Diatom Project Update: Oxbows
by Katherine Johnson, Research Scientist
Frustulia sp., Photo by Katherine M. Johnson
Along with sampling diatoms along the Savannah River, the Phinizy Center for Water Sciences (PCWS) will be conducting a base-line study of diatom species compositions and assemblages found in four of the river’s oxbows. These sites are labeled on the map below. This study will be carried out in conjunction with other oxbow studies that investigate species assemblages of fishes. With the biogeochemical data from these studies we may be able to gain further insight to ecosystem health, which will allow us to better assess possible water quality changes in the future.
Synedra sp., Photo by Katherine M. Johnson
From an initial pilot study (July-September), we have deployed, retrieved and processed collections for the first group of periphytometers (diatometers). Our samples have come from the following oxbows: Possum Eddy, Conyers, and Miller. So far, throughout this study, we have been able to identify 29 genera! A couple of diatoms from these samples are pictured here. Diatoms may be unicellular, or solitary, like the Frustulia sp. cell seen here. However, others are colonial, usually producing ribbon or chainlike filaments. The photo of Synedra sp. provides a good example of a diatom filament. Check out our blog next month to find out more about different types of diatoms.
Map by Jason Moak
Savannah River Oxbow Study Update
by Jason Moak, Senior Research Manager
Phinizy Center researchers have completed their first round of fish community seasonal sampling in four oxbows along the Savannah River. In late July and early August, they collected a total of 1,044 individual fish representing 13 families, 19 genera, and 26 species.
In terms of numbers, bluegill were the dominant species captured, comprising 38% of the total number of fish captured. In terms of weight, longnose gar (57 kg) and gizzard shad (48 kg) made up the majority of the total of all fish captured (247 kg). A table listing all of the fish species captured in this sampling event is included below.
Phinizy Center sampled these fish communities using boat electrofishing and gill in collaboration with scientists from Georgia Southern University and Augusta University. The four oxbows sampled – Possum Eddy, Conyers, Miller, and Whirligig – each have an average depth of 5 feet or less and have surface areas of between 4 and 9 hectares. The lakes are located in Screven County on the Georgia DNR’s Tuckahoe Wildlife Management Area.
Oxbow lakes are remnant sections of river channels that have been cut off from the main river flow. Research on oxbows around the world has revealed their important role in supporting healthy rivers. In July 2015, Phinizy Center began a study examining the impact of various flows on the aquatic life in oxbow lakes found along the Savannah River downstream of Augusta. Our scientists are assessing the connectedness of many of the oxbows between Augusta and Savannah using high-accuracy GPS survey equipment. We are also monitoring surface and groundwater levels in four oxbows, two that are still connected to the river by surface water, and two that are disconnected. Additionally, Phinizy scientists are monitoring water quality and analyzing water samples for nutrient, algae, and zooplankton levels. This research is being funded by a grant from the South Carolina Water Resources Center at Clemson University.
How does temperature effect a gas?
by Kelsey Laymon, Research Scientist
Figure 1: Soda on the left in a hot water bath; soda on the right in a cold water bath
Point-Source & Non Point-Source Pollution
By Ruth Mead, Sr. Environmental Educator
Point Source Pollution, Non-Point Source Pollution – just what are we talking about? Point source pollution includes known discharges such as water treatment plants and industry like textile mills, paper mills and chemical plants. The passage of the Clean Water Act set standards and allows us to regulate the source in order to maintain healthy water quality in our streams. Before the Clean Water Act, point source pollution was a major problem. Non-point on the other hand is much harder to control. The exact source is often unknown, and it is currently a bigger issue in our country’s streams than point source. Non-point includes sources such as unmaintained septic systems, domestic pet waste, fertilizers and pesticides, road salts and dirt particles.
Water is essential for life, but in recent history – the past 200 years – we humans have done a pretty good job of degrading the quality of water in our local streams. Here in the United States, we realized the problem, and though it took a battle, we were able to pass the Clean Water Act of 1972. This act of Congress has done a tremendous job in controlling point source pollution and to some extent non-point sources. Some waterways in other parts of the world have no laws protecting them. These occasionally show up as headline horror stories in our news, and hopefully make us realize just how important our laws are.
Making citizens aware of water quality issues is a first step in helping protect our waterways. Want to know how you can help? Visit our World Water Monitoring Day blog.
World Water Monitoring Day
by Ruth Mead, Sr. Environmental Educator
Happy World Water Monitoring Day – officially September 18! Wow – just what does that mean? Sounds like a day for scientist to stick lots of probes in the water and run back to the lab with lots of samples. Wait – no – they do that every day. So why do they need a special day to celebrate? World Water Monitoring Day is a day for everyone to celebrate our waterways: from the trickling brook running through the backyard to our larger waterways such as the Savannah River – the lifeblood of Augusta.
This special day was established as an international education and outreach program to build public awareness of the importance of protecting water resources around the world. In 2012, the World Water Monitoring Challenge grew out of World Water Monitoring Day and it runs from March 22 to Dec 31. This challenge educates and engages citizens in the protection of the world’s water resources by giving them the opportunity to conduct basic monitoring of their local water bodies. So why monitor? It helps us know when our streams might be in trouble. Can we swim in them, fish from them, draw drinking water from them?
Here at the Phinizy Center, every day is Water Monitoring Day! For nearly 10 years our research team has been continuously monitoring 200 miles of the Savannah River. We are now in the Ogeechee and Edisto Rivers. With our datasondes, we are able to monitor every 15 minutes – continuously. That’s a lot of data! It’s like having a movie of what’s happening in the river instead of a snapshot of one point in time. It allows us to see just what happens to the water quality over time, which helps regulators set limits and detect problems when they arrive.
Phinizy Center education gives students a chance to monitor a local stream. Through our school field trips, summer camp program, Creek Freaks, GA Master Naturalist classes and GA Adopt-A-Stream training, students become scientists, putting on waders to collect water samples and making conclusions on water quality. We feel the best way to teach about water quality issues is to get citizens involved – the same philosophy as World Water Monitoring Day!
Georgia Adopt-A-Stream (AAS) also celebrates water monitoring every day. They offer citizens the tools and training to become citizen scientists and monitor their local streams. With over 14,000 volunteers statewide, they are truly raising awareness on water quality issues in our state. Plus, the volunteers are making a difference for our streams.
What can you do? Get involved! Celebrate World Water Monitoring Day by visiting your local stream. Have a picnic by the waters, skip a rock across the surface, dip your toes in the water, and thank the stream for all it provides. Get involved – learn how you can monitor your stream, join a GA AAS training or go online for your World Water Monitoring Challenge kit. Plan a cleanup or join in on one. Phinizy Center hosts an annual River’s Alive cleanup day. This year’s event is scheduled for October 24 from 9 to 12 with a cookout following the event – and the first 100 volunteers to register will receive a free t-shirt. So what are you waiting for? Head out to your nearest stream!
The Air We Breathe, and the Water We Drink: Why Diatoms are So Important
By: Katherine M. Johnson, Phinizy Center Research Scientist
Diatoms are a type of microscopic algae that date back to the Jurassic Period. Although they photosynthesize just like plants, due to differences in cellular structure they are classified as protists! What makes them even more interesting, other than their classification and having shared the planet with dinosaurs, are their ornate cell walls. These walls are composed of silica, which is the same compound used in the production of glass. Because of this quality, diatoms are said to “live in glass houses.” Differences in these patterns allow taxonomists to identify them by species.
Photo by Chalisa Fabillar: Cymbella tumida
What most people do not realize about diatoms is just how much we may depend on them. Diatoms are considered the largest primary producers of oxygen on our planet. It is estimated that through photosynthesis, diatoms produce between 20% and 40% of the oxygen we breathe. During photosynthesis diatoms use energy from light to convert water and carbon dioxide into sugars for food. Byproducts created from this transformation include organic carbon and oxygen. This process is called carbon fixation. Some estimate diatoms to facilitate up to 25% of all organic carbon fixation occurring on Earth. This percentage is about equal to the carbon fixation by all tropical forests combined! Currently, researchers are using this information to investigate the role of diatoms in reducing greenhouse gasses.
Here at the Phinizy Center for Water Sciences (PCWS) Research Department, we are investigating the role of freshwater diatoms in aquatic ecosystems as biological indicators for ecosystem health and water quality. Diatoms serve as good bio-indicators because some species are more tolerant to pollution than others. Therefore, through collecting and sampling we can get an idea of not only species composition (which species and how many of each are present in a community), but how polluted that water may be as well. Because diatoms are at the base of the aquatic food web, their species composition could play a role in the species composition of higher trophic level organisms, like fish. With water becoming a scarce resource around the globe, this information is vital in assessing watersheds and sources of our drinking water for management protocols.
Richard Melton, Phinizy Summer Intern
The Turtle Leech
By Richard Melton, Phinizy Summer Intern
A leech is a common invertebrate closely related to the earthworm. Leeches are known for parasitizing vertebrates by sucking their blood. Here in the swamp, leeches are found in many of the bodies of water. The Smooth Turtle Leech (Placobdella parasitica) is one species that routinely occurs in the southeast. Though this is an aquatic leech, it doesn’t swim very well and actually spends most of its time either on the bottom or on the bodies of turtles. These turtles incidentally supply these leeches with a source of food through their blood and protection from the water and predators like fish which commonly eat these leeches.
A brief study conducted at Phinizy showed that nearly two thirds of the turtles caught had leeches on them. The turtles that were hosting the leeches included the Yellow-Bellied slider (Trachemys scripta scripta), common snapping turtle (Chelydra serpentina) and musk turtles (Sternotherus odoratus). Two of the turtles we surveyed, a Yellow-bellied slider and a snapping turtle, had over one hundred leeches each on them.
Turtle Marked with Notches
During this study, we also started a turtle marking system. To mark the turtles, we took a metal file and created notches in specific areas of the turtle’s shell. This doesn’t hurt the turtles and it allows us to permanently mark them so we will know if we catch them again in the future.
Phinizy Center Starts New Project to Provide Needed Information on Ecosystem Flow Requirements for the Savannah River
Photo courtesy of the US Army Corps of Engineers
River flow below Clarks Hill Lake is regulated by the United States Army Corps of Engineers at Thurmond Dam. In recent years there has been an increased effort to understand how different flows affect the ecology of the river and incorporate this information into how water is managed in the Savannah River Basin. This information is vital during drought conditions when we need to conserve water in the reservoirs but still provide enough water to protect the aquatic ecology within the river below the dam. Data from this project will help support the ongoing Savannah River Basin Comprehensive Study (Interim 2), which focuses on reservoir and river management during drought conditions.
This month, our research team will begin a new 14-month project on the Savannah River. The goal of this study is to determine how different flows in the river affect certain organisms; this will allow us to develop flow recommendations during times of drought. We will collaborate with Dr. Richard Horwitz, a fisheries expert with the Academy of Natural Sciences of Drexel University (ANSP-DU), to develop annual flow recommendations using ANSP-DU’s annual Savannah River fisheries data which dates back to 1952 and historical United States Geological Survey flow data. From this data we can determine how flows in one year affected different fish species survival and growth in subsequent years. This approach works well for long-lived species like fish, but is insufficient for making recommendations for species with shorter lifespans. As a result, we will develop monthly flow recommendations using aquatic insect production, which is simply a measure of how much insect growth occurs over a given time. Insects perform an important function in aquatic food webs by eating bacteria, algae, and dead plant material and serving as prey for other aquatic animals like fish. To measure this production, we will sample aquatic insects for 12 months to determine how long each generation lives in the water and measure growth rates for each species. We will be able to determine how flows impact these organisms and provide monthly flow recommendations from the aquatic insect data. We will collaborate with Dr. Checo Colon-Gaud at Georgia Southern University on this portion of the project.
A portion of the funding for this project was awarded to Phinizy Center for Water Sciences by the Savannah-Upper Ogeechee Water Council through a matching grant opportunity from the Georgia Environmental Protection Division’s Regional Water Plan Seed Grant program. Funds provided to Phinizy Center from Columbia County’s Water Utility Program, in support of our Savannah River research program, were used as matching funds for this grant.
Lagrangian Sampling? Application to Environmental Studies in an Ever-changing System
by Matt Erickson
Figure 1. Research scientists Matt Erickson (left) and Jason Moak (right) measure discharge using a velocimeter.
One of our poster presentations at the Georgia Water Resources Conference this year was about a research project to find the source of high bacteria counts in one of our local streams. The focus of this presentation was the unique sampling scheme we used to collect water samples called “lagrangian sampling.” Prior to the project, we had collected water samples at different places on the stream to find the place where bacteria counts were highest. We found high counts in multiple places, but no one site consistently had higher counts than all the other sites. We determined the source of bacteria was not confined to one specific location, but instead, appeared to be spread out across a large area. This is known as a “non-point source.”
Figure 2. A data sonde, suspended from a tripod, measures dye concentration in the water.
To better understand where the bacteria were coming from, we applied a lagrangian sampling approach. The basic idea is that you collect water samples from the same “packet” of water as it moves downstream. The way we do that is by adding a special dye to the creek that we can track with a measuring device. When we detect the dye downstream, we know we are seeing the same packet of water and it’s time to collect our sample. The more traditional approach would also involve taking water samples from different places in the creek, but without targeting the same packet of water. Lagrangian sampling takes a lot more time and effort, but we think the data we collect this way is far more valuable. When we take samples from a moving body of water like a stream or river, that water sample has been influenced by the conditions it experienced on its path to our location. If you sample different packets of water, they may have experienced different conditions. By sampling the same packet of water, we can compare a water sample with another from a site upstream, and know that any differences are a result of something happening between the two sample locations.
Figure 3. The amount of bacteria increases at a consistent rate as you move downstream.
Experience has shown us that bacterial counts tend be highly variable, even among samples from the same times and places. A lagrangian-style sampling approach for bacteria helped to reduce variability from confounding factors, and in this case, produced a surprising result. We found an extremely strong correlation between the amount of bacteria present and the distance downstream of each site. If there were some entry point of bacteria to the stream, you would expect to see high counts at that point, and lower counts moving further downstream. What we saw was the amount of bacteria increased at a consistent rate as you move downstream. What does that mean about the location of the source and how it’s being transported into the stream? One hypothesis is that the bacteria could be living in the stream bottom and the streambed itself is the source. There are studies in the scientific literature suggesting that bacteria can survive in sediments longer than previously thought. The bacteria in question are not necessarily pathogenic (disease-causing) themselves, but are often used as indicators of potential health hazards due to waste contamination. This would beg the question, “Are these good indicators of contamination and health risk?” The results of this study have given us new perspectives and unique insights, and in this case may have revealed more questions than answers.
Figure 4. The peak dye concentration reaches a sampling site.