Over-fishing, pollution, river development, global climate changes, etc. are threatening a large number of migratory fish. Among the endangered species, one can cite the European eel whose numbers have been divided by 10 over the two last decades. To save the species, the priority is better management of the populations subjected to the pressures of the environment.
However, this first assumes better knowledge of the species’ biology and ecology. The exercise is complex, because the European eel’s life cycle is still not fully understood. The species has long been considered a migratory fish that reproduces at sea and grows in rivers. Yet studies conducted over the last 10 years have shown that certain individuals do not spend their growth period in freshwaters. Migratory divergences may exist at the elver stage. At Bordeaux and Saint-Pée-sur-Nivelle, in doctoral work co-supervised by Cemagref and the INRA, Sarah Bureau du Colombier has been studying the source of these different migratory patterns in European eel elvers.Sorting migrant fish and sedentary fish
All of these data were then used to feed an estuarial migration model that will eventually be used to simulate the migratory behaviour of elvers according to different parameters, some of which are related to global climate changes.Contacts:
Agnès Bardonnet, email@example.com (INRA, Saint-Pée-sur-Nivelle)
A complex life cycle
The European eel reproduces near the North American coast in the Sargasso Sea. The young larvae, called leptocephalus, cross the Atlantic Ocean on the ocean currents. Near the European and North African coasts, they metamorphose into elvers (young yellow eels). These individuals then settle in coastal zones or in estuaries, or swim up rivers. After they have metamorphosed into silver eels, the adults embark on their migration and reproduction in the Sargasso Sea.
Marie Signoret | alfa
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy