Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Underwater Microscope Finds Biological Treasures in the Subtropical Ocean

28.06.2006
Scientists towing an underwater digital microscope across the Atlantic have found possible missing links to the global nitrogen cycle, which in turn is linked to ocean productivity.

In a recent report in the journal Science, researchers from the Woods Hole Oceanographic Institution (WHOI) found abundant colonies of Trichodesmium. The multi-celled, filamentous organism is thought to play a significant role in the input of nitrogen to the upper layers of the tropical and subtropical ocean, nearly half of the Earth’s surface.


The video plankton recorder (VPR) on the deck of research vessel Oceanus. (Photo by Cabell Davis, Woods Hole Oceanographic Institution)


Collage of images of Trichodesmium collected by the video plankton recorder. The spherical images are the puffs and the elongated images the tufts. (Courtesy Cabell Davis, Woods Hole Oceanographic Institution)

Lead author Cabell Davis, a senior scientist in the WHOI Biology Department, and co-author Dennis McGillicuddy, an associate scientist in the WHOI Applied Ocean Physics and Engineering Department, suggest that nitrogen fixation rates for Trichodesmium may be 2.7 to 5 times higher than previously estimated from traditional sampling.

Trichodesmium is one of many tiny photosynthetic organisms that use the sun’s energy, carbon dioxide and other nutrients to make organic material that constitutes the basis of the marine food web. Production of biomass in surface waters is typically limited by nitrogen, but Trichodesmium is able to escape that constraint by virtue of its ability to utilize nitrogen gas, which is plentiful in the atmosphere and upper ocean.

Trichodesmium abundance has been difficult to measure using traditional net sampling because the colonies are easily damaged or destroyed during collection. Sampling with bottles has provided estimates of abundance of the organism, but it is a snapshot view.

The Video Plankton Recorder (VPR) is a noninvasive instrument, consisting of a digital video-microscope on a towed vehicle that samples at 30 frames per second and automatically sorts the Trichodesmium images from other organisms.

“If traditional sampling has underestimated colonies in other regions of the world, our estimates of global Trichodesmium abundance will increase dramatically,” Davis said. “That increase could potentially account for a significant portion of the global nitrogen cycle, thus changing our perception of the importance of this organism to the productivity of the world ocean.”

Davis and McGillicuddy towed the VPR across the North Atlantic between the Azores and the Slope Water south of Woods Hole in 2003, skirting category 3 hurricane Fabian. The vehicle was towed at six meters per second, about 12 nautical miles an hour, surveying continually and automatically between the surface and about 130 meters (400 feet) deep like a yo-yo. Nearly 7,000 vertical profiles were taken during the 5,517 kilometer (about 3,443 miles) transit across the North Atlantic.

While the colonies of Trichodesmium are fragile and thought to be destroyed when mixed by strong winds, the team found no evidence that hurricane Fabian, with winds up to 200 kilometers an hour (about 125 miles per hour), had caused them any damage. The team sampled the upper layers of the ocean across the wake of the storm.

The researchers also found a strong correlation between temperature, salinity and abundance of Trichodesmium colonies in the various eddies and the Gulf Stream the VPR crossed during its survey.

Two forms of Trichodesmium, called puffs and tufts because of their shapes, were found in higher concentrations in warm salty water. Higher concentrations of the organism were also found in warm anticyclonic eddies than in cold cyclonic ones, but the reasons are unclear.

Davis and McGillicuddy are doing similar survey aboard WHOI’s research vessel Knorr, which just passed through the Panama Canal. The researchers will deploy the VPR and survey across the Caribbean Sea, a region known to have very high concentrations of Trichodesmium. The ship will arrive back at Woods Hole on June 29.

Davis says the new Caribbean VPR survey will provide much needed information about Trichodesmium population estimates in its tropical home, information that has been difficult to obtain due to the patchy nature of the species in ocean waters.

The project was supported by the Richard B. Sellars Endowed Research Fund, the Andrew W. Mellon Foundation Endowed Fund for Innovative Research, the WHOI Ocean Life Institute, the National Science Foundation and NASA.

Shelley Dawicki | EurekAlert!
Further information:
http://www.whoi.edu

More articles from Life Sciences:

nachricht Joining forces for immune research
13.08.2018 | Max-Delbrück-Centrum für Molekulare Medizin in der Helmholtz-Gemeinschaft

nachricht The “TRiC” to folding actin
10.08.2018 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

Im Focus: A molecular switch may serve as new target point for cancer and diabetes therapies

If certain signaling cascades are misregulated, diseases like cancer, obesity and diabetes may occur. A mechanism recently discovered by scientists at the Leibniz- Forschungsinstitut für Molekulare Pharmakologie (FMP) in Berlin and at the University of Geneva has a crucial influence on such signaling cascades and may be an important key for the future development of therapies against these diseases. The results of the study have just been published in the prestigious scientific journal 'Molecular Cell'.

Cell growth and cell differentiation as well as the release and efficacy of hormones such as insulin depend on the presence of lipids. Lipids are small...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

NRL's sun imaging telescopes fly on NASA Parker Solar Probe

13.08.2018 | Physics and Astronomy

UT-ORNL team makes first particle accelerator beam measurement in six dimensions

13.08.2018 | Physics and Astronomy

ASU astrophysicist helps discover that ultrahot planets have starlike atmospheres

13.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>