Manojkumar, T G; Dr.Madhusoodana,Kurup B(Cochin University of Science and Technology, March 22, 2006)
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This thesis entitled Fish habitats and species assemblage in the selected rivers of kerala and investigation on life history traits of puntius carnaticus (JERDON,1849). Ecology is a new and exceedingly complex field of study, even though its concept was recognized by the Apostles in their use of the phrase ‘all flesh is grass.central role to play both in order to understand better the biodiversity phenomenon and to be able to draw up clear guidelines for careful resource management. In a review by WWF, IUCN and UNEP on the ways of conserving genetic diversity of freshwater fish it was recommended that the best way to conserve species diversity is to conserve habitat.The habitat studies in freshwater ecosystems are very essential for the proper understanding and management of human impact on fish diversity, to study the relationship between habitat variables and fish species assemblage structure, quantification of ecosystem degradation, habitat quality and biotic integrity of the ecosystems, development of habitat suitability index (I-ISI) models and classification of river reaches based on their physico-chemical properties. Therefore in the present study an attempt was made to assess the biodiversity potential and the relationship between habitat variables and fish species assemblage structure in six major river systems of Kerala which would be very useful in impressing upon the seriousness of habitat degradIn the present study, in Kabbini river system 15 locations encompassing between 721 946m above MSL were surveyed.ation and biotic devastation undergone in the major river systems of Kerala.During the present study the Habitat Quality Score (HQ) developed by the Ohio EPA was applied for the first time in India.The result of the present study revealed that, among various variables analysed, altitude has a very significant influence in deciding the fish diversity in six major river systems of Kerala. The fish diversity studied on the basis of Shanon-Weiner and Simpson diversity indices revealed that even though some minor variations occur with the suitability and complexity of habitats, the altitude showed inverse relationship with fish diversity.The present study revealed that the National Policy on the interlinking of rivers would permanently alter the HSI indices of the above mentioned fish species, which are now solely protected by the individuality of the rivers where their limited occurrence was notice.
Description:
School of Industrial
Fisheries,Cochin University of Science and Technology
Nisha,N R; Singh,A D(Department of Marine Geology and Geophysics,Faculty of Marine Sciences, 2002)
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In the present investigation, an attempt is made to study late Quaternary foraminiferal and pteropod records of the shelf of northern Kerala and to evaluate their potentiality in paleocenographic and paleoclimatic reconstruction. The study gives details of sediment cores, general characteristics of foraminifera and pteropod species recorded from the examined samples and their systematic classification, spatial distribution of Recent foraminifera and pteropods and their response to varying bathymetry, nature of substrate, organic matter content in sediment and hydrography across the shelf. An attempt is also made to establish an integrated chronostratigraphy for the examined core sections. An effort is also made to identify microfaunal criteria useful in biostratigraphic division in shallow marine core sections. An attempt is made to infer various factors responsible for the change in microfaunal assemblage. Reconstruction of sea level changes during the last 36,000 years was attempted based on the pteropod record. The study reveals a bathymetric control on benthic/planktic (BF/PF) foraminiferal and pteropods/planktic foraminiferal (Pt/PF) abundance ratio. Bathymetric distribution pattern of BF/PF ratio is opposite to the (Pt/PF) ratio with decreasing trend of former from the shore across the shelf. Quantitative benthic foraminiferal record in the surficial sediments reveals a positive correlation between the diversity and bathymetry. R-mode cluster analysis performed on 30n significant Recent benthic foraminiferal, determines three major assemblage.
Jeena, N S; Dr.Gopalakrishnan, A(Cochin University of Science And Technology, May 23, 2013)
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The management of exploited species requires the identification of
demographically isolated populations that can be considered as independent
management units (MUs), failuring in which can lead to over -fishing and
depletion of less productive stocks. By characterizing the distribution of genetic
variation, population sub structuring can be detected and the degree of
connectivity among populations can be estimated. The genetic variation can be
observed using identified molecular markers of both nuclear and mitochondrial
origin. Hence, the present work was undertaken to study the genetic diversity
and population/stock structure in P. homarus homarus and T. unimaculatus
from different landing centres along the Indian coast using nuclear (RAPD) and
mitochondrial DNA marker tools which will help towards developing
management strategies for management and conservation of these declining
resources.To make consistent conservation and fisheries management decisions,
accurate species identifications are needed. It is also suggested that it is not
always desirable to rely on a single sequence for taxonomic identification.
Thus, the feasibility of using partial sequences of additional mitochondrial
genes like 16SrRNA, 12SrRNA and nuclear 18SrRNA has also been explored
in our study. Phylogenies provide a sound foundation for establishing
taxonomy. The present work also attempts to reconstruct the phylogeny of
eleven species of commercially important lobsters from the Indian EEZ using
molecular markers
Description:
National Bureau of
Fish Genetic Resources (NBFGR) Cochin Unit, Central Marine Fisheries Research
Institute, Cochin
The thesis deals with the results of the study of the population characteristics of the marine penaeid prawn, Penaeus monodon from South India. The present findings on the morphometric and biochemical genetic structure support the hypothesis that the populations of P.monodon of South India have homogeneous stock structure. To the contrary, the significantly different random amplified polymorphic DNA (RAPD) profiles in samples of Kochi and Chennai support the hypothesis that east and west cost populations of P.monodon are separate stocks.
Manju, Nair P; Dr. Sujatha, C.H(Cochin University of Science & Technology, June , 2014)
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Geochemical composition is a set of data for predicting the climatic condition existing in an ecosystem. Both the surficial and core sediment geochemistry are helpful in monitoring, assessing and evaluating the marine environment. The aim of the research work is to assess the relationship between the biogeochemical constituents in the Cochin Estuarine System (CES), their modifications after a long period of anoxia and also to identify the various processes which control the sediment composition in this region, through a multivariate statistical approach. Therefore the study of present core sediment geochemistry has a critical role in unraveling the benchmark of their characterization. Sediment cores from four prominent zones of CES were examined for various biogeochemical aspects. The results have served as rejuvenating records for the prediction of core sediment status prevailing in the CES
Reji,Srinivas; Sajan,K(Department of Marine Geology and Geophysics, School of marine Sciences, 2002)
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In this study, an attempt has been made to find the textural, geochemical, sedimentological characteristics of sediments and water phases of the kayamkulam estuary located in the Southwest coast of Kerala, besides the impact of gas based thermal power plant located at the northern part of the estuary. Estuaries are an important stage in the transport of the solid weathering product of the earth’s crust. These weathered products or sediments are complex mixtures of a number of solid phases that may include clays, silica, organic matter, metal oxides, carbonates, sulfides and a number of minerals. Studies on the aquatic systems revealed the fact that it posses severe ecological impairments due to heavy discharge of sediments from 44 rivers, the continued disposal of pollutants rich materials from industries, sewage channels, agricultural areas and retting yards
Hariharan,G N; Nambiar,C G(Department of Marine Geology & Geophysics, School of Marine Sciences, 2001)
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The present work deals with the texture, mineralogy and geochemistry of bedload sediments of the main stream of the Chaliyar basin, a typical small drainage system of the tropics enjoying heavy rain fall and moderate climate, located essentially in the Northern Kerala and flowing over the crystalline rocks (and their laterized duricrust) of the South Indian granulite terrain. As the Chaliyar is the major river draining the Wynad Gold Fields and is known for its placer gold occurrences, the thesis gives special emphasize on understanding the nature and distribution of detrital gold in sediments of the basin, while attempting to infer the provenance characteristics and factors involved in the evolution of sediments in general. Minerologically the chaliyar basin sands are quartzose. The quartz and feldspar contents in the coarse sand fraction of the basin range from 64 to 86% and 2 to 16% respectively. The Q/F ration ranges from 4 to 38 with a slight decrease in the lower reaches. Other minerals present include, hornblende, pyroxene and heavy minerals like opaques, garnet, rutile, biotite, spene, silliminite, zircon, apatite and monazite some of which are seen as inclusions in quartz. The major element composition of Chaliyar bedload sediments in the main channel and the headwater tributaries is related to the mineralogical and textual characteristics of sediments.
Soney Kurien, P; Dr.Nambiar,C G(Cochin University Of Science And Technology, May 2, 2000)
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This report deals essentially with the geochemistry and petrogenesis
of Perinthatta anorthosite. The work also addresses the geological setting
of the pluton in terms of its field relationships and petrography and the
structure and metamorphism of the region and examines its relation with
the associated plutons. For the sake of convenience, the thesis is divided
into six chapters
Description:
Department of Marine Geology and Geophysics, School of Marine Sciences, Cochin
University of Science and Technology
Siby,Varghese; Chandramohanakumar, N(National Institute of Oceanography & CUSAT, 2003)
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Rare earth elements have occupied an important role in marine geochemical research, particularly as used in the format of REE abundance patterns to describe the geochemical pathways in marine sedimentation and authigenesis. This study concentrates on the distribution pattern of Rare earth elements in the sediments, behavior of Eu and Ce with respect to their occurrence in multiple oxidation states. It also concentrate the depth wise variation of sediment REEs from near shore areas (30m) to deeper depths 200m) in the Arabian Sea. It includes the downcore variation of REEs and other trace elements in the sediment cores and a comparison between the REE distributions of Arabian Sea sediment with the sediments of Andaman Sea. The study gives a general introduction regarding the importance of RRE studies, its occurrence and abundance, electronic configuration, lanthanide contraction, oxidations states and REE supply to the ocean, seawater and sediments.
Laluraj, C M; Dr.Muraleedharan Nair, S(Cochin University of Science and Technology, February , 2009)
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The metals present in the surface sediments have high demand on a
global perspective, and the main reservoir of these elements is believed to be
the ocean floor. A lot of studies on metals are going on throughout the world
for its quantification and exploitation. Even though, some preliminary
attempts have been made in selected areas for the quantitative study of
metals in the western continental shelf of India, no comprehensive work has
been reported so far. The importance of this study also lies on the fact that
there has not been a proper evaluation of the impact of the Great Tsunami of
2004 on the coastal areas of the south India. In View of this, an attempt has
been made to address the seasonal distribution, behavior and mechanisms
which control the deposition of metals in the sediments of the western
continental shelf and Cochin Estuary, an annex to this coastal marine region.Surface sediment samples were collected seasonally from two
subenvironemnts of southwest coast of India, (continental shelf of Kerala and
Cochin estuarine system), to estimate the seasonal distribution and geochemical
behavior of non-transition, transition, rare-earth elements, Th and U. Bottom
water samples were also taken from each station, and analysed for temperature,
salinity and dissolved oxygen, hence the response of redox sensitive elements to
oxygen minimum zone can be addressed. In addition, other sedimentary
parameters such as sand, silt, clay fractions, CaCO3 and organic carbon content
were also estimated to evaluate the control factors on level of metals present in
the sediment. The study used different environmental data analysis techniques
to evaluate the distribution and behavior of elements during different seasons.
This includes environmental parameters such as elemental normalisation,
enrichment factor, element excess, cerium and europium anomalies and
authigenic uranium.
Description:
Department of Chemical Oceanography,Cochin University of Science and Technology