DEHRADUN: A recent study by Wildlife Institute of India, Dehradun, has revealed that Snow trout (Schizothorax richardsonii), the cold water fish species found in Himalayan rivers, will lose its habitat by 16 per cent in the next 30 years and by over 26 per cent by 2070 due to climate change factors.
The study titled ‘Is There Always Space at The Top’ and funded by the department of science & technology (DST) was published earlier this week in the ‘Ecological Indicators’, a journal of international repute based at the Netherlands.
"The net habitat loss under three RCP scenarios (Representative Concentration Pathways) (RCPs 2.6, 4.5 and 8.5) was estimated to range from 7.41 per cent to 16.29 per cent for the year 2050 which would further increase in the year 2070 ranging from 9.46 per cent to 26.56 per cent, " said the study by the group of experts and scientists including Aashna Sharma, Vineet Kumar Dubey, Jeyaraj Antony Johnson, Yogesh Kumar Rawal and Kuppusamy Sivakumar.
The experts stating in their analysis that the Himalayan region is predicted to be warming at a rate much higher than global average rate of 0.4 °C, warned, "Mountain systems throughout the globe are conspicuously sensitive to on-going climate alterations.
This condition is much more detrimental in the Himalaya, where the rate of warming and thus the glacier meltdown is much higher than elsewhere. The Himalayan coldwater species are concerningly most vulnerable to these changes because of their limited thermal range."
The study recommends reducing the 'unsustainable harnessing of rivers' for hydropower development projects and energy efficiency by improving green energy potential advocating for regular 'state of art monitoring' of Himalayan rivers, the majority of which still stay unexplored along with regular monitoring of fish populations at the foothills of the Himalaya.
The experts state in the study that 'a wide-ranging mid-elevation river network' is currently suitable for the snow trout in Himalaya and added that a significant part of its current distributional range would be lost over time.
"Our results highlight that snow trout would expand their range upwards into the high-altitude streams with a concurrent predominant range contraction in most of their lagging edges, ultimately creating a high-altitude squeeze," said the study.
The species which is listed as vulnerable in the IUCN Red List faces serious threats due to river valley modifications, destructive fishing practices and exotic salmonid introductions said the studies.
The study which happens to be a part of the government’s National Mission for Sustaining the Himalayan Ecosystem (NMSHE) to research the impact of climate change on the Himalayan ecosystem is aimed at evaluating the performance and response of topographic, hydrogeomorphic, and climatic variables and to quantify the future range shifts by using multi-projection ensemble for reducing the translocation uncertainties and an appropriate mitigation measure for species climate adaptations in future.
Further adding that the species is likely to lose habitat which will force it to take refuge at high-altitude areas which would act as the 'only saviors' if suitable habitat connectivity is offered. The study also added that the current massive network of dams across the Himalayan rivers which is 'rampantly building up' poses a strong deterrent for the species to colonize the potential refugia at higher altitudes.
"The situation in Himalaya can thus be grave with an existential dearth in the understanding of abundance and distribution patterns of the fishes. Our predictions also reveal that the high-altitude tributaries of Jhelum, Chenab, Satluj, Beas, and the upper Ganges basin would potentially contribute as snow trout refugia in the future environments," said the scientists in the study.
The study said to be an 'ensemble of 72 statistical models across the Himalayas' also call for cooperation between India, Nepal and Bhutan to further broaden the scope of conservation and research.