Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UGA researchers explain recent decline in Georgia’s blue crab population

24.11.2004


Two researchers at the Skidaway Institute of Oceanography in Savannah have offered an explanation for the recent decline in Georgia’s blue crab population that has devastated one of the state’s most important coastal fisheries.



In an article in the November/December issue of the American Scientist, Richard F. Lee and Marc E. Frischer, working on a grant from the Georgia Sea Grant Program at the University of Georgia, say their research shows that Georgia’s recent drought, working in conjunction with an opportunistic parasite, is ultimately to blame for the decline in blue crab numbers.

Prior to the recent drought, the 45-year average for blue crab landings in the state was 8.6 million pounds per year, but at the height of the drought landings fell to 1.8 million pounds. This sharp and sustained reduction in yearly catch drove most of the state’s blue crab fishermen out of business and many into bankruptcy. Lee and Frischer discovered that many of the crabs caught during the drought seemed to be suffering from a parasitic infection. The infection was determined to be Hermatodinium perezi. Though crabs infected with Hermatodinium were not unknown to the Georgia coast, Lee and Frischer set out to determine why the parasite crashed the local population so suddenly.


According to the researchers, an important part of the puzzle is the effect drought has on the delicate balance of salt water and fresh water that exists in coastal estuaries. Blue crabs spend most of their lives in this brackish water. During a drought, less fresh water comes down the state’s rivers to mix with salt water that tides bring in from the Atlantic Ocean. This raises the salt content in coastal estuaries. And it is in water with this higher percentage of salt that Hermatodinium thrives and spreads from crab to crab.

Lee and Frischer found a direct correlation between the state’s recent drought and the prevalence of the disease in the state’s blue crab population. They also cite data showing that during times of high river flow, when the percentage of salt in the estuaries is lower, blue crab landings historically have increased. That the blue crab fishery is suffering from a weather-related problem could be good news for Georgia crabbers. With the drought officially at an end, anecdotal evidence seems to suggest that blue crab populations are on the rise, and the prevalence of the Hermatodinium infection is decreasing.

Kim Carlyle | EurekAlert!
Further information:
http://www.uga.edu

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

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: Manipulating Electron Spins Without Loss of Information

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...

Im Focus: The proton precisely weighted

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...

Im Focus: On the way to a biological alternative

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....

Im Focus: The 1 trillion tonne iceberg

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,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

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 –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

Topologische Quantenchemie

21.07.2017 | Life Sciences

Pulses of electrons manipulate nanomagnets and store information

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>