OREGON STATE UNIVERSITY

environment and natural resources

Urban areas tough on fish – but Portland leads way on mitigation

CORVALLIS, Ore. – The restoration of salmon and steelhead habitat in the Pacific Northwest has focused largely on rural areas dominated by agricultural and forested lands, but researchers increasingly are looking at the impact of urban areas on the well-being of these fish.

Metropolitan areas – and even small towns – can have a major impact on the waterways carrying fish, researchers say, but many progressive cities are taking steps to mitigate these effects. The issues, policies and impacts of urban areas on salmon, steelhead and trout are the focus of a new book, “Wild Salmonids in the Urbanizing Pacific Northwest,” published by Springer.

The influx of contaminants and toxic chemicals are two of the most obvious impacts, researchers say, but urban areas can heat rivers, alter stream flows and have a number of impacts, according to Carl Schreck, a professor of fisheries and wildlife at Oregon State University and a contributing author on the book.

“One of the biggest issues with cities and towns is that they have huge areas of compacted surfaces,” Schreck pointed out. “Instead of gradually being absorbed into the water table where the ground can act as a sponge and a filter, precipitation is funneled directly into drains and then quickly finds its way into river systems.

“But urban areas can do something about it,” Schreck added, “and Portland is very avant-garde. They’ve put in permeable substrate in many areas, they’ve used pavers instead of pavement, and the city boasts a number of rain gardens, roof eco-gardens and bioswales. When it comes to looking for positive ways to improve water conditions, Portland is one of the greenest cities in the world.”

The origin of the “Wild Salmonids” book began in 1997, when the Oregon Legislature established the Independent Multidisciplinary Science Team (IMST) to address natural resource issues. In 2010, the group – co-chaired by Schreck – created a report for Oregon Gov. John Kitzhaber and the legislature that provided an in-depth look at the issues and policies affecting salmonid success in Oregon and the influence of urban areas. That report was so well-accepted by Oregon communities, the researchers wrote a book aimed at the public.

The new book, “Wild Salmonids in the Urbanizing Pacific Northwest,” is available from Springer at: http://bit.ly/J5Dn8x. Dozens of scientists contributed to the book, which was edited by Kathleen Maas-Hebner and Robert Hughes of OSU’s Department of Fisheries and Wildlife, and Alan Yeakley of Portland State University, who was senior editor.

“One of the things we’re trying to do is add the social dimension to the science,” said Kathleen Maas-Hebner, a senior research scientist and one of the editors of the book. “The science is important, but the policies and the restoration efforts of communities are a huge part of improving conditions for fish.”

Many Northwest residents are unaware of some of the everyday ways in which human activities can affect water quality and conditions, and thus fish survivability. Products from lawn fertilizers to shampoos eventually make their way into rivers and can trigger algal blooms. Even septic tanks can leach into the groundwater and contribute the byproducts of our lives.

“Fish can get caffeine, perfume and sunblock from our groundwater,” Schreck said. “The water that flows from our cities has traces of birth control pills, radiation from medical practice, medical waste, deodorants and disinfectants. We could go on all day. Suffice it to say these things are not usually good for fish.”

The most effective strategy to combat the problem may be to reduce the use of contaminants through education and awareness, and ban problematic ingredients, Maas-Hebner said.

“Phosphates, for example, are no longer used in laundry detergents,” she said. “Fertilizer and pesticide users can reduce the amounts that get into rivers simply by following application instructions; many homeowners over-apply them.”

Another hazard of urban areas is blocking fish passage through small, natural waterways. Many streams that once meandered are channeled into pipe-like waterways, and some culverts funnel water in ways that prevent fish from passing through, Schreck said.

“If the water velocity becomes too high, some fish simply can’t or won’t go through the culvert,” said Schreck, who in 2007 received the Presidential Meritorious Rank Award from the White House for his fish research.  “Some cities, including Salem, Ore., are beginning to use new and improved culverts to aid fish passage.”

Other tactics can also help. Smaller communities, including Florence, Ore., offer incentives to developers for maintaining natural vegetation along waterways, the researchers say.

Despite the mitigation efforts of many Northwest cities and towns, urban hazards are increasing for fish. One of the biggest problems, according to researchers, is that no one knows what effects the increasing number of chemicals humans create may have on fish.

“There are literally thousands of new chemical compounds being produced every year and while we may know the singular effects of a few of them, many are unknown,” Schreck said. “The mixture of these different compounds can result in a ‘chemical cocktail’ of contaminants that may have impacts beyond those that singular compounds may offer. We just don’t know.

“The research is well behind the production of these new chemicals,” Schreck added, “and that is a concern.”

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Carl Schreck, 541-737-1961; carl.schreck@oregonstate.edu; Kathy Maas-Hebner, 541-737-6105; kathleen.maas-hebner@oregonstate.edu

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DeltapondsEugene Delta Ponds, Eugene

riparianCorvallis Corvallis wetland

 

urban pollution sources

Older, wealthier Oregonians most likely to take water conservation seriously

CORVALLIS, Ore. – A survey about water use and attitudes toward conservation among Oregonians has found that older, more affluent residents are most likely to take steps to conserve water.

Contrary to some past research, the Oregon State University analysis did not find significantly more conservation behavior among younger residents, those with more education, or those who live in urban, as opposed to rural settings.

The findings, published in The Social Science Journal, outline some of the challenges policy makers may face in motivating more people to conserve water, as the state increasingly will struggle to keep up with demand in the future.

“This research showed that most Oregonians clearly understand we are going to face water shortages in the future, although most of them say they haven’t yet been affected by this,” said Erika Wolters, an instructor of political science in the OSU College of Liberal Arts, which supported this study.

“We expected to find young people more involved in water conservation, but actually found the opposite,” Wolters said. “Gender also didn’t appear to play much of a role. Water conservation was most closely associated with age and income, possibly the ability to afford water-saving devices and interest in reducing costs.

“Those with higher income may also have more time and resources to commit to the environmental causes they believe in,” she added.

The report suggested that if higher income is predictive of water conservation behavior, then efforts to motivate such behavior may need to consider discussion of rebates, incentives or other programs that would appeal to lower-income residents.

The study also concluded, however, that some water-saving practices are fairly common by many people of all ages, incomes and situations – things like washing full loads of laundry, repairing leaky faucets, watering plants less often.

Both climate change and population growth in Oregon and the West are expected to place much greater demands upon limited water supplies in the future, the report noted. And although Oregon has a reputation for being an environmentally progressive state – it was named number two in “America’s Greenest States” in one 2007 survey – it’s not as certain whether environmental attitudes will always translate directly into behavior.

This study of 808 Oregonians tried to determine what sociodemographic factors were most closely linked to water conservation behavior. It did find that most residents understand there’s a problem, and a majority of them take at least some personal steps to save water. But unlike some other research, the analysis did not find that young, female and urban residents were the ones most likely to conserve water. Only higher income was predictive of that behavior.

The research ultimately concluded that neither attitudes nor sociodemographics could completely predict environmental behavior, and that old, established habits and issues of self-identity may play a large role.

 

 

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Erika Wolters, 541-737-1421

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US Drought Monitor
Drought map


McKenzie River

Future water declines

Large study shows pollution impact on coral reefs – and offers solution

CORVALLIS, Ore. – One of the largest and longest experiments ever done to test the impact of nutrient loading on coral reefs today confirmed what scientists have long suspected – that this type of pollution from sewage, agricultural practices or other sources can lead to coral disease and bleaching.

A three-year, controlled exposure of corals to elevated levels of nitrogen and phosphorus at a study site in the Florida Keys, done from 2009-12, showed that the prevalence of disease doubled and the amount of coral bleaching, an early sign of stress, more than tripled.

However, the study also found that once the injection of pollutants was stopped, the corals were able to recover in a surprisingly short time.

“We were shocked to see the rapid increase in disease and bleaching from a level of pollution that’s fairly common in areas affected by sewage discharge, or fertilizers from agricultural or urban use,” said Rebecca Vega-Thurber, an assistant professor in the College of Science at Oregon State University.

“But what was even more surprising is that corals were able to make a strong recovery within 10 months after the nutrient enrichment was stopped,” Vega-Thurber said. “The problems disappeared. This provides real evidence that not only can nutrient overload cause coral problems, but programs to reduce or eliminate this pollution should help restore coral health. This is actually very good news.”

The findings were published today in Global Change Biology, and offer a glimmer of hope for addressing at least some of the problems that have crippled coral reefs around the world. In the Caribbean Sea, more than 80 percent of the corals have disappeared in recent decades. These reefs, which host thousands of species of fish and other marine life, are a major component of biodiversity in the tropics.

Researchers have observed for years the decline in coral reef health where sewage outflows or use of fertilizers, in either urban or agricultural areas, have caused an increase in the loading of nutrients such as nitrogen and phosphorus. But until now almost no large, long-term experiments have actually been done to pin down the impact of nutrient overloads and separate them from other possible causes of coral reef decline.

This research examined the effect of nutrient pollution on more than 1,200 corals in study plots near Key Largo, Fla., for signs of coral disease and bleaching, and removed other factors such as water depth, salinity or temperature that have complicated some previous surveys. Following regular injections of nutrients at the study sites, levels of coral disease and bleaching surged.

One disease that was particularly common was “dark spot syndrome,” found on about 50 percent of diseased individual corals. But researchers also noted that within one year after nutrient injections were stopped at the study site, the level of dark spot syndrome had receded to the same level as control study plots in which no nutrients had been injected.

The exact mechanism by which nutrient overload can affect corals is still unproven, researchers say, although there are theories. The nutrients may add pathogens, may provide the nutrients needed for existing pathogens to grow, may be directly toxic to corals and make them more vulnerable to pathogens – or some combination of these factors.

“A combination of increased stress and a higher level of pathogens is probably the mechanism that affects coral health,” Vega-Thurber said. “What’s exciting about this research is the clear experimental evidence that stopping the pollution can lead to coral recovery. A lot of people have been hoping for some news like this.

“Some of the corals left in the world are actually among the species that are most hardy,” she said. “The others are already dead. We’re desperately trying to save what’s left, and cleaning up the water may be one mechanism that has the most promise.”

Nutrient overloads can increase disease prevalence or severity on many organisms, including plants, amphibians and fish. They’ve also long been suspected in coral reef problems, along with other factors such as temperature stress, reduced fish abundance, increasing human population, and other concerns.

However, unlike factors such as global warming or human population growth, nutrient loading is something that might be more easily addressed on at least a local basis, Vega-Thurber said. Improved sewage treatment or best-management practices to minimize fertilizer runoff from agricultural or urban use might offer practical approaches to mitigate some coral reef declines, she said.

Collaborators on this research included Florida International University and the University of Florida. The work was supported by the National Science Foundation and Florida International University.

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Rebecca Vega-Thurber, 541-737-1851

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Diver doing research


Bleached coral

Diseased coral


Nutrient dispenser

Nutrient dispenser


A video interview with
Dr. Vega-Thurber is also
available online:
http://bit.ly/IdPqAt

Viruses associated with coral epidemic of “white plague”

CORVALLIS, Ore. – They call it the “white plague,” and like its black counterpart from the Middle Ages, it conjures up visions of catastrophic death, with a cause that was at first uncertain even as it led to widespread destruction – on marine corals in the Caribbean Sea.

Now one of the possible causes of this growing disease epidemic has been identified – a group of viruses that are known as small, circular, single-strand DNA (or SCSD) viruses. Researchers in the College of Science at Oregon State University say these SCSD viruses are associated with a dramatic increase in the white plague that has erupted in recent decades.

Prior to this, it had been believed that the white plague was caused primarily by bacterial pathogens. Researchers are anxious to learn more about this disease and possible ways to prevent it, because its impact on coral reef health has exploded.

“Twenty years ago you had to look pretty hard to find any occurrences of this disease, and now it’s everywhere,” said Nitzan Soffer, a doctoral student in the Department of Microbiology at OSU and lead author on a new study just published in the International Society for Microbial Ecology. “It moves fast and can wipe out a small coral colony in a few days.

“In recent years the white plague has killed 70-80 percent of some coral reefs,” Soffer said. “There are 20 or more unknown pathogens that affect corals and in the past we’ve too-often overlooked the role of viruses, which sometimes can spread very fast.”

This is one of the first studies to show viral association with a severe disease epidemic, scientists said. It was supported by the National Science Foundation.

Marine wildlife diseases are increasing in prevalence, the researchers pointed out. Reports of non-bleaching coral disease have increased more than 50 times since 1965, and are contributing to declines in coral abundance and cover.

White plague is one of the worst. It causes rapid tissue loss, affects many species of coral, and can cause partial or total colony mortality. Some, but not all types are associated with bacteria. Now it appears that viruses also play a role. Corals with white plague disease have higher viral diversity than their healthy counterparts, the study concluded.

Increasing temperatures that stress corals and make them more vulnerable may be part of the equation, because the disease often appears to be at its worst by the end of summer. Overfishing that allows more algae to grow on corals may help spread pathogens, researchers said, as can pollution caused by sewage outflows in some marine habitats.

Viral infection, by itself, does not necessarily cause major problems, the researchers noted. Many healthy corals are infected with herpes-like viruses that are persistent but not fatal, as in many other vertebrate hosts, including humans.

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Coral disease

Coral with white plague


Marine research

Taking samples

Overgrazing turning parts of Mongolian Steppe into desert

CORVALLIS, Ore. – Overgrazing by millions of sheep and goats is the primary cause of degraded land in the Mongolian Steppe, one of the largest remaining grassland ecosystems in the world, Oregon State University researchers say in a new report.

Using a new satellite-based vegetation monitoring system, researchers found that about 12 percent of the biomass has disappeared in this country that’s more than twice the size of Texas, and 70 percent of the grassland ecosystem is now considered degraded. The findings were published in Global Change Biology.

Overgrazing accounts for about 80 percent of the vegetation loss in recent years, researchers concluded, and reduced precipitation as a result of climatic change accounted for most of the rest. These combined forces have led to desertification as once-productive grasslands are overtaken by the Gobi Desert, expanding rapidly from the south.

Since 1990 livestock numbers have almost doubled to 45 million animals, caused in part by the socioeconomic changes linked to the breakup of the former Soviet Union, the report said. High unemployment led many people back to domestic herding.

The problem poses serious threats to this ecosystem, researchers say, including soil and water loss, but it may contribute to global climate change as well. Grasslands, depending on their status, can act as either a significant sink or source for atmospheric carbon dioxide.

“This is a pretty serious issue,” said Thomas Hilker, an assistant professor in the OSU College of Forestry. “Regionally, this is a huge area in which the land is being degraded and the food supply for local people is being reduced.

“Globally, however, all ecosystems have a distinct function in world climate,” he said. “Vegetation cools the landscape and plays an important role for the water and carbon balance, including greenhouse gases.”

Even though it was clear that major problems were occurring in Mongolia in the past 20 years, researchers were uncertain whether the underlying cause was overgrazing, climate change or something else. This report indicates that overgrazing is the predominant concern.

Mongolia is a semi-arid region with harsh, dry winters and warm, wet summers. About 79 percent of the country is covered by grasslands, and a huge surge in the number of grazing animals occurred during just the past decade - especially sheep and goats that cause more damage than cattle. Related research has found that heavy grazing results in much less vegetation cover and root biomass, and an increase in animal hoof impacts.

Collaborators on this research included Richard H. Waring, a distinguished professor emeritus of forest ecology from OSU; scientists from NASA and the University of Maryland; and Enkhjargal Natsagdorj, a former OSU doctoral student from Mongolia. The work has been supported by NASA and OSU.

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Thomas Hilker, 541-737-2608

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Overgrazing in Mongolia

Grazing in Mongolia


Grazing in Mongolia

Mongolian herders

Tours available on OSU research vessel to dock in Portland at end of STEM cruise

NEWPORT, Ore. – For three days this week, Oregon high school students and teachers are joining scientists at Oregon State University aboard the research vessel Oceanus to gain at-sea research experience off the Oregon coast as part of a project to enhance their STEM, or science, technology, engineering and math skills.

This Friday, the young scientists and their professional partners will journey up the Columbia River aboard the R/V Oceanus and dock at Riverplace Marina in Portland, where they will spend the weekend doing a series of activities, including tours for K-12 students and the public.

The public tours will be held from 9 a.m. to 2:30 p.m. Saturday, Sept. 17. Space is limited and advance registration is required. For more information or to register for a tour, visit: http://bit.ly/2bTKyQ0.

The project is a collaborative effort from Oregon Sea Grant and the Oregon Coast STEM Hub, which serves educators, students and communities along the Oregon coast and is located at OSU’s Hatfield Marine Science Center in Newport. The students and high school teachers participating in the cruise are from Bandon, North Bend, Waldport, Newport and Warrenton.

“This is an opportunity for Oregon high school students and teachers to work with marine researchers and really dig into investigative scientific methods,” said Tracy Crews, marine education manager for Oregon Sea Grant. “It also provides an opportunity for graduate students to work as mentors with these young students alongside top scientists addressing some very real issues facing our oceans.”

Leigh Torres, a principal investigator with OSU’s Marine Mammal Institute, will serve as chief scientist on the cruise, which will include line transect surveys for marine mammals and seabirds off the Oregon coast.

“We will record where and when we observe different species assemblages of marine mammals and seabirds off the Oregon coast, and link this data with habitat and prey data collected during the cruise,” Torres said. “This will demonstrate the patchiness of ocean resources and how species are distributed differently relative to their particular needs.”

“We’re really hoping that this hands-on experience will trigger interest in STEM and enthusiasm for working on environmental challenges,” added Stacia Fletcher, director for the Oregon Coast STEM Hub.

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Tracy Crews, 541-867-0329, tracy.crews@oregonstate.edu

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Research vessel Oceanus; photos by Pat Kight

R/V Oceanus

Oceanus004PK

When kids learn to conserve energy, their behavior also spreads to parents

CORVALLIS, Ore. – Girl Scouts and their parents reported increases in energy-saving behaviors, such as turning off power strips at night and washing clothes in cold water, after the children participated in an intervention program, according to a study published today in the journal Nature Energy.

The new energy conservation program was developed by researchers from Oregon State University and Stanford University, who designed and tested the program’s effectiveness with 30 Girl Scout troops in northern California.

The researchers found that the increased energy-saving behavior, as self-reported by the children, continued for more than seven months after the trial program ended. They also found that the intervention had an effect on parents’ energy-saving behavior for more than eight months. The findings suggests that these kinds of educational programs could have a significant and lasting impact on family energy consumption, said Hilary Boudet, an assistant professor of climate change and energy at Oregon State University and lead author of the paper.

“Children are a critical audience for environmental programs, because their current behavior likely predicts future behavior,” said Boudet, who teaches in the School of Public Policy at OSU’s College of Liberal Arts. “By adopting energy-saving behaviors now and engaging family and community members in such efforts, children can play an important role in bringing about a more sustainable future.”

The study was supported by grants from the U.S. Department of Energy’s Advanced Research Projects Agency – Energy Program, the California Energy Commission, the Child Health Research Institute and the Precourt Energy Efficiency Center. Co-authors of the study are Nicole Ardoin, June Flora, K. Carrie Armel, Manisha Desai and Thomas N. Robinson of Stanford University.

The researchers set out to develop a new energy conservation intervention program for children, using best practices from social cognitive theory and public health interventions to guide the program’s design.
 
“The goal of the program was to get the girls actively practicing and mastering the skills, and modeling the behaviors that would lead to reduced energy use,” Boudet said. “But we also recognized the importance of making the project fun and engaging.”
 
The program, called Girls Learning Environment and Energy, or GLEE, offered two interventions designed to promote energy-saving behaviors either at home or in food and transportation decisions. Using a randomized control trial, the 318 participating girls, all fourth- and fifth-graders, were randomly assigned to one of the programs.
 
In 50- to 60-minute lessons once a week for five weeks, the Girl Scouts learned about different ways to save energy in their assigned intervention group and participated in activities designed to support the lessons.
 
The girls and their parents completed surveys about their energy-saving behaviors in those areas at the beginning and end of the five-week program and again several months later.
 
The study’s authors estimate that the reported behavior changes associated with the home energy savings intervention represent an annual household energy savings of approximately 3-5 percent immediately following the intervention and 1-3 percent at follow-up. If magnified across the population, those savings become quite significant, Boudet said.
 
Girls participating in the food and transportation intervention also reported a significant increase in energy-saving behavior at the end of the program, but there was no significant change noted at the seven-month follow-up or among parents.
 
Boudet said the food and transportation program may have proved more challenging for the children, in part, because they have less control over the types of transportation used by their families or the types of food their families buy and eat. Additional study could help researchers understand which pieces of the program worked best and which could be improved, she said.
 
Based on GLEE’s initial success, researchers are working to disseminate the curriculum to Girl Scout leaders around the country. They are also hoping to adapt the program for other groups, including schools and youth-focused organizations such as 4-H. More information is available online at  https://sites.stanford.edu/glee/.

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Hilary Boudet, 541-737-5375, hilary.boudet@oregonstate.edu

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Girl Scouts participate in the Girls Learning Environment and Energy program, or GLEE. Credit: Oregon State University

GLEE

GLEE

Hydropeaking of river water levels is disrupting insect survival, river ecosystems

CORVALLIS, Ore. – A group of researchers concluded today in a study in the journal BioScience that “hydropeaking” of water flows on many rivers in the West has a devastating impact on aquatic insect abundance.

The research was based in part on a huge citizen science project with more than 2,500 samples taken on the Colorado River in the Grand Canyon, and collaboration of researchers from the U.S. Geological Survey, Oregon State University, Utah State University and Idaho State University. 

It raises serious questions about the current practice of raising river volumes up and down every day – known as hydropeaking – to meet hour-by-hour electricity demand, which has nearly wiped out local populations of some insects that feed local river ecosystems.

“Insects have evolved to live with occasional extreme floods and droughts, and gradual or seasonal changes in river levels,” said David Lytle, a professor of integrative biology in the OSU College of Science. 

“These large daily rises and peaks in river flows due to hydropower dams are not normal. Prior to the construction of dams, there were almost no major daily changes in river levels. This can interrupt the egg-laying practices of some species, and the impact of this is poorly appreciated. Until now no one really looked at this, and it’s a serious problem.”

Hydropeaking is used around the world and is particularly common with hydropower dams in the American West. Rivers are some of the most extensively altered ecosystems on Earth, the researchers wrote in their study, and more than 800,000 dams exist globally. Hydropower provides 19 percent of the world’s electricity supply and far exceeds the generation of all other renewable sources combined. 

Lytle is a national expert on how organisms and communities are shaped by disturbances such as floods, droughts, and dams, with much of his research focused on aquatic insects. Hydropower dams, in this case, have a particular impact on insects that lay their eggs near the shore of streams, such as a mayfly, stonefly or caddis fly. Given normal water conditions, the eggs are laid slightly below the water surface and soon hatch. But if the water level drops suddenly, they can be stranded, dry out and die before hatching.

In this study, the researchers found a clear correlation between hydropeaking and the number of insect species present, and an almost complete absence of certain insects in some parts of rivers where they should have been present – including the Colorado River downstream of Glen Canyon and Hoover Dams. A majority of aquatic insects are vulnerable to this phenomenon, the scientists said in their report, and they can be “subject to acute mortality.” 

Some of these insects, Lytle said, are the food base for fish, birds, bats, and other wildlife.

“The loss of these aquatic insects can have a major impact on fisheries and other aspects of ecosystem health,” Lytle said. 

The researchers did point out in their study that one possible way to address the problem might be to leave river levels stable for several days at a time – possibly on weekends when electricity demands did not vary as much – so that insects could lay their eggs with success. This might help address but not totally solve the problem, Lytle said.

It’s been known that dams can impose serious environmental problems, including alterations of flow, temperature, sediment regimes and migratory fish barriers. However, the researchers called the impact of dams on aquatic insects a “hitherto unrecognized life history bottleneck.”

“For the first time, this study determines the ecological impacts of hydropeaking separated from other dam-imposed stressors, and identifies the specific cause-and-effect relationships responsible for biodiversity loss below hydroelectric dams,” said Ted Kennedy, a USGS scientist and lead author of the study. “These results may help resource managers improve river health while still meeting societal needs for renewable hydroelectricity.”

Funding for this study was provided by the Bureau of Reclamation’s Glen Canyon Dam Adaptive Management Program, the U.S. Geological Survey’s Southwest Biological Science Center, and the Department of Energy’s Western Area Power Administration.

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Coal-tar based sealcoats on driveways, parking lots far more toxic than suspected

CORVALLIS, Ore. – The pavement sealcoat products used widely around the nation on thousands of asphalt driveways and parking lots are significantly more toxic and mutagenic than previously suspected, according to a new paper published this week by researchers from Oregon State University.

Of particular concern are the sealcoat products based on use of coal tar emulsions, experts say. Studies done with zebrafish – an animal model that closely resembles human reaction to toxic chemicals – showed developmental toxicity to embryos. 

Sealcoats are products often sprayed or brushed on asphalt pavements to improve their appearance and extend their lifespan. Products based on coal tar are most commonly used east of the U.S. continental divide, and those based on asphalt most common west of the divide.

The primary concern in sealcoats are polycyclic aromatic hydrocarbons, or PAHs, which are common products of any type of combustion, and have been shown to be toxic to birds, fish, amphibians, plants and mammals, including humans. 

There are many different types of PAHs. This study was able to examine the presence and biologic activity of a much greater number of them in sealcoats than has been done in any previous research. The OSU program studying PAHs is one of the most advanced of its type in the world, and can identify and analyze more than 150 types of PAH compounds.

It found some PAHs in coal tar sealcoats that were 30 times more toxic than one of the most common PAH compounds that was studied previously in these products by the U.S. Geological Survey. 

The OSU study also showed that new PAH compounds found in coal tar sealcoats had a carcinogenic risk that was 4 percent to 40 percent higher than any study had previously showed. Among the worst offenders were a group of 11 “high molecular weight” PAH derivative compounds, of which no analysis had previously been reported.

By contrast, the study showed that sealcoats based on asphalt, more commonly used in the West, were still toxic, but far less than those based on coal tar. Use of coal tar sealcoats, which are a byproduct of the coal coking process, is most common in the Midwest and East. 

The research was reported this week in Environmental Science and Technology Letters, in work supported by the National Institute of Environmental Health Science’s Superfund Research Program, and done by researchers in the OSU College of Agricultural Sciences and OSU College of Science.

“Our study is consistent with previous findings made by the USGS,” said Staci Simonich, a professor with appointments in OSU’s departments of Environmental and Molecular Toxicology and Chemistry. “But we were able to study a much wider number of PAH compounds than they did. As a result, we found even higher levels of toxicity in coal-tar based sealcoats than has previously been suspected.” 

“This should assist individuals and municipalities to make more informed decisions about the use of sealcoats and weigh their potential health risks against the benefits of these products,” said Simonich, the corresponding author on the study. “And if a decision is made to use sealcoats, we concluded that the products based on asphalt are significantly less toxic than those based on coal tar.”

The previous research done by the USGS about the potential health risks of sealcoat products has been controversial, with some industry groups arguing that the federal government agency overstated the risks. The new OSU study indicates that previous research has, if anything, understated the risks. 

A 2011 report from the USGS outlined how PAH compounds from sealcoat products can find their way into soils, storm waters, ponds, streams, lakes, and even house dust, as the compounds are tracked by foot, abraded by car tires, washed by rain and volatilize into the air. They reported that the house dust in residences adjacent to pavement that had been treated with a coal tar-based sealcoat had PAH concentrations 25 times higher than those normally found in house dust.

Some states and many municipalities around the nation have already banned the use of coal tar-based sealcoats, due to the human, wildlife and environmental health concerns. In the European Union, use of coal tar-based sealcoats is limited or banned.

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Staci Simonich, 541-737-9194 or staci.simonich@oregonstate.edu

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Researcher Staci Simonich

Staci Simonich, OSU professor

OSU lecture to explore the 'Lost City' and ocean research

CORVALLIS, Ore. – A veteran of more than 50 dives to the ocean floor in the submersible Alvin will describe in a lecture at Oregon State University a remarkable new underwater warm spring system she discovered.

Deborah Kelley’s find, dubbed “Lost City,” is the focus of the annual Hydrothermal Vent Discovery Lecture, hosted by OSU’s College of Earth, Ocean, and Atmospheric Sciences. This free public talk will begin at 4 p.m. on Friday, April 1, in OSU’s Gilfillan Auditorium.

In 2000, Kelley discovered a new kind of seafloor hot spring vent in the Atlantic Ocean, with huge limestone spires hosting a novel assemblage of organisms.

“This astounding vent system, ‘Lost City,’ possesses a unique chemistry which supports a novel ecosystem,” said OSU oceanographer Robert Collier, one of the organizers of the lectures.

“This discovery vastly expands the regions of the seafloor still to be explored for hydrothermal vents," added OSU oceanographer Martin Fisk, another organizer of the events. 

Kelley is a marine geologist whose dives in the Alvin probe the ocean to a depth of 4,000 meters, or more than 13,000 feet. The hot springs at these vent sites can reach temperatures of more than 680 degrees Fahrenheit. 

She also will give a seminar on Thursday, March 31, at noon in Burt Hall Room 193 on research opportunities using the Cabled Observatory off the Oregon coast – part of the National Science Foundation-funded Ocean Observatories Initiative. OSU is one of the leaders on the project.

The lecture series celebrates the discovery of hydrothermal vents and their ecosystems on mid-ocean ridges in 1977 by a research team that included OSU scientists. Since that initial discovery, more than 300 vent fields have been explored.

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Martin Fisk, 541-737-5208, mfisk@coas.oregonstate.edu