Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Overfishing in inland waters reduces biodiversity and threatens health

02.12.2005


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.


Allan and colleagues identify two main types of overfishing. One leads to marked declines in catch per unit effort and size of individuals captured. The second type is characterized by sequential declines of species and depletion of individuals and species of large size, especially piscivores. These types are illustrated by case studies of fish declines in Australia, in the lower Mekong River of Southeast Asia, in the Great Lakes of North America, and in the Oueme River of the Republic of Benin.

Allan and his coauthors warn that overfishing of inland waters has the potential for severe impacts on human health, particularly in developing countries. For example, fish consume the vectors of important diseases such as schistosomiasis. The authors also conclude that there is ample evidence of the global importance of overfishing as a threat to inland water biodiversity. They recommend that management of inland fisheries should be guided by sustainability of yields, maintenance of biodiversity, protection from habitat degradation and other anthropogenic stressors, and provision of socioeconomic benefits to a broad spectrum of consumers.

Donna Royston | EurekAlert!
Further information:
http://www.aibs.org

More articles from Ecology, The Environment and Conservation:

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Ultrafast snapshots of relaxing electrons in solids

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...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

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...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

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...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

Im Focus: Artificial Enzymes for Hydrogen Conversion

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,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

New quantum phenomena in graphene superlattices

19.09.2017 | Physics and Astronomy

A simple additive to improve film quality

19.09.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>