In 1991, an exotic bivalve called the zebra mussel moved into the Hudson River. Over the past two decades, the prolific species has colonized habitats with hard sediments, becoming the most abundant animal in the rivers freshwater reaches. As competitors in the aquatic food chain, scientists have long speculated that zebra mussels may impact fish. A recent Canadian Journal of Fisheries and Aquatic Sciences article, written by Dr. David L. Strayer of the Institute of Ecosystem Studies (IES) and Drs. Kathryn A. Hattala and Andrew W. Kahnle of the NY State Department of Environmental Conservation (NYSDEC), has revealed that open-water fish species, like the commercially important American shad, are declining in response to the exotic invader.
Invasive species research is often limited by a lack of ecological data on pre-invasion conditions. Since the 1970s, utility companies on the Hudson River have gathered long-term data on juvenile fish populations as a condition of withdrawing cooling water from the river. These surveys began prior to the zebra mussel introduction, allowing for pre and post invasion assessment. Hudson River food web data has been collected by IES since the 1980s. Through analysis of this data, Strayer and colleagues have discovered that open-water fish, such as American shad and striped bass, have decreased in growth and abundance since the zebra mussel invasion. Conversely, species like sunfishes, which prefer vegetated shoreline habitat, have increased significantly.
Many of the open-water fish population declines were large and involved species of commercial or recreational importance, such as American shad and black bass. Strayer notes, "The changes we observed may lead to fewer adults of species such as American shad, and more adults of species such as redbreast sunfish in the Hudson. Maintaining a sustainable fishery for species like American shad, in the face of sharp population reductions, will be challenging. When a rivers ability to support young fish changes, it becomes more difficult to develop and evaluate sound management strategies."
Lori M. Quillen | EurekAlert!
Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus
How to detect water contamination in situ?
22.09.2016 | Tomsk Polytechnic University (TPU)
Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.
Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...
At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.
In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...
27.09.2016 | Event News
23.09.2016 | Event News
20.09.2016 | Event News
27.09.2016 | Life Sciences
27.09.2016 | Physics and Astronomy
27.09.2016 | Life Sciences