Ongoing global climate change causes changes in the species composition of marine ecosystems, especially in shallow coastal oceans. This applies also to fish populations. Previous studies demonstrating a link between global warming and declining fish stocks were based entirely on statistical data.
However, in order to estimate future changes, it is essential to develop a deeper understanding of the effect of water temperature on the biology of organisms under question. A new investigation, just published in the scientific journal Science, reveals that a warming induced deficiency in oxygen uptake and supply to tissues is the key factor limiting the stock size of a fish species under heat stress.
Scientists of the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven investigated the relationship between seasonal water temperature and population density using eelpout (Zoarces viviparus), a fish species from the Southern North Sea. The goal of the study was to identify those physiological processes exhibiting the most immediate response to warming in the field. Comparing ecological field data with laboratory investigations of the eelpout's physiology, the authors were able, for the first time, to demonstrate a direct link between temperature dependent oxygen limitation experienced by the eelpouts and warming induced changes in their population density.
During evolution, animals have specialised on environmental conditions and are often very limited in their tolerance to environmental change. In this context, fish species from the North Sea which experience large seasonal temperature fluctuations, are more tolerant to higher temperatures and display wider thermal windows than, for instance, fishes from polar regions living at constant low temperatures. The latter are able to grow and reproduce only within a very limited thermal tolerance window.
Investigations at the Alfred Wegener Institute show the key importance of oxygen uptake and distribution – through respiration and blood circulation – in setting the animals' thermal tolerance range, in that these processes are optimised to only a limited temperature window. With increasing temperature, the organism's oxygen supply is the first to deteriorate, followed by other biochemical stress responses. Finally, oxygen supply fails entirely, leaving the organism to perish. These results represent a significant step forward towards understanding the mechanisms involved in climate-induced alterations in marine ecosystems.
The paper 'Climate change affects marine fishes through the oxygen limitation of thermal tolerance' is published on January 5, 2007 in the scientific journal Science.
Dr. Ude Cieluch | EurekAlert!
Listening in: Acoustic monitoring devices detect illegal hunting and logging
14.12.2017 | Gesellschaft für Ökologie e.V.
How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.
A study carried out by an international team of researchers and published in the journal Physical Review X shows that ion-trap technologies available today are suitable for building large-scale quantum computers. The scientists introduce trapped-ion quantum error correction protocols that detect and correct processing errors.
In order to reach their full potential, today’s quantum computer prototypes have to meet specific criteria: First, they have to be made bigger, which means...
Since 2016, German and Spanish researchers, among them scientists from the University of Göttingen, have been hunting for exoplanets with the “Carmenes”...
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
18.12.2017 | Life Sciences
18.12.2017 | Materials Sciences
18.12.2017 | Life Sciences