Contribution of size fractions of planktonic algae to primary organic productivity in the coastal waters of Cochin- south west coast of lndia

This thesis entitled “Contribution of size fractions of planktonic algae to primary organic productivity in the coastal waters of cochin,south west coast of india”. Marine ecosystems planktonic algae are the most important primary producers on wliich considerable attention is being given on account of their supreme status in the marine food chain.The study of primary production in the Indian Ocean started With DANA (I928-30),, John Murray t I933-34). Discovery ( I934) and Albatross (I947-48) expeditions which tried to evaluate productivity from nutrients and standing crop of phytoplankton .The bioproductivity of the marine environment is dependent on various primary producers. ranging in size from picoplankton to larger macro phytoplankton. The quantity and quality of various size fractions of planktonic algae at any locality depend mainly on the hydrographic conditions of the area .In the coastal waters of Cochin- south west coast of lndia. Planktonic algal community is composed mainly of the diatoms, the dinoflagellates, the blue-green algae and the silicoflagellates, the former two contributing the major flora and found distributed in the all size fractions. The maximum number of species of diatoms at station 1 and station 2 was found in the pre-monsoon season.. The size groups of planktonic algae greater than 53 um are dominated by filamentous- chain forming and colonial diatoms. The coastal waters of Cochin. planktonic algae less than 53 um in size contribute significantly to primary productivity and the biodiversity of the microflora, indicating the presence of rich fishery resources in the south west coast of india.The study of different size fractions of planktonic algae and their relative contribution to the primary organic production is a useful tool for the estimation of the quantity and quality of fisheries.A deeper investigation on the occurrence of these microalgae and proper identification of their species would be of immense help for the assessment of the specificity and magnitude of fishery resources.

STUDIES ON TAXONOMY, DISTRIBUTION, ECOLOGY AND REPRODUCTIVE POTENTIAL OF ROTIFERS FROM SELECTED CENTRES IN COCHIN BACKWATER SYSTEM, KERALA

The studies were conducted in nine stations with varying ecological characteristics along Cochin backwaters and adjoining canals. Many workers opined that the distribution of rotifers is cosmopolitan. The significance of rotifers as first food for early larvae was indicated by Fujita. Aquaculture is a fast growing field in fisheries sector and it is gaining more importance as the fish landings and supply are getting irregular. A consistent supply of fish/shellfish can only be achieved through aquaculture. The success of any culture activity depends on the timely production of seeds of finfishes/shellfishes. The availability of wild seed is seasonal and erratic. So, a dependable source of seed of fishes and shellfishes is possible only through large scale production in hatchery. A successful seed production activity depends on the availability of a variety of suitable live feed organisms in sufficient quantities at the proper time for use in the larval stages. As the live feeds promote high growth rates, easy digestion, assimilation and the quality of not contaminating the culture water when compared to other artificial feeds, make the culture of live feed organisms the principal means of providing food for the larvae of finfishes and shellfishes. Rotifers are considered to be an excellent and indispensable food for larvae of many finfishes and crustaceans. It (1960) was the first to culture Brachionus plicatilis for feeding marine fish larvae, and now it is being extensively used as live feed in hatcheries all over the world. They are a group of microscopic organisms coming under the Phylum Rotifera which comprises of about 2000 species. Their slow swimming habits, ability to tolerate a wide range of salinities, parthenogenetic mode of reproduction and ability to get enriched easily, make rotifers an ideal live feed organism. The major factors such as temperature, salinity and food that influence the reproductive potential and thereby the population size of rotifer, Salinity is one of the most important aspect influencing the reproductive rate of rotifers. The feed type and feed concentration play a vital role in influencing the reproductive rate of rotifers. For culture of rotifers, the commonly used micro algae belong to Chlorella, Nannochloropsis, Isochrysis and Tetraselmis. While some studies have suggested that, algal diet has little effect on reproductive rates in 1979 while using the rotifer, Brachionus plicatilis as feed for the larvae of red sea bream, Pagrus major. It is generally accepted that rotifers play a pivotal role in the successful rearing of marine fish larvae.

Study on tropical rain with special reference to rain Drop Size Distribution and integral rain parameters using ground-based and satellite measurements

Department of Physics, Cochin University of Science and Technology

Factors Underlying Heterogeneous Individual Growth in Macrobrachium rosenbergii and the Effect of Size Heterogeneity on Economic Feasibility of Farming in Kuttanad ( Kerala )

School of Industrial Fisheries, Cochin University of Science and Technology

Effect of pore size on the catalytic activities of K-I 0 clay and H-zeolites for the acetalization of ketones with methanol

One-pot acetalizations of cyclohexanone. acetophenone and benzophenone were carried out using methanol over H-montmorillonite clay (a mesoporous material). silica, alumina, and different zeolites such as HFAU-Y.HBeta, H-ZSM-5, and H-mordenite. In all the cases a single product-the corresponding dimethylacetal-was obtained in high yields. Hemiacetal formation was not observed with any catalyst. A comparison of catalytic activity indicated that montmorillonite K-10 is the most active catalyst for the reaction. As evidenced by the reaction time studies, the catalyst decay is greater over the zeolite catalyst than over the clay.

Investigations on The Finite Size Effects of Some Inverse Spinels and Studies on Their Composites Based on Nitrile Rubber

Magnetism and magnetic materials have been an ever-attractive subject area for engineers and scientists alike because of its versatility in finding applications in useful devices. They find applications in a host of devices ranging from rudimentary devices like loud speakers to sophisticated gadgets like waveguides and Magnetic Random Access Memories (MRAM).The one and only material in the realm of magnetism that has been at the centre stage of applications is ferrites and in that spinel ferrites received the lions share as far as practical applications are concerned.It has been the endeavour of scientists and engineers to remove obsolescence and improve upon the existing so as to save energy and integrate in to various other systems. This has been the hallmark of material scientists and this has led to new materials and new technologies.In the field of ferrites too there has been considerable interest to devise new materials based on iron oxides and other compounds. This means synthesising ultra fine particles and tuning its properties to device new materials. There are various preparation techniques ranging from top- down to bottom-up approaches. This includes synthesising at molecular level, self assembling,gas based condensation. Iow temperature eo-precipitation, solgel process and high energy ball milling. Among these methods sol-gel process allows good control of the properties of ceramic materials. The advantage of this method includes processing at low temperature. mixing at the molecular level and fabrication of novel materials for various devices.Composites are materials. which combine the good qualities of one or more components. They can be prepared in situ or by mechanical means by the incorporation of fine particles in appropriate matrixes. The size of the magnetic powders as well as the nature of matrix affect the processability and other physical properties of the final product. These plastic/rubber magnets can in turn be useful for various applications in different devices. In applications involving ferrites at high frequencies, it is essential that the material possesses an appropriate dielectric permittivity and suitable magnetic permeability. This can be achieved by synthesizing rubber ferrite composites (RFC's). RFCs are very useful materials for microwave absorptions. Hence the synthesis of ferrites in the nanoregirne.investigations on their size effects on the structural, magnetic, and electrical properties and the incorporation of these ferrites into polymer matrixes assume significance.In the present study, nano particles of NiFe204, Li(!5Fe2S04 and Col-e-O, are prepared by sol gel method. By appropriate heat treatments, particles of different grain sizes are obtained. The structural, magnetic and electrical measurements are evaluated as a function of grain size and temperature. NiFel04 prepared in the ultrafine regime are then incorporated in nitrile rubber matrix. The incorporation was carried out according to a specific recipe and for various loadings of magnetic fillers. The cure characteristics, magnetic properties, electrical properties and mechanical properties of these elastomer blends are carried out. The electrical permittivity of all the rubber samples in the X - band are also conducted.

Size-dependent enhancement of nonlinear optical properties in nanocolloids of ZnO

We have investigated the third-order nonlinearity in ZnO nanocolloids with particle sizes in the range 6-18 nm by the z-scan technique. The third-order optical susceptibility χ(3) increases with increasing particle size (R) within the range of our investigations. In the weak confinement regime, an R2 dependence of χ(3) is obtained for ZnO nanocolloids. The optical limiting response is also studied against particle size.

Size dependent fluorescence spectroscopy of nanocolloids of ZnO

In this article we present size dependent spectroscopic observations of nanocolloids of ZnO. ZnO is reported to show two emission bands, an ultraviolet (UV) emission band and another in the green region. Apart from the known band gap 380 nm and impurity 530 nm emissions, we have found some peculiar features in the fluorescence spectra that are consistent with the nanoparticle size distribution. Results show that additional emissions at 420 and 490 nm are developed with particle size. The origin of the visible band emission is discussed. The mechanism of the luminescence suggests that UV luminescence of ZnO colloid is related to the transition from conduction band edge to valence band, and visible luminescence is caused by the transition from deep donor level to valence band due to oxygen vacancies and by the transition from conduction band to deep acceptor level due to impurities and defect states. A correlation analysis between the particle size and spectroscopic observations is also discussed.

Studies on the effect of selected metals on the productivity of two species of algae

The thesis embodies the results of a study on the variations in the parameters of productivity of two test species, a chlorophycean alga and a diatom. The chlorophycean alga Scenedesmus abundans was isolated from a fresh water pond whereas the diatom Nitzschia clausii was from the Cochin backwaters. Their growth parameters and their variations due to the effect of addition of some heavy metals have been studied. The growth parameters include biomass, production, respiration, photosynthetic pigments and end products of photosynthesis. The cell numbers were estimated by using a haemocytometer and production and respiration by oxygen light and dark technique. Spectrophotometric analysis for pigments, anthrone method for carbohydrate and heated biuret method for protein were the different methods employed in the present investigation. The present study is confined to nickel, cobalt, trivalent and hexavalent chromium. Different metals are discharged from various industries in and around Cochin. The effects of these metals individually and in combination are studied. Experiments to determine the effects of interaction of metals in combination enabled the assessment of the antagonistic and synergistic effect of metals on test species. The concentration or accumulation of metals on algae was determined by Atomic Absorption Spectrophotometry. The thesis has been divided into seven chapters. The introductory chapter explains the relevance of the present investigation. Chapter two presents the review of literature based on the work in relation to toxicity. Third chapter gives a detailed description of the material and specialized methods followed for the study. The effects of various metals selected for study - nickel, cobalt, trivalent and hexavalent chromium on the qualitative and quantitative aspects of productivity forms the subject of matter of the fourth chapter. The fifth chapter gives the impact of metals in combination on two species of algae. A general discussion and summary are included in the sixth and seventh chapters

Algae in industrial effluent treatment

The present research is based on two broader aspects of pollution assessment ,and treatability of petroleum and petrochemical effluents by algae. The objectives of the investigation are to study the algal ecology and trophic status of an oil refinery effluent holding pond , isolate and identify pure cultures of algae, study the role of algae in petroleum and petrochemical effluent treatment, develop strains of algae tolerant to toxic effluents, study the biotreatment potential of the tolerant algal strains developed The thesis comprises of six chapters. The first chapter gives the significance and objectives of the present study. The second chapter describes the methodology, and results of studies on the algal ecology, and trophic status of the effluent holding pond of Cochin Refineries Ltd., Ambalamugal, Kochi. The third chapter deals with the isolation, and development of pure cultures of algae, the algal bioassay of the refinery effluent, and the analyses of Chitrapuzha river water. The analysis, and assessment of the algal growth potential of the petrochemical effluent of Hindustan Organic Chemicals Ltd., Ambalamugal, Kochi. are summarised in the fourth chapter The fifth chapter deals with the algal growth potential in phenol and phenolic effluent, and subsequent absorption of phenol and total dissolved solids. The summary and conclusion of the present study are given in the sixth chapter.

Studies on The Ecology And Production of Algae in Prawn Culture Systems

Existing method of culture were largely based on empirical knowledge. Lacking a scientific basis as such methods did, they were often wasteful and suffered severe limitation. Modern methods of fish and prawn culture based on scientific research, have revolutioned the industry in recent years and not only extended its scope to cover the whole country but led to increased fish and prawn production. An understanding of the biological capability of the water in the perennial and seasonal culture ponds, and the nature and extent of the influence of the abiotic factors on the production of organisms in the primary level of food chain would contribute to effectively implement management measures in the stocking strategies and in the evaluation of economics of production of prawns. It is against this background that the present topic of investigation "Studies on the ecology and production of algae in prawn culture systems” was selected.

Studies on the ecophysiology of periphytic algae in cochin estuary

The estuaries are highly productive ecosystems and characteristically are more productive than the adjacent river or sea. Estuarine producers which include planktonic algae, periphyton, herpobenthos as well as macrophytes are capable of nearly year round photosynthesis. Productivity of an environment is mainly the contribution of various groups of autotrophic flora. Any quantitative estimation excluding any one of these would be an underestimation. Periphyton plays a very important role in the productivity of estuarine and coastal waters. It has been reported that periphytic algae attain high biomass (Moss, 1968; Hansson, 1988a) and may contribute up to 80% of the primary production (Persson gt gtt, 1977); Considerable amount of work has been done on the productivity in Cochin backwaters by different investigators (Qasim, 1973, 1979; Nair gt gtt, 1975; Gopi— nathan gt gtt, 1984). All of them have estimated the primary production based only on phytoplankton of the estuary. Considering the contribution of other autotrophic components of the estuary such as periphyton (haptobenthos), sediment flora (herpebenthos) and macropytes, the productivity estimated by earlier authors were essentially underestimations. The present work is an attempt inter glig to assess the contribution of periphytic flora towards the total organic production in the estuary

“Seaweed exudates and settlement behaviour of sedentary organisms"

The present investigation has looked exclusively into the aspect of the biological phenomenon of settling behaviour by two serious fouling offenders encountered in the tropical seas mainly on the hulls of ships and stationary structures in the harbours. The cue to study the behaviour was adopted from the observations so far made by scientists on the epizoic growth of these organisms on the surfaces of algal fronds of variegated shape, texture, size etc. The results do indicate that there are sufficient qualities of bioactive substances produced by plants occupying the lowest categories in organic evolution and curiously enough these substances have withstood the test of time.

”Investigations on The Finite Size Effects of Some Inverse Spinels and Studies on Their Composites Based on Nitrile Rubber”

In the present study, nano particles of NiFe3O4, I_.l()5Feg5O4 and CoFegO4 are prepared by sol gel method. By appropriate heat treatments, particles of different grain sizes are obtained. The structural, magnetic and electrical measurements are evaluated as a function of grain size and temperature. NiFe3O4 prepared in the ultrafine regime are then incorporated in nitrile rubber matrix. The incorporation was carried out according to a specific recipe and for various loadings of magnetic fillers. The cure characteristics, magnetic properties, electrical properties and mechanical properties of these elastomer blends are carried out. The electrical permittivity of all the rubber samples in the X — band are also conducted

Growth enhancement of micro algae, Chaetoceros calcitrans and Nannochloropsis oculata, using selected bacterial strains

In natural systems phytoplankton interact with planktonic (free living) and attached epiphytic bacteria both synergistically and antagonistically. The specificity of the association with micro algae and bacteria differs in terms of adhesion mechanisms and metabolic cooperation. Present research was carried out to study the effect of bacterial isolates namely Bacillus sp. and Pseudomonas sp. from algal culture systems on the growth of micro algae such as Chaetoceros calcitrans and Nannochloropsis oculata. C. calcitrans (F= 15.34; P<0.05) and N. oculata (F=12.52; P<0.05) showed significantly higher growth, in treatments with Bacillus sp. and Pseudomonas sp when compared to control.