Featured Research

from universities, journals, and other organizations

Prehistoric Decline Of Freshwater Mussels Tied To Large-scale Maize Cultivation

Date:
June 12, 2005
Source:
Southern Research Station - USDA Forest Service
Summary:
USDA Forest Service (FS) research suggests that a decline in the abundance of freshwater mussels about 1000 years ago may have been caused the large-scale cultivation of maize by Native Americans.

Tennessee riffleshell (Epioblasma propinqua).
Credit: Photo : Kevin Cummings, Illinois Natural History Survey

USDA Forest Service (FS) research suggests that a decline in the abundance of freshwater mussels about 1000 years ago may have been caused by the large-scale cultivation of maize by Native Americans.

In the April 2005 issue of Conservation Biology, Wendell Haag and Mel Warren, researchers with the FS Southern Research Station (SRS) unit in Oxford , MS, report results from a study of archaeological data from 27 prehistoric sites in the southeastern United States.

Worldwide, freshwater mussels have proven to be highly susceptible to human-caused disturbance, and represent the most endangered group of organisms in North America. Of 297 species found in the United States, 269 freshwater mussel species are found in the Southeast.

“We can tie declines of specific mussel populations to the construction of dams, stream channelization, or pollution from a specific source,” says Haag, “but the worldwide patterns of decline in these animals implies that larger-scale disturbances such as sedimentation and nonpoint-source pollution may have an equal impact.”

Among freshwater mussels, members of the genus Epioblasma -- commonly called riffleshells -- are the most endangered. Epioblasma consists of 20 species and eight subspecies; at least 13 of these species and four subspecies are presumed extinct. Of the remaining, the snuffbox mussel ( Epioblasma triquetra ) is the only species not listed on the Federal endangered list.

“Human population in the Southeast began to increase steadily about 5000 years ago,” says Warren. “With increasing population came land disturbance from agriculture. This intensified about 1000 years ago, with the beginning of large-scale maize cultivation. No one has really tried to look at how this change in land use impacted water quality and aquatic organisms such as freshwater mussels.”

Working with Evan Peacock from the Cobb Institute of Archaeology at Mississippi State University , Warren and Haag used survey data from prehistoric shell middens -- refuse heaps of shells discarded after eating -- to examine differences in the abundance of Epioblasma species before and after maize cultivation started in the Southeast. They compiled data from both published and unpublished archaeological reports from 27 different sites along 12 rivers in the Southeast.

“As far as we can tell, Native Americans harvested mussels without preference for species,” says Haag. “Shell middens provide us with a way to establish the range of freshwater mussel species before human impacts, and to chart changes in relative abundance as impacts increased.”

The researchers found that the relative abundance of riffleshell mussels in the rivers they studied declined gradually during the period between 5000 and 1000 years ago; however, the decline accelerated markedly during the period between 1000 and 500 years ago, when thousands of acres of land were cleared for farming.

“We know that freshwater mussels are very sensitive to stream alterations,” says Warren. “Although we cannot entirely rule out the influence of long-term changes in climate, the dramatic changes in land use in this period provide a compelling explanation for the changes in mussel abundance we found.”

Today, none of the riffleshell species the researchers found in ancient middens survive at the study sites, where they were gathered by Native Americans over the millennia before European settlement. Most are extinct as a result of modern land disturbances.

“Our results from prehistory support the notion that increases in human activities such as land clearing have measurable effects on freshwater mussel communities,” says Haag, “and that prehistoric human activities put pressures on aquatic ecosystems that were similar to, though certainly less acute than, present-day activities.”

Full text version of the article: http://www.srs.fs.usda.gov/pubs/9281


Story Source:

The above story is based on materials provided by Southern Research Station - USDA Forest Service. Note: Materials may be edited for content and length.


Cite This Page:

Southern Research Station - USDA Forest Service. "Prehistoric Decline Of Freshwater Mussels Tied To Large-scale Maize Cultivation." ScienceDaily. ScienceDaily, 12 June 2005. <www.sciencedaily.com/releases/2005/06/050608063414.htm>.
Southern Research Station - USDA Forest Service. (2005, June 12). Prehistoric Decline Of Freshwater Mussels Tied To Large-scale Maize Cultivation. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2005/06/050608063414.htm
Southern Research Station - USDA Forest Service. "Prehistoric Decline Of Freshwater Mussels Tied To Large-scale Maize Cultivation." ScienceDaily. www.sciencedaily.com/releases/2005/06/050608063414.htm (accessed September 30, 2014).

Share This



More Earth & Climate News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Balloon Descends to Bottom of Croatian Cave

Raw: Balloon Descends to Bottom of Croatian Cave

AP (Sep. 29, 2014) An Austrian balloon pilot has succeeded in taking a balloon deep underground, a feat which he believes is a world first. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Bodies Recovered from Japan Volcano Eruption

Bodies Recovered from Japan Volcano Eruption

AP (Sep. 29, 2014) Rescue crews finished recovering the remaining 27 bodies from atop Japan's Mount Ontake Monday. At least 31 people were killed Saturday in the mountain's first fatal volcanic event in modern history. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Raw: Japan's Mount Ontake Erupts

Raw: Japan's Mount Ontake Erupts

AP (Sep. 27, 2014) A volcano erupted in central Japan on Saturday, sending a large plume of ash high into the sky and prompting a warning to climbers and others to avoid the area. (Sept. 27) Video provided by AP
Powered by NewsLook.com
California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
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