| dc.description.abstract | A study of the diversity and ecology of the freshwater fishes of four river systems of Uttara Kannada District, Karnataka, India
The Uttara Kannada district (74°9’ to 75°10’ E longitude and 13°55’ to 15°31’ N latitude), which lies along the central part of the hill ranges called the Western Ghats, has a number of perennial as well as temporary water bodies, like tanks, pools, lakes, streams, and rivers. There are both smaller east flowing rivers (Dharma, Varada) as well as larger west flowing rivers (Kali, Aghanashini, Bedti, Sharavati, Venkatapura, etc.). There has been very little work on the fish communities of this region, except for taxonomic accounts of fishes in some areas. Four of the west flowing rivers were chosen to study the diversity, distribution, and ecology of the freshwater fish communities of these rivers.
There are varying levels of different kinds of human disturbances in these river systems. Among the four rivers studied, Kali has four major dams along its stretch: Supa, Bommanahalli, Kodsalli, and Kadra. Sharavati also has two major dams: Linganamakki and Gersoppa. At Dandeli, effluents from paper mills built near the banks of Kali are discharged, affecting water quality in the region. Bedti is polluted to some extent by sewage discharge from the town of Hubli and surrounding areas, while Aghanashini has very minimal levels of effluents, mostly from agricultural wastes and pesticides from plantations and settlements along its banks. Local fish kills by poisoning and dynamiting to harvest large numbers of fish without much effort are also causing losses in species numbers and abundances. Thus, a study on species diversity, community composition, distribution patterns, and the effects of these disturbances is much needed to underscore the need to protect and conserve these natural habitats and the existing fish diversity in these river systems. | |
