Tennessee Aquarium and UGA’s River Basin Center to Host Pioneering Workshop Addressing Freshwater Microplastic Pollution

Writer: Casey Phillips

Chattanooga, Tenn. (Sept. 10, 2020) – It is the inevitable destiny of all water that falls on land to eventually return to the sea. And like an enthusiastic tourist, it can’t help but pick up souvenirs along the way, whether it’s dirt, fertilizers or — as many scientists now suspect — plastic.

In recent years, the world slowly has awoken to the, ironically, enormous impact microscopic plastic has on marine life. Every year, an average of 8.8 million tons (about 17.6 billion pounds) of plastic fragments or manufactured plastic objects measuring smaller than five millimeters across enter the ocean. There, they’re consumed by microscopic organisms and eventually work their way up the food chain to humans.

Although the bulk of plastic waste originates inland, microplastic is largely seen as a coastal issue thanks to images of plastic debris piled up on beaches or found inside marine animals. Little is known about how this plague of plastic affects the rivers, lakes and streams through which it passes on its way to the sea.

On Sept. 14, the Tennessee Aquarium Conservation Institute hopes to make inroads to answering that question as host to a virtual workshop on freshwater microplastic research. The workshop was organized in partnership with the River Basin Center at the University of Georgia. 

Among other topics, participants in the one-day summit will focus on developing standards to ensure current and future researchers can reliably compare and build on each other’s findings.

“In a new field of research where so many different methods are being used, it is extremely important that studies are designed and conducted so we can compare and replicate results from different labs,” says Dr. Anna George, the Aquarium’s vice president of conservation science and education.

“Not only will these studies improve our understanding of how plastic pollution reaches the ocean, they will also provide insight into an emerging threat to maintaining clean water for us all.”

The workshop initially was scheduled to take place in April at the Conservation Institute’s headquarters on the banks of the Tennessee River. However, the ongoing health crisis necessitated a different approach, and it now will be held via Zoom video conference.  

Dr. Krista Capps, an assistant professor with the Odum School of Ecology and Savannah River Ecology Lab, helped organize the workshop of 50 participants. Her research into how microplastic is affected by water treatment facilities has been hampered by a lack of agreed-upon research standards.

The issues caused by this absence of structure spurred the idea for the upcoming workshop, Dr. Capps says.

“There are currently no accepted standard methodologies to collect and identify microplastic pollution, as the field is developing so quickly,” she says. “Many researchers I contacted were also frustrated by this situation. The workshop is an outgrowth of my search for expert advice and a quest to develop standard quality assurance and quality control protocols for sampling and analysis.”

The workshop participants represent a variety of institutions, including the University of Georgia, Sewanee: The University of the South, Auburn University, Mississippi State University, the University of Alabama and Vanderbilt University as well as Riverkeeper organizations, SeaGrant consortiums and government agencies.

“Plastic pollution is a problem that affects everyone,” Dr. Capps says. “The greater diversity of stakeholders and academic disciplines involved in working on this problem, the more holistic our approach to understanding plastic pollution will be.”

The workshop will feature presentations by several experts, including:

·         Dr. Rae McNeish, an assistant professor of biology at California State University, Bakersfield

·         Dr. Jeremy Conkle, an associate professor of physical and environmental science at Texas A&M University, Corpus Christi

·         Dr. Andreas Fath, a professor of physical chemistry and analytics at Germany’s Furtwangen University

Dr. Fath made headlines in 2017 with a record-setting marathon swim of the entire 652-length of the Tennessee River. During this 34-day undertaking, he and his team took daily measurements of various water quality indicators, including the presence of microplastics. With data from locations along the entire course of the river, this “swim for science” represented one of the first comprehensive studies of how microplastic moves through freshwater systems.

Analysis of the project’s findings found microplastic levels in the Tennessee River that were 80 times higher than Dr. Fath detected during a similar study of Germany’s Rhine River in 2014. These results were a clear sign that microplastics have a greater, if largely uninvestigated, potential to impact freshwater sources than previously assumed, Dr. George says.

“Some freshwater-focused scientists, myself included, thought plastic in freshwater was moving out to the ocean so quickly that it probably wasn’t having a major impact on freshwater habitats or animals,” she says. “Dr. Fath’s work demonstrated that there was enough microplastic pollution in freshwater habitats that we needed to learn more about its impact in our streams and rivers.”

For more information about the Tennessee Aquarium Conservation Institute, visit tnaqua.org/conserve

To learn more about the River Basin Center at the University of Georgia, visit ecology.uga.edu.

Details about Dr. Andreas Fath’s TenneSwim project are at en.rheines-wasser.eu.

UPPER OCONEE SCIENCE AND POLICY SUMMIT

In partnership with the Upper Oconee Watershed Network, the UGA River Basin Center, UGA Office of Sustainability, ACC Stormwater,  and ACC Water Conservation will host the third biennial Upper Oconee Watershed Policy Summit.  “Exploring the Intersection of Science and Policy in the Upper Oconee Watershed” will occur on Friday September 25, 2020. This will be a virtual event!

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The Role of Freshwater Crabs in Neotropical Streams

Freshwater crabs play an important role in the breakdown of nutrients from natural materials that fall into streams, but few studies have looked into exactly how their relationships with other detritivores and the leaf litter itself impacts ecosystems.  

River Basin Center graduate student Carol Yang shed light on these relationships in neotropical streams in two recently published papers.

In a paper published in Freshwater BiologyYang did an in-stream experiment in Monteverde, Costa Rica to examine the leaf litter in enclosures that contained crabs as compared to enclosures without crabs. One dynamic that Yang and colleagues hoped to learn more about was the relationship between crabs and other detritivores—which contribute to leaf breakdown, but that crabs frequently prey upon. 

Throughout the study, Yang and collaborators regularly sampled the leaf litter. They found that enclosures with crabs had faster rates of breakdown than those without, indicating that their manipulation and consumption of leaves had a larger impact than their consumption of other detritivores and shredders. 

In a follow up study published in Nauplius, Yang used a laboratory setting to gain a more in-depth understanding of the crab behaviors that most impacted leaf litter. The crabs were collected from Monteverde, Costa Rica, and transported to aquariums along with unfiltered stream water and leaves from a common subcanopy tree. 

Yang and colleagues found that the leaf mass was significantly higher in tanks with crabs than those without. They also used visual observations and recordings to watch as the crabs used their claws to grasp and shred the leaves, which aided in ingestion. At the end of the experiment, they observed that leaves in tanks with crabs were broken up into multiple pieces, whereas leaves in tanks without them remained whole.    

These studies suggest that crabs play an important role in helping to process the detritus that accumulates in neotropical streams, especially given their abundance in tropical streams. 

RBC Graduate Student Shishir Rao Featured in Nature inFocus

River Basin Center graduate student Shishir Rao’s research was recently feature in Nature inFocus, as part of the Save Every Drop Series. Rao studies how hydroelectric power (including small dams, which are installed in higher altitude rivers in the Western Ghats impact river biodiversity.

Rao has found the installation of these small hydroelectric projects disrupt migratory species, the diversion of water (which causes other portions of the river to dry up), the fluctuation of water levels, which threaten sensitive species, the accumulation of silt and sediment, which are later released and can suffocate fish. They may also contribute to human-elephant conflicts in neighboring communities.

To read more, check out the article here: https://www.natureinfocus.in/save-every-drop/a-voice-for-our-rivers

A Wild Gopher Frog Chase

UGA Researcher Dr. Stacey Lance Searches for Gopher Frogs 

In a partnership with The Longleaf Alliance, a group dedicated to ensuring a sustainable future for the longleaf pine ecosystem in the Southeastern United States, River Basin Center and Savannah River Ecology Lab researcher Dr. Stacey Lance is working to identify suitable habitat for Carolina gopher frogs, a species identified as endangered in the Carolinas, Georgia and Alabama, and to survey existing populations on private lands. 

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