Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Prehistoric Decline of Freshwater Mussels Tied to Rise in Maize Cultivation

08.06.2005


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 They compiled data from both published and unpublished archaeological reports from 27 different sites along 12 rivers in the Southeast.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: www.srs.fs.usda.gov/pubs/9281

For more information:
Wendell Haag at (662-234-2744 x245) or whaag@fs.fed.us
Mel Warren at (662-234-2744 x34) or mwarren01@fs.fed.us

Wendell Haag | EurekAlert!
Further information:
http://www.srs.fs.usda.gov/

More articles from Life Sciences:

nachricht Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex

nachricht New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>