Studies on the Effects of Bottom Trawling on the Benthic Fauna off Veraval Coast, Gujarat

Bottom trawling is one among the most destructive human induced physical disturbances inflicted to seabed and its living communities. The bottom trawls are designed to tow along the sea floor, which on its operation indiscriminately smashes everything on their way crushing, killing, burying and exposing to predators the benthic fauna. Bottom trawling causes physical and biological damages that are irreversible, extensive and long lasting. The commercial trawling fleet of India consists of 29,241 small and medium-fishing boats. The northwest coast of India has the largest fishing fleet consisting of 23,618 mechanized vessels, especially the bottom trawlers. However, attempts were not made to study the impact of bottom trawling along Northwest coast of India. The estimated optimum fleet size of Gujarat is 1,473 mechanised trawlers while 7402 commercial trawlers are operated from the coast of Gujarat. Veraval port was designed initially for 1,200 fishing trawlers but 2793 trawlers are being operated from this port making it the largest trawler port of Gujarat. The aim of this study was to investigate the effects of bottom trawling on the substratum and the associated benthic communities of commercial trawling grounds of Veraval coast. The study compared the differences between the samples collected before and after experimental trawling to detect the impacts of bottom trawling. Attempts were made to assess the possible impact of bottom trawling on:(i) the sediment characteristics (ii)the sediment heavy metals (iii) epifauna (iv) macrobenthos and (v) meiobenthos. This study is expected to generate information on trawling impacts of the studied area that will help in better management of the biological diversity and integrity of the benthic fauna off Veraval coast. An exhaustive review on the studies conducted around the world and in India on impact of bottom trawling on the benthic fauna is also detailed.In the present study, the bottom trawling induced variations on sediment organic matter, epifauna, macrobenthos and meiobenthos were evident. It was also observed that the seasonal/ natural variations were more prominent masking the trawling effect on sediment texture and heavy metals. Enforcement of control of excess bottom trawlers and popularization of semi pelagic trawls designed to operate a little distance above the sea bottom for off bottom resources will minimize disturbance on the sea bottom. Training and creating awareness in responsible fishing should be made mandatory requirements, to the coastal communities. They should be made wardens to protect the valuable resources for the benefit of sustainability. To protect the biodiversity and ecosystem health, the imminent need is to survey and make catalogue, identification of sensitive areas or hot spots and to adopt management strategies for the conservation and biodiversity protection of benthic fauna. The present study is a pioneering work carried out along Veraval coast. This thesis will provide a major fillip to the studies on impact of bottom trawling on the benthic fauna along the coast of India.

Institutional Dynamics in Community-Based Fisheries Resources Management for Sustainable Development of Marine Fisheries in Kerala

Department of Applied Economics, Cochin University of Science and Technology

Linear Low Density Polyethylene-Biodegradability Using Bacteria from Marine Benthic Environment and Photodegradability Using Ultraviolet Light

Various compositions of linear low density polyethylene(LLDPE) containing bio-filler(either starch or dextrin)of various particle sizes were prepared.The mechanical,thermal,FTIR,morphological(SEM),water absorption and melt flow(MFI) studies were carried out.Biodegradability of the compositions were determined using a shake culture flask containing amylase producing bacteria(vibrios),which were isolated from marine benthic environment and by soil burial test. The effect of low quantities of metal oxides and metal stearate as pro-oxidants in LLDPE and in the LLDPE-biofiller compositions was established by exposing the samples to ultraviolet light.The combination of bio-filler and a pro-oxidant improves the degradation of linear low density polyethylene.The maleation of LLDPE improves the compatibility of the c blend components and thepro-oxidants enhance the photodegradability of the compatibilised blends.The responsibility studies on the partially biodegradable LLDPE containing bio-fillers and pro-oxidants suggest that the blends could be repeatedly reprocessed without deterioration in mechanical properties.

Sustainability and Livelihood Issues of Vembanad Ecosystem Fisherfolk Communities

Dept.of Applied Economics,Cochin University of Science and Technology

Mangrove plant Ceriops tagal as a potential source of anti White Spot Syndrome Virus preparations for Penaeus monodon

White spot syndrome virus (WSSV) is the deadliest virus among crustaceans ever discovered having several unique and novel features. Recent developments in genomics and proteomics could elucidate the molecular process involved in the WSSV infection and the host pathogen interaction to some extent. Until now no fool proof treatment or prophylactic measure has been made available to control WSSV out breaks in culture system. Even though there are technologies like application of immunostimulants, vaccines, RNAi and several antiviral natural products none of them has been taken to the level of clinical trials. However, there are several management options such as application of bioremediation technologies to maintain the required environmental quality, maintenance of zero water exchange systems coupled with application of probiotics and vaccines which on adoption shall pave way for successful crops amidst the rapid spread of the virus. In this context the present work was undertaken to develop a drug from mangrove plants for protecting shrimp from WSSV.Mangroves belong to those ecosystems that are presently under the threat of destruction, diversion and blatant attack in the name of so called ‘developmental activities’. Mangrove plants have unique ecological features as it serves as an ecotone between marine and terrestrial ecosystem and hence possess diversity of metabolites with diverse activities. This prompted them being used as remedial measures for several ailments for ages. Among the mangrove plants Ceriops tagal, belonging to the family Rhizophororaceae was in attention for many years for isolating new metabolites such as triterpenes, phenolic compounds, etc. Even though there were attempts to study various plant extracts to develop anti-viral preparations their activity against WSSV was not investigated as yet.

Ecophysiology of nontuberculous Mycobacteria in marine aquaculture ponds

The world demand for fish and fishery products is increasing steadily and it is generally accepted that it will not be possible to meet the heavy demand with resources exploited from capture fishery alone. Now aquaculture is well established and fastdeveloping industry in many countries and is a major focus sector for development. During recent decades, aquaculture has gained momentum, throughout the world especially in developing countries. According to Food and Agricultural Oganisation (FAO, 2000), global aquaculture production was 26.38 tones in 1996 have reached 32.9 million tonnes during 1999. Only marine aquaculture sector has contributed 13.1 million tonnes during 1999.India is a major fish producing country. About one half of lndia’s brackish water lands are currently being utilized for farming in order to reduce the gap between supply and demand for fish. Aquaculture has become a major source of livelihood for people and its role in integrated rural development, generation of employment and earning foreign exchange, thereby alleviating poverty is being greatly appreciated around the world.Among the infectious agents, bacteria are becoming the prime causal organisms for diseases in food fishes and other marine animals. Sindermann, (1970) reported that bacterial fish pathogen most commonly found among marine fishes is species of Pseudomonas, Vibrio and Mycobacterium. These can be categorized into primary pathogens; secondary invaders that may cause systemic disease in immunocompromised hosts; and normal marine flora which are not pathogenic but may occur on body surfaces or even within the tissues of the host. I-Iigh density of animals in hatchery tanks and ponds is conducive to the spread of pathogen and the aquatic environment with regular application of protein rich feed, is ideal for culturing bacteria. Bacteria, which are normally present in seawater or on the surface of fish, can invade and cause pathological effects in fishes, which are injured or subjected to other environmental stresses.Mycobacteria except parasites are known as nontuberculosis mycobacteria (NTM), atypical mycobacteria or mycobacteria other than tuberculosis(MO'l'l"). This group of mycobacteria includes opportunistic pathogens and saprophytes. Environmental mycobacteria are ubiquitous in distribution and the sources may include soil, water, warm-blooded as well as cold-blooded animals. Disease caused by environmental mycobacterial strains in susceptible humans (Goslee & Wolinsky, 1976; Grange, 1987), animals and fishes are increasingly attracting attention. Greatest importance of environmental mycobacteria is believed to be their role in immunological priming of humans and animals, thereby modifying their immune responses to subsequent exposure to pathogenic species.

Studies on taxonomy and ecology of Mysidacea from the EEZ of India

Members of the order Mysidacea are important component in marine and estuarine plankton inhabiting all regions of the oceans. There are many brackish water species and few species occur in fresh water, some have become adapted to the specialized environments of caves and wells. They are omnivores, responsible for remineralisation of a substantial portion of the detritus in the water column. They form an important link in the food chain (between microbial producers and secondary consumers) and therefore play a major role in the cycling of energy within the aquatic ecosystem. In tropical and subtropical waters, swarms of mysids are exploited commercially and marketed as preserved cooked food. Mysids have been used in fish farming as live feed resource. They are also excellent experimental organism, extremely useful in the studies of potential impact of various pollutants in the aquatic environment. Mysids are also used in wood pulp effluent plants.Considering the significant role of mysids in the productivity of tropical and coastal ecosystems,the present study has been undertaken to extend our knowledge on the systematics, species composition, distribution,abundance and ecology of mysid fauna of the Indian EEZ and adjoining areas. The present study therefore will undoubtedly fumish valuable information on Mysidacea of the Indian waters.

Studies on improved practices of prawn farming for higher production in central Kerala

The thesis entitled "Studies on improved practices of prawn farming for higher production in central Kerala" prepared by the author describes various practices prevailing in the study area in order to elucidate their relative merits. The study on semi-intensive farming at Mundapuram, Kannur was also carried out and included in the thesis for comparison.The author felt it important to make a critical study of the existing culture practices in the central Kerala, a region where it has been existing since time immemorial.Careful analysis of data accrued by the author has helped him to identify strength, weakness, opportunities and threats confronting the shrimp farming. As a result it was possible to evolve an appropriate management technology taking into consideration the various ecological (location specific), social and economical conditions prevalent in the vast study area.

Spatial and Temporal Variation of Microbial Community Structure In Surficial Sediments of Cochin Estuary

This thesis entitled spatial and temporal variarion of microbial community structure in surficial sediments of cochin estuary.In the estuarine and coastal systems, organic matter (OM) is derived not only from autochthonous primary production, but also from allochthonous (terrestrial) organic matter (OM) delivered by river discharge and runoff. A significant portion of the OM sinks through the water column and is ultimately stored in carbon pool in the sediments.Analysis of spatial and temporal variation in benthic microbial community of a tropical estuary was conducted for the first time using non selective measures that affirms that PLFA approach is a sensitive and reliable method in determining microbial community structures of surficial sediments of estuary.The close relationship between the concentrations of the microbial fatty acids and total biomass indicates that bacteria could account for the largest proportion of the biomass in the sediments.This is first study that has documented the changes in microbial community composition linkage to biotic and abiotic variables in benthic estuarine ecosystem. This contemporaneous community will be the backdrop for understanding the response of autochthonous community to increasing anthropogenic stress.

L-Glutaminase production by Marine Bacteria

L-glutaminases (L—glutamine amidohydrolase EC.3.5.l.2) is proposed as a prospective candidate for enzyme therapy cnf cancer and also as zui important additive during enzymatic digestion of shoyu koji since it could enhance glutamate content of soysauce. Commercial production of glutaminase could make possible its wide application in these areas, which would demand availability of potential sources and suitable fermentation techniques. The ‘present investigation highlighted marine environment as a potential source of efficient glutaminase producing bacteria mainly species of pseudomonas, aeromonas ,vibrio,alcaligenes, acinetobacter bacillus and planococci.Among them pseudomonas fluorescens ACMR 267 and v.cholerae ACMR 347 were chosen as the ideal strains for glutaminase production.Extracellular glutaminase fraction from all strains were in higher titres than intracellular enzymes during growth in mineral media, nutrient broth and nutrient broth added with glutamine.Glutaminase from all strains were purified employing (NH4)2SO4 fractionation followed tnr dialysis and ion exchange chromatography. The purified glutaminase from all strains were observed to be active and stable over a wide range of gfii and temperature.Optimization studies cflf environmental variables that normally influence time yiehi of glutaminase indicated that the optimal requirements of these bacteria for maximal glutaminase production remained stable irrespective of the medium, they are provided with for enzyme production. However, solid state fermentation technique was observed to be the most suitable process for the production of Glutaminase.

A marine candida sake as source of immunostimulants to fenneropenaeus indicus

Aquaculture has developed rapidly over the last three decades to become an important activity worldwide.The Food and Agricultural Organization (FAO) of the UN acknowledge that global fishery output must be increased by at least 50% to offset projected shortfalls in dietary protein by 2030.LAquaculture has developed rapidly over the last three decades and has become an importat industry as today’s demand for fish exceeds the natural supply.lmmunostimulants are chemical compounds that activate the immune system of animals and render them more resistant to infections by viruses, bacteria, fungi, and parasites. lmmunostimulants have been obtained from diverse natural sources where, microbial cell wall acts as the main source.The salient findings of the study are summariseSeven marine yeasts were screened for growth promoting and immunostimulant property in F. indicus. Candida sake S165 was found to be best in terms of its support for growth and protection against white spot virus infection.The study revealed that marine yeast Candida sake can be effectively used as potential source of immunostimulants for application in penaeid prawns culture systems. The study emphasise the fact that the dose and frequency of application of immunostimulants are to be standardised and validated before commercialisation to achieve optimum stimulation of the immune system and to avoid immune fatigue die to verdose.Marine yeast (whole cell) was found to support better immunostimulation compared to its cell wall component B-1,3-glucan. This study shows that administration of marine yeast (whole cell) or B-1,3-glucan as immunostimulants in aquaculture would definitely help in protection of the stock to a few more days even though total protection is not being imparted. This partial protection itself would be highly helpful to the farming industry so that they can get sufficient time to plan for a safe harvest and save the crop from cent percent mortality.

Synergic Reactions in the Estuarine Environment leading to Modulation of Aluminium metal during Transport Processes (in Cochin Estuary)

The research work which was carried out to Synergic Reactions in the Estuarine Environment leading to Modulation of Aluminium metal during Transport Processes (in Cochin Estuary)Estuaries are considered as sink or source for terrestrial and various anthropogenically generated materials. These include naturally occurring elements Al, Si, Fe or trace inorganics or industrial pollutants of different types. There have been reports on both positive and negative impacts by the introduction of above materials into the ecosystem.This thesis deals with the trace metal Aluminium (Al) whose average concentration (about 8%) in the earths crust is surpassed only by that of Oxygen and Silicon. There can be no doubt that most of the land derived materials reaches the ocean through rivers via estuaries. An important aspect noticed here is that the concentration of dissolved Al is much lower in sea water than in river water.On critically analysing Cochin estuary, for the entire cycles, covering monsoon, postmonsoon and premonsoon, the following salient features are documented as hereunder. Dissolved Al exhibits high and variable trends in Cochin estuary, the influencing parameters being salinity, SPM, pH and dissolved Si. A general profile showed removal in upper/mid estuary followed by regeneration in the mid/lower estuary and further decrease seawards in the southern/northem arms.Distribution appears to be a function of freshwater input, the monsoon season exhibiting very high concentrations throughout the estuary. As the river discharge decreased with the progress of seasons, dissolved Al concentration also decreased, the metal limiting itself to the upper and mid estuary.

Trace metal speciation in the Cochin Estuary

This thesis Entitled Trace metal speciation in the cochin estuary.Natural waters provide a favourable environment for speciation studies because of the prevailing variable chemical matrix and the variety of metal forms which may exist there.An estuary is a mixing zone of riverine and oceanic waters with widely varying compositions where end members interact both physically and chemically. The trace element chemistry in the estuarine environment has been an area of considerable research in the past decades. The trace metal distribution in the Cochin estuary is considerably influenced by the tropical features of the location and by human activities. The lower Periyar river and the Cochin estuary have been particularly selected for this investigation in view of the impact of trace metals on the estuarine ecosystem as well as in attempt quantify the phenomenon of metal speciation in the waters of a tropical coastal plain waterbody. If the concentration in the water media is very low, then, many of the fractions that could be estimated by speciation schemes for metals will fall below the detection limits, a factor which is undesirable.The study would also delineate the features of metal speciation which modify the chemical regime of ionic elements that traverse natural boundaries in aquatic environments, especally in those tropical areas prone to multivariate geographical settings.

Studies on certain exploted marine finfish resource of India

This thesis Entitled Studies on certain exploited marine Finfish Resources of india.Marine fish catch forecasting is short term or long term basis for purposes of explation and management. Among the short term forecasts, two approaches need serious consideration in India: 1. to improve the methods of understanding the influence of environmental characteristics on the abundance or availability of fish in different areas in different periods and to make the forecasts of the same, 2. to make analysis of time series catch data (ARIMA models) to make forecasts of catch in the next year or in a particular period during next year. There is some evidence of suitability of these approaches to Indian marine fisheries but attempts aiming at comprehensive studies should be made. In the area of long term forecasts, considerable work is done in India on single species assessments but in the context of multi species, multigear nature of Indian marine fisheries, assessments of all species together in a mixed fishery are urgently required for effective managements of fisheries.