Fish diversity, composition and invasion of exotic fishes in river Yamuna under altered water quality conditions

摘要

Impacts of water quality parameters on the fish diversity of the river Yamuna were studied from January 2010 to December 2011 at 11 sampling sites from uppermost Badwala to Allahabad. Certain key water quality parameters were showing considerable increase in their values from Badwala to Etawah. The highest value of chloride was observed at Mathura (217.4 ppm). The fish diversity of the river Yamuna were investigated for the first time and 112 fish species belonging to 10 orders, 29 families and 73 genera were identified. Indian major carp fishery has considerably declined in the system while exotics, especially Cyprinus carpio and Oreochromis niloticus, are increasing at an alarming rate in the middle and downstream stretches. The exotic common carp was observed at all sampling sites except the uppermost, almost pristine Badwala and formed a maximum 27.0% of the total fish catch at Arail (Allahabad), Tilapia was recorded between the Panipat to Allahabad stretch, and formed a maximum 84.8 % population at highly polluted Etawah. The population of exotics comprised 93.0% of the total fish catch at Etawah.