General description:
The problem of marine pollution due to various types of contaminants such as organochlorine pesticides (OCP), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs) petroleum hydrocarbons (PHCs), polychlorinated dibenzo-dioxins (PCDDs), heavy metals (mercury, cadmium, arsenic, cobalt, manganese, etc.) and nutrient salts, has become a global concern because of the accumulation of their residues in the tissues of various species of marine organisms and their bio-magnification through the food-chain leading to hazards to human health.In case of nutrients, excessive concentrations of these salts in coastal waters can lead to eutrophication and proliferation of toxic algal blooms.
The study of the impact of such toxic compounds, in general, and toxic action of these contaminants, in particular is of great importance to understand their impact on the ecosystem. The toxicity of pollutants to aquatic eco-system largely depends on the chemical and physical state in which the pollutants exist, and the toxic effects depend on their uptake, distribution, elimination and bio-transformation. Moreover, the toxic potentials of various contaminants can be correlated with their active concentrations in the bio-phase (i.e. body compartment where the contaminant exerts its effect; the contaminant then turns into being a pollutant) leading to significant changes in the biological responses.
In order to detect and assess the impact of pollution, particularly low concentration of increasingly complex mixtures of contaminants, on environmental quality, the current trend of biomarker research has drawn worldwide attention.Biomarkers are biological indicators that react to the presence of certain pollutants through responses (cellular, molecular, biochemical or physiological changes) like, damage to DNA, damage to liver, changes in reproductive pattern or at community level - proliferation of certain species at the cost of others.
As a result of human developmental activities, a number of environmental pollutants enter the water courses – rivers, estuaries, coastal waters – through air, river discharge, land drainage, etc.Within the water bodies, the pollutants undergo physical and/or chemical transformations in their properties through processes like sedimentation/re-suspension, flocculation, adsorption/desorption, precipitation, oxidation/reduction, etc., due to varying environmental conditions (pH, salinity, dissolved oxygen, redox potential, etc.) prevailing in these natural water bodies.Quite often, these transformations are microbially mediated.The behaviour and fate of pollutants, as well as their toxicity to marine organisms largely depend on the physical and chemical state in which they are present, and the prevailing environmental conditions.Hence, to evaluate the effects of these pollutants on the ecosystem, it is necessary to understand their behaviour under varying environmental conditions, and the mechanisms of the processes that control it.
Environmental Impact Assessment (EIA) is evaluation of impact on the environment due to a particular developmental activity in the area of concern.When any developmental activity is planned in a certain area, it is necessary to evaluate its impacts (on land, water, air, local population, local flora and fauna, socio-economic aspects, climate, etc.) and accordingly formulate the Environmental Management Plan (EMP).
What has been done so far:
- Extensive work has been carried out to monitor the level of pollution in the seas around India by measuring the concentrations of toxic metals (Cd, Pb, Hg, Mn, Co, Ni, Zn, etc.), pesticides, PCBs, petroleum hydrocarbons and nutrients, in different compartments (water, sediments and biota) of the seas,
- Bacterial population has been characterized in the estuarine and coastal waters, and various marine bacteria have been identified for bioremediation of pollution,
- Studies on the role of bacteria in metal speciation under different redox regimes have been initiated,
- Investigations on various biomarkers, such as acetylcholinesterase activity, cytochrome P450 enzyme induction (EROD), metallothianine activities, have been carried out to assess the impact of the pollutants on various species of marine organisms, and
- Evaluation of various Oil Spill Dispersants (OSDs) have been carried out for their suitability for use in Indian marine conditions, and approved.
Expectations from this work
- Enhance our capability to predict the effects of pollution in Indian marine environment.
- Making use of available data, identify the sources of pollution and the pathways of their dissemination.
- Application of biomarkers for rapid assessment of marine pollution including the evaluation of reproductive and immunological damage.
- Bioremediation of major pollutants using marine bacteria
- Abatement of coastal pollution from industrial/domestic discharge using other suitable marine resources
- Unravel the molecular mechanisms leading to DNA damage in various species of marine organisms
What next
- To bring out a map of distribution of various types of pollutants in the seas around India
- To identify sources of pollution and suggest steps for control
- To develop water quality models for Mandovi and Zuari estuaries using MIKE 21 software
- To develop useful and easy to use biomarkers to provide early warning of impending pollution
- To develop predictive model for pollution in the marine environment
Scientific components and achievements:
Plan of work (approach)
- Samples of water, suspended particulates, sediment and biota will be collected from estuarine and coastal waters, and analyzed for pollutants (nutrients, heavy metals, petroleum hydrocarbons, cogeners of PCBs and organo-chlorine pesticides, etc.) to study their distribution and partitioning among the different compartments. Their distribution at various locations will be evaluated in relation to environmental parameters.
- Bacterial population will be characterized in the estuarine and coastal waters.Their role in metal speciation under different redox regimes will be investigated.
- Testing and evaluation of indigenous standard materials will be carried out.
- Environmental data collected under various programmes will be utilized to prepare a water quality model for Mandovi and Zuari estuaries using the recently acquired MIKE-21 software.
- Studies will be carried out on the following biomarkers for use in pollution monitoring:
- Changes in the integrity of DNA in marine organisms in the presence of various pollutants (DNA strand break and Comet assay)
- DNA damage and histochemical/histological alterations in fish due to the presence of poly-aromatic hydrocarbons (PAH)
- Formation of metallothionein in fish and bivalves as indicators of metal pollution Ø Studies on activities of enzymes acetyl-cholinesterease to evaluate the neurotoxicity of contaminants in marine environment
- Induction of alkaline phosphatase activity in relation to phosphate in marine environment.A novel marine microorganism (Pseudomonas CH07) capable of degrading different congeners namely coplanar, sterically hindered and other chloro-biphenyls present in a technical grade PCBs (Clophen A-50); the aerobic bacterial strain, identified as Pseudomonas CH07 isolated from coastal zone of Arabian sea near Goa, India subjected to intense anthropogenic activity is shown to degrade PCBs of chlorine content (4-7 chlorine atoms per biphenyl).
- Our studies have shown for the first time that PAHs in the presence of nitrite could have serious physiological impact on estuarine fish.
- Bacteria Highly Resistant to Mercury (BHRM) isolated from the coastal waters and sediments along the west coast of India, were characterized and tested for growth in the presence of different pollutants – heavy metals, pesticides, phenols, formaldehyde, tributyl tin (TBT) and PCBs, to investigate their potential to detoxify a variety of xenobiotics. All the environmental strains of BHRM used in this study were capable of growth at far higher concentrations (>50ppm) of mercury than reported previously. Likewise, their ability to grow in the presence of toxic xenobitics, either singly or in combination, was superior to those bacteria incapable of growth in media containing mercury at concentrations >5ppm.
Achievements:
- Considerable amount of data on the distribution of various pollutans in the estuarine and coastal waters of Goa has been collected over a period of time through systematic monitoring studies.
- Several projects for conducting EIA were undertaken before the commencement of development activities along the India coast sponsored by government and industry.
- All the data on water and sediment quality, biology, microbiology, waves, tides and currents in the estuarine and coastal waters of Goa, collected under ICMAM project have been compiled and submitted to ICMAM-PD (DOD).
- Studies on bioaccumulation of metals in the commercially important clam Papia Malabarica was done.
- Completed sponsored projects for the evaluation of foreign and Indian based Oil spill Dispersants for their suitability for use in Indian coastal waters for combating oil spills.
- Completed the Indo-Portuguese collaborative project on Biomarker responses in estuarine/marine fishes for pollution monitoring and management.
- Experimental studies for the investigation of the relationship between histopathological and genetic anomalies (e.g., DNA damage and micronucleus formation) and the various biochemical markers of contaminant exposure namely, EROD, sSDH and biliary FACs in marine fish exposed to PAHs in the presence and absence of nitrite were carried out.
- Developed a technique for evaluation of neurotoxic substances in the marine environment
- Determined the integrity of DNA in various species of marine organisms as biomarker of pollution.
- Participated in Intercallibration excercises in water and sediment quality parameters .
- Team members have participated in cruises for coastal monitoring between Goa to Ratnagiri.
- Project Reports for Kandla Port Trust and Mormugao Port Trust have been completed.
- Invited lectures were delivered at Conferences/ Seminars/ Symposiums/ Universities by the participants
- International workshop on marine pollution and ecotoxicology during 25-26 February, 2004 held at NIO, Dona Paula, Goa in collaboration with International Water Association, U.K. and DST, CSIR.
- Interactive workshop on A Review of Current status, Policies and Legislation on POPs in India 30 June, 2004, at NIO Seminar Hall. Sponsored by AEEL Pvt. Ltd., CII, Bharuch Enviro Infrastructure Ltd., Mins of Env. & Forest, UNIDO, CSIR-ITRC.
- Guidence and facilities for local and international students for the Ph.D. degree , internship training and dissertation work was provided.
Progress in work (e.g. sample analysis, models, software / instrument developed):
- A number of samples of different types of marine mollusks (clams, oysters and snails) are being collected from the coastal regions of Goa, to isolate the DNA from their tissues and evaluate its integrity.
- Marine shellfish samples (oysters, clams and mussels) are collected from estuarine and coastal waters of Goa and are being analyzed for heavy metal concentrations.
- Annual monitoring along coastal transects: off Mormugao and off Ratnagiri is being done.
- Annual monitoring of Beaches in Goa- Candolim, Velsao, Benaulim,Mobor and Ratnagiri is carried out under the COMAPS programme.
- Continuous Pollution monitoring at Mandovi and Zuari mouth and coastal transects is carried out to determine the water and sediment quality. Physico-chemical,biological and microbiological characteristics are determined in order to keep a check on the health of our coastal waters.
- Analysis of Trace metals Total petroleum Hydrocarbons in fish samples collected along Orissa coast under ONGC sponsored project.
- Testing and licencing of Oil Spill Dispersants supplied by various manufacturers is an ongoing activity.
- Experimental work on DNA damage in fish exposed to PAH is in progress.
- Testing and certification of Indigenous Standard Reference Materials is an ongoing activity
Facilities available:
- Acquisition and installation of a 4-channel auto-analyser for nutrient analysis.
- Acquisition and installation of a Coulometer for CO 2 analysis in seawater.
- Facility for testing trace metals
- Facility for testing Oil Spill Dispersants.
Any Other information :
United States Patent:6,544,773
- Author: Sarkar , A.et al, April 8, 2003
- Title: Microbial process for degradationof PCBS in clophen A-50 using a novel marine microorganism, Pseudomonas CH07
- Inventors: Sarkar; Anupam (Goa, IN); De; Jaysankar (Goa, IN); Nagappa; Ramaiah (Goa, IN)
- Current U.S. Class: 435/253.3 ; 435/262.5; 588/207, Intern'l Class: C12N 001/20; B09B 003/00, Field of Search: 435/253.3,262.5 588/207
- US Patent No. 7,118,906 dt. 10/10/2006 granted to C.Raghukumar, M.S.Shailaja and Shilpa Kamat for "Process of removal of polycyclic aromatic hydrocarbons inwastewater and contaminated sites."
Work opportunities (without payments)
- Join this group as a junior research fellow, Senior research fellow, research associate (CSIR/UGC)
- Join this group as a student for doing M.Sc thesis
- Join this group for Ph.D programme under the guidance of scientist
- Develop new techniques for biomarker studies
Develop new areas of studies for marine pollution
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