Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New system can measure productivity of oceans

11.02.2005


Researchers at Oregon State University, NASA and other institutions announced today the discovery of a method to determine from outer space the productivity of marine phytoplankton – a breakthrough that may provide a new understanding of life in the world’s oceans.



Phytoplankton are the incredibly abundant microscopic plant forms that provide the basis for most of the marine food chain, half the oxygen in our atmosphere and ultimately much of the life on Earth. They have rapid growth rates and are constantly being produced and consumed in huge amounts – but until now, it was impossible to determine their rate of growth on any broad, useful scale.

The new findings, which were developed with funding from NASA and the National Science Foundation, have been published in Global Biogeochemical Cycles, a professional journal. A group of scientists also explained the new study today in a national teleconference. "The new information on phytoplankton growth rates and biomass will greatly advance our understanding of the Earth’s oceans," said Michael Behrenfeld, a research professor in the Department of Botany and Plant Pathology at OSU.


"We don’t have the satellite technology available yet to fully take advantage of this new approach," he said. "But ultimately this system should have a great potential to effectively monitor phytoplankton productivity and understand the physical and chemical forces that drive it."

Although too tiny to see, phytoplankton have a net annual production that’s comparable to the total amount of terrestrial plant life on Earth, scientists say. They produce about 50-65 billion tons of organic matter each year, and in the process absorb carbon dioxide and pour oxygen into the atmosphere.

Their abundance dictates the location and health of most marine fisheries. They play a critical role in marine water quality issues, can help regulate climate, are affected by climate, and are responsible for red tides and other harmful algal blooms. The very basis of sustainable ecological systems is almost impossible to understand without a good grasp of phytoplankton productivity, and its implications for global climate change.

Behrenfeld is an expert on phytoplankton, and has studied them from their molecular and metabolic pathways to their measurement from outer space. "It was only in the late 1800s that we even realized these tiny plants formed the base of the marine food web," Behrenfeld said. "By the 1950s, we had figured out how to accurately measure their production and use observations of chlorophyll to determine their biomass. But until now, we’ve never been able to measure their rate of production over large areas."

That production can be enormous, and highly variable. Phytoplankton biomass can double in as little as one day, and it’s routine for the entire mass of phytoplankton in an area to either be consumed by other life forms or die and sink to the ocean bottom in less than a week. "Obviously, there’s a very tight coupling between phytoplankton production and its consumption or death," said Emmanuel Boss at the University of Maine, a co-author on the paper. "So it’s almost impossible to really understand what’s going on in the oceans without understanding that rate of production. Now we have a way to do that."

The researchers accomplished this by moving beyond the old standard for monitoring phytoplankton, the observation of chlorophyll. "The growth rate of phytoplankton can change dramatically based on such factors as water temperature, nutrients and light," Behrenfeld said. "And it’s the growth rate of phytoplankton we have to know, to really take the pulse of the oceans. That’s the missing piece of the puzzle." The new approach is based on the premise that the ’greenness’ in phytoplankton – its level of pigmentation per cell – is a reflection of its growth rate, said David Siegel of the University of California, Santa Barbara, the third author on the paper. The researchers have discovered a means to measure phytoplankton biomass from ocean light scattering properties and infer growth rates from simultaneous measurements of how green the individual phytoplankton are, all from outer space.

The mathematics behind this approach, the researchers say, is conceptually similar to technology that’s used in a home supply or paint store when someone brings in a color chip and wants to "match" the paint color. A computer analysis is done that determines the final color of the paint, factors in the base colors used to produce it and then determines the original formula needed to reproduce the paint chip. To fully use this approach, new satellite systems will be necessary that can more accurately determine both the color and brightness of marine waters, Behrenfeld said. He and colleagues are already working on a satellite concept to do that called ORCA, or Ocean Radiometer for Carbon Assessment.

However, in studies already done, the scientists have demonstrated that carbon-based values are considerably higher in tropical oceans, show greater seasonality at middle and high latitudes, and illustrate important differences in the formation and demise of regional algal blooms. Researchers anticipate a fundamental change in how they can model and observe carbon cycling in the global oceans.

Michael Behrenfeld | EurekAlert!
Further information:
http://www.oregonstate.edu

More articles from Earth Sciences:

nachricht Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>