Featured Research

from universities, journals, and other organizations

Ocean: Assessing the effect of climate change on upwelling ecosystems

Date:
October 14, 2013
Source:
Institut de Recherche pour le Développement (IRD)
Summary:
Assessing the effect of climate change on upwelling ecosystems is essential to be able to predict the future of marine resources. The zones concerned by this upwelling of cold deep water, which is very rich in nutrients, provide up to 20 % of global production of fish. Since the 1990s, the theory adopted by the majority of the scientific community affirmed that these phenomena were intensifying. The rising temperatures of the air masses above the continents were expected to quicken the trade winds, which would in turn increase the upwellings, thereby cooling the surface water. But this theory has been contradicted by the recent work.

Assessing the effect of climate change on upwelling ecosystems is essential to be able to predict the future of marine resources.
Credit: © Lichtspiel-IRD

Assessing the effect of climate change on upwelling ecosystems is essential to be able to predict the future of marine resources. The zones concerned by this upwelling of cold deep water, which is very rich in nutrients, provide up to 20 % of global production of fish. Since the 1990s, the theory adopted by the majority of the scientific community affirmed that these phenomena were intensifying. The rising temperatures of the air masses above the continents were expected to quicken the trade winds, which would in turn increase the upwellings, thereby cooling the surface water. But this theory has been contradicted by the recent work of researchers from the IRD and its partners.

Coastal waters are getting considerably warmer

In their new study, led off the coast of North and West Africa, the scientists reviewed the wind measurements taken over the past 40 years and the data of the meteorological models along the Spanish and West African coastline, and discovered that they do not show an acceleration of the wind on a regional scale that would be likely to significantly cool the coastal waters. In fact, quite the opposite is true, since the satellite images and in situ measurements of the surface water temperature show a distinct upward trend in the temperature for the entire zone, at a rate of 1°C per century. These new findings contradict the hypothesis that the upwelling of the Canary Current is intensifying.

A reinterpretation of the paleoclimatic data

Until now, the study of this ecosystem focused primarily on paleoclimatic reconstructions based on samples of marine sediments. According to the geochemical analysis of these samples, planktonic organisms have evolved in an increasingly cold environment over the last few decades. This led scientists to conclude that the temperature of the surface water was dropping. But in view of the new findings, the oceanographers have put forward another explanation: the thermal signal deduced from the paleoclimatic data is due to a progressive migration of plankton towards the depths because, on the contrary, the surface water is getting warmer!

The reaction of the coastal ecosystems to climate change remains complex, because it depends greatly on local specificities -- other upwelling systems, such as that of the California Current, clearly show a trend of intensification and cooling of the water in recent decades. At the level of the ecosystem itself, the effects of the warming of the surface waters can be antagonistic: it can for example encourage the growth of fish larvae, but also increase the temperature gradient between the surface water and the deeper water and thereby modify the food chain, etc. Researchers will now have to address all these questions.


Story Source:

The above story is based on materials provided by Institut de Recherche pour le Développement (IRD). Note: Materials may be edited for content and length.


Journal Reference:

  1. E.D. Barton, D.B. Field, C. Roy. Canary current upwelling: More or less? Progress in Oceanography, 2013; 116: 167 DOI: 10.1016/j.pocean.2013.07.007

Cite This Page:

Institut de Recherche pour le Développement (IRD). "Ocean: Assessing the effect of climate change on upwelling ecosystems." ScienceDaily. ScienceDaily, 14 October 2013. <www.sciencedaily.com/releases/2013/10/131014094216.htm>.
Institut de Recherche pour le Développement (IRD). (2013, October 14). Ocean: Assessing the effect of climate change on upwelling ecosystems. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2013/10/131014094216.htm
Institut de Recherche pour le Développement (IRD). "Ocean: Assessing the effect of climate change on upwelling ecosystems." ScienceDaily. www.sciencedaily.com/releases/2013/10/131014094216.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