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Tuesday, March 27, 2012

glaciar meltdown spells more doom, biodiversity at risk


Bhutan’s major concerns relate to the effect of rising temperature on glaciers that feed the rivers originating in the Himalayas

It is not an unknown fact that glacial meltdown in the long run will have serious implications on Bhutan’s main economic backbone – hydropower, and people’s livelihood consequently. If what a new study reveals is true, there is more to it than what meets the eye.
A recent study published by the journal, Nature Climate Change, says that rapid melting of glaciers from the Himalayas is likely to have a profound impact on the region’s ecosystems, resulting in significant loss of biodiversity in the glacier fed rivers. All of Bhutan’s rivers are glacier fed.
The study has found that glacier melt water increases biodiversity in mountains freshwater ecosystems. But it also says with as glaciers start to vanish due to global warming so will those species dependent upon the icy runoff from melting ice.
This could eventually strike a double blow to the country. According to the findings of the study, Bhutan stands to lose both in terms of revenue from hydropower generation as quantity of water flow dwindles and also lose the country’s rich biodiversity.
The findings come from a team that looked at the diversity of insect larvae in water at 103 sites fed by glaciers in Ecuadorian Andes, the European Alps and Alaska’s coastal mountains.
Dean Jacobsen, a freshwater biologist at the University of Copenhagen, and one of the study’s authors, says the findings are new and startling.
The study reveals that the greatest numbers of freshwater macroinvertebrates are found in mountain streams where glacial run off contributes to the total volume of water.
“We had no idea that so many small invertebrates were restricted to this kind of environment,” says Dean Jacobsen.
Bhutan has a large number of inland water resources comprising a network of freshwater rivers, wetlands, glaciers, lakes, and underground water. The conservation of these water resources has a positive effect on the downstream ecological processes and the lives and livelihoods of people in Bhutan and further downstream in India.
Bhutan has four major river systems, the Drangme Chu, the Puna Tsang Chu, the Wang Chu and the Amo Chu. The largest river system is the Drangme Chu and the smallest is the Amo Chu.
The impact of climate change where there is a rapid shrinking of glaciers results in a reduction in glacial melt water contribution to river flow. These changes potentially affect the biodiversity of specialized glacier fed river communities.
The study published in the Nature Climate Change compared the number of species to the percentage of glacier cover in the catchment area. In areas with high glacial cover, they predict, several species will start to disappear when cover drops to 50%.
If the glaciers in all three regions (research sites) were to disappear, between 9 and 14 species would be totally lost. “If all the glaciers were to vanish entirely, it is expected that between 11 to 38% of the regions total macroinvertebrate species would be lost,” says the study.
“The expected losses would be particularly high for species, which have adapted to the unique and otherwise challenging living conditions of glacier streams,” adds the study.

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