Threats to freshwater fisheries and associated biodiversity largely unrecognized, authors state
Systematic overfishing of fresh waters occurs worldwide but is largely unrecognized because of weak reporting and because other pressures can obscure fishery declines, according to an article in the December 2005 issue of BioScience. Although the status of inland waters and their fish species should be of broad concern, threats to freshwater fisheries and associated biodiversity have received scant attention from conservation groups and the media, according to author J. David Allan of the University of Michigan and his colleagues. Allan and colleagues refer to the relative lack of attention to fresh waters as a "dangerous" imbalance, since freshwater ecosystems are by some accounts more threatened than marine ecosystems.
Fishing is a crucial source of livelihoods in developing nations, and in 2000 constituted an estimated 15.3 percent of human consumption of animal protein. About 1 billion people rely on fish as their primary protein source. Landings from inland waters have increased more than fourfold since 1950, mainly in developing nations, though in developed countries, in contrast, catches have decreased. But catch statistics are difficult to interpret for inland species because they may exclude recreational and illegal fisheries, and because landings are dispersed. Moreover, overfishing may not immediately cause declines in the total catch––and its weight may even transiently increase. Overfishing leads to numerous changes in both the target species and other species. Larger individuals and species are often successively replaced in the catch by smaller ones. At the same time, some fish populations respond to fishing pressure with reductions in mean size at maturation.
Donna Royston | EurekAlert!
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...
Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.
Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
19.09.2017 | Event News
19.09.2017 | Physics and Astronomy
19.09.2017 | Power and Electrical Engineering