Biological Water Quality Monitoring: Insights and Opportunities !!

India is considered as a land of rivers. Civilizations from ancient to modern era have thrived on the banks of rivers. Himalayan and Peninsular are the two river systems prevailing in India. Apart from capping the needs of human society, rivers have an important role in religious, cultural and metaphysical aspects. Unfortunately in present age, rapid increase in industrialization has put tremendous pressure on aquatic ecosystems both in terms of usage and waste water discharges. Uncontrolled usage of pesticides, chemicals fertilizers, industrial and urban discharges leads to rise in harmful algal blooms in the water body that depletes the oxygen level making it inhabitable for fresh water species. On the other hand the toxic chemical substances accumulate in the body tissues leading to bioaccumulation of pollutants in the species that reaches higher trophic levels upon consumption.

Traditional physico-chemical water quality monitoring techniques (simply performance based) just determines the level of pollutants and its sources which are just a snapshot and momentary. They determine the physical health of the aquatic ecosystem at the time of sampling but shed no light upon the biological responses of the pollutants.

Several questions arise like…Do these pollutants have any impact on the biological well being of aquatic organism? If yes, what are the impacts and how we can estimate the impact??

The answer to this is “Biological monitoring or Bio-monitoring” of water bodies.

In simpler words, bio-monitoring is the assessment of health status of life below water. Biological communities integrate all the stress generated due to anthropogenic activities over a period of time and reflects in terms of behavior, health and population level. Aquatic organisms like fishes, planktons, benthic macro invertebrates are useful indicators as they cope up with the stress generated due to pollutants in the course of time. 

  

Even the United Nations (UNs) has listed “LIFE BELOW WATER” as one of the goals in Sustainable Development Goals (SDGs) to conserve our aquatic resources (https://sdgs.un.org/goals/goal14). Aquatic organisms are useful bio-indicators as they integrate all the stress over a longer period of time. As a result, the number of organisms, species diversity, density etc. determines the quality of water bodies. It also assists in determining, weather a pollutant is causing loss of aquatic species or not.

There are several cases accounted around regarding the death of fish species or disappearance of native species from a particular area due to discharge of polluted water. Do you know why this happened?? Because, these organisms failed to cope up with the harmful impacts of certain pollutants. These organisms serve as the bio-indicators of pollution that can be studied to assess the health of aquatic ecosystems.  

 National Vs International Scenario

Bio-monitoring is a regular practice carried out in several developed countries of the western world under the aegis of their “National Water Quality Monitoring Program”.  It is carried out along with regular physico-chemical analysis to have a clear cut picture of overall water quality. Several developing countries have made bio-monitoring mandatory and included it in their water quality monitoring program.

Data pertaining to bio-monitoring in Indian sub continent is very sketchy which could be due to several factors. It is being carried out by CPCB under Proficiency Testing (PT) program. There is an immense need to integrate Bio-monitoring in National Water Quality Monitoring Program. 

Our country is very rich in species diversity due to its geographical location and seasonal variability; several species of insects, fauna have not been discovered yet. For entomologist, this area has unique opportunity enlightening policy driven research which can further aid in classifying Indian water's based upon species diversity.  Policy makers should emphasize to bring bio-monitoring in regular practice for better management of Indian aquatic ecosystems.