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 Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

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: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers create artificial materials atom-by-atom

28.03.2017 | Physics and Astronomy

Researchers show p300 protein may suppress leukemia in MDS patients

28.03.2017 | Health and Medicine

Asian dust providing key nutrients for California's giant sequoias

28.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>