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!
Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction