OREGON STATE UNIVERSITY

environment and natural resources

Bacteria discovery offers possible new means of controlling crop pest

CORVALLIS, Ore. – A bacterium common in insects has been discovered in a plant-parasitic roundworm, opening up the possibility of a new, environmentally friendly way of controlling the crop-damaging pest.

The worm, Pratylenchus penetrans, is one of the “lesion nematodes” -- microscopic animals that deploy their mouths like syringes to extract nutrients from the roots of plants, damaging them in the process. This particular nematode uses more than 150 species as hosts, including mint, raspberry, lily and potato.

The newly discovered bacterium is a strain in the genus Wolbachia, one of the world’s most widespread endosymbionts – organisms that live within other organisms. Wolbachia is present in roughly 60 percent of the globe’s arthropods, among them insects, spiders and crustaceans, and also lives in nematodes that cause illness in humans.

Postdoctoral scholar Amanda Brown in the Oregon State University Department of Integrative Biology was the lead author on the study, and recently accepted an assistant professor position at Texas Tech. Findings were published in the journal Scientific Reports.

Depending on the host species, Wolbachia can be an obligate mutualist – the bacteria and the host need each other for survival – or a reproductive parasite that manipulates the host’s reproductive outcomes in ways that harm the host and benefit the bacteria. Parasitic Wolbachia can cause its host populations to heavily skew toward female.

In the case of the crop-pest nematode, Pratylenchus penetrans, that Brown and her colleagues studied, the bacteria-host relationship appears to not be one of obligate mutualism – many examples of non-infected worms have been found, meaning the worm doesn’t rely on Wolbachia to survive.

But more study is needed to determine the exact nature of the relationship, said Dee Denver, an associate professor in the Department of Integrative Biology in the College of Science.

Whatever the relationship, simply discovering Wolbachia in Pratylenchus penetrans opens up the potential for managing the roundworm’s population via biocontrol rather than environment-damaging fumigants, such as methyl bromide, that are being phased out by the U.S. Environmental Protection Agency.

“We can use what’s already infecting them against them,” Denver said.

Nematode biocontrol would involve releasing Wolbachia-infected worms into farm fields whose worm populations weren’t infected. From there, a couple of situations, both favorable to the crops, might arise:

  •  The bacterium could hinder the worms’ ability to reproduce;
  •  It also might force the worm to devote energy to dealing with the bacterium, effectively distracting it from being as damaging to the crops as it otherwise would be.

Wolbachia is already being used as a biocontrol strategy in Colombia and Brazil, where infected mosquitoes are being released in an effort to control the Zika, dengue and malaria viruses. Mosquitoes are a vector for those diseases, but Wolbachia-infected mosquitoes pass the bacteria to their offspring, who lose their ability to transmit the diseases. Wolbachia also can interfere with the mosquitoes’ ability to reproduce at all.

“We can see where all of that goes and learn from it to help our decision making on how the strategy might get deployed to control the population of plant-parasitic nematodes,” Denver said. “One big thing with nematodes is the load. Many crops have some, but once you get above certain thresholds, fields go down and there are economic losses.”

In addition to the potential for an environmentally safe way to deal with a crop pest, the research is noteworthy for providing genomic evidence that nematodes, not arthropods, were the original Wolbachia hosts. The strain that OSU researchers discovered – known as wPpe – proved to be the earliest diverging Wolbachia, meaning the bacteria adapted to arthropods and then later evolved to reinvade nematodes.

“Were they originally reproductive parasites or play-nice mutualists?” Dee said. “These are outside the range of better-studied Wolbachia, so we don’t know, but we have preliminary data and we think they’re reproductive parasites.”

Another unanswered question: How widespread is Wolbachia among plant-parasitic nematodes?

“There are thousands of nematode species infecting plants,” Denver said. “Wolbachia has always been thought of as an arthropod thing, an insect thing. It was kind of a serendipitous discovery for us. We were sequencing genomes from nematodes for the purpose of understanding nematodes, and the mapping went to Wolbachia.”

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Steve Lundeberg, 541-737-4039

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Pratylenchus penetrans

Pratylenchus penetrans

The golden drool: Study finds treasure trove of info in saliva of foraging bears

CORVALLIS, Ore. – The rivers and streams of Alaska are littered in the summer and fall with carcasses of tens of thousands of salmon that not only provide a smorgasbord for hungry brown bears but are also the newest database in the arsenal of wildlife biologists.

A new study, published this week in the journal PLOS ONE, documents the ability of researchers to gather DNA from residual saliva on partially consumed salmon to the point that they can even identify individual bears from the genetic samples. The discovery should provide a significant boost to research on the population and health of brown bears, which can grow to a size of 1,500 pounds. 

“In the past, population estimates have been largely based on visual observations and on the analysis of fecal samples,” said Taal Levi, an assistant professor of fisheries and wildlife at Oregon State University and co-author on the study. “We found that using bear saliva is not only easier and cheaper as a research tool, it is more effective.”

In their study, the researchers examined 156 partially consumed salmon carcasses of lakeshore-spawning sockeye salmon in the Chilkoot watershed and stream-spawning chum salmon at Herman Creek in the Klehini watershed – both near Haines, Alaska. They also swabbed a total of 272 brown bear “scats,” or fecal samples, from those same locations. 

They found that the saliva collected from the salmon carcasses delivered a higher rate of genotyping success, allowing the researchers to identify individual bears more accurately and quickly than the fecal samples, and required significantly less labor.

“Bears love salmon because they are such a rich food source, and fortunately for us, the way they consume them lends itself to genetic monitoring,” said the study’s lead author, Rachel Wheat, who conducted the research as part of her doctoral dissertation at the University of California, Santa Cruz. 

“When salmon are plentiful, bears rarely eat the entire fish. In some cases, they only eat the brain, and we’ve found that swabbing along the edges of the braincase gives us the best results for extracting DNA,” Wheat said. “We also had success with swabbing inside distinct bite holes, and in the muscle tissue where the bears have stripped the skin off the salmon.”

The researchers were able to get brown bear genotypes for 55 percent of all the salmon carcasses sampled for saliva, compared to 34 percent for the scat samples. 

From a purely cost-savings perspective, the saliva sampling proved cheaper. It costs the researchers roughly $370 per bear to genetically identify individual animals using scat samples; the cost with saliva samples dropped to $118.

“This advance will help allow us to more effectively – and more economically – study one of the largest bears on the planet,” Wheat said. 

Levi agreed and also noted that the method does not have to be restricted to bear research. It could be adapted to other species, as well.

 “Many predators leave saliva on food remains,” he said. “We feel this type of saliva sampling could become an important tool for wildlife population monitoring.”

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Taal Levi, 541-737-4067, taal.levi@oregonstate.edu; Rachel Wheat, 719-439-3397, r.e.wheat@gmail.com

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Bear with salmon (Photo by Jennifer Allen)

Bear with salmon

Chum salmon (Photo by Rachel Wheat)

Chum salmon

Kelp forests globally resilient, but may need local solutions to environmental threats

CORVALLIS, Ore. – The first global assessment of marine kelp ecosystems shows that these critically-important habitats have exhibited a surprising resilience to environmental impacts over the past 50 years, but they have a wide variability in long-term responses that will call for regional management efforts to help protect their health in the future.

The findings were published today in Proceedings of the National Academy of Sciences.

Scientists noted that kelp forests have a remarkable ability to recover quickly from extreme damage, but they can still be overwhelmed in some instances by the combination of global and local pressures.

This points to the need for regional management efforts that carefully consider local conditions when trying to offset human-caused impacts from climate change, overfishing and direct harvests, researchers said.

Kelp forests, the largest species of algae in shallow, coastal waters almost everywhere except the tropics, are a globally important foundation species that occupy almost half of the world’s marine ecoregions. Often harvested directly, they help support commercial fisheries, nutrient cycling, shoreline protection, and are valued in the range of billions of dollars annually.

The new research was conducted by an international team of 37 scientists who analyzed changes in kelp abundance in 34 regions of the planet that had been monitored over the past 50 years.

“Kelp forests are cold-water, fast-growing species that can apparently withstand many types of environmental disturbances,” said Mark Novak, an assistant professor of integrative biology in the College of Science at Oregon State University, co-author of the study, and an organizer of the international group at the National Center for Ecological Analysis and Synthesis that conducted this research.

“The really surprising thing in this study was how much region-to-region variation we found, which is quite different from many other ecosystems. Thus, despite global threats like climate change and ocean acidification, the battle to protect our kelp forests of the future may best be fought locally – in the U.S., by states, counties, even individual cities and towns.”

These forests can grow fast, tall, and are highly resilient – but also are often on the coastal front line in exposure to pollution, sedimentation, invasive species, fishing, recreation and harvesting. Even though “they have some of the fastest growth rates of any primary producer on the planet,” the researchers wrote, there are limits to what they can take.

In their study the scientists concluded that of the kelp ecosystems that have been studied, 38 percent are in decline; 27 percent are increasing; and 35 percent show no detectable change. On a global scale, they are declining at 1.8 percent per year.

Where kelp resilience is eroding and leading to declines in abundance, impacts to ecosystem health and services can be far-reaching, the researchers wrote in their report.

This research was supported by the National Science Foundation, the University of California/Santa Barbara, and the state of California.

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Mark Novak, 541-737-3610

mark.novak@oregonstate.edu

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Kelp Forest
Kelp forests

A better battery: one-time pollutant may become valued product to aid wind, solar energy

CORVALLIS, Ore. - Chemists at Oregon State University have discovered that one or more organic compounds in a family that traditionally has been known as pollutants could offer an important advance to make cheap, reliable batteries.

Such batteries might be of particular value to store electricity from some clean energy systems. The inability to easily and cheaply store energy from the wind and sun, which is highly variable and intermittent, has been a key constraint to wider use of those forms of energy.

Although pumped hydro systems or compressed air facilities comprise almost all of the alternative energy storage capacity of this type, they have limitations. There is a tremendous demand, scientists say, for energy storage solutions that are modular and particularly suited to community storage, “smart grid” and micro-grid uses.

A new advance, published in ACS Energy Letters, has shown that at least one, and probably more compounds known as polycyclic aromatic hydrocarbons, or PAHs, can function as a potentially low-cost, long-lasting and high-performance cathode in “dual-ion” batteries.

Such batteries would contain a carbon electrode as the anode and solid PAH as the cathode, with no need for the rare or costly metal elements now usually used.

Traditionally thought of as pollutants, PAHs are usually products of combustion – anything from a campfire to an automobile exhaust or coal-burning power plant – and pose significant concerns as toxins and carcinogens, often when inhaled.

But in this study, scientists found that at least one PAH compound called coronene, in a safe, crystallized solid form, makes a high-functioning electrode material with promising characteristics in dual-ion batteries.

“Prior to this work, PAHs were not considered stable when storing large anions,” said Xiulei (David) Ji, an assistant professor of chemistry in the OSU College of Science, and recipient of a 2016 National Science Foundation CAREER Award, the most prestigious award for junior faculty.

“We found that coronene crystalline solid, a PAH, can lose electrons and provide a good capacity of anion storage while being structurally and chemically stable. Coronene had good performance as an electrode and the ability to have a very long cycle life, or the number of charges and discharges it can handle.”

Avoiding the use of metals in the electrodes is a huge advantage for dual-ion batteries and makes them much more sustainable, Ji said. Graphite cathodes can do this, but a serious challenge that has held them back for two decades is that they operate at levels hostile to the non-aqueous solvents in the electrolyte. The batteries based on coronene largely eliminate this problem, and would significantly improve the maintenance cost and sustainability of a stationary battery system.

The researchers in this study demonstrated the potential of coronene, but also said that other PAH compounds as well may have similar potential.

This research opens the door to an entirely new concept in battery construction, they said, which might take what had once been an unwanted pollutant and turn it into a safe, valued product.

Primary collaborators on this project in OSU’s Department of Chemistry included lead author and graduate student Ismael Rodriguez-Perez, and professors Michael Lerner and Rich Carter.

The research was supported by the American Chemical Society Petroleum Research Fund.

 

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David Ji, 541-737-6798

david.ji@oregonstate.edu

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New battery
New battery

New technologies – and a dash of whale poop – help scientists monitor whale health

NEWPORT, Ore. – A lot of people think what Leigh Torres has done this summer and fall would qualify her for a spot on one of those “World’s Worst Jobs” lists.

After all, the Oregon State University marine ecologist follows gray whales from a small inflatable boat in the rugged Pacific Ocean and waits for them to, well, poop. Then she and her colleagues have about 20-30 seconds to swoop in behind the animal with a fine mesh net and scoop up some of the prized material before it drifts to the ocean floor.

Mind you, gray whales can reach a length of more than 40 feet and weigh more than 30 tons, making the retrieval of their daily constitutional somewhat daunting. Yet Torres, a principal investigator in the university’s Marine Mammal Institute, insists that it really isn’t that bad.

“We’re just looking for a few grams of material and to be honest, it doesn’t even smell that bad,” she said. “Now, collecting a DNA sample from a whale’s blow-hole – that’s a bad job. Their breath is horrendous.”

Being a marine pooper-scooper isn’t some strange fetish for the Oregon State research team. They are conducting a pilot project to determine how gray whales respond to ocean noise – both natural and human – and whether these noises cause physiological stress in the animals. Technology is changing the way the researchers are approaching their study.

“New advances in biotechnology allow us to use the fecal samples to look at a range of things that provide clues to the overall health and stress of the whales,” Torres said. “We can look at their hormone levels and genetically identify individual whales, their sex and whether they are pregnant. And we can analyze their prey and document what they’ve been eating.

“Previously, we would have to do a biopsy to learn some of these things and though they can be done safely, you typically don’t repeat the procedure often because it’s invasive,” she added. “Here, we can follow individual whales over a four-month feeding season and pick up multiple samples that can tell us changes in their health.”

The study is a pilot project funded by the National Oceanic and Atmospheric Administration’s Ocean Acoustics Program to determine the impacts of noise on whale behavior and health. Torres, who works out of OSU’s Hatfield Marine Science Center in Newport, Oregon, focuses on gray whales because they are plentiful and close to shore.

“Many marine mammals are guided by acoustics and use sound to locate food, to navigate, to communicate with one another and to find a mate,” said Torres, a faculty member in OSU’s Department of Fisheries and Wildlife and an ecologist with the Oregon Sea Grant program.

Ten years ago, such a study would not have been possible, Torres acknowledged. In addition to new advances in genetic and hormone analyses, the OSU team uses a drone to fly high above the whales. It not only detects when they defecate, it is giving them unprecedented views of whale behavior.

“We are seeing things through the drone cameras that we have never seen before,” Torres said. “Because of the overhead views, we now know that whales are much more agile in their feeding. We call them ‘bendy’ whales because they make such quick, sharp turns when feeding. These movements just can’t be seen from the deck of a ship.”

The use of small, underwater Go-Pro cameras allows them to observe what the whales are feeding upon below. The researchers can identify zooplankton, benthic invertebrates, and fish in the water column near feeding whales, and estimate abundance – helping them understand what attracts the whales to certain habitats.

Joe Haxel and Sharon Nieukirk are acoustic scientists affiliated with OSU's Cooperative Institute for Marine Resources Studies and the NOAA Pacific Marine Environmental Laboratory at the Hatfield center who are assisting with the project. They deploy drifting hydrophones near the whales to record natural and human sounds, help operate the overhead drone camera that monitors the whales’ behavior, and also get in on the fecal analysis.

“Gray whales are exposed to a broad range of small- and medium-sized boat traffic that includes sport fishing and commercial fleets,” Haxel said. “Since they are very much a coastal species, their exposure to anthropogenic noise is pretty high. That said, the nearshore environment is already very noisy with natural sounds including wind and breaking surf, so we’re trying to suss out some of the space and time patterns in noise levels in the range of habitats where the whales are found.”

It will take years for the researchers to learn how ocean noise affects whale behavior and health, but as ocean noises continue increasing – through ship traffic, wave energy projects, sonar use, seismic surveys and storms – the knowledge they gain may be applicable to many whale species, Torres said.

And the key to this baseline study takes a skilled, professional pooper-scooper.

“When a whale defecates, it generates this reddish cloud and the person observing the whale usually screams “POOP!” and we spring into action,” Torres said. “It’s a moment of excitement, action - and also sheer joy. I know that sounds a little weird, but we have less than 30 seconds to get in there and scoop up some of that poop that may provide us with a biological gold mine of information that will help protect whales into the future.

“That’s not such a bad job after all, is it?”

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Leigh Torres, 541-867-0895, leigh.torres@oregonstate.edu

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Link to: the whale fluke photo

 

 

For a video of the research, click here

 

 

 

 


 

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Aerial shot of a gray whale.

 

 

 

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Researchers use a drone to monitor whale behavior

 

 

 

 

OSU student receives $132,000 EPA STAR fellowship

CORVALLIS, Ore. – Christina Murphy, a doctoral student at Oregon State University, has received a $132,000 Science to Achieve Results, or STAR fellowship, from the U.S. Environmental Protection Agency.

Murphy, who is pursuing a Ph.D. in the Department of Fisheries and Wildlife at OSU, is conducting research on how best to manage dams to protect salmon.

STAR graduate fellows are selected from a large number of applications in a highly competitive review process, EPA officials say. Since the program began in 1995, the EPA has awarded nearly 2,000 students a total of more than $65 million in funding.

Murphy earned three honors bachelor’s degrees at OSU, in biology, fisheries and wildlife, and international studies, then conducted a Fulbright research project in Chile. She earned a master’s degree at the Universitat de Girona in Spain, and then returned to Oregon State to pursue her doctorate.

“Northwest reservoirs have different hydrologic regimes and changes in timing and magnitude of drawdown,” Murphy said. She is evaluating physical and chemical conditions in the water, as well as phytoplankton, zooplankton, benthic insects, diversity and populations of fish, and habitat availability within reservoirs – both before and after hydrologic changes – in order to inform decisions on dam and reservoir management.

Murphy is focusing her studies on four reservoirs in the upper Willamette basin in Oregon – Blue River, Fall Creek, Lookout Point and Hills Creek.

“The Pacific Northwest relies on hydropower for more than half of its electricity, with high-head dams forming large reservoirs on rivers historically supporting anadromous salmon,” Murphy said. “Improved understanding of the ecological mechanisms and responses of Pacific Northwest reservoirs with respect to water-level fluctuations is critical to ensuring ecologically sound practices for the long-term operation and greening of our hydropower infrastructure.”

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Christina Murphy, 541-505-1393, Christina.Murphy@oregonstate.edu

Salmon trucking success could open miles of historical spawning habitat

NEWPORT, Ore. – For the past several years, technicians have been trucking spring Chinook salmon above Foster Dam in Sweet Home to see if they would spawn, and if their offspring could survive the passage over the dam and subsequent ocean migration to eventually return as adults some 3-5 years later.

A new study examining the genetic origin of adult spring Chinook returning to Foster Dam offers definitive proof that the offspring survived, potentially opening up miles of spawning habitat on the upper South Santiam and other river systems.

Results of the study have been published in the Canadian Journal of Fisheries and Aquatic Sciences.

“With a little human assistance, it is now clear that we can restore natural production to areas above some dams and there is prime habitat on some river systems, such as the North Santiam above Detroit Dam,” said Kathleen O’Malley, an Oregon State University geneticist and principal investigator on the project. “This could really contribute to the long-term population viability in some river systems.”

Some past studies have explored whether salmon that spawned above dams could survive as juveniles going back through the dams, but this new study is one of the first to assess whether those fish successfully would return years later as adults.

Beginning in 2007, technicians from Oregon Department of Fish and Wildlife and the U.S. Army Corps of Engineers took genetic samples of adult salmon trucked above the dam. During the first two years, most of those adult salmon were reared in hatcheries and released as juveniles, but in 2009 they began using only wild-born fish, hoping to give a boost to that population. Since then, researchers have taken genetic samples from returning adult salmon to see if their parents were among those released above the dam.

The key is the “cohort replacement rate,” O’Malley said. If you release 100 female salmon above the dam, will you get at least 100 females from that population returning as adults to the dam for a rate of 1.0?  The researchers have to sample for several years to determine the success rate of one cohort, since spring Chinook can return as 3-, 4- or 5-year olds.

In 2007, ODFW released 385 hatchery-origin adult salmon and 18 wild-born salmon above Foster Dam, and the cohort replacement rate was .96. In 2008, 527 hatchery-origin fish and 163 wild-born fish were released, and the replacement rate was 1.16.

In 2009, the shift was made to all wild-born fish and ODFW released 434 spring Chinook above Foster Dam. When the researchers completed their genetic analysis for that year they found a cohort replacement rate of 1.56.

“It could be a one-year anomaly, or it may be an indication that wild-born fish are fitter and better able to survive and reproduce above the dams,” O’Malley said. “It is promising, though.”

Dams can limit downstream damage from potential floods, the researchers say, but there is little protection for spawning salmon above the dams. One flood occurred in 2010, and the researchers are just finishing their analysis of that year. Many of the spawning beds were wiped out, thus the cohort replacement rate likely will be lower. Although re-establishment of spawning activity above the dams has the potential to enhance productivity, those efforts are vulnerable to environmental processes.

“One limiting factor is that we don’t know for sure what an appropriate replacement rate is,” O’Malley pointed out. “We know that 1.0 is the bare minimum – one fish dies and another takes its place. But it won’t be clear what a good number will be to sustain and expand the population until we have several years of research.”

Researchers and fisheries managers note that ocean conditions play an important role in determining the number of adult salmon that survive to return and spawn, and can account for a significant amount of inter-annual variability in salmon abundance. It is important to have a population that is sufficiently productive across years in order to survive poor environmental conditions – in the ocean, or in fresh water – in any single given year.

ODFW also has released fish above dams on the North Santiam River and Fall Creek and OSU researchers are using genetics to monitor some of the first returning adults in these systems.

“One reason we think that the South Santiam reintroduction is going so well is that the reservoir is smaller and the dam is lower than in others systems in the Willamette basin,” O’Malley said. “The salmon’s downstream survival rate is likely higher than it may be on other river systems.”

The project is funded by the Army Corps of Engineers.

O’Malley is an associate professor in the Department of Fisheries and Wildlife at OSU, who is affiliated with the Coastal Oregon Marine Experiment Station at the university’s Hatfield Marine Science Center in Newport.

Other authors on the study include Melissa Evans and Dave Jacobson of Oregon State; Jinliang Wang of the Zoological Society of London; and Michael Hogansen and Marc Johnson of the Oregon Department of Fish and Wildlife. Evans, the lead author, now works for the Fish and Wildlife Department of the Shoshone-Bannock Tribes in Idaho.

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Kathleen O’Malley, 541-961-3311, kathleen.omalley@oregonstate.edu

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Aerial video of South Santiam: https://www.youtube.com/watch?v=zEb5l8lGtb8&

 

 

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Spring Chinook bypassing Foster Dam

 

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Foster Dam trapping operation

OSU Press publishes “Ricky’s Atlas,” a sequel to its first children’s book

CORVALLIS, Ore. – The Oregon State University Press has published “Ricky’s Atlas: Mapping a Land on Fire,” a sequel to its first book aimed at children, written by two OSU faculty members.

In 2013, the press published “Ellie’s Log: Exploring the Forest Where the Great Tree Fell,” the story of two children exploring an old-growth forest in the Oregon Cascades. Written by Judith Li, and illustrated by M.L. Herring, the book received several honors, including the Green Earth Book Award Short List for books aimed at children., and an honorable mention from the John Burroughs Riverby Award Committee.

“Ricky’s Atlas” continues to explore the nature of Oregon, this time east of the Cascade Mountains, where Ricky Zamora and his friend Ellie delve further into the relationship between people, plants and animals, while dealing with a wildfire sparked by lightning.

The two young explorers hike across a natural prairie, climb a fire tower, study historical photos and maps, and learn about the role of fire in nature. Ricky’s love of map-making and his natural curiosity help shape the story.

“Upper elementary kids will enjoy the mixture of amazing adventures with actual historical, physical and ecological data about the region,” said Marty Brown, marketing manager for the OSU Press. “Woven into the story are the small pleasures of ranch life, intriguing stories of Native Americans and early settlers, and almost unbelievable views of ancient fossils.

“Ricky and Ellie’s explorations, accompanied by their hand-written notes, introduce readers to a very special landscape and history east of the Cascades.”

Li is a retired associate professor in the Department of Fisheries and Wildlife at OSU, where she worked as a stream ecologist and participated in the National Science Foundation-sponsored Long-Term Ecological Research program at the H.J. Andrews Experimental Forest.

Herring is a science writer and illustrator who heads the communications program in OSU’s College of Agricultural Sciences.

“Ricky’s Atlas” is available at book stores and for order at http://osupress.oregonstate.edu

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Marty Brown, 541-737-3866, marty.brown@oregonstate.edu

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An image of the book cover is available at: https://flic.kr/p/J5Fiyq

“Weather@Home” offers precise new insights into climate change in the West

CORVALLIS, Ore. – Tens of thousands of “citizen scientists” have volunteered some use of their personal computer time to help researchers create one of the most detailed, high resolution simulations of weather ever done in the Western United States.

The data, obtained through a project called Weather@Home, is an important step forward for scientifically sound, societally relevant climate science, researchers say in a an article published in the Bulletin of the American Meteorological Society. The analysis covered the years 1960-2009 and future projections of 2030-49.

“When you have 30,000 modern laptop computers at work, you can transcend even what a supercomputer can do,” said Philip Mote, professor and director of the Oregon Climate Change Research Institute at Oregon State University, and lead author on the study.

“With this analysis we have 140,000 one-year simulations that show all of the impacts that mountains, valleys, coasts and other aspects of terrain can have on local weather,” he said. “We can drill into local areas, ask more specific questions about management implications, and understand the physical and biological climate changes in the West in a way never before possible.”

The sheer number of simulations tends to improve accuracy and reduce the uncertainty associated with this type of computer analysis, experts say. The high resolution also makes it possible to better consider the multiple climate forces at work in the West – coastal breezes, fog, cold air in valleys, sunlight being reflected off snow – and vegetation that ranges from wet, coastal rain forests to ice-covered mountains and arid scrublands within a comparatively short distance.

Although more accurate than previous simulations, improvements are still necessary, researchers say. Weather@Home tends to be too cool in a few mountain ranges and too warm in some arid plains, such as the Snake River plain and Columbia plateau, especially in summer. While other models have similar errors, Weather@Home offers the unique capability to improve simulations by improving the physics in the model.

Ultimately, this approach will help improve future predictions of regional climate. The social awareness of these issues has “matured to the point that numerous public agencies, businesses and investors are asking detailed questions about the future impacts of climate change,” the researchers wrote in their report.

This has led to a skyrocketing demand for detailed answers to specific questions – what’s the risk of a flood in a particular area, what will be future wind speeds as wind farms are developed, how should roads and bridges be built to handle extremely intense rainfall?  There will be questions about heat stress on humans, the frequency of droughts, future sea levels and the height of local storm surges.

This type of analysis, and more like it, will help answer some of those questions, researchers say.

New participants in this ongoing research are always welcome, officials said. If interested in participating, anyone can go online to “climateprediction.net” and click on “join.” They should then follow the instructions to download and install BOINC, a program that manages the tasks; create an account; and select a project. Participation in climateprediction.net is available, as well as many others.

The work has been supported by Microsoft Corp., the U.S. Bureau of Land Management, the California Energy Commission, the U.S. Geological Survey and the USDA.

Collaborators on the report were from OSU, Oxford University in the United Kingdom, and the Met Office Hadley Centre in the United Kingdom.

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Phil Mote, 541-913-2274

pmote@coas.oregonstate.edu

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Elevation map
Elevation map

Coral reefs fall victim to overfishing, pollution aggravated by ocean warming

CORVALLIS, Ore. – Coral reefs are declining  around the world because a combination of factors – overfishing, nutrient pollution, and pathogenic disease – ultimately become deadly in the face of higher ocean temperatures, researchers have concluded.

A study published today in Nature Communications, based on one of the largest and longest field experiments done on this topic, suggests that the widespread coral deaths observed in recent decades are being caused by this combination of multiple local stressors and global warming.

These forces greatly weaken corals, and allow opportunistic pathogens to build to such levels that corals cannot survive.

The findings were made by researchers from six institutions following a three-year experiment that simulated both overfishing and nutrient pollution on a coral reef in the Florida Keys. The large body of field data collected over an extended period of time helped resolve some of the fundamental questions about the cause of coral reef declines, scientists said.

“This is grim news, but at least it will help settle the argument over why corals are dying,” said Rebecca Vega Thurber, an assistant professor in the College of Science at Oregon State University and corresponding author on the study.

“This makes it clear there’s no single force that’s causing such widespread coral deaths. Loss of fish that help remove algae, or the addition of excess nutrients like those in fertilizers, can cause algal growth on reefs. This changes the normal microbiota of corals to become more pathogenic, and all of these problems reach critical levels as ocean temperatures warm.”

The end result, scientists say, is a global decline of coral reefs that is now reaching catastrophic proportions.

“We need to know how human activities are affecting coral reef ecosystems,” says David Garrison, program director in the National Science Foundation’s Division of Ocean Sciences, which funded the research.  “Coral reefs are among the most sensitive indicators of the health of the oceans. This report is a major contribution toward understanding how reefs will fare in the future.”

Scientists say the problems caused by bacterial infections due to local stressors and warm temperatures are in addition to damage from mass coral bleaching events already under way. Only in the early 1980’s did researchers observe the first mass bleaching event in recorded history. There have now been three such events just in the past 20 years.

“About 25-35 percent of the corals on the Great Barrier Reef are dying right now,” Vega-Thurber said. “In 2014-16 large portions of tropical reef across the planet experienced bleaching, and this past April, 90 percent of the Great Barrier Reef bleached as part of a massive El Nino event. Corals everywhere seem to be dying.”

In addition to helping to sort out the effects of known stressors like overfishing and nutrient pollution, the researchers made one bizarre and totally unexpected finding.

In normal conditions, parrotfish, like many other species, are essential to the health of coral reefs, nibbling at them to remove algae and causing no permanent damage. But in one part of the experiment corals were so weakened by nitrogen and phosphorus pollution that when parrot fish would bite them, 62 percent of the corals would die. A normally healthy fish-coral interaction had been turned into a deadly one.

“Normally benign predation by the parrotfish turned into coral murder,” said Deron Burkepile, also a corresponding author on the study at the University of California – Santa Barbara. “But it’s not the parrotfishes, they’re like the reef janitors, keeping it clean. Those extra nutrients — nutrient pollution — turn parrotfishes into an actual source of mortality by facilitating pathogens in the wounds left by their bites. Excess nutrients turn a coral accomplice into a coral killer.”

The researchers said they want to make it clear that parrotfish are not the problem, they are an essential part of healthy reef ecosystems.

“The problem is when corals are so weakened they cannot withstand normal impacts,” Vega-Thurber said. “And the solution will be to help those corals recover their health, by ensuring that their local environment is free of nutrient pollution and that fish stocks are not depleted.”

Among the findings of the study:

  • Overfishing, nutrient pollution and increased temperature all lead to an increase in pathogens;
  • The sheer abundance of pathogens is more important than what particular type or species they are;
  • Coral reef mortality mirrors the abundance of pathogens;
  • Heat exacerbates these problems, with 80 percent of coral deaths coming in the summer or fall, but only when fish are removed or nutrient pollution is present;
  • While high thermal stress has received the most attention, even modest temperature increases make corals more vulnerable to bacteria;
  • Loss of fish can increase algal cover up to six times;
  • In a distressed system with many algae, coral disease levels double and coral mortality increases eight times;
  • Increased algal cover or elevated temperature can reduce levels of naturally-secreted antibiotics that help protect corals from harmful bacteria;
  • Direct algal contact driven by overfishing and nutrient pollution destabilizes the coral microbiome, in some cases leading to a 6- to 9-time increase in mortality.

The findings, researchers say, make it clear that in the face of global warming, some of the best opportunities to protect coral reefs lie in careful management of fishing and protection of water quality. This would give corals their best chance to have a healthy microbiome and resist warmer conditions without dying.

Collaborators on this research were from Florida International University, the University of California/Santa Barbara, Penn State University, Rice University, the University of Florida/Gainsville, SymbioSeas and Marine Applied Research Center, and the Laboratoire d’Excellence.

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Editor Notes: Video and audio are available to illustrate this story.

 

Interview with Rebecca Vega-Thurber:  http://bit.ly/1TSUe1N

Link to audio-only version of same interview: http://bit.ly/24ubTg0

YouTube view-only link of same video: https://youtu.be/dq8jtyuYp_U

Story By: 
Source: 

Rebecca Vega-Thurber, 541-737-1851

rebecca.vega-thurber@oregonstate.edu

Multimedia Downloads
Multimedia: 

Coral surveys

Divers in field study


Sampling coral microbiome


Testing coral microbiome


Experimental design


Study design


Parrot fish on coral reefs
Parrot fish cleaning coral