18. Integration of Biomarker Approach in Pollution Monitoring Programme of Aquatic Ecosystem

Water bodies are subjected to a considerable pressure from sewage and industrial wastes. Monitoring methods adopted so far have helped in the assessment level of contaminants in water but not the interaction of these pollutants with living organisms. Water quality testing programmes use two traditional methods for water quality assessment that includes physico-chemical parameters and bio-monitoring. Looking at the limitations of these two traditional methods, a new method known as ‘biomarkers of pollution’ should be adopted. Evaluating various biomarkers in sentinel species can be of great help in environmental monitoring programme as they forecast various risks and hazards associated with the habitats of aquatic animals. Several countries have adopted Biomarkers in their environmental monitoring programmes; however, to make it a routine and well-recognized tool in the water quality monitoring programme, efforts are still required from scientific communities. The major advantage of Biomarkers is that bioavailability or potential exposure to toxicants can be demonstrated which is not possible in chemical analysis. Persistent organic pollutants (POPs) are chemical substances that do not degrade easily and persist in the environment and detecting some classes of POPs, for example organochlorine compounds, are very difficult as the limits of detection are very low. With the advancement of analytical methods, these chemicals can be now detected in every environmental matrices but changes caused physiologically in living organisms remains unknown. This limitation can be overcome with the help of biomarkers which can detect whether organisms are exposed meaningfully and the physiology is altered in comparison to normal. Whenever any pollutants enter the biological system, it brings molecular changes and the response time of molecular changes are faster than it appears at community level. This leads the scientific communities to start some research work in this area in order to develop some early warning signal or biomarkers. Measurement of molecular changes at the level of body fluids, cells or tissues reflecting an alteration in normal functioning/magnitude due to the presence of toxicants forms the basis of selection of particular parameter as a biomarker. This chapter presents the importance of various core biomarkers used as diagnostic and prognostic tools to monitor the water quality assessing the risks associated with the health of aquatic biota. This is high time to focus on the biological responses which are more relevant to predict the health status of any aquatic ecosystem before occurrence of any catastrophic events which are unmanageable.