Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New UF study shows river turtle species still suffers from past harvesting

26.09.2012
University of Florida researchers studying river turtles in Missouri found populations of the northern map turtle have not recovered from harvesting in the 1970s.

Scientists used data collected by Florida Museum of Natural History herpetology curator Max Nickerson in 1969 and 1980 as a baseline, then surveyed the same stretch of river in the Ozarks in 2004 to determine the northern map turtles had not recovered from a previous 50 percent population loss caused by harvesting, likely for food.

River turtles help ecosystems function by cycling nutrients and maintaining food web dynamics. Assessment of the northern map turtle, a protected species in some states, is essential as increasing human populations and global warming further alter its habitat. The study was published Sept. 14 in Volume 3 of Copeia, and is scheduled to appear online this week.

“The importance of river turtles is really underplayed,” said lead author Amber Pitt, a Clemson University postdoctoral research fellow who conducted research for the study as a UF graduate student. “River turtles are long-lived, rely on the same water resources that we do and can serve as indicators of water quality. People should be concerned if turtles are impacted by poor water quality because we are likely being affected, too.”

Inhabiting river systems from southern Arkansas to Quebec, the northern map turtle, Graptemys geographica, is among the most wide-ranging map turtles in the U.S. They are dietary specialists and depend mainly on snails, making the species especially susceptible to biodegradation. Formally known as the common map turtle due to its wide geographic distribution, its name was changed in 2000 so people would not assume it was abundant, Pitt said. The northern map turtle is listed in Appendix III of the Convention on International Trade in Endangered Species of Wild Fauna and Flora and this research may be used as a guideline for conservation or protection of other turtle species.

Scientists determined harvesting was likely the cause of the 50 percent population loss between 1969 and 1980 based on analysis of data published by Nickerson and Pitt in the Florida Museum of Natural History Bulletin in August. Data showed fewer adult females, which are larger than males and preferred for the food trade, and local residents confirmed turtle harvesting occurred in the river, Nickerson said.

“This shows that harvesting, even if it’s a one-time event, can cause a turtle population to significantly decline and remain impacted for decades, because this species doesn’t reproduce quickly,” Pitt said. “It was really discouraging to see that even without the pressure of further harvesting, they couldn’t recover over that long time period, which is partially due to their biology but may also be associated with habitat degradation and disturbance.”

Researchers used similar methods to survey the nearly 3-mile stretch of the North Fork of White River in Ozark County, Missouri, in 2004 by snorkeling to locate, tag and record information about the turtles. Based on the 2004 examination of the river, habitat degradation was apparent because of increased siltation, sedimentation and algal blooms.

“What’s happening in these big spring-fed rivers is very important,” Nickerson said. “When you clear the banks of a river, you increase siltation, which affects the food sources, reproduction, plant growth, species composition and basic ecology of that section of the stream, and perhaps the entire river.”

River degradation has been partially caused by human recreation, which drastically increased by 2004, Nickerson said. People swimming and boating also frighten turtles so they may not bask as much as needed to maintain their health and maximize egg production.

Although scientists generally agree many turtle populations are declining worldwide, little has been published on river turtle communities, said Don Moll, a professor emeritus at Missouri State University who co-authored a textbook on freshwater turtles.

“This is a very important study because it follows the dynamics of this turtle community over a more than 30-year time period, and really it’s the only published river turtle study I can think of that does that,” Moll said. “It’s a real contribution in that sense — it’s so unique.”

One concern with attracting conservation efforts to river turtles may have to do with their small size because they do not garner as much public attention as larger marine species, Pitt said. Adult female northern map turtles are about 11 inches long.

“Often times with conservation, you have the charismatic mega fauna that people care about, such as sea turtles — everybody cares about sea turtles, including me,” Pitt said. “But river turtles are facing just as many threats as sea turtles. People are also harvesting river turtles and there are very few laws in place to stop this harvest — it’s a global epidemic that is causing turtle populations to be wiped out.”

Credits

Writer
Danielle Torrent, dtorrent@flmnh.ufl.edu
Source
Max Nickerson, maxn@flmnh.ufl.edu, 352-273-1946

Max Nickerson | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>