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.

Technological Change and the Development of the Primary Fishing Industry of Kerala - A Study of Limited Growth

Induction of growth in the primary marine fishing industry of Kerala is a sine gua Qgn for improving the economy of the fishermen, the state's domestic product as well as earning more foreign exchange for the country. The State Administration has been trying to instil growth into the industry eversince the output of the industry showed marked sign of decline (particularly after 1975). Significantly, it has attempted to strengthen the traditional sector, (which is considered to be the crucial sector of the primary marine fishing industry of the state) by introducing intermediate technology and by revamping the organisational structure of the industry. But it appears that the production system in the primary marine fishing industry of Kerala has been severely constrained by the existing technology, organisation of production and marketing institutions. Regeneration of growth in the industry calls forth an understanding of the 'process' of growth in the industry and the need to réorganise it with new technology, and new organisations. The present study is an attempt to unraval the process of growth in the primary marine fishing industry of Kerala since 1951

Application of primary haemocyte culture of Penaeus monodon in the assessment of cytotoxicity and genotoxicity of heavy metals and pesticides

Lack of shrimp cell lines has hindered the study of pollutants which adversely affects shrimp health and its export value. In this context a primary haemocyte culture developed from Penaeus monodon was employed for assessing the cytotoxicity and genotoxicity of two heavy metal compounds, cadmium chloride and mercuric chloride and two organophosphate insecticides, malathion and monocrotophos. Using MTT assay 12 h IC50 values calculated were 31.09 16.27 mM and 5.52 1.16 mM for cadmium chloride and mercuric chloride and 59.94 52.30 mg l 1 and 186.76 77.00 mg l 1 for malathion and monocrotophos respectively. Employing Comet assay, DNA damage inflicted by these pollutants on haemocytes were evaluated and the pollutants induced DNA damage in >60% of the cells. The study suggested that haemocyte culture could be used as a tool for quantifying cytotoxicity and genotoxicity of aquaculture drugs, management chemicals and pollutants

Primary Productivity Of The Retiing Zones In The Kadinamkulamestuary, South-West Coastof India

Retting.of coconut husk is one of the major problems of pollution in the estuaries (Kayals) of Kerala. This paper discusses the salient features associated with the variation in gross and net primary productivity values in the Kadinarnkularn Kayal based on lortnightlydala from twosclected stations frorn Octobcr1987 to September 1988.The gross primary productivity value in the surface water ranged from 0.06 to 0.29gC/m3/day at Station Iand from 0.06 to 1.49gC/rn3/dayatstation II. In the bottom wateritrangcdfrorn oto 0.21 gC/m2/ day at station I whereas that at station II from 0.03 to 1.41gC/m3j day. The net productivity in the surface water at station I varied from 0 to 024 gC/m Iday Whereas that atstation II varied from 0.02to 1.44gC/m3Iday.AI the bottomwaterilvaried from ato 0.19gC/m3/ day at station I and from 0.01 to 1.21gC/m3/day at station II. The monsoon period showed the highest mean seasonal value at stations I and II. The total depletion of dissolved oxygen giving rise to anoxic condition coupled with the production of large quantities of hydrogen sulphide was found to be detrimental to the gross and net productivity values in the retting zone