Featured Research

from universities, journals, and other organizations

'Unprecedented' Warming Drives Dramatic Ecosystem Shifts In North Atlantic, Study Finds

Date:
November 7, 2008
Source:
Cornell University
Summary:
While Earth has experienced numerous changes in climate over the past 65 million years, recent decades have experienced the most significant climate change since the beginning of human civilized societies about 5,000 years ago, says a new Cornell University study.

This graphic shows the path of low-salinity water discharged from the Arctic Ocean in 1989 as it progresses along the continental shelf of eastern North America.
Credit: Image courtesy of Cornell University

While Earth has experienced numerous changes in climate over the past 65 million years, recent decades have experienced the most significant climate change since the beginning of human civilized societies about 5,000 years ago, says a new Cornell University study.

The paleo-climate record shows very rapid periods of cooling in the past, when temperatures have dropped by as much as 18 degrees Fahrenheit (10 degrees Celsius) in a matter of years to decades, "the rate of warming we are seeing [now] is unprecedented in human history," said Cornell oceanographer Charles Greene, the lead author of the paper appearing in the November 2008 issue of the journal Ecology, which is published by the Ecological Society of America.

During the past 50 years, melting Arctic ice sheets and glaciers have periodically released cold, low-salinity slugs of water from the Arctic Ocean into the North Atlantic. This has led to dramatic ecosystem shifts as far south as North Carolina and extensive geographic range shifts of many plant and animal species. One microscopic algal species from the Pacific Ocean, not seen in the North Atlantic for over 800,000 years, has successfully crossed over the Arctic Ocean and reinvaded the North Atlantic during the past decade.

By reviewing climate changes in the past, the researchers were able to more clearly observe how this influx of fresher water has led to changes in ecosystems as well as the geographic distributions of species, said Greene.

Interestingly, the study reports findings counter to the expectations of most ecologists: that the distributions of southern species will move northward and those of northern species will retreat as the climate warms. Instead, as colder, fresher Arctic waters flow south along the Northwest Atlantic shelf, from the Labrador Sea south of Greenland all the way to North Carolina, the distributions of many northern species have actually moved southward, said Greene.

In addition, the periodic freshening of shelf waters can extend the growing seasons of phytoplankton and tiny drifting animals, like copepods, which together make up the base of the marine food chain. Such climate-driven changes can alter the structure of shelf ecosystems from the bottom of the food chain upwards, said Greene.

"While it is true that cod stocks never rebounded from 20th-century overfishing, part of their failure to recover can be attributed to the climate bringing colder waters to Newfoundland since the 1990s," said Greene. Cod don't grow and reproduce as rapidly in the colder water. The decline in cod, combined with the ocean's colder temperatures, enabled populations of cold-water crustacean species, like snow crab and shrimp, to increase.

"As climate changes, there are going to be winners and losers, both in terms of biological species and different groups of people," said Greene. "The cod fishermen are out of luck, but the fishermen that have decided to go after snow crab and shrimp are very successful now." He added that adapting to climate change is partly being able to predict what we can expect.

The study was funded by the National Science Foundation.


Story Source:

The above story is based on materials provided by Cornell University. Note: Materials may be edited for content and length.


Cite This Page:

Cornell University. "'Unprecedented' Warming Drives Dramatic Ecosystem Shifts In North Atlantic, Study Finds." ScienceDaily. ScienceDaily, 7 November 2008. <www.sciencedaily.com/releases/2008/11/081106153534.htm>.
Cornell University. (2008, November 7). 'Unprecedented' Warming Drives Dramatic Ecosystem Shifts In North Atlantic, Study Finds. ScienceDaily. Retrieved August 31, 2014 from www.sciencedaily.com/releases/2008/11/081106153534.htm
Cornell University. "'Unprecedented' Warming Drives Dramatic Ecosystem Shifts In North Atlantic, Study Finds." ScienceDaily. www.sciencedaily.com/releases/2008/11/081106153534.htm (accessed August 31, 2014).

Share This




More Earth & Climate News

Sunday, August 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Volcano Erupts on Papua New Guinea

Raw: Volcano Erupts on Papua New Guinea

AP (Aug. 29, 2014) Several communities were evacuated and some international flights were diverted on Friday after one of the most active volcanos in the region erupts. (Aug. 29) Video provided by AP
Powered by NewsLook.com
Raw: Small Volcanic Eruption in Iceland

Raw: Small Volcanic Eruption in Iceland

AP (Aug. 29, 2014) Icelandic authorities briefly raised the aviation warning code to red on Friday during a small eruption at the Holuhraun lava field in the Bardabunga volcano system. (Aug. 29) Video provided by AP
Powered by NewsLook.com
As Drought Continues LA "water Police" Fight Waste

As Drought Continues LA "water Police" Fight Waste

AFP (Aug. 29, 2014) In the midst of a historic drought, Los Angeles is increasing efforts to go after people who waste water. Five water conservation "cops" drive around the city every day educating homeowners about the drought. Duration: 02:17 Video provided by AFP
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
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:
from the past week

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