Several methods of water quality classification have been developed using biological indices. Saprobic system ,was developed first by Kolkwitz and Marsson(1908) and is widely used.
This system is based on the tolerance of aquatic organisms to four l...
Several methods of water quality classification have been developed using biological indices. Saprobic system ,was developed first by Kolkwitz and Marsson(1908) and is widely used.
This system is based on the tolerance of aquatic organisms to four levels of pollution. Other systems are based on the diversity and tolerance of aquatic species as affected by pollution. Biological indices offer some advantages when compared to chemical indicators.
These methods are more comprehensive and reflect the overall water quality, conditions over a period of time preceding the survey, but preclude an accurate quantification of water quality using only biological indicators.