AN ANALYTICAL STUDY ON THE PREVALENCE OF THE COLIFORM BACTERIA IN THE THEKKUMBHAGAM CREEK OF ASHTAMUDI LAKE, KERALA, INDIA

The Ashtamudi estuary is of extra ordinary importance for its hydrological functions, biodiversity, rich fishery resources, a good source of fin fishes, prawns, crabs, oysters and thus provides livelihood to thousands of people. Thekkumbhagam is one among the eight creeks of Ashtamudi estuary located in the Kollam district. A perusal of existing literature revealed that no detailed study was carried out regarding the microbial load of this creek. Hence the present work involved the study of the Total Plate Count of the Thekkumbhagam creek that would help in understanding the extent of water pollution. House boats, floating restaurants with hanging latrines, reclamation, destruction of 90% mangrove vegetation by infrastructural development, inadequate port sanitation facilities, land encroachment, sand mining, toilet waste due to improper sanitation facilities for local people residing on the banks on this creek etc added to the deterioration of water quality of this creek. The total plate count ranged from 100 cfu/ml to 43x103 cfu/ml that indicated the intensity of microbial pollution. The bacteriological investigation revealed that the total coliforms ranged from 11 MPN/100ml to 17000MPN/100 ml, faecal coliforms varied form 1MPN/100 ml to 100 MPN/100 ml and Escherichia coli ranged from 1 MPN /100ml to110MPN/100ml. Among the stations, station 4 showed the maximum value for total coliforms and station 2 exhibited the maximum value for faecal coliforms and Escherichia coli. The comparison of MPN of coliforms with Indian standards for inland waters revealed that the four stations exhibited a total coliform count and Escherichia coli count that exceeded the desirable limits which indicated a high level of microbial load. As this estuary serves as the best settling places for clams and oysters besides acting as nursery ground for a variety of shrimps and finfishes, this microbial status report will be useful to the estuarine managers to identify the bottlenecks in the management and development. This emphasizes the need for proper sanitization, preventing indiscriminate dumping of wastes and also to rely upon proper treatment methods to be used to get rid of the degraded water quality.