Gharial (Gavialis gangeticus) populations and human influences on habitat on the River Chambal, India

Katdare, Suyash; Srivathsa, Arjun; Joshi, Apoorva; Panke, Pritish; Pande, Ruchik; Khandal, Dharmendra; Everard, Mark

Abstract

The gharial, Gavialis gangeticus (Gmelin 1789), a piscivorous reptile of Asian river systems, is increasingly threatened by diverse human pressures. Three survey expeditions were launched to monitor gharial populations, notable wildlife, and the activities and attitudes of local people in a 110km stretch of the Chambal River in the National Chambal Reserve (NCS), India. Only 15% of gharial observed in December 2009 were in the upstream 54% of the surveyed river length. This coincides with the highest density of disturbance including water pumps, fishermen, and the highest growth in fishing activity since December 2008. Although fishing is recognized as a significant threat to gharial, no strong relationship was found between numbers of gharial and fishermen. However, numbers of water pumps, indicative of the intensity of agricultural activity, had a negative relationship with gharial numbers. This relationship was strengthened by omitting the upstream (Pali to Rameshwaram) survey reach, the tourist area of the NCS, which is also potentially affected by upstream reaches. The downstream 46% of surveyed river length in December 2009 supported 85% of gharial (consistent with trends in other surveys), including 91.6% of males and 81.8% of juveniles. This reach is classified as a High Population Recorded Area of high potential conservation importance, also containing better habitat quality and lower human disturbance. A positive relationship was found between gharial numbers and sand habitat features. However, the Davar to Ghoonsai survey reach had low gharial numbers despite abundant sand features, perhaps due to a substantial length of the Ghoonsai sand bank having been converted or agriculture. This may have significant implications for gharial conservation. Copyright © 2011 John Wiley & Sons, Ltd. Copyright © 2011 John Wiley & Sons, Ltd. 21 4 June 2011 10.1002/aqc.1195 Research Article Research Articles Copyright © 2011 John Wiley & Sons, Ltd..

• Journal Article Type: Article
• Publication Date: Jun 1, 2011
• Deposit Date: Feb 18, 2015
• Publicly Available Date: Apr 19, 2016
• Journal: Aquatic Conservation: Marine and Freshwater Ecosystems
• Print ISSN: 1052-7613
• Electronic ISSN: 1099-0755
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 21
• Issue: 4
• Pages: 364-371
• DOI: https://doi.org/10.1002/aqc.1195
• Keywords: Chambal River, gharial, mugger, survey, threats, fishing, agriculture, habitat loss
• Public URL: https://uwe-repository.worktribe.com/output/961988
• Publisher URL: http://dx.doi.org/10.1002/aqc.1195
• Additional Information: Additional Information : This is the accepted version of the following article: Katdare, S., Srivathsa, A., Joshi, A., Panke, P., Pande, R., Khandal, D. and Everard, M. (2011) Gharial (Gavialis gangeticus) populations and human influences on habitat on the River Chambal, India. Aquatic Conservation: Marine and Freshwater Ecosystems, 21 (4). pp. 364-371. ISSN 1052-7613, which has been published in final form at http://dx.doi.org/10.1002/aqc.1195
• Contract Date: Apr 19, 2016