971 resultados para China coast
Resumo:
The present study of the parasitic copepods gives an account of the taxonomic description of seventy seven species of parasites collected from the food fishes of the Kerala coast. Out of the seventy seven species described, fourteen are new to science, two new records for the Indian waters and ten new host records. The males of Parapetalus longipinnatus Rangnekar and Lerna~thropus indicus Pillai were collected and described for the first time. The parasites described belong to the suborders Cyclopoida, Caligoida and Lernaeopodoida. The available description of many species of this locality is reviewed and supplemented with the help of the present detailed study. The general observations made during this study reveale certain interesting aspects of the host parasite relationship, host specificity, adaptive modification and geographical distribution. A brief discussion of these observations made is also presented.
Resumo:
The present study is aimed at observing the variations, in space and time, of see of the important hydrographic parameters such as sea water temperature, salinity and Resolved oxygen within the coastal waters along the south-west coast of Indiametween Ratnagiri (17°OO*N,73°20'E) and cape comorin ( 8°10'N,77°30*E). Specific data relating to the process of upwelling and sinking was collected mainly to evaluate the extent and intensity of the vertical mixing processes active in the area under study. The study also attempted possible correlations between the observed parameters and the occurrence and migrations of some of the major pelagic fishery resources such as sardine,mackerel and anchovy in the area under study
Resumo:
This thesis deals with the population characteristics of Artemia and the effect of different environmental parameters on the different stages of Artemia in a salina at Tuticorin, south east coast of India. The present investigation was carried out from 1985 to I987. The study was initiated by undertaking a survey to find out suitable Artemia habitats along the south east coast of India and a perennial salina with an area of 0.25 ha was selected at Karapad (Tuticorin). Weekly samplings were made for two full calender years (1986-87) to collect the different stages of Artemia population as well as the different environmental parameters. The thesis comprises of the following sections: Introduction, materials and methods, systematics, biology and distribution of Artemia, results and discussion, summary and bibliography. The section on results and discussion gives the characteristics of Artemia population in the salina, the seasonal variations of different environmental parameters in the salina and their effects on different stages of Artemia population. Description of an experiment conducted to show the sudden changes of salinity on different stages of Artemia is also given as a separate section.
Resumo:
As a result of the issues of care and conservation and sustainable utilisation, the proper management of mangrove forests have become more pressing than ever. Much recent ecological and toxicological debate has been centered around the question of validity of making predictions about the future of mangrove ecosystemas a result of the newly evolved environmental policy. Though muchinformation exist on the biodiversity, floristic composition and characteristics, geographical distribution and uses of mangroves, systematic documentation of the various sedimentological and geochemical phenomena in relation to the mangrove flora are scarce. Hazardous, persistent, man-made chemicals and waste produces are entering the mangrove ecosystem at from the adjacent watersheds which strengthened alarming rates the indispensible need for further researches on the environmental behaviours, fate and the effect of such products. Studies on the effect of heavy metals, pesticides and the other toxic signals through bioassay and toxicity tests on mangrove species as well as in sediments definitely will furnish ample clues to establish the actual operative mechanisms of these environments. A thorough review of literature made in this angle reveals that some attempts have already been initiated the world over the record the physico-chemical characteristics of major abiotic components such as sediments and water of many mangrove ecosystem, however, adequate information is lacking in the Indian Environmental Science scenario. The present investigation is an attempt to record the sedimentological, mineralogical and geochemical characteristics of sediments as well as the heavy metal enrichment in the various species ofmangrove flora of three important mangrove ecosystems of Kerala, located at Veli (SouthKerala), Kochi (Central Kerala) and Kannur (North Kerala). The results of the above investigation have been analysed statistically, discussed based on the available literature and presented in this thesis under seven chapters
Resumo:
In the present study. extensive investigations were carried out on various factors affecting the selectivity of prawn gill nets with reference to material, mesh size, coefficient of hanging secolouration. Effect of tidal current on fishing height of prawn gill net and seasonal variation of catch during the course of these investigations were also studied.
Resumo:
Mechanized fishing started in Indian waters in mid —fifties and large-scale operation of trawl fishing began in the mid sixties by the surfeit of individual entrepreneurs. The southwest coast of India especially the coastal waters of Kerala are the most productive area in the subcontinent and the state has been in the forefront in marine fish production (Kurup, 2001a). Though the coastline of Kerala is one tenth of the coastline of India, the state occupies the foremost position in the marine fish production of the country, accounting for more than 30% of the marine fish landings (Thomas, 2000). The coastal waters of Kerala have rich and diversified fishery resources, which are prone to heavy exploitation by a unprecedently high number of fishing gears, among them, mechanized bottom trawlers with a numerical strength of 4550 (Kurup, 2001a) against the permissible number of 1145 (Kalawar, et al., 1985) are the most destructive. Trawling operations during monsoon periods in Kerala has been a subject of controversy between traditional fishermen and trawl fishers on a subject that trawl fishing destroys large amount of juveniles and young ones of fishes since this period is the major breeding season of most of the fish and prawns (John, 1996). Therefore Government of Kerala imposed a ban on bottom trawling activities from 1988 onwards for a period varying from 21-70 days, which usually commences from June 15th. Though many studies revealed that large amount of non-target groups were destroyed in the commercial trawl fishing in the Indian waters, no concerted study has been conducted so far to evaluate the real impact of bottom trawling on the sea bottom and its living communities. The present study was conducted to assess the impact of excessive bottom trawling exerted on the sea bottom habitat and its living communities, which would be useful in impressing up on the seriousness of habitat degradation and biotic devastation, enabling the concerned to adopt relevant conservation and management steps to conserve the resources for sustainable exploitation
Resumo:
Some investigations on the spectral and statistical characteristics of deep water waves are available for Indian waters. But practically no systematic investigation on the shallow water wave spectral and probabilistic characteristics is made for any part of the Indian coast except for a few restricted studies. Hence a comprehensive study of the shallow water wave climate and their spectral and statistical characteristics for a location (Alleppey) along the southwest coast of India is undertaken based on recorded data. The results of the investigation are presented in this thesis.The thesis comprises of seven chapters
Resumo:
Detailed information on the biology of fishes is an essential prerequisite for their proper conservation, management and exploitation. An amplified knowledge on the biology isfundamentally essential to plan sound management policies for rational utilization of Nemipterid fishes along the Indian coast. Any information on the biochemical composition of fishes will be of immense use in assessing their nutritive value. The importance of understanding body composition during growth is essential in production studies. Detailed work on Nemipterid fishes has been done in other parts of the world whereas along the Indian coast_ not much work has been carried out. Hence the present investigation is undertaken on the systematics of Nemipterids available at Cochin and the biology and biochemical aspects of_N. jagonicus and_M. mesogrion
Resumo:
Reducing fishing pressure in coastal waters is the need of the day in the Indian marine fisheries sector of the country which is fast changing from a mere vocational activity to a capital intensive industry. It requires continuous monitoring of the resource exploitation through a scientifically acceptable methodology, data on production of each species stock, the number and characteristics of the fishing gears of the fleet, various biological characteristics of each stock, the impact of fishing on the environment and the role of fishery—independent on availability and abundance. Besides this, there are issues relating to capabilities in stock assessment, taxonomy research, biodiversity, conservation and fisheries management. Generation of reliable data base over a fixed time frame, their analysis and interpretation are necessary before drawing conclusions on the stock size, maximum sustainable yield, maximum economic yield and to further implement various fishing regulatory measures. India being a signatory to several treaties and conventions, is obliged to carry out assessments of the exploited stocks and manage them at sustainable levels. Besides, the nation is bound by its obligation of protein food security to people and livelihood security to those engaged in marine fishing related activities. Also, there are regional variabilities in fishing technology and fishery resources. All these make it mandatory for India to continue and strengthen its marine capture fisheries research in general and deep sea fisheries in particular. Against this background, an attempt is made to strengthen the deep sea fish biodiversity and also to generate data on the distribution, abundance, catch per unit effort of fishery resources available beyond 200 m in the EEZ of southwest coast ofIndia and also unravel some of the aspects of life history traits of potentially important non conventional fish species inhabiting in the depth beyond 200 m. This study was carried out as part of the Project on Stock Assessment and Biology of Deep Sea Fishes of Indian EEZ (MoES, Govt. of India).
Resumo:
Kerala has been one of the leading maritime states in India for the exploitation and export of mud crabs (Raj, 1992). Many brackishwater systems like the Ashtamudi lake, Vembanad lake, Cochin backwaters and Korapuzha estuary are well known for their rich population of mud crabs. Realizing the imperative need to build up a strong scientific base for proper management and conservation of the resource and also to develop proper technologiesfor seed production and farming of mud crabs, a detailed study was undertaken on the mud crabs of Kerala coast and the results are described in the thesis. The thesis is presented in four chapters
Resumo:
A study on the different aspects of spiny lobster fishery of south west coast of India with respect to the factors relevant to production, including conservation and management measures for putting this fishery on sound basis needs no emphasis. There are some aspects of this fishery which have not been sufficiently inquired into and some others which have been touched upon intermittantly and in a languid way. The attempt here is to throw light on these aspects from a production point of view. Emphasis is on harvest technology and the conservation and management measures and it is proposed to make a critical review of such measures in vogue in other lobster fishing countries and discuss about suitable methods for this fishery
Resumo:
Satellite remote sensing is being effectively used in monitoring the ocean surface and its overlying atmosphere. Technical growth in the field of satellite sensors has made satellite measurement an inevitable part of oceanographic and atmospheric research. Among the ocean observing sensors, ocean colour sensors make use of visible band of electromagnetic spectrum (shorter wavelength). The use of shorter wavelength ensures fine spatial resolution of these parameters to depict oceanographic and atmospheric characteristics of any region having significant spaio-temporal variability. Off the southwest coast of India is such an area showing very significant spatio-temporal oceanographic and atmospheric variability due to the seasonally reversing surface winds and currents. Consequently, the region is enriched with features like upwelling, sinking, eddies, fronts, etc. Among them, upwelling brings nutrient-rich waters from subsurface layers to surface layers. During this process primary production enhances, which is measured in ocean colour sensors as high values of Chl a. Vertical attenuation depth of incident solar radiation (Kd) and Aerosol Optical Depth (AOD) are another two parameters provided by ocean colour sensors. Kd is also susceptible to undergo significant seasonal variability due to the changes in the content of Chl a in the water column. Moreover, Kd is affected by sediment transport in the upper layers as the region experiences land drainage resulting from copious rainfall. The wide range of variability of wind speed and direction may also influence the aerosol source / transport and consequently AOD. The present doctoral thesis concentrates on the utility of Chl a, Kd and AODprovided by satellite ocean colour sensors to understand oceanographic and atmospheric variability off the southwest coast of India. The thesis is divided into six Chapters with further subdivisions
Resumo:
Continental shelf is of particular significance in marine geology , because it links the two basically different structural zones in the earth's crust; the continents and ocean basins. The shelf area has much wider importance in many fields of activity such as scientific, economic, social, political and strategic. The pace of development has ultimately put pressure on mankind to look for exploitable resources and accessibility to the continental shelf area and beyond. Added to the above, the developmental activities in the coastal area would readily and directly influence the innershelf sediments. This situation demands a thorough geological knowledge of the continental shelf area. Moreover, a successful management of the continental shelf zone requires an optimum data base on the physico-chemical nature of the shelf sediments. Although sedimentological studies were carried out along the western continental shelf of India, a well documented systematic study of the inner shelf off Trivandrum coast is still found to be lacking. Considering the physiographic settings and the vicinity of two renowned placer deposits at Chavara and Manavalakurichi, such a sedimetological inventory has become all the more vital. In view of the above, a research programme has been drawn up to account the salient sedimentological and mineralogical aspects of the innershelf and beach sediments between Paravur and Kovalam, Trivandrum district, Kerala (latitudes 8° 7'00" to 8° 47'45" and longitudes 76°43'00" to 77° 40'45"). The findings are presented in six chapters formatted to address the aim of this research.
Resumo:
Fish, a natural resource, has received great attention from all over the world. since it provides a cheap protein, employment and income to the millions of people for centuries. So fishermen, industrialist and multinationals are trying to exploit the marine resources to their maximum benefit by using modern craft, advance fishing equipments and efficient gear. Fishery resources in the open system particularly in oceans, were considered to be unlimited. However, recent developments in the innovation of efficient craft and gear using well tested material fitted with modern equipments that have greatly enhanced the mobility of craft, agility of gear and the ability of equipments to locate fishery resources have proved otherwise. Hence as the exploitation increases with more effort entering the fishery, the catch per unit of fishing effort starts to decline due to the limitness of the resources. The heavy fishing pressure in the recent past led to commercial extinction of a number of stocks such as. the North Sea herring, California sardine, Japanese Sardine and Peruvian anchovy (FAO. 1968: Gulland, 1974). In India, seer fish from Palk-Bay declined due to uncontrolled fishing (Devaraj 1983).
Resumo:
Tsunamis are water waves generated by a sudden vertical displacement of the water surface. They are waves generated in the ocean by the disturbance associated with seismic activity, under sea volcanic eruptions, submarine landslides, nuclear explosion or meteorite impacts with the ocean. These waves are generated in the ocean and travel into coastal bays, gulfs, estuaries and rivers. These waves travel as gravity waves with a velocity dependent on water depth. The term tsunami is Japanese and means harbour (tsu) and wave (nami). It has been named so because such waves often develop resonant phenomena in harbours after offshore earthquakes.