Management of Pacific Salmon has been an issue for years. To determine whether management goals are working, knowledge of historical populations can prove quite useful. In a recent study published in Ecology, Deanne C. Drake, Robert J. Naiman, and James M. Helfield, all of the University of Washington, paired annual tree ring growth with catch data to determine what salmon stocks looked like 200 years ago.
Born in freshwater lakes and rivers, salmon swim to the ocean where they feed and mature. After a few years, they return to the river or lake of their birth to reproduce and die. As their bodies decay, they leave behind ocean nutrients in the freshwater ecosystems.
"There is a great need to understand how many salmon returned to rivers historically," said Naiman. "Once we knew nutrients from salmon carcasses affected tree growth in certain species, it seemed possible to use tree rings to estimate how many salmon returned to a river in any one year. This was a trial project to see if the idea would work."
Annie Drinkard | esa
Bioinvasion on the rise
15.02.2017 | Universität Konstanz
Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
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24.02.2017 | Life Sciences
24.02.2017 | Trade Fair News