Asias bear-sized catfish are disappearing
One of the worlds largest freshwater fish, an Asian catfish as big as a bear, may disappear in the near future, warns a UC Davis conservation biologist from his research base in Cambodia.
The giant catfish (Pangasianodon gigas), which grows to 10 feet long and 650 pounds, is a migratory species in the rivers of Thailand, Cambodia and Laos. It has been a mainstay for local fishers for centuries.
Now very few fish are being caught. At one typical traditional fishing spot on the Mekong River at Chiang Khong, Thailand, 30 fish were caught in 1995, seven in 1997, two in 1998 and none in 2000 and 2001.
Zeb Hogan is a conservation biologist and a UC Davis doctoral student studying the fish on the Mekong and Tonle Sap rivers. "Id go down to where the fishermen had their nets out and ask, Caught any fish? And they never did," Hogan said.
"Here is a fish that has been caught for hundreds of years. Now it looks like its on the way out."
Hogans doctoral adviser is UC Davis fisheries biologist Peter Moyle. Like some of the California native fish that Moyle studies, the giant catfish migrate hundreds of miles each year between downstream feeding areas and upstream spawning areas.
"The giant catfish and other fish in this diverse ecosystem are extremely important to the health and economic well-being of local peoples but are threatened by the construction of hydropower dams and other problems," Moyle said. "We hope that Zebs work will help call attention to a potential impending ecological and social disaster."
Hogans research is funded by the Cambodian Department of Fisheries, the conservation group Save Cambodias Wildlife and the National Geographic Societys Conservation Trust.
Sylvia Wright | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
Larsen C Ice Shelf rift finally breaks through
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...