Atlantic Archipelagos Research Consortium
Digital Humanities at The University of Georgia
Scientists have found that the amount of vegetation along the Georgia coast has declined significantly in the last 30 years, spurring concerns about the overall health of marshland ecosystems in the area.
Sweetgum trees thrive under diverse conditions, grow as fast as pine trees and provide the type of fiber needed for specialty papers-and they’ve long been desired by paper and bioenergy producers.
A contaminant known as Aroclor 1268—composed of a suite of toxic chemical compounds that include polychlorinated biphenyls—has spread beyond the site of a former chemical plant near Brunswick, Ga., according to researchers at UGA’s Savannah River Ecology Laboratory.
Gary Mills, a biogeochemist at SREL and an adjunct associate professor of geology, used advanced analytical tools to detect the individual chemical components of Aroclor 1268 in egg and tissue samples of least terns, a species of short-range migratory seabirds.
Tissue samples taken from the local least terns contained enough Aroclor 1268 to cause a number of adverse effects, including lower egg production, physical abnormalities and immune-system disorders in their offspring.
The Aroclor 1268 was used to produce insulation materials at a Linden Chemical plant, now closed, which has been designated a Superfund site by the federal government. And “because its only use in the Southeast was at the Linden plant, we know this is the original source of the contaminant,” Mills said.
This is the first study to investigate the presence of Aroclor 1268 in fish-eating birds, said the study’s senior investigator Sonia M. Hernandez, associate professor at the Warnell School of Forestry and Natural Resources and a member of the Southeastern Cooperative Wildlife Disease Study.
The study sites ranged from 68 miles north of the Linden plant to Savannah to 43 miles south, near Kingsland and Cumberland Island.
Given their findings, the researchers are concerned about the population risk to the least tern and the potential transmission of the toxic materials to predator and scavenger species, Hernandez said.
The rapid emergence of antibiotic-resistant bacteria has prompted the medical community, nonprofit organizations, public health officials and the national media to alert the public to the dangers of overusing antibiotics. But although this effort is necessary, it may not be sufficient. UGA researchers are concerned that there’s more to the problem than the misapplication of certain prescription drugs.
J. Vaun McArthur, senior research ecologist at the Savannah River Ecology Laboratory and Odum School of Ecology, believes that other environmental contaminants may also be to blame for the general rise in bacterial resistance, and he tested this hypothesis in streams within the U.S. Department of Energy’s Savannah River Site near Aiken, South Carolina.
To test five antibiotics on 427 strains of E. coli bacteria in nine streams, his research team collected water and sediment samples from 11 locations. The results revealed high levels of antibiotic resistance in eight of them.
“Because the site was constructed and closed to the public before antibiotics were used in medical practices and agriculture,” McArthur said, “the streams have no source of antibiotic input.” So the researchers suspect that the high levels of antibiotic resistance in the samples are due to environmental contaminants such as cadmium and mercury in these streams.
“The findings of this study may very well explain why resistant bacteria are so widely distributed,” he noted.
The use of chemical dispersants to help clean up after maritime crude-oil spills may actually be inferior to just letting nature do its thing, according to a new study led by UGA marine scientists.
Based on laboratory-simulated conditions that mimicked conditions in Gulf of Mexico waters immediately following the 2010 Deepwater Horizon oil spill, the researchers found that dispersants, meant to stimulate certain microorganisms that degrade hydrocarbons, also retard other populations of naturally occurring oil-degrading microbes.
Chemical dispersants were applied in unprecedented volume to the sea surface and deep waters of the Gulf of Mexico after the 2010 spill, which released more than 750 million liters of oil into the Gulf.
In response, some 7 million liters of chemical dispersants, known to promote the growth of oil-degrading Colwellia microorganisms, were added to the Deepwater Horizon plume.
But by thus favoring Colwellia, the dispersants significantly altered the microbial composition of Gulf deep water. “The naturally occurring communities of oil-degrading microorganisms, especially Marinobacter, are quite proficient at degrading oil,” said the study’s lead author Samantha Joye, Georgia Athletic Association Professor of Arts and Sciences.
Yet “during the spill, Marinobacter were not abundant in deep water plume samples, possibly as a consequence of dispersant applications,” according to coauthor Sara Kleindienst, junior group leader at the University of Tübingen in Germany.
Indeed, “compelling results [from our simulations] show that oil biodegradation is more efficient in the absence of chemical dispersants,” said Joye.
In other words, dispersion of the oil spilled in the Gulf might have been faster and more extensive if chemical dispersants had not been added. What remains is to determine just how the intervention inhibited the Marinobacter.
Said Kleindienst: “Whether natural hydrocarbon degraders were outcompeted by dispersant degraders or whether they were directly affected by dispersant-derived compounds needs to be resolved in future studies.”
This research was supported by the Ecosystem Impact of Oil and Gas Inputs to the Gulf (ECOGIG) research consortium, which is funded by the Gulf of Mexico Research Initiative.
For more information about the project, visit ecogig.org.
If environmentalists want to protect fragile ecosystems from developers—in the United States and around the globe—they should team up with ecotourists, according to a recent UGA study.
Environmentalists often fear that tourists will trample sensitive natural resource areas, but tourism may in fact bring the needed economic incentives to help drive conservation, said Bynum Boley, assistant professor of natural resources recreation and tourism at UGA’s Warnell School of Forestry and Natural Resources.
In their paper, coauthors Boley and Gary Green—associate professor of natural resources, recreation, and tourism at the Warnell School—maintain that despite past tensions between the tourism industry and environmentalists, the two groups should form alliances to fight the development of virgin territory. In fact, ecotourists often provide a boost to the local economy and also motivate landowners and governments to preserve their land in its natural state.
Too often, Boley and Green said, decision makers convert unique natural resource areas into industrial, agricultural or residential developments without having considered their ecotourism potential. In addition to the lost tourism revenue, there are a host of negative environmental consequences,
including reduced biodiversity, water and food shortages and the land’s inability to help mitigate the effects of climate change. When these areas are not valued for their ecotourism potential or for the valuable ecosystem services they provide, said Green, “we lose them.”
Tourists have historically been seen as having a negative impact on the environment. Critics complain that they violate fragile and threatened natural environments while contributing to greenhouse gases from the increased number of flights to these exotic and often remote locales.
But responsible programs on ecological conservation and environmental sustainability can foster a greater appreciation of these areas, said Green. And “although ecotourism has its pitfalls, environmentalists may have no other choice but to work with the tourism industry to protect these key ecosystems.”
Boley and Green have proposed a new model where researchers consider how much money tourists bring to a region via ecotourism when calculating the value of its ecosystems. They also suggest that leaders in these destinations increasingly aim their marketing efforts at responsible ecotourists in order to attract these types of travelers.
Vibrio can cause serious illness in humans and other marine organisms.
A team of researchers led by faculty at the University of Georgia has discovered the fate of much of the freshwater that pours into the surrounding oceans as the Greenland ice sheet melts every summer.
A new reef system has been found at the mouth of the Amazon River, the largest river by discharge of water in the world.
While humans are now scarce in the Chernobyl Exclusion Zone, continued studies—including a just-published camera study conducted by researchers from the University of Georgia’s Savannah River Ecology Laboratory—validate findings that wildlife populations are abundant at the site.
UGA Researchers warn that the extinction of two amphibian species may be hastened by the combined effects of climate change and copper-contaminated wetlands.
Researchers from UGA’s Warnell School of Forestry and Natural Resources found that where landowners cut down the forests that bordered streams—turning them into pastures or lawns—the structure and even the amount of aquatic habitat changes dramatically.
By Sandi Martin
If environmentalists want to protect fragile ecosytems from landing in the hands of developers—in the U.S. and around the globe—they should team up with ecotourists, according to a University of Georgia study published in the Journal of Ecotourism.
Environmentalists often fear that tourists will trample all over sensitive natural resource areas, but tourism may bring the needed and only economic incentives to help drive conservation, said study co-author Bynum Boley, an assistant professor in UGA’s Warnell School of Forestry and Natural Resources. Ecotourism and natural resource conservation already have a mutually beneficial relationship that is ideal for creating a sustainable partnership.
“Ecotourism destinations benefit in the form of enhanced tourism competitiveness from the protection of quality natural resources,” he said. “Meanwhile, the conservation of these natural resources is increasingly valued since these pristine natural resources are the foundation of the ecotourism industry and the driver of all economic benefits associated with ecotourism.”
Tourism is a $7.6 trillion global industry, provides 277 million jobs and is a primary income source for 20 of the world’s 48 least-developed countries, according to the World Travel and Tourism Council. It also subsidizes environmental protection and helps protect, conserve and value cultural resources that might otherwise be undervalued by the host community, Boley said.
In the new paper, Boley and co-author Gary Green, an associate professor also in the Warnell School, said that despite past tension between the tourism industry and environmentalists, the two should team up as allies to fight off increasing conversion of land away from its natural state.
Ecotourists not only provide a boost to the economy in such places, they can also motivate landowners into keeping the environment in its natural state instead of converting it into something unsustainable. They could also influence the public perception of conservation, Boley explained, which does not often favor environmental protection.
“The public has become increasing less prone to respond to environmental messages,” he said. “Economic messages are needed in order to attract the public’s interest.”
Too often, Boley and Green said, unique natural resource areas are converted into urban, suburban and agricultural developments without considering their ecotourism potential. In addition to the lost ecotourism revenue, there are a host of negative environmental consequences such as biodiversity loss, water and food shortages and the land being unable to mitigate the effects of climate change. These areas are not valued for their unique attributes or the valuable natural resources they provide, Green said, “so we lose them.”
Tourists have historically been seen as having a negative impact on the environment. Critics complain that they violate fragile and threatened natural environments while contributing to greenhouse gases from the increased number of flights to these exotic and often remote locales.
While these criticisms are justified, Boley and Green said responsible programs promote education of ecological conservation and environmental sustainability, fostering a greater understanding and appreciation of these exotic areas.
“Although ecotourism has its downfalls, environmentalists may have no other choice but to work with the tourism industry to protect key ecosystems,” Green said.
Boley and Green argue that ecotourists should be considered an ally to the environment and outline what they call a symbiotic relationship where an increase in conservation leads to ecotourism competitiveness.
“The health of an ecotourism destination and the health of its ecosystem go hand-in-hand because they coalesce to place a higher economic value on natural landscapes than would be represented through converting that land to other uses,” Boley said.
Boley and Green have proposed a new model where researchers consider how much money tourists bring to a region via ecotourism when calculating the value of that ecosystem, precisely because of this symbiotic relationship. They also suggest that managers of these destinations should begin tailoring their marketing toward responsible ecotourists to draw these travelers-and their money-there.
It’s also important to increase public awareness of the effects ecotourism has on protecting fragile ecosystems, Boley said.
“A key point is that there is the potential for this type of symbiotic, mutually beneficial relationship,” he said. “The success of this relationship between ecotourism and natural resource conservation hinges on the ability to strike a balance between tourism development and resource protection, and the ability for those in control to take a long-term view of success where cumulative profits, resident quality of life and ecosystem health are valued over short-term economic gains.”
The study, “Ecotourism and natural resource conservation: The ‘potential’ for a sustainable symbiotic relationship,” is available online athttp://www.tandfonline.com/doi/abs/10.1080/14724049.2015.1094080?journalCode=reco20.
By Alan Flurry
The billions of marine microorganisms present in every liter of seawater represent a structured ecological community that regulates how the Earth functions in practically every way, from energy consumption to respiration. As inhabitants of the largest environment on Earth, microbial marine systems drive changes in every global system.
The function and behavior of this community will determine how the global ocean responds to broader environmental changes, according to a new review article published in the journal Science by University of Georgia marine scientist Mary Ann Moran.
The ocean microbiome covers the majority of the Earth’s surface, extending an average of more than 2 miles deep to the sea floor. Made up of an extraordinary diversity of microorganisms, the ocean microbiome was one of the first microbiomes to be studied. As its distribution and makeup become better understood, questions about its functional capabilities under stress have grown.
“Marine microbes make up a vast biological network,” said Moran, a Distinguished Research Professor in the UGA Franklin College of Arts and Sciences. “Microbes are responsible for virtually all the photosynthesis that occurs in the ocean, as well as the cycling of carbon, nitrogen, phosphorus and other nutrients and trace elements. They literally run the oceans.”
The article recounts the history of investigations into the microbial communities that populate the ocean—and, critically, help supply a large proportion of the oxygen in the atmosphere.
“A consistent link is emerging between ocean temperature and both the composition and productivity of microbes inhabiting surface seawater,” she wrote in Science. “Earth’s changing climate will affect characteristics of the ocean microbiome.”
Moran explains that, by the mid-1970s, the idea that microorganisms are the major consumers of energy in the sea had been formally articulated and a new paradigm established that this community played a role in every one of the Earth’s major elemental cycles.
Microbes interact as communities; they respond to disturbances in their surroundings and populations shift and change as their environments are altered. Even as improved technological and data management capabilities have provided a means to greater understanding of the communities’ cells, proteins, genes and molecules, linking these constituent parts with their functions remains a challenge.
“Improved understanding of the function of microbiomes is crucial, not only in the ocean but in systems as varied as the human body, agricultural soils and groundwater,” Moran said. “The next decade will bring a period of rapid learning about how microbes communicate, redistribute materials and regulate activities that have implications for environmental integrity and human health.”
By Alan Flurry
The use of chemical dispersants meant to stimulate microbial crude oil degradation can in some cases inhibit the microorganisms that naturally degrade hydrocarbons, according to a new study led by University of Georgia marine scientists. Their findings are based on laboratory-simulated conditions that mimic Gulf of Mexico deep waters immediately following the Deepwater Horizon oil spill.
The study, published in the Proceedings of the National Academy of Sciences, examined microbial oil degradation in the Deepwater plume, simulating oil concentrations and dispersants concentrations observed during the incident. The team found that the presence of dispersants significantly altered the microbial composition of Gulf deep water by promoting the growth of Colwellia, a group of microorganisms capable of dispersant degradation.
However, when oil alone was added to parallel samples in the absence of chemical dispersants, the growth of natural hydrocarbon-degrading Marinobacter was stimulated.
“These compelling results show the naturally occurring communities of oil-degrading microorganisms, especially Marinobacter, are quite proficient at degrading oil and that oil biodegradation was more efficient in the absence of chemical dispersants,” said the study’s lead author Samantha Joye, Georgia Athletic Association Professor of Arts and Sciences.
“During the spill, Marinobacter were not abundant in deep-water plume samples, possibly as a consequence of dispersant applications,” said study co-author Sara Kleindienst, junior group leader at the University of Tübingen in Germany. “Whether natural hydrocarbon degraders were outcompeted by dispersant degraders or whether they were directly affected by dispersant-derived compounds needs to be resolved in future studies.”
Widely used in emergency responses to oil spills in marine environments as a means of stimulating microbial degradation of oil, chemical dispersants were applied in an unprecedented volume to the sea surface and deep waters of the Gulf of Mexico after the 2010 spill. As a “first line of defense,” 7 million liters (about 1.8 million gallons) of chemical dispersants were applied to increase the use and breakdown of oil compounds by microorganisms.
The uncontrolled oil well blowout released more than 750 million liters of oil into the Gulf.
“Our results showed preferential degradation and enrichment of distinct organic compounds when dispersant is used to chemically break up oil,” said study co-author Patricia Medeiros, an assistant professor of marine sciences at UGA. “In the future, it will be important to further study these compounds and possibly include them when tracking the fate of oil-dispersant mixtures in the environment.”
The study addresses fundamental questions about the use of chemical dispersants and how they affect both the oil discharge from accidents and the indigenous microbial community. This comprehensive data set, including direct measurements of oil biodegradation rates, raises concerns about whether chemical dispersants stimulate microbial oil degradation in the ocean.
“The fact that dispersants drove distinct microbial community shifts that impacted oil degradation efficiently came as a big surprise,” Joye said. “It is critical to quantify the factors that influence the efficiency of oil biodegradation in the environment, and that includes dispersants.”
This research was supported by the Ecosystem Impact of Oil and Gas Inputs to the Gulf (ECOGIG) research consortium, which is funded by the Gulf of Mexico Research Initiative.
“This research was made possible through the interdisciplinary collaborative network that a program like ECOGIG creates,” Joye said. “This team effort allowed us to make critical progress toward identifying and understanding how dispersants impact microbial hydrocarbon degradation in the oceans, including the potential role of dispersants in facilitating the formation and sedimentation of microbially derived ‘marine oil snow.'”
More information on ECOGIG is available at https://ecogig.org/.
