Johny T, Varghese; Dr. Madhusoodana Kurup, B(Cochin University of Science and Technology, April , 2007)
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Abstract:
Controlling the inorganic nitrogen by manipulating carbon /
nitrogen ratio is a method gaining importance in aquaculture
systems. Nitrogen control is induced by feeding bacteria with
carbohydrates and through the subsequent uptake of nitrogen from
the water for the synthesis of microbial proteins. The relationship
between addition of carbohydrates, reduction of ammonium and the
production of microbial protein depends on the microbial conversion
coefficient. The carbon / nitrogen ratio in the microbial biomass is
related to the carbon contents of the added material. The addition of
carbonaceous substrate was found to reduce inorganic nitrogen in
shrimp culture ponds and the resultant microbial proteins are taken
up by shrimps. Thus, part of the feed protein is replaced and feeding
costs are reduced in culture systems.The use of various locally available substrates for periphyton
based aquaculture practices increases production and profitability .However, these techniques for extensive shrimp farming have not so far been
evaluated. Moreover, an evaluation of artificial substrates together
with carbohydrate source based farming system in reducing inorganic
nitrogen production in culture systems has not yet been carried-out.
Furthermore, variations in water and soil quality, periphyton
production and shrimp production of the whole system have also not
been determined so-far.This thesis starts with a general introduction ,
a brief review of the most relevant literature, results of various
experiments and concludes with a summary (Chapter — 9). The
chapters are organised conforming to the objectives of the present
study. The major objectives of this thesis are, to improve the
sustainability of shrimp farming by carbohydrate addition and
periphyton substrate based shrimp production and to improve the
nutrient utilisation in aquaculture systems.
Description:
School of
Industrial Fisheries, Cochin University of Science and Technology
Nisha, P C; Dr. George, K C(Central Marine Fisheries Research Institute, October , 2006)
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Abstract:
The present investigation revealed three types of circulating haemocytes
in the haemolymph of F. indicus: hyalinocytes, small-granule haemocytes, and
large-granule haemocytes. Intermediate stages indicate the maturing process of a
single cell. The presence of enzymes such as peroxidase, phenoloxidase and acid
phosphatase in the haemocytes, and the substantial production of oxygen radicals
during phagocytosis show that the haemocytes are capable of mounting a fme
cellular defense mechanism. The enzyme activities of the serum and the presence
of agglutinins in the serum, which may act as opsonins, agglutinate foreign
particles and augment phagocytosis, confirm the presence of a superior humoral
immune system in F. indicus.Bacterial infection caused considerable variations in the cellular and
humoral factors, such as the number of circulating cells and haemagglutinating
activity, especially in the initial hours of infection. The total haemocyte count,
haemagglutination titer and phenoloxidase enzyme showed significant reductions
on bacterial presence and could be used as indicators of bacterial infection.The number of circulating cells showed drastic fluctuation on exposure to
pollutants. Nuvan at low concentrations was able to produce changes in the
haemolymph factors and in the tissue organization, which implies that the animal
is under stress and is easily prone to infections. Exposure to nuvan resulted in
significant variation in all of the cellular and humoral factors, especially, the total
haemocyte count, percentage of small granule haemocytes, phagocytic activity
and the haemagglutinating activity, which might be good indicators of pesticide
pollution. Heavy metal exposure caused significant increase in total haemocyte
count and reduction in phenoloxidase enzyme activity Even changes in the
physio-chemical parameters, such as salinity caused fluctuations in the defense
factors, indicating stress in this euryhaline species. The dietary incorporation of a
commercial immunostimulant containing P-l,3 glucan resulted in stimulation of
some of the humoral defense factors of F indicus, but was time dependent. The
modulations, on exposure to various external factors, in the cellular and humoral
factors, especially, total haemocyte count, phagocytic activity, haemagglutinating
activity and the phenoloxidase and acid phosphatase enzymes suggest that these
parameters could be used as indicators of the health status of F indicus, which
assist in better monitoring and effective health management of this important
cultured species.
Zeena P, Ravi; Dr.Chandramohanakumar, N(Cochin University of Science & Technology, May , 2005)
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Abstract:
Mangrove swamps are unique inter-tidal wetland ecosystems found in sheltered tropical and subtropical shores.Mangrove sediments can be considered as large reservoirs of amino acids,which exist in several different forms,like free amino acids in the sediment micropores,as amino acids,peptides or proteins bound to clay minerals or as amino acids,peptides or proteins bound to humic colloids.Inorder to assess survival conditions of organisms of mangroves,it is important to understand stability of amino acids in the sediments.The amounts of amino acids present in sediment represent a balance between its synthesis and destruction by microorganisms.Thus amino acid analysis offers more insight into the processes of diagenesis,which changes the nature and characteristics of organic matter deposition and decomposition.
Description:
Department of Chemical
Oceanography Cochin University of Science
and Technology
Balachandran,K K; Sankaranarayanan,V N(National Institute of Oceanography, 2001)
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Abstract:
The present study is an attempt to understand some of the chemical oceanographic processes of the coastal water and the backwaters of Cochin. The importance of this study lies in the fact that there has been an increasing concern on the environmental degradation of Cochin backwaters with respect to water and sediments due to various anthropogenic activities. The study comprises the results and discussion of the hydro chemical parameters of coastal waters of Cochin during different seasons with statistical analysis. The parameters dealt with are salinity, temperature, pH, dissolved oxygen, nitrite-N, nitrate-N, ammonia-N, Silicate-Si, phosphate-P, chlorophyll ‘a’ and suspended solids, dissolved trace metals and sediment characteristics including sediment metals
Renjith, K R; Dr. Chandramohanakumar, N(Cochin University of Science and Technology, December , 2006)
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Abstract:
The amplified human role in shaping natural processes makes it imperative to understand the interactions between abiotic and biotic processes, whcih pertain particularly to the most dyanamic aboitic factor,water. The assessment of environmental parameters is indispensable for the sustainable management of the aqutic system .The conscious harnessing and pampering to protect the characteristics of the ecosystems is the of the day.This thesis attempts to characterize the chemical dynamacity of a tropical estury in relation to the bio, geo and physical processes and thereby to propose a management scheme for its sustainability. Micro speciation is used as a tool for this.
Smitha, B R; Dr. Sajeev, R(Cochin University of Science and Technology, November , 2010)
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Abstract:
Upwelling regions occupies only a small portion of the global ocean
surface. However it accounts for a large fraction of the oceanic primary
production as well as fishery. Therefore understanding and quantifying
the upwelling is of great importance for the marine resources
management. Most of the coastal upwelling zones in the Arabian Sea are
wind driven uniform systems. Mesoscale studies along the southwest
coast of India have shown high spatial and temporal variability in the
forcing mechanism and intensity of upwelling. There exists an
equatorward component of wind stress as similar to the most upwelling
zones along the eastern oceanic boundaries. Therefore an offshore
component of surface Ekman transport is expected throughout the year.
But several studies supported with in situ evidences have revealed that
the process is purely recurring on seasonal basis. The explanation
merely based on local wind forcing alone is not sufficient to support the
observations. So, it is assumed that upwelling along the South Eastern
Arabian Sea is an effect of basin wide wind forcing rather than local
wind forcing. In the present study an integrated approach has been made to understand the process of upwelling of the South Eastern Arabian Sea.
The latitudinal and seasonal variations (based on Sea Surface
Temperature, wind forcing, Chlorophyll a and primary production),
forcing mechanisms (local wind and remote forcing) and the factors
influencing the system (Arabian Sea High Saline Water, Bay of Bengal
water, runoff, coastal geomorphology) are addressed herewith.
Description:
Department of
Physical Oceanography,Cochin
University of Science and Technology
Krishna Kumar, K N; Dr. Prasada Rao, G S L H V; Dr. Ram Mohan, H S(Cochin University of Science and Technology, October , 2011)
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Abstract:
The present investigation on “Coconut Phenology and Yield Response to
Climate Variability and Change” was undertaken at the experimental site, at the
Regional Station, Coconut Development Board, KAU Campus, Vellanikkara. Ten
palms each of eight-year-old coconut cultivars viz., Tiptur Tall, Kuttiadi (WCT),
Kasaragod (WCT) and Komadan (WCT) were randomly selected.The study therefore, reinforces our traditional knowledge that the coconut palm
is sensitive to changing weather conditions during the period from primordium
initiation to harvest of nuts (about 44 months). Absence of rainfall from December to
May due to early withdrawal of northeast monsoon, lack of pre monsoon showers and
late onset of southwest monsoon adversely affect the coconut productivity to a
considerable extent in the following year under rainfed conditions. The productivity
can be increased by irrigating the coconut palm during the dry periods.Increase in temperature, aridity index, number of severe summer droughts and
decline in rainfall and moisture index were the major factors for a marginal decline or
stagnation in coconut productivity over a period of time, though various
developmental schemes were in operation for sustenance of coconut production in the
State of Kerala. It can be attributed to global warming and climate change.
Therefore, there is a threat to coconut productivity in the ensuing decades due to
climate variability and change. In view of the above, there is an urgent need for proactive
measures as a part of climate change adaptation to sustain coconut productivity
in the State of Kerala.The coconut productivity is more vulnerable to climate variability such as
summer droughts rather than climate change in terms of increase in temperature and
decline in rainfall, though there was a marginal decrease (1.6%) in the decade of
1981-2009 when compared to that of 1951-80. This aspect needs to be examined in
detail by coconut development agencies such as Coconut Development Board and
State Agriculture Department for remedial measures. Otherwise, the premier position of Kerala in terms of coconut production is likely to be lost in the ensuing years under
the projected climate change scenario.
Among the four cultivars studied, Tiptur Tall appears to be superior in terms of
reproduction phase and nut yield. This needs to be examined by the coconut breeders
in their crop improvement programme as a part of stress tolerant under rainfed
conditions.
Crop mix and integrated farming are supposed to be the best combination to
sustain development in the long run under the projected climate change scenarios.
Increase in coconut area under irrigation during summer with better crop management
and protection measures also are necessary measures to increase coconut productivity
since the frequency of intensity of summer droughts is likely to increase under
projected global warming scenario.
Description:
Department of Atmospheric Sciences, Cochin University of Science
and Technology
Anil, Earnest; Dr. Rajendran, C P(Cochin University of Science and Technology, May , 2007)
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Abstract:
The Andaman-Nicobar Islands in the Bay of Bengal lies in a zone where the
Indian plate subducts beneath the Burmese microplate, and therefore forms a belt
of frequent earthquakes. Few efforts, not withstanding the available historical and
instrumental data were not effectively used before the Mw 9.3 Sumatra-Andaman
earthquake to draw any inference on the spatial and temporal distribution of large
subduction zone earthquakes in this region. An attempt to constrain the active
crustal deformation of the Andaman-Nicobar arc in the background of the December
26, 2004 Great Sumatra-Andaman megathrust earthquake is made here,
thereby presenting a unique data set representing the pre-seismic convergence and
co-seismic displacement.Understanding the mechanisms of the subduction zone earthquakes is both
challenging sCientifically and important for assessing the related earthquake hazards.
In many subduction zones, thrust earthquakes may have characteristic patterns
in space and time. However, the mechanism of mega events still remains
largely unresolved.Large subduction zone earthquakes are usually associated with high amplitude
co-seismic deformation above the plate boundary megathrust and the elastic relaxation
of the fore-arc. These are expressed as vertical changes in land level with the
up-dip part of the rupture surface uplifted and the areas above the down-dip edge
subsided. One of the most characteristic pattern associated with the inter-seismic
era is that the deformation is in an opposite sense that of co-seismic period.This work was started in 2002 to understand the tectonic deformation along the
Andaman-Nicobar arc using seismological, geological and geodetic data. The occurrence
of the 2004 megathrust earthquake gave a new dimension to this study, by
providing an opportunity to examine the co-seismic deformation associated with
the greatest earthquake to have occurred since the advent of Global Positioning
System (GPS) and broadband seismometry.
The major objectives of this study are to assess the pre-seismic stress regimes, to
determine the pre-seismic convergence rate, to analyze and interpret the pattern of
co-seismic displacement and slip on various segments and to look out for any possible
recurrence interval for megathrust event occurrence for Andaman-Nicobar
subduction zone. This thesis is arranged in six chapters with further subdivisions
dealing all the above aspects.
Anu,Gopinath; Chandramohanakumar,N(Department of Chemical Oceanography,School of Marine Sciences, 2002)
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Abstract:
The present study focuses on the biochemical aspects of six islands belonging to Lakshadweep Archipelago – namely Kavaratti, Kadamath, Kiltan, Androth, Agathy and Minicoy. Lakshadweep, which is an area biologically significant due to isolation from the major coastline, remains as one of the least studied areas in Indian Ocean. The work, processed out the distributional pattern of trace metals among the biotic (corols, sea weeds and sea grass) and abiotic component (sediments) of ecosystem. An effort is made to picturise the spatial distribution pattern of different forms of nitrogen and phosphorus in the various sedimentary environments of the study area. Studies on the biogeochemical and nutrient aspects of the concerned study area scanty. In Lakshadweep, the local life is very dependent on reefs and its resources. The important stress which produce a threatening effort on the existence for coral reefs are anthropogenic-namely-organic and inorganic pollution from sewage, agricultural and industrial waters, sediment damage from excessive land cleaning, and over exploitation particularly through destructive fishing methods. In addition these one other more localized or less service anthropogenic stress: pollution by oil and other hydrocarbons, complex organic molecular and heavy metal pollution, and destructive engineering practices.
Gopakumar, S D; Dr. Gopinathan, C P(Cochin University of Science & Technology, August , 2004)
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Abstract:
The present study is an attempt to standardize the environmental condition like pH, salinity and photoperiod, and also the feed for the maximum production of rotifers. Considering the deficiency of essential fatty acids in rotifers, enrichment experiments were carried out and fatty acids profile were analysed. Attempts were made to improve the production of clown fish (Amphiprion sebae) juveniles using enriched rotifers. Attempts were also made to rear various larval stages of Penaeus monodon with enriched rotifers as a substitute for Artemia nauplii.