Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Muscling Their Way Into the Food Chain: Zebra Mussels Alter Fish Populations in the Hudson River

18.08.2004


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 river’s 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 river’s ability to support young fish changes, it becomes more difficult to develop and evaluate sound management strategies."


Why are open-water fish and vegetated shoreline fish impacted so differently? The answer is how the river responds to the zebra mussel’s prodigious appetites. Adult zebra mussels feed by grazing on food particles suspended in the water column. There are so many zebra mussels in the Hudson River that they filter all of the water in the river every 1-4 days, removing the microscopic plants and animals that make up their diet. This can be problematic for fish species that rely on the same food resources. "Zebra mussels have significantly reduced populations of zooplankton and other animals that are a dietary staple of open-water larval and juvenile fish," Strayer comments.

When mussel beds remove food particles, a byproduct is increased light penetration. In shallow light-limited areas, increased sunlight results in the growth of aquatic plants and the invertebrates associated with them, creating more fish food in vegetated shorelines. Thus when zebra mussels abound, open-water food resources decline and shoreline food resources increase. This explains the population shifts Strayer and colleagues observed, with open-water species moving downriver, away from the invasion, and shoreline species moving upriver.

This has been the first study to link the spread of the zebra mussel to the management of the affected fish species in the Hudson River.

Lori M. Quillen | EurekAlert!
Further information:
http://www.ecostudies.org

More articles from Ecology, The Environment and Conservation:

nachricht Managing an endangered river across the US-Mexico border
18.07.2016 | International Institute for Applied Systems Analysis (IIASA)

nachricht The European pet trade is jeopardising the survival of rare reptile species
13.07.2016 | Helmholtz-Zentrum für Umweltforschung - UFZ

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Mapping electromagnetic waveforms

Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.

Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...

Im Focus: Continental tug-of-war - until the rope snaps

Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases

Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...

Im Focus: A Peek into the “Birthing Room” of Ribosomes

Scaffolding and specialised workers help with the delivery – Heidelberg biochemists gain new insights into biogenesis

A type of scaffolding on which specialised workers ply their trade helps in the manufacturing process of the two subunits from which the ribosome – the protein...

Im Focus: New protocol enables analysis of metabolic products from fixed tissues

Scientists at the Helmholtz Zentrum München have developed a new mass spectrometry imaging method which, for the first time, makes it possible to analyze hundreds of metabolites in fixed tissue samples. Their findings, published in the journal Nature Protocols, explain the new access to metabolic information, which will offer previously unexploited potential for tissue-based research and molecular diagnostics.

In biomedical research, working with tissue samples is indispensable because it permits insights into the biological reality of patients, for example, in...

Im Focus: Computer Simulation Renders Transient Chemical Structures Visible

Chemists at the University of Basel have succeeded in using computer simulations to elucidate transient structures in proteins. In the journal Angewandte Chemie, the researchers set out how computer simulations of details at the atomic level can be used to understand proteins’ modes of action.

Using computational chemistry, it is possible to characterize the motion of individual atoms of a molecule. Today, the latest simulation techniques allow...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

GROWING IN CITIES - Interdisciplinary Perspectives on Urban Gardening

15.07.2016 | Event News

SIGGRAPH2016 Computer Graphics Interactive Techniques, 24-28 July, Anaheim, California

15.07.2016 | Event News

Partner countries of FAIR accelerator meet in Darmstadt and approve developments

11.07.2016 | Event News

 
Latest News

Hey robot, shimmy like a centipede

22.07.2016 | Information Technology

New record in materials research: 1 terapascals in a laboratory

22.07.2016 | Physics and Astronomy

University of Graz researchers challenge 140-year-old paradigm of lichen symbiosis

22.07.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>