Breakthrough made in assessing marine phytoplankton health

May 28, 2009
This digital image shows how the input of iron into marine ecosystems can affect phytoplankton growth in the oceans.

Researchers from Oregon State University, NASA and other organizations said today that they have succeeded for the first time in measuring the physiology of marine phytoplankton through satellite measurements of its fluorescence - an accomplishment that had been elusive for years.

With this new tool and the continued use of the MODIS Aqua satellite, scientists will now be able to gain a reasonably accurate picture of the ocean's health and productivity about every week, all over the planet.

Data such as this will be critically important in evaluating the effect on oceans of global warming, climate change, desertification and other changes, the researchers said. It will also be a key to determining which areas of the ocean are limited in their productivity by - as this study just showed the Indian Ocean was.

"Until now we've really struggled to make this technology work and give us the information we need," said Michael Behrenfeld, an OSU professor of botany. "The fluorescence measurements allow us to see from outer space the faint red glow of tiny marine plants, all over the world, and tell whether or not they are healthy. That's pretty cool."

Ocean phytoplankton are single-celled organisms that are responsible for half of the photosynthetic productivity on Earth. They fuel nearly all marine and are the base of the marine food chain.

Measurements of phytoplankton are an important way to understand the broader health and productivity of the ocean, researchers say. Some of the measurements available prior to this, such as phytoplankton or their carbon-to-chlorophyll ratio, provided part of the picture, but were often only available for tiny portions of the ocean at a time.

To grow, however, these phytoplankton absorb energy from the sun, and then allow some of that energy to escape as red light that is called fluorescence. The new measurements of fluorescence, literally the dim glow that these plants put off, will help complete the understanding of ocean health on a much broader and more frequent basis.

Some surprises are already in.

It was known, for instance, that parts of the equatorial Pacific Ocean, some regions around Antarctica and parts of the sub-Artic Pacific Ocean below Alaska were limited in production by the poor availability of iron. The newest data, however, show that parts of the northern Indian Ocean during the summer are also iron limited - a phenomenon that had been suggested by some ocean and climate models, but never before confirmed.

"Iron is often brought to the oceans by dust coming off terrestrial regions, and is a necessary nutrient that often limits the potential for marine phytoplankton growth," said Allen Milligan, an OSU assistant professor of botany and co-author of this study, which is being published in the journal Biogeosciences.

"If forces such as global warming, circulation changes or the growth of deserts change the amount of dust entering the oceans, it will have an impact on marine productivity," Milligan said. "Now we'll be able to track those changes, some of which are seasonal and some of which may happen over much longer periods of time. And we'll also be able to better assess and improve the climate models that have to consider these phenomena."

Funding for this research was provided by the Biology and Biogeochemistry Program of NASA, which announced the findings today in a news conference. Other collaborators were from the University of Maine/Orono, University of California/Santa Barbara, University of Southern Mississippi, the Goddard Space Flight Center, Woods Hole Oceanographic Institution, Cornell University, and the University of California/Irvine.

In continued studies, researchers at OSU hope to reproduce the marine environment that these cells live in, learn more about their basic biology and better understand why and how they can be seen from space. Further research may also explore how the oceans might respond to iron enrichment.

Source: Oregon State University

Explore further: Six Nepalese dead, six missing in Everest avalanche

add to favorites email to friend print save as pdf

Related Stories

Study Solves Ocean Plant Mystery

Aug 31, 2006

A NASA-sponsored study shows that by using a new technique, scientists can determine what limits the growth of ocean algae, or phytoplankton, and how this affects Earth's climate.

NASA Development May Help Solve Ocean Biology Problem

Feb 11, 2005

NASA and university scientists have made a breakthrough in using satellites to study the tiny, free-floating ocean plants, called phytoplankton. The plants form the base of the ocean food chain and produce half of the oxygen ...

Summer Storms Could Mean More Dead Zones

Jul 11, 2008

(PhysOrg.com) -- It's summertime and people are flocking to the coasts around the country. But when summer storms arrive, it's not only beach-goers who are affected; the rains can also have an impact on living ...

Recommended for you

Six Nepalese dead, six missing in Everest avalanche

33 minutes ago

At least six Nepalese climbing guides have been killed and six others are missing after an avalanche struck Mount Everest early Friday in one of the deadliest accidents on the world's highest peak, officials ...

Clean air: Fewer sources for self-cleaning

14 hours ago

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

There's something ancient in the icebox

14 hours ago

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Image: Grand Canyon geology lessons on view

21 hours ago

The Grand Canyon in northern Arizona is a favorite for astronauts shooting photos from the International Space Station, as well as one of the best-known tourist attractions in the world. The steep walls of ...

First radar vision for Copernicus

21 hours ago

Launched on 3 April, ESA's Sentinel-1A satellite has already delivered its first radar images of Earth. They offer a tantalising glimpse of the kind of operational imagery that this new mission will provide ...

User comments : 0

More news stories

Six Nepalese dead, six missing in Everest avalanche

At least six Nepalese climbing guides have been killed and six others are missing after an avalanche struck Mount Everest early Friday in one of the deadliest accidents on the world's highest peak, officials ...

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

White House updating online privacy policy

A new Obama administration privacy policy out Friday explains how the government will gather the user data of online visitors to WhiteHouse.gov, mobile apps and social media sites. It also clarifies that ...