Laura Naslund, sitting in a canoe on a pond, smiles while taking emissions data.

A Day in the Life of a Pond: Measuring Small-Reservoir Emissions to Inform Infrastructure Decisions

By 7:45 a.m. on Tuesday, June 21, Laura Naslund had already spent over an hour in a canoe on a little pond on the east side of Athens, Georgia. Naslund, a graduate student in the Odum School of Ecology and a 2022 Spencer Grant recipient, was finishing up the first field sampling event of her new research project. She’d started work early on Monday morning, and was still paddling a canoe out to measure gas emissions all over the pond 24 hours later.

“The idea is to understand the times, places and pathways that are most important for emissions,” Naslund said over a quick breakfast, “and then apply that information to a later study at more sites which examines the drivers of the differences in emissions between sites.” 

There are 364 reservoirs in Athens-Clarke County, but only 23 of them are listed in the National Inventory of Dams, leaving hundreds of smaller reservoirs that receive far less attention from freshwater research and management alike.

Laura Naslund and volunteer assistant Ally Whiteis paddle a canoe across a small pond for field sampling.
Laura Naslund and volunteer assistant Ally Whiteis paddle a canoe across a small pond for sampling, around the 2-hour mark of the 24-hour field sampling.

Naslund believes these small reservoirs may have a much larger impact on inland water systems than we currently recognize. She hopes to expand our understanding of freshwater reservoir emissions by focusing research attention on the small ponds of Athens. The end goal of Naslund’s research is to help inform infrastructure decisions regarding which of these dams have the greatest environmental impact and which may be highest priority for removal.

“Particularly as we are about to have the largest infrastructure investment probably in my lifetime, I think now’s a good time to start thinking about how we can use ecological knowledge to inform where and what kind of infrastructure we have,” she explained. “And this project, I think, is a little bit unique among that body of work in that it’s focused on the end of an infrastructure life cycle.”

Naslund is particularly dedicated to accurate field testing: data collection for this research will involve sampling all over each test reservoir for over 24 hours at each event. These methods were designed to get the most accurate possible understanding of where, when and how gases are emitted throughout a day.

Laura Naslund paddles a canoe across a wollfia-covered pond.
Laura Naslund paddles a canoe across a wollfia-covered pond, around the 6-hour mark of her 24-hour field sampling.

“I think researchers have thought about spatial variation a lot, we’ve thought about seasonal variation a lot, but we’ve though less about the variation in emissions that happens over the course of a single day,” Naslund explained. By focusing on variation at a daily scale, Naslund hopes to collect emissions data that more accurately represents the natural history and spatial heterogeneity of a system.

It’s strenuous work to sample for 30 hours at a time, but Naslund doesn’t mind camping out. “The places that I’m working in are beautiful. So that always helps!”

She also acknowledged that she could not do this research alone. Her team of volunteer assistants included professors, undergraduates, and fellow graduate students, who came in shifts throughout the 30-hour sampling. “It’s been really great to collaborate with people, to show them new techniques, and to learn from them,” Naslund said.

Ally Whiteis, Odum undergraduate, paddles a canoe on a wolffia-covered pond.
Ally Whiteis, Odum undergraduate, paddling a field canoe.
Olivia Allen, Odum undergraduate, sitting behind Laura Naslund in a field canoe and recording data.
Olivia Allen, Odum undergraduate, recording data.

Naslund’s research is funded by the Network for Engineering With Nature, a collaboration between UGA and the US Army Corps of Engineers, along with a grant from the Odum School of Ecology and a 2022 Spencer Grant from the River Basin Center. The Spencer Grants are annual awards given to graduate students studying freshwater management and conservation. The grant is named for the late John Kyle Spencer, an Odum graduate student who was passionate about freshwater research. Research like Naslund’s is a reflection of this passion for freshwater science and cooperation among environmental researchers.

Photos and story by Olivia Allen

Precision Conservation of Imperiled Species

A tiny, rainbow-finned fish lives in the swiftly flowing waters of Georgia’s Etowah River. Known as the Etowah darter (Etheostoma etowahae), it exists only in the Etowah River Basin, mainly inhabiting the mountain streams of North Georgia.

The Etowah darter is only one example of the diverse array of freshwater fish, amphibians, crawfish and mussels that live in Georgia, including many endemic, imperiled species. However, the state is also a bustling transportation hub, with 1,253 miles of interstate highway and the busiest airport in the world.

Many of these species are highly sensitive to the threats associated with development.

In a recent project that brought together the University of Georgia’s River Basin Center and Institute for Resilient Infrastructure Systems, the Georgia Department of Transportation, the Georgia Department of Natural Resources and the U.S. Fish and Wildlife Service, researchers pinpointed ways to facilitate important construction projects around the state while tailoring conservation practices to each imperiled species’ needs.

Read the full article here.

Climate and Water Research Slam

Save the date: Climate and Water Research SlamThursday, May 12 1:00-5:00

The River Basin Center, the Georgia Initiative for Climate and Society, and the Office of Sustainability have joined forces for a climate and water “research slam” — a series of five-minute lightning talks by faculty and students on climate OR water (or both) followed by a social.

We have an awesome lineup of 24 5-minute lightning talks from a diverse group of speakers from across the UGA campus. Join us to hear about the wide range of water and climate work at UGA, to network with colleagues, and to celebrate the end of the semester. After the talks we’ll have a social with beverages and heavy snacks. Please join us!

Location: Innovation Hub, 210 Spring Street 

Schedule of Events:

  1:00 – 2:40  Session 1

  3:00 – 4:20  Session 2

  4:20 – 5:00  Social with beverages and snacks

Registration is free! But to help us plan for enough food and beverages, we ask you to please fill out this registration form by Monday May 9.

To see the full lineup, check out the draft detailed schedule (subject to correction for the next couple of days).

Third Wednesday Game Night with Dr. Karen Bareford

Last week Dr. Karen Bareford, the National Sea Grant and Water Resources Lead, delivered a Third Wednesday talk on the water resource efforts of the Sea Grant Network and its key partners, as well as the publicly available National Water Model. Afterwards, she presented the new Watershed Game: Coast Model, an engagement tool allowing players to take on the roles of policy and decisionmakers and collaborate in the management of water resources. Thank you to Dr. Bareford for speaking and showing this community-engaging activity!

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.