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 Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Quantum Technology for Advanced Imaging – QUILT

24.04.2018 | Information Technology

AWI researchers measure a record concentration of microplastic in arctic sea ice

24.04.2018 | Earth Sciences

Complete skin regeneration system of fish unraveled

24.04.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>