Featured Research

from universities, journals, and other organizations

Understanding patterns of seafloor biomass

Date:
February 10, 2011
Source:
National Oceanography Centre, Southampton (UK)
Summary:
Analysis of a comprehensive database has revealed strong links between biological productivity in the surface oceans and patterns of biomass and abundance at the seafloor, helping to explain large regional differences.

Global seafloor invertebrate biomass.
Credit: Dan Jones, NOC; data courtesy Chih-Lin Wei, Department of Oceanography, Texas A&M U

Analysis of a comprehensive database has revealed strong links between biological productivity in the surface oceans and patterns of biomass and abundance at the seafloor, helping to explain large regional differences. The research was conducted by an international, multi-institutional research team including scientists from the National Oceanography Centre (NOC), and incorporated data from the Census of Marine Life (CoML).

The vast majority of the biological production in the world's oceans occurs within sunlit surface waters -- the so-called photic zone. Through the process of photosynthesis, tiny marine plants called phytoplankton use the energy of sunlight to build the carbon-rich organic molecules needed for growth. When they die, a proportion of the organic matter sinks to the ocean depths, where it is used as food by all manner of deep-sea life.

"With the exception of chemosynthetic communities living around hydrothermal vents and other chemical energy sources, deep-sea ecosystems are entirely dependent on the supply of organic material from miles above," said Dr Brian Bett of the NOC.

"An important question is whether variation in food supply explains patterns of regional seafloor biomass, or whether other oceanic factors such as seafloor relief and bottom water characteristics are responsible," he explained.

To help address the issue, the researchers assembled data on the biomass and abundances of species living at the seafloor in different regions. Many of these data were collected during CoML field projects.

They then used a computer algorithm called Random Forests to model and predict seafloor standing stocks from biological production in the photic zone, the amount of organic matter exported to the depths, seafloor relief, and bottom water characteristics.

"Random Forests uses input data to generate a global picture of seafloor biomass and abundance, learning from its own mistakes as it goes along," explained Dr Bett.

The researchers used the algorithm to generate individual and composite maps of predicted global seafloor biomass and abundance of bacteria, small and medium sized animals living on or in the seafloor sediments, as well as larger animals such as crabs and fish.

They found a strong positive relationship between surface production and organic matter export, on the one hand, and predicted patterns of seafloor biomass and abundance on the other, with seafloor relief and bottom water characteristics playing secondary but significant regional roles.

According to their analysis, seafloor biomass is highest around the poles, and on continental margins, where upwelling waters supply nutrients needed for phytoplankton growth in the photic zone. Values are also high near the equator where the interaction of wind-driven currents causes upwelling. In contrast, they found consistently low seafloor biomass on the central abyssal plains of the major ocean basins.

The dominance of different groups of organisms in terms of their abundance or biomass depends on seafloor depth. Smaller-bodied organisms tend to dominate the food limited depths of the ocean.

"The Census and associated maps provide important insights into the functioning of deep-sea ecosystems and their role in the global carbon cycle, and will also contribute to evidence-based ocean management," said Dr Bett. "Our study truly highlights the tremendous value and continuing importance of long-term observations and international collaboration in understanding our oceans and their ecosystems."


Story Source:

The above story is based on materials provided by National Oceanography Centre, Southampton (UK). Note: Materials may be edited for content and length.


Journal Reference:

  1. Chih-Lin Wei, Gilbert T. Rowe, Elva Escobar-Briones, Antje Boetius, Thomas Soltwedel, M. Julian Caley, Yousria Soliman, Falk Huettmann, Fangyuan Qu, Zishan Yu, C. Roland Pitcher, Richard L. Haedrich, Mary K. Wicksten, Michael A. Rex, Jeffrey G. Baguley, Jyotsna Sharma, Roberto Danovaro, Ian R. MacDonald, Clifton C. Nunnally, Jody W. Deming, Paul Montagna, Mélanie Lévesque, Jan Marcin Weslawski, Maria Wlodarska-Kowalczuk, Baban S. Ingole, Brian J. Bett, David S. M. Billett, Andrew Yool, Bodil A. Bluhm, Katrin Iken, Bhavani E. Narayanaswamy. Global Patterns and Predictions of Seafloor Biomass Using Random Forests. PLoS ONE, 2010; 5 (12): e15323 DOI: 10.1371/journal.pone.0015323

Cite This Page:

National Oceanography Centre, Southampton (UK). "Understanding patterns of seafloor biomass." ScienceDaily. ScienceDaily, 10 February 2011. <www.sciencedaily.com/releases/2011/02/110209105554.htm>.
National Oceanography Centre, Southampton (UK). (2011, February 10). Understanding patterns of seafloor biomass. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2011/02/110209105554.htm
National Oceanography Centre, Southampton (UK). "Understanding patterns of seafloor biomass." ScienceDaily. www.sciencedaily.com/releases/2011/02/110209105554.htm (accessed October 23, 2014).

Share This



More Earth & Climate News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) — The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Trick-or-Treating Banned Because of Polar Bears

Trick-or-Treating Banned Because of Polar Bears

Buzz60 (Oct. 21, 2014) — Mother Nature is pulling a trick on the kids of Arviat, Canada. As Mara Montalbano (@maramontalbano) tells us, the effects of global warming caused the town to ban trick-or-treating this Halloween. Video provided by Buzz60
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) — The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins