Tuesday, November 3, 2015

Thirst-lands: Water Quality and Availability in the Chobe Region

IN a country as dry as Botswana, perennial water sources assume a naturally heightened significance. Each year during the dry season, concentrations of game along the Chobe River rise to almost unbelievable levels - making this place one of the world's most popular tourist destinations. The region's importance as a wildlife sanctuary could hardly be overstated, in fact, particularly in terms of species like elephant, populations of which are in steady decline across much of the rest of the continent. 

The relative abundance of these animals present a number of challenges, though. One of these was highlighted in a recent paper by J. Tyler Fox and Dr Kathleen Alexander, published in the journal PLOS ONE, in which they argue that these seasonal concentrations of game - particularly large herbivores such as elephant - can result in the deterioration of water quality. 

These findings, based on three years of water quality monitoring and data collection along the course of the river, are surprising given the fact that we would expect a greater correlation between human activities such as agriculture and industry and declines in water quality than anything resulting from the presence or activities of wildlife populations - particularly in an area where human population densities are growing as fast as they are in the Chobe region. 

In an interview with Science Daily, Fox described these findings as follows: "Activities of elephants and other large animals play an essential role in maintaining the long-term integrity of river corridors in southern Africa, adding nutrients and increasing patch heterogeneity of the riparian landscape. In areas where wildlife concentrate in riparian corridors, however, this influence may extend beyond the terrestrial environment to impact seasonal water quality dynamics."

The shoe, it would seem, is on the other foot for once. This would all seem to suggest that the health and well-being of human populations along the river are actually being negatively impacted by seasonal concentrations of wildlife: references to annual diarrheal disease outbreaks (which are likewise the subject of ongoing research by Dr Alexander and her team) and the role played by levels of Escherichia coli in the waters of the Chobe, much of which is deposited in the faeces of large herbivores, would seem to bear this out.  

While this is partly true at least, this does not represent the whole of the paper’s findings. Perhaps the most interesting aspect of the work takes the form of a series of recommendations around the issue of land-use and development – and, once again, the seasonal availability of water resources is at the heart of the issue.

In order to relieve the pressure on the region’s scarce perennial water sources, Fox and Alexander argue, major efforts should be made in future to make water sources available across a much greater area – including protected areas. Indeed there are signs that this kind of thinking is gaining traction among the country’s conservation-minded leadership, who have already done so much to establish the country’s role as a wildlife refuge, and who seem eager to ensure that this situation is managed sustainably in the future. Here human activities once more take the fore given the lack of natural water sources across most of the country. In practice this will most likely mean the installation and maintenance of a system of boreholes across the arid expanse of the North, and the good news is that this process has already begun with a government-sponsored program of sustainable solar-powered boreholes already yielding dividends across large swathes of the North. 

The potential benefits of this kind of work and this kind of thinking are immense, not least of which are the reduction of seasonal pressures on the delicate ecology of the Chobe River system and all who call it home. It will also open up greater portions of the country to the benefits of ecotourism, minimize human-wildlife conflict in areas where there is currently competition for grazing areas and access to water, and contribute greatly to the health of human and wildlife populations as a whole.

Read the full paper here:


For a synopsis and commentary from the first author himself, check this article in Science Daily:


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