Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How will migratory amphihaline fish be distributed in Europe in 2100?

06.11.2008
Overfishing, water pollution, excessive riverside development, etc. have contributed to the regression of amphihaline migratory fish populations in Europe.

Today, most species are in danger. Restoration programs at different spatial and temporal scales have been initiated with, notably, support to populations and rehabilitation of habitats.

However, in the current context of climate change, the distribution of species and the characteristics of their migration need to change. In Bordeaux, Cemagref researchers have been using biogeographic models to predict the distribution of European amphihaline migratory species on the 2100 horizon.

The scientific community is beginning to apprehend the impacts of global warming on the distribution of forest essences and the progression of nesting birds in Europe. To date, few studies have been conducted on the effects of the rise in river and ocean temperatures on the distribution and the future of migratory amphihaline fish. Yet most European species are now in danger. As indicated by the label “amphihaline migrators,” these fish migrate great distances to complete their life cycle between ocean and river. A simulation of the future geographic distribution of migratory fish integrating climate change has just been completed for a doctoral dissertation at the Bordeaux Cemagref. On the 2100 horizon, the results predict consequential losses in climatically favorable watersheds, which raises the question of the future of the majority of European species.

- A historical model of species distribution...

The researchers began by inventorying migratory amphihaline fish species throughout Europe, the Middle East, and North Africa. This large geographical scale covered the near totality of the geographical area occupied by each of the 28 European species included in the census. How will temperature limit the distribution zone of these species? To answer this question, 200 watersheds were studied to describe the distribution of each species in terms of presence-absence and abundance. The study established a distribution model for each species at a time when humans exerted little pressure on the milieux. The 1900s were chosen as the reference period. More than 400 bibliographical references were analyzed and lists were made by partner laboratories of the European Diadfish1 network. In addition to air temperature, four other factors known to influence freshwater fish distribution were studied: longitude at the mouth of the watershed, the surface area of the watershed, altitude at the river’s source, and precipitations.

- What future is in store for amphihaline migratory fish in 2100?

The next step applied these distribution models to a context of climate change, using the four reference climate scenarios developed by the Intergovernmental Expert Group on Climate Change (Groupement d’Experts Intergouvernementaux sur l’Evolution du Climat, GIEC, 2000). The study’s term was set at 2100 so as to have sufficient distance to measure significant evolution in the fish populations. In addition, this date corresponds to the order of magnitude for most restoration plans successfully carried out for migratory amphihaline fish. Based on a temperature evaluation between 1 and 7°C, species’ responses can be classified into three categories: one shrinking their distribution area, one extending their distribution area, and one showing little or no change in distribution. This study shows that for most species the situation will deteriorate. For example, smelt and arctic char should lose approximately 90% of the favorable watersheds for zero or reduced gains. Only two species, the thick-lipped grey mullet and the twaite shad, will be able to expand toward the north, beyond their initial distribution area. Finally, as predicted, the southern watersheds risk losing most of their species. Could this be an opportunity for more exotic migratory amphihaline fish? Researchers are very reserved on the subject, even pessimistic, because the migratory amphihaline species swim along the coast of West Africa since they have no permanent rivers in which to live.

It is therefore urgent to restore milieux and populations. The predictive models established within these studies are relevant tools to be used to set up conservation programs over the long term at different scales of action.

Marie Signoret | alfa
Further information:
http://www.cemagref.fr
http://www.cemagref.fr/Informations/Presse/InfMediaEV/infomedia86EV/im86_rech3_EV.htm

More articles from Ecology, The Environment and Conservation:

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

nachricht World Water Day 2017: It doesn’t Always Have to Be Drinking Water – Using Wastewater as a Resource
17.03.2017 | ISOE - Institut für sozial-ökologische Forschung

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: 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...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

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

Pulverizing electronic waste is green, clean -- and cold

22.03.2017 | Materials Sciences

Astronomers hazard a ride in a 'drifting carousel' to understand pulsating stars

22.03.2017 | Physics and Astronomy

New gel-like coating beefs up the performance of lithium-sulfur batteries

22.03.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>