Ruben Sommaruga, Professor am Institut für Ökologie, erforscht im Rahmen eines von FWF geförderten Projekts die Konsequenzen des Rückgangs der Gletscher auf die Strukturen und Funktionen von Bergseen. Unterstützt von seinem Team untersucht er das mikrobielle Leben in den Seen.
Gletscherseen gehören weltweit zu den bisher am wenigsten erforschten Seen und das, obwohl die meisten Seen in Nordamerika und Europa durch das Schmelzen von Gletschern nach der letzten Eiszeit vor etwa 10.000 bis 12.000 Jahren entstanden sind. Die Wissenschaftlerinnen und Wissenschaftler haben es sich zur Aufgabe gemacht, diese Seen genauer unter die Lupe zu nehmen. Wie erste Ergebnisse zeigen, haben sich die Untersuchungen bereits gelohnt. (more…)
Saturn’s moon Titan might be in for some wild weather as it heads into its spring and summer, if two new models are correct. Scientists think that as the seasons change in Titan’s northern hemisphere, waves could ripple across the moon’s hydrocarbon seas, and hurricanes could begin to swirl over these areas, too. The model predicting waves tries to explain data from the moon obtained so far by NASA’s Cassini spacecraft. Both models help mission team members plan when and where to look for unusual atmospheric disturbances as Titan summer approaches.
“If you think being a weather forecaster on Earth is difficult, it can be even more challenging at Titan,” said Scott Edgington, Cassini’s deputy project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We know there are weather processes similar to Earth’s at work on this strange world, but differences arise due to the presence of unfamiliar liquids like methane. We can’t wait for Cassini to tell us whether our forecasts are right as it continues its tour through Titan spring into the start of northern summer.” (more…)
New findings overturn understanding of light-dependent environmental oxidants
Breathing oxygen… can be hazardous to your health?
Indeed, our bodies aren’t perfect. They make mistakes, among them producing toxic chemicals, called oxidants, in cells. We fight these oxidants naturally, and by eating foods rich in antioxidants such as blueberries and dark chocolate.
All forms of life that breathe oxygen—even ones that can’t be seen with the naked eye, such as bacteria—must fight oxidants to live. (more…)
It’s not exactly icing on a cake, but it could be icing on a lake. A new paper by scientists on NASA’s Cassini mission finds that blocks of hydrocarbon ice might decorate the surface of existing lakes and seas of liquid hydrocarbon on Saturn’s moon Titan. The presence of ice floes might explain some of the mixed readings Cassini has seen in the reflectivity of the surfaces of lakes on Titan.
“One of the most intriguing questions about these lakes and seas is whether they might host an exotic form of life,” said Jonathan Lunine, a paper co-author and Cassini interdisciplinary Titan scientist at Cornell University, Ithaca, N.Y. “And the formation of floating hydrocarbon ice will provide an opportunity for interesting chemistry along the boundary between liquid and solid, a boundary that may have been important in the origin of terrestrial life.”(more…)
Professor and students study how microbial life changes along the river
The mercury is pushing 100, but professor Michael Sadowsky and two assistants leave the indoor coolness for the bank of the Mississippi River as it flows by the University of Minnesota Twin Cities campus.
The three men send a bucket splashing into the current and haul back a water sample. That doesn’t affect the river much, but information locked away in bacteria from the sample may tell them a great deal about how the river’s microbial communities change along its course through Minnesota and how human activity affects them.(more…)
Environmental change is the selective force that preserves adaptive traits in organisms and is a primary driver of evolution. However, it is less well known that evolutionary change in organisms also trigger fundamental changes in the environment.
Yale University researchers found a prime example of this evolutionary feedback loop in a few lakes in Connecticut, where dams built 300 years ago in Colonial times trapped a fish called the alewife.
In a study published May 23 in the journal Proceedings of the Royal Academy B, the Yale team describes how this event fundamentally changed the structure of the alewife and, with it, the water flea that the alewife feeds upon and the food chain that supports them both. (more…)
A new study analyzing data from NASA’s Cassini spacecraft suggests that the lake, known as Ontario Lacus, behaves most similarly to what we call a salt pan on Earth.
A group led by Thomas Cornet of the Université de Nantes, France, a Cassini associate, found evidence for long-standing channels etched into the lake bed within the southern boundary of the depression. This suggests that Ontario Lacus, previously thought to be completely filled with liquid hydrocarbons, could actually be a depression that drains and refills from below, exposing liquid areas ringed by materials like saturated sand or mudflats.(more…)
The amount of water flowing in streams and rivers has been significantly altered in nearly 90 percent of waters that were assessed in a new nationwide USGS study. Flow alterations are a primary contributor to degraded river ecosystems and loss of native species.
“This USGS assessment provides the most geographically extensive analysis to date of stream flow alteration,” said Bill Werkheiser, USGS Associate Director for Water. “Findings show the pervasiveness of stream flow alteration resulting from land and water management, the significant impact of altered stream flow on aquatic organisms, and the importance of considering this factor for sustaining and restoring the health of the Nation’s streams and ecosystems.” (more…)
