Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Water color and phytoplankton growth in the Gulf of Maine are changing

22.04.2016

Henry Bryant Bigelow's century-old data compared with current conditions

Dr. William "Barney" Balch's team at Bigelow Laboratory for Ocean Sciences has been sampling the waters of the Gulf of Maine regularly over the same transect for the last 18 years as part of a NASA-funded study. Working with scientists from the U.S. Geological Survey, Dr. Thomas Huntington and Dr. George Aiken, Balch reported in a recent paper an overall reduction in productivity in the Gulf of Maine.


Using a Forel-Ule scope scientists concluded that the Gulf of Maine has yellowed over the last century, particularly in coastal Maine waters.

Credit: Bigelow Laboratory for Ocean Sciences

The researchers found that the amount of dissolved organic carbon from rivers emptying into the Gulf of Maine has increased over the last 80 years, a trend they predict will continue through 2100 if annual precipitation continues to increase. The adjacent Gulf of St. Lawrence also was found to supply a significant amount of organic material into the Gulf of Maine via the Scotia Shelf Current. Collectively, these conditions appear to be contributing to the decline in the Gulf's primary productivity, as reported in the American Geophysical Union's journal, Global Biogeochemical Cycles, Volume 30, Issue 2, February 2016, pages 268-292.

Balch explained the significance of this finding: "As increasing amounts of dissolved organic matter leaches from the soil into rivers after rains, these materials ultimately flow directly into the Gulf of Maine or indirectly from the Gulf of St. Lawrence via the Scotian Shelf Current. This organic matter is rich in colored humic materials that impart a brown color to the rivers in Maine--think of a dark "tea" steeped from dead leaves and soil. This input actually changes the color of the seawater and appears to be reducing the light available to phytoplankton for photosynthesis and growth, causing a decline in overall productivity."

"Ocean color serves as a useful proxy for understanding some of the changes in fundamental processes that are happening in the sea as the climate changes. Normally the ocean is blue with little light absorption. When there is a lot of chlorophyll-containing phytoplankton (microscopic plants) in the water, the water has a greenish color, just like plants do on land. However, the dissolved organic matter delivered to the Gulf of Maine by rivers, has a yellowish-brown "tea" color which gives the normally blue ocean a yellow tint. This organic matter also absorbs light necessary for photosynthetic organisms, and can thereby influence the ecology of the Gulf of Maine. Our data suggest that increases in precipitation and runoff during the last 80 years result in more of this organic, dark-colored "tea" being delivered to the Gulf of Maine which could be affecting how marine plants are able to photosynthesize and grow." added Aiken.

Because ocean color is one of the best indicators of what is happening in ocean waters, Balch and his team compared their color measurements of the Gulf of Maine with 1912-1913 color data recorded by Henry Bryant Bigelow, considered the founder of modern oceanography and for whom Bigelow Laboratory was named. In 1912, Henry Bigelow had the foresight to make manual ocean color measurements as he plied the Gulf of Maine aboard his schooner, Grampus. Bigelow used a simple technique published in 1890 by François-Alphonse Forel, a Swiss lake scientist. Balch's team compared Bigelow's original color data with current water color measurements to document color change over a century time scale. The conclusion is that the Gulf has yellowed over the last century, particularly in coastal Maine waters.

Climate and hydrologic models predict increasing precipitation and runoff in the Gulf of Maine watershed in the 21st century. Based on these projections, Balch, Huntington, and Aiken predict that river discharge of soil-derived dissolved organic carbon into the Gulf of Maine could increase close to 30% over the next 80 years, potentially contributing to a continued decline in the productivity of this coastal marine food web.

Today scientists use NASA's Earth-observing satellites and sophisticated shipboard optical measurements to document ocean color. The Bigelow Laboratory-USGS research team also showed a direct link for the first time between satellite-derived measurements of dissolved organic carbon across the Gulf of Maine with dissolved organic carbon discharged in rivers as estimated by the USGS, which go far to validate the satellite-derived measurements as an important predictive tool. With this solid foundation of data and collaboration, the research team expects to continue to mine the data to advance understanding of ongoing changes in the Gulf of Maine.

###

Bigelow Laboratory for Ocean Sciences, an independent not-for-profit research institution on the coast of Maine, conducts research ranging from microbial oceanography to large-scale ocean processes that affect the global environment. Recognized as a leader in Maine's emerging innovation economy, the Laboratory's research, education, and technology transfer programs are spurring significant economic growth in the state. For more information, http://www.bigelow.org or @BigelowLab or social.

The U.S. Geological Survey provides science for a changing world. Visit USGS.gov, and follow us on Twitter @USGS and our other social media channels. Subscribe to our news releases via e-mail, RSS or Twitter.

Media Contact

Darlene Trew Crist
dtcrist@bigelow.org
207-315-2567 x103

 @BigelowLab

http://www.bigelow.org 

Darlene Trew Crist | EurekAlert!

More articles from Earth Sciences:

nachricht Volcanoes and glaciers combine as powerful methane producers
20.11.2018 | Lancaster University

nachricht Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Nonstop Tranport of Cargo in Nanomachines

20.11.2018 | Life Sciences

Researchers find social cultures in chimpanzees

20.11.2018 | Life Sciences

When AI and optoelectronics meet: Researchers take control of light properties

20.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>