Biochemical effects of the pesticide Chlorpyrifos on the fish Oreochromis mossambicus (Peters)

Man uses a variety of synthetic material for his comfortable materialistic life. Thus human interactions may become harmful for various terrestrial and aquatic lives. This is by contaminating their habitat and by becoming a threat to organisms itself. Thus the application and dispersal of several organic pollutants can lead to the development of several mutated forms of the species when exposed to sublethal concentrations of the pollutants. Otherwise, a decrease in number or extinction of these exposed species from earth's face may happen. Pesticides, we use for the benefit of crop yield, but its persistence may become havoc to non-target organism. Pesticides reaching a reservoir can subsequently enter the higher trophic levels. Organophosphorus compounds have replaced all other pesticides, due to its acute toxicity and non-persistent nature.Hence the present study has concentrated on the toxicity of the largest market-selling and multipurpose pesticide, chlorpyrifos on the commonly edible aquatic organism, fish. The euryhaline cichlid Oreochromis mossambicus was selected as animal model. The study has concentrated on investigating biochemical parameters like tissue-specific enzymes, antioxidant and lipid-peroxidation parameters, haematological and histological observations and pesticide residue analysis.Major findings of this work have indicated the possibility of aquatic toxicity to the fish on exposure to the insecticide chlorpyrifos. The insecticide was found as effective to induce structural alteration, depletion in protein content, decrease in different metabolic enzyme levels and to progress lipid peroxidation on a prolonged exposure of 21 days. The ion-transport mechanism was found to be adversely affected. Electrophoretic analysis revealed the disappearance of several protein bands after 21days of exposure to chlorpyrifos. Residue, analysis by gas chromatography explored the levels of chlorpyrifos retaining on the edible tissue portions during exposure period of 21days and also on a recovery period of 10 days.

Phytotoxicological Assessment of Two Wetlands in Eloor, Kochi Using Aquatic Macrophyte Spirodela Polyrhiza

In the current study, the duckweed aquatic macrophyte Spirodela polyrrhiza was employed for assessing the toxicity of two wetlands in the Eloor industrial estate, Ernakulam district, Kerala, South India. The assessments were made according to OECD guidelines for testing (2006). The studies involve study of growth parameters, Growth Index, Biomass and changes in productivity. The water samples were collected from two different wetland sites at the same time. The spirodela plants were introduced into several dilutions of wetland water samples. The parameters were measured after 7 days of exposure. All samples except control affected all parameters. The results of this study emphasize the significance of duckweeds as standard and reliable testing material for biological parameters in polluted aquatic ecosystem

Utilization of aquatic macrophyte Spirodela polyrhiza as phytotoxicological assessment and phytoremediation tool in selected polluted wetland sites in Ernakulam district

One of the objectives of the current investigation was to evaluate the effectiveness of Spirodela polyrhiza to remove heavy metals and other contaminants from the water samples collected from wetland sites of Eloor and Kannamaly under controlled conditions .The results obtained from the current study suggest that the test material S. polyrrhiza should be used in the biomonitoring and phytoremediation of municipal, agricultural and industrial effluents because of their simplicity, sensitivity and cost-effectiveness. The study throws light on the potential of this plant which can be used as an assessment tool in two diverse wetland in Ernakulum district. The results show the usefulness of combining physicochemical analysis with bioassays as such approach ensures better understanding of the toxicity of chemical pollutants and their influence on plant health. The results shows the suitability of Spirodela plant for surface water quality assessment as all selected parameters showed consistency with respect to water samples collected over a 3-monitoring periods. Similarly the relationship between the change in exposure period (2, 4 and 8 days) with the parameters were also studied in detail. Spirodela are consistent test material as they are homogeneous plant material; due to predominantly vegetative reproduction. New fronds are formed by clonal propagation thus, producing a population of genetically homogeneous plants. The result is small variability between treated individuals. It has been observed that phytoremediation of water samples collected from Eloor and Kannamaly using the floating plant system is a predominant method which is economic to construct, requires little maintenance and eco friendly.

Phase Transitions of Trace Metals in the Aquatic Environment of Kuttanad, Kerala

This thesis is a modest attempt in assessing the trace metal levels and their behavior in the aquatic environment of Kuttanad, an aquatic system that is severely affected by man’s intervention on natural processes, by study seriously evaluating the levels of trace metals in dissolved and particulate phases and also in the different chemical fractions of the sediments. Understanding of the distributions, variations and transfer processes of trace metals in different environmental phases in the backwaters of Kuttanad is vital for the assessment of the water pollution problems and study the ecology of the area which contributes 20% of the rice production in the State of Kerala. Kuttand is a low-lying, shallow bay formed as a result of geological uplift. The major economic activity is agriculture involving 40% of the population. About 1.5% of the people are engaged in aquaculture. The trace metal distribution in the Kuttand backwaters is considerably influenced by the tropical features of the location and by human activities including agricultural activities and construction of salinity barrier. In this study an attempt is made to differentiate the metals in the sediment into exchangeable, reducible and resistant fractions in the sediments.

Studies on the prevalence of algal blooms along Kerala coast, India

Algal blooms are naturally occurring phenomena in the aquatic environment. These blooms cause mass mortalities of wild and farmed fish and shellfish, human intoxications which sometimes result in death, alteration of marine trophic structure through adverse effects on larvae and other life history stages of commercially important species and death of marine animals. Occurrences of harmful algal blooms and associated mortality have been reported along the coastal waters of India since the early period of the last century. The present study was taken up to study the dynamics of major phytoplankton blooms, which occur along the Kerala coast. The results of quantitative and qualitative analysis of phytoplankton in the coastal waters of Vizhinjam and Chombala, their species diversity and community structure is presented and the major algal blooms recorded along the coast of Kerala during the study period is described and their occurrence is related to the hydrographic and meteorological variations. There is a clear evident from these works in the Indian region that the fishes avoid areas where these harmful algae bloom, either due to the toxicity or due to some irritant property of the chemicals secreted by the algae. Taxonomic diversity studies indicated a change in the community structure of commercial finfishes, crustaceans and molluscs due to the bloom of C.marina and funnel plots indicated the deviation in taxonomic distinctness during the bloom period from theoretical mean for the region.

Toxicity of Effluent from a Titanium Dioxide Factory on some Marine Animals

Toxicity of effluent from a titanium dioxide factory containing sulphuric acid residue with soluble iron metallic salts and insoluble material such as silica, etc. on fishes, decapods and molluscs was studied. The effluent caused changes in pH and oxygen depletion of the sea water. Sublethal effects of the precipitate of ferrous salts were also studied. Dilutions of effluent up to 1:150 were LC100 for all organisms used while 1:200 dilution was LC50 for fishes at 36 hr and for other organisms at 48 hr. But death of organisms at this concentration was caused by pH changes and oxygen depletion and did not account for the effects of the precipitate. Below this level precipitation started soon after mixing with sea water causing death of organisms by choking their gills and siphons. Dilutions,< 1:1000 were 96 hr LCO.

Environmental Impacts of Chromated Copper Arsenate (CCA) Treated Rubber Wood for Aquatic Applications

Faculty of Marine Sciences, Cochin University of Science and Technology

HEAVY METAL TOXICITY IN BIVALVE- HISTOLOGICAL AND HISTOCHEMICAL ENQUIRY

Division of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology

Investigations on the Effects of Petroleum Hydrocarbons on the Marine Bivalves Perna viridis (Linnaeus) and Sunetta scripta (Linne')

The thesis deals with different aspects connected with the distribution and toxicity of PHC in crude oils in the aquatic environment and marine molluscs. Information has been gathered and presented on the present status of research in the field based on a thorough review of recent literature. It is seen from the literature that the resident time of PHC becomes lesser and lesser when crude oil is discharged in large quantities into the coastal waters where excess oxygenation light penetration, temperature availability and strong tidal currents persist. This results in the reduction of the onslaught of oil pollution. This probably shows that taxic insult of crude oil in tropical shores will be relatively lesser than that occurring in temperate and boreal waters. However, there is no record of major episodal oil pollution comparable in quantum and extent to that of Torrey Canyon or Amoco Cadiz which prevents a more reliable analysis on the issue. Considerable controversy exists on the method of estimation of PHC in seawater. However, Ultra-violet fluorescence spectroscopy has been widely recommended as an analytical tool for the determination of total hydrocarbons. Similarly representation of values as chrysene equivalents has been recognised as the most reliable method of Quantum representation.

Chromated Copper Arsenate (CCA) Treatment for Rubber Wood Preservation and its Impact on the Aquatic Biota

Faculty of Marine Sciences, Cochin University of Science and Technology

Biochemical Effects of Anionic, Cationic and Non Ionic Surfactants on a Tropical Teleost Oreochromis Mossambicus(Peters) and a Marine Cyanobacterium Synechocystis Salina Wislouch

The present work is a base line attempt to investigate and assess the toxicities of three surfactants viz. anionic sodium dodecyl sulfate (SDS), non ionic Triton X-1OO (TX-IOO) and cationic cetyl trimethyl ammonium bromide (CTAB). These compounds represent simple members of the often neglected group of aquatic pollutants i.e. the anionic alkyl sulfates, non ionics and the cationics. These compounds are widely used In plastic industry, pesticide/herbicide formulations, detergents, oil spill dispersants, molluscicides etc. The test organisms selected for the present study are the cyanobacterium Synechocystis salina Wislouch representing a primary producer in the marine environment and a fresh water adapted euryhaline teleost Oreochromis mossambicus (peters) at the consumer level of the ecological pyramid. The fish species, though not indigenous to our country, is now found ubiquitously in fresh water systems and estuaries. Also it is highly resistant to pollutants and has been suggested as an indicator of pollution in tropical region .