A chemical signature recorded on the ear bones of Chinook salmon from Alaska’s Bristol Bay region could tell scientists and resource managers where they are born and how they spend their first year of life. (more…)
Tag Archives: daniel schindler
Freshwater fish with bellies full of shrews – one trout a few years back was found to have eaten 19 – aren’t as random as scientists have thought.
In some years, probably when shrew populations boom, the small mouse-like land animals end up in the stomachs of a quarter of rainbow trout and Arctic grayling larger than a foot, according to University of Washington-led research in the coastal lakes and streams of Southwest Alaska. (more…)
Nitrogen derived from human activities has polluted lakes throughout the Northern Hemisphere for more than a century and the fingerprint of these changes is evident even in remote lakes located thousands of miles from the nearest city, industrial area or farm.
The findings, published in the journal Science Dec. 16, are based on historical changes in the chemical composition of bottom deposits in 36 lakes using an approach similar to aquatic archeology. More than three quarters of the lakes, ranging from the U.S. Rocky Mountains to northern Europe, showed a distinctive signal of nitrogen released from human activities before the start of the 20th century, said Gordon Holtgrieve, a postdoctoral researcher at University of Washington School of Aquatic and Fishery Sciences and lead author of the report. The UW and a dozen other research institutions contributed to the research. (more…)