Unnikrishnan,P; Muraleedharan, Nair S(Department of Chemical Oceanography, School of Marine Sciences, 2000)
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Abstract:
This thesis is a modest attempt in assessing the trace metal levels and their behavior in the aquatic environment of Kuttanad, an aquatic system that is severely affected by man’s intervention on natural processes, by study seriously evaluating the levels of trace metals in dissolved and particulate phases and also in the different chemical fractions of the sediments. Understanding of the distributions, variations and transfer processes of trace metals in different environmental phases in the backwaters of Kuttanad is vital for the assessment of the water pollution problems and study the ecology of the area which contributes 20% of the rice production in the State of Kerala. Kuttand is a low-lying, shallow bay formed as a result of geological uplift. The major economic activity is agriculture involving 40% of the population. About 1.5% of the people are engaged in aquaculture. The trace metal distribution in the Kuttand backwaters is considerably influenced by the tropical features of the location and by human activities including agricultural activities and construction of salinity barrier. In this study an attempt is made to differentiate the metals in the sediment into exchangeable, reducible and resistant fractions in the sediments.
Rajalekshmi Amma, P; Dr.Mohandas, A(Cochin University of Science And Technology, 1992)
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Abstract:
Industrialisation affects air, water, and soil. Industrial
effluents which enter the aquatic environment either by direct
disposal or through run off, affect living organisms at
morphological and physiological levels. In any living tissue
toxic materials exert their effects first at molecular and
biochemical levels (Robbins and Angell, 1976). Most of the
industrial effluents contain elevated concentrations of organic
and inorganic chemicals capable of eliciting stimulatory or
inhibitory effects on the metabolism of aquatic organisms.
Heavy metals form an important group of environmental
pollutants. Effects of pollution on the aquatic environment by
heavy metals have received considerable attention in recent years
due to their toxicity even at very low levels, persistence in the
environment, and chances of getting biomagnified. A pollutant
that does not affect a particular process under normal unstressed
condition may affect the ability of the animal to adjust to
changing environmental conditions which ultimately decrease its
chances of survival (Thurberg et al., 1973
Description:
School of Environmental Studies, Cochin University of Science And Technology
Philip,Mathew; Dr.Ravindranatha Menon,N(Cochin University of Science and Technology, August , 1990)
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Abstract:
The present scientific investigation of the effects of copper, mercury and cadmium has focussed on their effects on two commercially important marine bivalve species, Perna indica (brown mussel) and Donax incarnatus (wedge clam), conspicuous representatives of the tropical intertidal areas. The investigation centred around delineating the cause and effects of heavy metal stress, individually and in combination on these species under laboratory conditions. A clear understanding of the cause and effect can be had only if laboratory experiments are conducted employing sub-lethal concentrations of the above toxicants. Therefore, during the course of the investigation, sub-lethal concentrations of copper, mercury and cadmium were employed to assess the concentration dependent effects on survival, ventilation rate, O:N ratio and tissues. The results obtained are compared with the already available information and partitioned in sections to make a meaningful presentation.The thesis is presented in five chapters comprising INTRODUCTION, ACUTE TOXICITY, VENTILATION RATE, OXYGEN : NITROGEN RATIO and HISTOPATHOLOGY. Each chapter has been divided into various sections such as INTRODUCTION, REVIEW OF LITERATURE, MATERIAL AND METHODS, RESULTS and DISCUSSION
Description:
Head, Division of Marine Biology, Microbiology and
Biochemistry, School of Marine Sciences, Cochin University
of Science and Technology