and marine products for human and animal consumption. This demand has led to rapid growth of aquaculture, which some times has been accompanied by ecological impacts and economic loss due to diseases. The expansion of shrimp culture always accompanies local environmental degradation and occurrence of diseases.Disease out breaks is recognised as a significant constraint to aquaculture production. Environmental factors, water quality, pollution due to effluent discharge and pathogenic invasion due to vertical and horizontal transmission are the main causes of shrimp disease out breaks. Nutritional imbalance, toxicant and other pollutants also account for the onset of diseases. pathogens include viruses, bacteria, fungi and parasites.Viruses are the most economically significant pathogens of the cultured shrimps world wide. Disease control in shrimp aquaculture should focus first on preventive measures for eliminating disease promoting factors.ln order to design prophylactic and proactive measures against shrimp diseases, it is mandatory to understand the immune make up of the cultivable species, its optimum culture conditions and the physico chemical parameters of the rearing environment. It has been proven beyond doubt that disease is an end result of complex interaction of environment, pathogen and the host animal. The aquatic environment is abounded with infectious microbes.The transmission of disease in this environment is extremely easy, especially under dense, culture conditions. Therefore, a better understanding of the immune responses of the cultured animal in relation to its environmental alterations and microbial invasions is essential indevising strategic measures against aquaculture loss due to diseases. This study accentuate the importance of proper and regular health monitoring in shrimps employing the most appropriate haematological biomarkers for application of suitable prophylactic measures in order to avoid serious health hazards in shrimp culture systems. |
| URI: | http://dyuthi.cusat.ac.in/purl/3012 |
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| Dyuthi-T0991.pdf | (21.83Mb) |
| Abstract: | It is well known that under certain conditions, populations of oysters and clams are susceptible to destructive epizootics caused by pathogenic micro-organisms. It has also been shown that exposure of mammals to certain heavy metals causes increased susceptibility to and severity of microbial infections (Koller, 1980). Consequently, pollutants that affect haemocyte viability or interfere with internal defence functions of the haemocytes which are considered as the major means of defence in moliuscs against invading foreign organisms and pathogens (Cheng, 1981) may have profound effect on long term survival of molluscan populations. All these justify the significance of the present study in the context of the current status on molluscan culture programme, and how the data on molluscan haematological studies .could be taken as the reliable criteria for pollution monitoring studies. |
| Description: | School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3639 |
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| Dyuthi-T1618.pdf | (21.77Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1213 |
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| Suresh K 1988.PDF | (705.8Kb) |
| Description: | Division of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://hdl.handle.net/purl/2065 |
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| Dyuthi-T0415.pdf | (7.761Mb) |
| Abstract: | The marine environment is indubitably the largest contiguous habitat on Earth. Because of its vast volume and area, the influence of the world ocean on global climate is profound and plays an important role in human welfare and destiny. The marine environment encompasses several habitats, from the sea surface layer down through the bulk water column, which extends >10,000 meters depth, and further down to the habitats on and under the sea floor. Compared to surface habitats, which have relatively high kinetic energy, deep-ocean circulation is very sluggish. By comparison, life in the deep sea is characterized by a relatively constant physical and chemical environment. Deep water occupying the world ocean basin is a potential natural resource based on its properties such as low temperature, high pressure and relatively unexplored properties. So, a judicious assessment of the marine resources and its management are essential to ensure sustainable development of the country’s ocean resources. Marine sediments are complex environments that are affected by both physiological and biological factors, water movements and burrowing animals. They encompass a large extent of aggregates falling from the surface waters. In aquatic ecosystems, the flux of organic matter to the bottom sediments depend on primary productivity at the ocean surface and water depth. Over 50% of the earth’s surface is covered by deep-sea sediments that are primarily formed through the continual deposition of particles from the productive pelagic waters (Vetriani et al., 1999). These aggregates are regarded as ‘hot spots’ of microbial activity in the ocean (Simon et al., 2002). This represents a good nutritional substrate for heterotrophic bacteria and favours bacterial growth |
| Description: | School of Marine Sciences, Cochin University of Science And Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3718 |
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| Dyuthi-T1674.pdf | (5.730Mb) |
| Abstract: | The principal interest of the present investigation was to determine seasonal and vertical variation of chemoorganotrophic utilisation of glucose and sodium—acetate by the natural bacterial population in the aquaculture pond of Narakkal, Cochin using techniques which allow maintenance of the in situ gaseous concentrations during incubation. In addition salinity, dissolved oxygen, temperature, hydrogen—ion—.concentration, primary production, plant pigments and total bacterial concentration were determined seasonally and vertically because of their possible relationship to chemoorganotrophy. |
| Description: | Central Marine Fisheries Research Institute |
| URI: | http://dyuthi.cusat.ac.in/purl/3604 |
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| Dyuthi-T1596.pdf | (10.96Mb) |
| Abstract: | This thesis entitled “Histological ,Histochemical and biochemical characterisation of male morphotypes of macrobrachium rosenbergii(De Man). The giant fresh water prawn Macrobrachium rosenbergii (de Man) is emerging as a prime candidate species in fresh water aquaculture as a global basis and therefore, receiving much attention in recent years.the present work was aimed at to study the histological variations, if any, in the reproductive system viz. testes, vas deferens including androgenic gland, hepatopancreas and the neurosecretory system viz. eye stalk, brain and thoracic ganglion among the male morphotypes and their transitional stages of M.rosenbergii from growouts. This study was also aimed at to bring out the histochemical variations, if any, in the reproductive system comprising of testes, vas deferens including androgenic gland and the hepatopancreas among the male morphotypes and their transitional stages collected from growouts. Biochemical characterisation of various male morphotyes and their transitional stages have also been attempted in order to find out biochemical evidence, if any, in the morphotypic transformation.Histological study of the testes of three male morphotypes viz., SM, SOC and SBC and their 'transitional stages viz., WOC, tSOC, WBC and OBC have been carried out with a view to unravel the structural and functional differences of the testes, if any, of these morphotypes. Studies on the lipid components viz., cholesterol, phospholipid and triglyceride In the muscle tissue and hepatopancreas have been carried out. |
| Description: | School of Marine Science, Department of Industrial Fisheries, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3030 |
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| Dyuthi-T1005.pdf | (8.122Mb) |
| Abstract: | The present study is an investigation to address relevant chemical aspects of the three varied aquatic environments, such as mangroves, river and the estuary. The sampling locations include a thick mangrove forest with high tidal activity, a mangrove nursery with minimal disturbances and low tidal inundation, a highly polluted riverine system and an estuarine site, as reference. Nutrients and bioorganic compounds in the water column and surface sediment were estimated in an attempt to understand the regeneration properties of these different aquatic systems.Assessment of the trace metal pollution was also carried out. |
| Description: | Department of Chemical Oceanography, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2507 |
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| Dyuthi-T0671.pdf | (18.63Mb) |
| Abstract: | People in several parts of the world as well in India countenance an immense confront to meet the basic needs of water. The crisis is not due to lack of fresh water but its availability in adequate superiority. Environmental quality objectives should be developed in order to define acceptable loads on the terrain. There has been a number of initiatives in water quality monitoring but the next step towards improving its quality hasn’t taken the required pace. Today, there is a growing need to create awareness among citizens on the different technologies available for improving the water quality. Monitoring facilitate to apprehend how land and water use distress the quality of water and assist in estimating the extent of pollution. Once these issues are recognized, people can work towards local solutions to manage the indispensable resource effectively. Ground waters are extremely precious resources and in many countries together with India they represent the most important drinking water supply. They are generally microbiologically pure and, in most cases, they do not need any treatment. This communiqué is intended to act as a channel on the various paraphernalia and techniques accessible for groundwater quality assessment and suggesting the assured precautionary measures to embark on environment management. This learning is imperative considering that groundwater as the exclusive source of drinking water in the region which not makes situation alarming but also calls for immediate attention. The scope of this work is somewhat vast. Water quality in Ernakulam district is getting deteriorated due to the fast growth of urbanization. The closure of several water bodies due to land development and construction prevents infiltration of rainwater into the ground and hence recharge the aquifers. Most of the aquifers are getting polluted from the industrial effluents and chemicals and fertilizers used in agriculture. Such serious issues require proper monitoring of groundwater and steps are to be taken for remedial measures. This study helps in the total protection of the rich resource of groundwater and its sustainability. Socio-economic aspect covered could be used for conducting further individual case studies and to suggest remedial measures on a scientific basis. The specific study taken up for 15 sites can be further extended to the sources of pollution, especially industrial and agriculture |
| Description: | Department of Chemical Oceanography, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3703 |
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| Dyuthi-T1683.pdf | (14.51Mb) |
| Description: | Dept.of Marine Geology & Geophysics, Cochin University of Sceince and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2149 |
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| Dyuthi-T0508.pdf | (21.79Mb) |
| Abstract: | The present study deals with the different hydrogeological characteristics of the coastal region of central Kerala and a comparative analysis with corresponding hard rock terrain. The coastal regions lie in areas where the aquifer systems discharge groundwater ultimately into the sea. Groundwater development in such regions will require a precise understanding of the complex mechanism of the saline and fresh water relationship, so that the withdrawals are so regulated as to avoid situations leading to upcoming of the saline groundwater bodies as also to prevent migration of sea water ingress further inland. Coastal tracts of Kerala are formed by several drainage systems. Thick pile of semi-consolidated and consolidated sediments from Tertiary to Recent age underlies it. These sediments comprise phreatic and confined aquifer systems. The corresponding hard rock terrain is encountered with laterites and underlined by the Precambrian metamorphic rocks. Supply of water from hard rock terrain is rather limited. This may be due to the small pore size, low degree of interconnectivity and low extent of weathering of the country rocks. The groundwater storage is mostly controlled by the thickness and hydrological properties of the weathered zone and the aquifer geometry. The over exploitation of groundwater, beyond the ‘safe yield’ limit, cause undesirable effects like continuous reduction in groundwater levels, reduction in river flows, reduction in wetland surface, degradation of groundwater quality and many other environmental problems like drought, famine etc. |
| Description: | Dept. of Marine Geology and Geophysics School of Marine Sciences Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3527 |
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| Dyuthi-T1500.pdf | (12.95Mb) |
| Abstract: | This is an attempt to understand the important factors that control the occurrence, development and hydrochemical evolution of groundwater resources in sedimentary multi aquifer systems. The primary objective of this work is an integrated study of the hydrogeology and hydrochemistry with a view to elucidate the hydrochemical evolution of groundwater resources in the aquifer systems. The study is taken up in a typical coastal sedimentary aquifer system evolved under fluvio-marine environment in the coastal area of Kerala, known as the Kuttanad. The present study has been carried out to understand the aquifer systems, their inter relationships and evolution in the Kuttanad area of Kerala. The multi aquifer systems in the Kuttanad basin were formed from the sediments deposited under fluvio-marine and fluvial depositional environments and the marine transgressions and regressions in the geological past and palaeo climatic conditions influenced the hydrochemical environment in these aquifers. The evolution of groundwater and the hydrochemical processes involved in the formation of the present day water quality are elucidated from hydrochemical studies and the information derived from the aquifer geometry and hydraulic properties. Kuttanad area comprises of three types of aquifer systems namely phreatic aquifer underlain by Recent confined aquifer followed by Tertiary confined aquifers. These systems were formed by the deposition of sediments under fluvio-marine and fluvial environment. The study of the hydrochemical and hydraulic properties of the three aquifer systems proved that these three systems are separate entities. The phreatic aquifers in the area have low hydraulic gradients and high rejected recharge. The Recent confined aquifer has very poor hydraulic characteristics and recharge to this aquifer is very low. The Tertiary aquifer system is the most potential fresh water aquifer system in the area and the groundwater flow in the aquifer is converging towards the central part of the study area (Alleppey town) due to large scale pumping of water for water supply from this aquifer system. Mixing of waters and anthropogenic interferences are the dominant processes modifying the hydrochemistry in phreatic aquifers. Whereas, leaching of salts and cation exchange are the dominant processes modifying the hydrochemistry of groundwater in the confined aquifer system of Recent alluvium. Two significant chemical reactions modifying the hydrochemistry in the Recent aquifers are oxidation of iron in ferruginous clays which contributes hydrogen ions and the decomposition of organic matter in the aquifer system which consumes hydrogen ions. The hydrochemical environment is entirely different in the Tertiary aquifers as the groundwater in this aquifer system are palaeo waters evolved during various marine transgressions and regressions and these waters are being modified by processes of leaching of salts, cation exchange and chemical reactions under strong reducing environment. It is proved that the salinity observed in the groundwaters of Tertiary aquifers are not due to seawater mixing or intrusion, but due to dissolution of salts from the clay formations and ion exchange processes. Fluoride contamination in this aquifer system lacks a regional pattern and is more or less site specific in natureThe lowering of piezometric heads in the Tertiary aquifer system has developed as consequence of large scale pumping over a long period. Hence, puping from this aquifer system is to be regulated as a groundwater management strategy. Pumping from the Tertiary aquifers with high capacity pumps leads to well failures and mixing of saline water from the brackish zones. Such mixing zones are noticed from the hydrochemical studies. This is the major aquifer contamination in the Tertiary aquifer system which requires immediate attention. Usage of pumps above 10 HP capacities in wells taping Tertiary aquifers should be discouraged for sustainable development of these aquifers. The recharge areas need to be identified precisely for recharging the aquifer systems throughartificial means. |
| URI: | http://dyuthi.cusat.ac.in/purl/4954 |
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| Dyuthi-T2030.pdf | (10.21Mb) |
| Abstract: | The present investigation on " Hydrology, stratigraphy, and evolution of the palaeo-lagoon (Koleland basin)in the Central Kerala coast, India" is an integrated approach based on hydrogeological,geophysical,hydrochemical and stratigraphic aspects.A strong scientific data base of the study area is generated using interpretation of well observation and water quality analysis. The salient findings of the present study are given to provide a holistic picture on the hydrogeology (including groundwater resource and its quality),stratigraphy and evolution of the palaeo-lagoon |
| URI: | http://dyuthi.cusat.ac.in/purl/3023 |
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| Dyuthi-T1001.pdf | (48.18Mb) |
| Abstract: | Study of Kerala State in relation to the western Ghats, using The present thesis envisages a hydrometeorological various statistical techniques and the water balance concepts first developed by Thornthwaite. The first chapter of the thesis gives general introduction where the purpose and scope of the study have been given. Chapter II discusses the importance of hydrometeorological studies in general and of water balance in particular, in planning for the overall development of any region. Chapter III consists of the presentation of various geographical features of Kerala. An introduction to the physiography of the western Ghats and detailed hydroclimatic studies of the Western Ghats region which includes analysis of rainfall and the study of water balance elements form Chapter IV. In Chapter V, a detailed hydrometeorological study of Kerala State is made. Discussion of the results of the study and suggestions for optimum utilization of the available water resources for the overall development of the western Ghats region in general and Kerala in particular are made in Chapter VI. |
| Description: | Physical Oceanography and Meteorology Division, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3504 |
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| Dyuthi-T1455.pdf | (7.360Mb) |
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