Status Assessment of Ganges River Dolphin (Platanista gangetica gangetica) in Kulsi River, Assam, India in Pre-monsoon season
Shah Nawaz Jelil
Shah Nawaz Jelil, Pranjal Mahananda And Mridul Bora
Introduction: What conservation problem or question does your study address?
The Ganges River Dolphin (Platanista gangetica gangetica) commonly known as susu one of the three recognized extant obligate freshwater dolphins, endemic to the Indian sub-continent and has fairly extensive distribution range. Its status in a dry period like the pre-monsoon season is not clearly known. The present study aimed to investigate the status and site-specific threats of Ganges River Dolphin in the Kulsi river system in the pre-monsoon season.
Methods: What were the main research methods you used?
Reconnaissance survey was carried out before the actual field survey which was carried from October 2013 to February, 2014. This included questionnaire survey and secondary information collection from locals especially fishermen. For convenience of study, the whole river was fragmented and five sites were sampled.All surveys were done on foot or on traditional wooden canoes (vesse based survey). Day long surveys were carried out in all the five sample sites. Data such as channel width (narrow/wide), nearby confluences, meanders, weather, bank type (sandy/muddy/hard ground), and activities of humans in the river were recorded and filled into field datasheets. Observations on different fishing gears were done and questionnaire survey among locals was done. Threat assessment was done by carefully examining the scanty amount of literature, through questionnaire survey and through direct observation.
Results: What are your most important results?
Out of the 5 sites surveyed, dolphins were sighted in only one site (20%). Study altogether found 5 individuals in all the 5 sites. The encounter rate of dolphins in the whole stretch was found to be 0.065.The threats included sand mining, habitat degradation, fishing gears, unregulated motor boat running in the confluence of Kulsi and Brahmaputra, drying up of nearby wetlands in this season.
Discussion: What are your important discussion points and what is the relevance of your results to conservation (if any)?
The inference of the study was that during pre-monsoon season, the dolphins seek refuge in segments of the river which are comparatively deeper. Also, alternatively, we infer that since after 2009, no detailed status assessments have been carried out in Kulsi, the population might have decreased in these years owing to rapid habitat degradation. The study also recommends that the district authorities need to play a pro-active role safeguard this important water body.