PhD Theses (SACON)
Permanent URI for this collectionhttp://192.168.202.180:4000/handle/123456789/138
Browse
2 results
Search Results
Item Organochlorine pesticides, population and reproductive success of fish-eating birds in select heronries in Tamil Nadu(SACON, 2013) Jayakumar, S.; Murlidharan, S.Colonial water birds are one of the major vital components of a wetland ecosystem. They serve as an excellent indicator of wetland health. In India. destruction of fresh water wetlands and entry of contaminants pose significant threats to the long-term stability of the population of colonial water birds and their habitats. Enormous quantities of man-made chemicals are used in modern agriculture. Despite obvious benefits, their indiscriminately has resulted in accumulation of residues in food and animal tissues causing environmental and ecological impact. Presence of pesticide residues, particularly persistent organochlorines in different biological and non-biological components has raised concern about their long-term accumulation and effects. Birds occupy different trophic levels in different food chains and hence are exposed to different concentrations of contaminants through their food. III effects of pesticides on wildlife. especially raptors, waterfowl and fish-eating birds have been extensively studied around the world. But, in India such information on birds particularly fish-eating birds (colonial birds) is limited. Although. some information is available on the residue levels of pesticides present in eggs of fish-eating and insectivorous birds in lndia, they fail to bring out the exact scenario of pesticide usage in agricultural areas and residue levels in eggs, and the consequent impact on breeding outcome. Further. there are 110 studies which have repol1ed the residue levels in eggs and simultaneously monitored the population of birds over a period of time in India. The present work was conducted in select heronries in Tamil Nadu with the following objectives; identify the heronries in Tamil Nadu, monitor the population and study breeding ecology of colonial nesting birds in select locations. document the residue levels of organochlorine pesticides in fishes, eggs and tissues of colonial nesting birds and asses the impacts.Item Levels of organic contaminates and select biomarkers in the birds of Gujarat and Tamil Nadu, India(SACON, 2009) Dhananjayan, V.; Murlidharan, S.There has been an ongoing concern about the presence of different types of contaminants in the environment and their ill effects on wildlife, particularly birds. While substantial information is available on such in effects on birds elsewhere in the world , very limited data exist in India, A study was initiated to document the environmental residue levels of certain persistent organic contaminants, chemicals responsible for incidences of mortality of birds and, generate information on the levels of cholinesterase in brain and blood plasma of birds. The major objectives were to understand tissue specific accumulation of contaminants, namely organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polycyclic a romatic hydrocarbons (PAHs) in birds, examine the variation in accumulation pattern between sexes and feeding habits, identify normal or reference levels of biomarkers, namely acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) to explain mortality of birds. Two representative cities, namely Ahmedabad, Gujarat in the west and Coimbatore, Tamil Nadu in the south were selected as study locations