6. Potassium
In general, potassium content of the water declined consistently from July to December. The decline was of about 10 to 15 times at few spots. Higher values were observed at Kole, Ganesh Temple and Haripur Naka as campared with that of other spots. The potassium content of the water ranged between 1.0 mg/1 to 30 mg/1 during the study period.

7. Calcium
Calcium content of the river water was found to be quite high in July ( 52 mg/1 to 75 mg/1 at various spots ) It declined considerably during the month of October and increased marginally in November and December. It was interesting to note that except in the month of July, the calcium content rarely exceded 25 mg/1 at all the spots throughout the study period. Calcium content was less at Sangam and Krishna Bridge as compared with the Kole, Ganesh Temple and Haripur Naka spots.

8. Dissolved Oxygen
In general, dissolved oxygen level was found to be near or above saturation level at most of the spots studied, however, at some spots extremely low levels of dissolved oxygen were recorded, such as, in October and November the dissolved oxygen was nil at Haripur Naka spot. Dissolved oxygen cantent varied between nil to 13.6 mg/1 during the study period.

9. Biochemical Oxygen Demand
There was no marked seasonal variation in the BOD of the river water which ranged between 21 mg/1 to 130 mg/1 during the study period. Of the spots studied, higher BOD values were obtained at Kole, Jackwell, Ganesh Temple and Haripur Naka as compared with that of the other spots.

10. Alkalinity
The alkalinity of the river water ranged between 6.0 mg/1 to 256 mg/1 during the study period. It was quite high in the rainy season; declined thereafter during October and November and was found to be increasing in December. The variations between various spots was marked inasmuch as it was comparatively quite low at Sangam and Krishna Bridge and high at Kole, Ganesh Temple and Haripur Naka spots.

11. Most Probable Number
The most Probable Number of coliforms (MPN) studied to asses the fecal pollution load was more than 2400 cells/ml of the river water at all the spots in the months of July and August. In September, it continued to be higher at Sangam, Krishna Bridge, Khubi and Kole while it declined upto 240 cells/ml at the following spots. In November, it increased at all the spots bot declined at Khubi and Ganesh Temple. MPN was more or less same during December at all the spots but values were lower at Sangam spot as compared with that of other spots.

DISCUSSION

In India the rivers though constituting one of the most important freshwater resources are not only grossly polluted due to various human activities but also have been paid much less attention by the concerned.

The present study of the river Krishna, though limited, exposed the theatening dimension of human tempering with so precious a resource.

Starling from some general parameters of pollution assessment like light penetration turbidity and dissolved oxygen of the water through the concentration of various elements the microbiological aspects it was evident that the river is stressed to a greater extent by human activities along its banks.

The anoxic state of water, as observed at many spots indicated that the river is loaded with alarming amounts of biogenic and chemical wastes, the high amount of BOD only supported the contention; such conditions would make the survival of the organisms difficult and thus disbalance the ecosystem.Transparancy of the water never exceeded 1 m showing the higer particulate and dissolved matter load on the river. The amount of total suspended and dissolved solids was so high that at times it exceeded even 5 g/1. Though the high content of solids during the rainy season could be ascribed to large scale runoff from the catchment area, the higher values in lean season were mostly due to the discharge of sewage and various industrial wastes into the river. Jackwell, Ganesh Temple, Khubi, Kole and Haripur Naka spots contained significent quantities of solids in their waters. These were also the spots where streams bringing sewage and industrial waste merge into the river. The high ionic content of the water at these spots was also coroborated by high conductivity values. Amount of chlorides, sulphates, sodium, potassium and calcium were also found to be higher at these spots. The role of sewage and industrial wastes was further strengthened by comparing the values of these spots with those of Sangam, Krishna Bridge and Haripur, which were relatively free from such influences, despite the fact that at Sangam there is confluence of the Krishna and the Koyna. But few higher values of nutrient contents at at Krishna Bridge spot were due to the occasional discharge of sewage of the Karad city into the river at this point.

The elevated values of the nitrates during rainy season indicated towards the extent of supply of nitrates from the catchment area, where large quantities of nitrogenous fertilizers are used for agricultural purposes and from liberal discharge of organic wastes.

Though, the seasonal influence in various parameters is quite prominent as far as the general chemical composition of the water is concerned, nevertheless, the effects of pollutants of various sorts are striking.

The most probable number of coliform bacteria which is indicative of fecal pollution was considerably higher at most of the spots studied, clearly suggesting that water at those spots was not potable and would need perfect disinfection before use, especially at spots like Jackwell and Ganesh Temple at Sangli.

The Krishna river which is one of most important resources of this country, particularly the southern part, has played a vital role in the development of this region where water is used for irrigation, industries, human consumption etc. The impared quality of the river water will simply hinder the utilization of the water.