Two hydroelectricity dams appear to be threatening the health of Lake Victoria – and of the people living along its shores who depend on the lake for food. A new study¹ suggests that the dams’ systematic overuse of water has decreased the lake level by at least two meters between 2000 and 2006 – and that this drop was not influenced by weather. The study by Yustina Kiwango of Tanzania National Parks and Eric Wolanski of James Cook University in Australia was published online this week in the Springer journal Wetlands Ecology and Management.
The two dams, both located at the outlet of Lake Victoria in Uganda, have been using water at a rate of 20 to 50 percent above the allowable discharge agreed by Uganda and Egypt in 1957. Meanwhile, the dramatic drop in water level has dried the papyrus wetlands fringing the lake, resulting in an 80 percent collapse in tilapia fisheries recruitment - the juvenile fish using the wetlands as a refuge. A key staple of the local population living along the lake’s shores, this loss of the tilapia fish threatens the food security of people depending on the lake in Uganda, Kenya and Tanzania. In the long term, the commercially fished Nile Perch, which feeds on smaller fish such as tilapia, could also be affected.
Additional impacts of the drop in water level include increased eutrophication² and algal blooms. When submerged, the surrounding papyrus wetlands previously buffered the lake from excess levels of nitrogen and phosphorus; they could absorb about half of the nitrogen, and a quarter of the phosphorus, which flows into the lake. With the wetland now much drier, much of this function has been lost.
If overdrawing of water leads to permanent drying of these wetlands, the implications could be far-reaching, with large-scale eutrophication of the lake, exacerbation of invasion by the non-native water hyacinth, and accelerated global warming as the dried papyrus and its peat are burned to claim land for agriculture, duplicating the disastrous forest and peat fires in Indonesia.
In the authors’ view, “the future of Lake Victoria and its people is very closely related to the future of its papyrus wetlands.” They are calling on the states along the lakeshores, Kenya, Uganda and Tanzania, to urgently address the issue of managing the lake level in a way that involves all stakeholders.
Joan Robinson | EurekAlert!
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research