OREGON STATE UNIVERSITY

environment and natural resources

OSU part of major grant to study Southern Ocean carbon cycle

CORVALLIS, Ore. – A new six-year, $21 million initiative funded by the National Science Foundation will explore the role of carbon and heat exchanges in the vast Southern Ocean – and their potential impacts on climate change.

The Southern Ocean Carbon and Climate Observations and Modeling program will be headquartered at Princeton University, and include researchers at several institutions, including Oregon State University. It is funded by NSF’s Division of Polar Programs, with additional support from the National Oceanic and Atmospheric Administration and NASA.

The Southern Ocean acts as a carbon “sink” by absorbing as much as half of the human-derived carbon in the atmosphere and much of the planet’s excess heat. Yet little is known of this huge body of water that accounts for 30 percent of the world’s ocean area.

Under this new program known by the acronym SOCCOM, Princeton and 10 partner institutions will create a physical and biogeochemical portrait of the ocean using hundreds of robotic floats deployed around Antarctica. The floats, which will be deployed over the next five years, will collect seawater profiles using sophisticated sensors to measure pH, oxygen and nitrate levels, temperature and salinity – from the ocean surface to a depth of 1,000 meters, according to Laurie Juranek, an Oregon State University oceanographer and project scientist.

“This will be the first combined large-scale observational and modeling program of the entire Southern Ocean,” said Juranek, who is in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “It is a very important region, but difficult to access – hence the use of robotic floats to collect data. However, not everything that we need to know can be measured by sensors, so we’ll need to get creative.”

Juranek's role in this project is to develop relationships between the measured variables and those that can't be measured directly by a sensor but are needed for understanding Southern Ocean carbon dioxide exchanges. These relationships can be applied to the float data as well as to high-resolution models. To do this work she is partnering with colleagues at NOAA's Pacific Marine Environmental Laboratory.

In addition to its role in absorbing carbon and heat, the Southern Ocean delivers nutrients to lower-latitude surface waters that are critical to ocean ecosystems around the world, said program director Jorge Sarmiento, Princeton's George J. Magee Professor of Geoscience and Geological Engineering and director of the Program in Atmospheric and Oceanic Sciences. And as levels of carbon dioxide increase in the atmosphere, models suggest that the impacts of ocean acidification are projected to be most severe in the Southern Ocean, he added.

"The scarcity of observations in the Southern Ocean and inadequacy of earlier models, combined with its importance to the Earth's carbon and climate systems, means there is tremendous potential for groundbreaking research in this region," Sarmiento said.

Media Contact: 
Source: 

Laurie Juranek, 541-737-2368; ljuranek@coas.oregonstate.edu

Synchronization of North Atlantic, North Pacific preceded abrupt warming, end of ice age

CORVALLIS, Ore. – Scientists have long been concerned that global warming may push Earth’s climate system across a “tipping point,” where rapid melting of ice and further warming may become irreversible – a hotly debated scenario with an unclear picture of what this point of no return may look like.

A newly published study by researchers at Oregon State University probed the geologic past to understand mechanisms of abrupt climate change. The study pinpoints the emergence of synchronized climate variability in the North Pacific Ocean and the North Atlantic Ocean a few hundred years before the rapid warming that took place at the end of the last ice age about 15,000 years ago.

The study suggests that the combined warming of the two oceans may have provided the tipping point for abrupt warming and rapid melting of the northern ice sheets.

Results of the study, which was funded by the National Science Foundation, appear this week in Science.

This new discovery by OSU researchers resulted from an exhaustive 10-year examination of marine sediment cores recovered off southeast Alaska where geologic records of climate change provide an unusually detailed history of changing temperatures on a scale of decades to centuries over many thousands of years.

“Synchronization of two major ocean systems can amplify the transport of heat toward the polar regions and cause larger fluctuations in northern hemisphere climate,” said Summer Praetorius, a doctoral student in marine geology at Oregon State and lead author on the Science paper. “This is consistent with theoretical predictions of what happens when Earth’s climate reaches a tipping point.”

“That doesn’t necessarily mean that the same thing will happen in the future,” she pointed out, “but we cannot rule out that possibility.”

The study found that synchronization of the two regional systems began as climate was gradually warming. After synchronization, the researchers detected wild variability that amplified the changes and accelerated into an abrupt warming event of several degrees within a few decades.

“As the systems become synchronized, they organized and reinforced each other, eventually running away like screeching feedback from a microphone,” said Alan Mix, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences and co-author on the paper. “Suddenly you had the combined effects of two major oceans forcing the climate instead of one at a time.”

“The example that we uncovered is a cause for concern because many people assume that climate change will be gradual and predictable,” Mix added. “But the study shows that there can be vast climate swings over a period of decades to centuries. If such a thing happened in the future, it could challenges society’s ability to cope.”

What made this study unusual is that the researchers had such a detailed look at the geologic record. While modern climate observations can be made every day, the length of instrumental records is relatively short – typically less than a century. In contrast, paleoclimatic records extend far into the past and give good context for modern changes, the researchers say. However, the resolution of most paleo records is low, limited to looking at changes that occur over thousands of years.

In this study, the researchers examined sediment cores taken from the Gulf of Alaska in 2004 during an expedition led by Mix. The mountains in the region are eroding so fast that sedimentation rates are “phenomenal,” he said. “Essentially, this rapid sedimentation provides a ‘climate tape recorder’ at extremely high fidelity.”

Praetorius then led an effort to look at past temperatures by slicing the sediment into decade-long chunks spanning more than 8,000 years – a laborious process that took years to complete. She measured ratios of oxygen isotopes trapped in fossil shells of marine plankton called foraminifera. The isotopes record the temperature and salinity of the water where the plankton lived.

When the foraminifera died, their shells sank to the sea floor and were preserved in the sediments that eventually were recovered by Mix’s coring team.

The researchers then compared their findings with data from the North Greenland Ice Core Project to see if the two distinct high-latitude climate systems were in any way related.

Most of the time, the two regions vary independently, but about 15,500 years ago, temperature changes started to line up and then both regions warmed abruptly by about five degrees (C) within just a few decades. Praetorius noted that much warmer ocean waters likely would have a profound effect on northern-hemisphere climates by melting sea ice, warming the atmosphere and destabilizing ice sheets over Canada and Europe.

A tipping point for climate change “may be crossed in an instant,” Mix noted, “but the actual response of the Earth’s system may play out over centuries or even thousands of years during a period of dynamic adjustment.”

“Understanding those dynamics requires that we look at examples from the past,” Mix said. “If we really do cross such a boundary in the future, we should probably take a long-term perspective and realize that change will become the new normal. It may be a wild ride.”

Added Praetorius: “Our study does suggest that the synchronization of the two major ocean systems is a potential early warning system to begin looking for the tipping point.”

Media Contact: 
Source: 

Summer Praetorius, 541-737-6159, spraetorius@coas.oregonstate.edu; Alan Mix, 541-737-5212, amix@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

sediment core

Sediment cores

Hubbard Glacier ice front

Hubbard Glacier

summer

Summer Praetorius

alanmix
Alan Mix

Review: Lead ammunition can be deadly, though mitigation may help

CORVALLIS, Ore. – The ingestion of lead ammunition and lead fishing tackle accounts for illness and mortality in more than 120 different species of birds in North America, according to a newly published review of scientific studies on the issue.

What impact that has at the population level for species is less clear, the researchers say, as is how to deal with the growing controversy over the use of lead for hunting and fishing. The lead issue is complex and steps to mitigate the impacts will be challenging – from cost and performance factors to manufacturing output – but they are possible, the authors point out.

“Although lead shot has been banned for waterfowl hunting in the United States since 1991, and in Canada since 1999, exposure to lead remains a problem for many bird species,” said Susan Haig, supervisory wildlife ecologist with the U.S. Geological Survey and lead author on the study. “However, we did find several examples of ways wildlife managers have helped reduce exposure of birds to lead.”

The review of scientific studies, conducted by biologists from several different institutions and agencies, was published in the July edition of the journal The Condor: Ornithological Applications. A companion perspective article, written by Clinton Epps, an associate professor in the Department of Fisheries and Wildlife at Oregon State University, examines the challenges of transitioning to non-lead ammunition.

In their papers, the researchers do not call for any policy changes, but they outline some of the challenges of reducing the use of lead and explore tactics that have been used to reduce lead exposure.

“Shifting to non-lead alternatives is a lot more complicated than some people think,” said Epps, who has hunted for more than 30 years. “Any efforts to shift hunters and fishermen from using lead needs to be well-informed and collaborative. Everyone concerned with this issue must be prepared to invest time, money, and expertise to work not only with hunters and fishermen, but with ammunition and tackle manufacturers.”

Epps has looked at copper bullets as one less-toxic alternative to lead and notes that they generally work well in modern firearms commonly used for big game hunting. However, effective non-lead alternatives have not yet been developed for all types of hunting firearms, he added.

In the review article, the researchers outline the availability of non-lead ammunition in October 2013 in 35 different calibers and 51 rifle-cartridge configurations at three major online retailers. Of the non-lead options sold by those retailers, only a small proportion was actually in stock: Cabela’s had non-lead ammunition in 18 percent of available sizes; Cheaper Than Dirt, 27 percent; and Bass Pro Shops, 10 percent.

“Non-lead bullets can be difficult to find in all calibers needed, but availability is improving,” Epps said. “Premium quality hunting ammunition costs about the same for lead-based and non-lead options, but I see a lot of people using the cheaper options, which invariably contain lead, so cost may be an issue – particularly for high-volume users.”

The physical properties of lead – including high density, low melting point, malleability and resistance to corrosion – have made it popular in the manufacturing of ammunition and fishing sinkers. However, many birds are sensitive to lead exposure, affecting the structure and function of kidneys, bones, the central nervous system and the blood system. Impacts range from lethargy and anorexia, to reproductive issues and death.

In their review, the researchers noted that lead has widely varying impacts.

  • One study of common loon carcasses found across six New England states found that about 23 percent (118 of 522) of the deaths were caused by ingestion of lead fishing tackle and ammunition;
  • California condors are extremely susceptible to lead poisoning and suffer significant mortality, yet a related species known as turkey vultures can survive with greater and longer exposure to lead;
  • Few studies have been done on population-level impacts of lead with the most complete studies conducted on waterfowl, where deaths from lead poisoning are estimated to be 2-3 percent overall, and 4 percent in mallard ducks.

A survey by the U.S. Geological Survey in 2013 found that 69,000 metric tons (a metric ton is about 2,204 pounds) of lead were used in the production of ammunition in the United States in one year. Annual estimates of lead fishing weights sold in the U.S. equal 3,977 metric tons.

Birds and other animals ingest lead in different ways, according to Haig. Loons, for example, were found to have swallowed lead sinkers and jigs, perhaps mistaking them for prey. Scavengers including condors and eagles often feed on carcasses of animals killed by hunters and cannot avoid incidental lead ingestion.

“Some birds use lead pellets or fragments as grit to aid in digestion after consuming it at hunting areas or shooting ranges,” said Haig, who is a courtesy professor of wildlife ecology at OSU. “Another potentially important lead source is recreational shooting of ground squirrels, which leaves lead-laced carcasses available to be eaten by golden eagles, Swainson’s hawks and other birds of prey.

“We found one estimate that more than 1.1 million ground squirrels were shot in one state during a one-year period,” she added. “It would be helpful to better understand what kinds of risk this poses to raptor scavengers.”

The review outlines some steps to reduce lead exposure to birds, including redistributing shot in the surface soil by cultivating sediments; raising water levels in wetlands to reduce access by feeding birds; and providing alternative uncontaminated food sources.

“Managers have found a number of ways to reduce the risk of lead exposure to birds while preserving the important role hunting plays in wildlife conservation,” Haig said.

One example cited involved Arizona Game and Fish working with other groups in that state on a voluntary approach to the issue.

“They formed a coalition to educate hunters about the negative effects of lead,” Haig pointed out. “The result was more than 80 percent compliance with voluntary non-lead ammunition use among hunters on the Kaibab Plateau and no birds were found with lead poisoning the following year.”

Other authors on the review include Jesse D’Elia, U.S. Fish and Wildlife Service and OSU Department of Fisheries and Wildlife; Collin Eagles-Smith, U.S. Geological Survey and OSU Fisheries and Wildlife; Garth Herring, U.S. Geological Survey; Jeanne M. Fair, Los Alamos National Laboratory; Jennifer Gervais, Oregon Wildlife Institute and OSU Fisheries and Wildlife; James W. Rivers, OSU Department of Forest Ecosystems and Society; and John H. Schulz, University of Missouri.

Media Contact: 
Source: 

Susan Haig, 541-750-0981, susan_haig@usgs.gov; Clint Epps, 541-737-2478, Clinton.epps@oregonstate.edu

Multimedia Downloads
Multimedia: 

Figure 2 Magpie on carcass
magpie feedng on a carcass

SAR11, oceans’ most abundant organism, has ability to create methane

CORVALLIS, Ore. – The oxygen-rich surface waters of the world’s major oceans are supersaturated with methane – a powerful greenhouse gas that is roughly 20 times more potent than carbon dioxide – yet little is known about the source of this methane.

Now a new study by researchers at Oregon State University demonstrates the ability of some strains of the oceans’ most abundant organism – SAR11 – to generate methane as a byproduct of breaking down a compound for its phosphorus.

Results of the study are being published this week in Nature Communications. It was funded by the National Science Foundation and the Gordon and Betty Moore Foundation.

“Anaerobic methane biogenesis was the only process known to produce methane in the oceans and that requires environments with very low levels of oxygen,” said Angelicque “Angel” White, a researcher in OSU’s College of Earth, Ocean, and Atmospheric Sciences and co-author on the study. “In the vast central gyres of the Pacific and Atlantic oceans, the surface waters have lots of oxygen from mixing with the atmosphere – and yet they also have lots of methane, hence the term ‘marine methane paradox.’

“We’ve now learned that certain strains of SAR11, when starved for phosphorus, turn to a compound known as methylphosphonic acid,” White added. “The organisms produce enzymes that can break this compound apart, freeing up phosphorus that can be used for growth – and leaving methane behind.”

The discovery is an important piece of the puzzle in understanding the Earth’s methane cycle, scientists say. It builds on a series of studies conducted by researchers from several institutions around the world over the past several years.

Previous research has shown that adding methylphosphonic acid, or MPn, to seawater produces methane, though no one knew exactly how. Then a laboratory study led by David Karl of the University of Hawaii and OSU’s White found that an organism called Trichodesmium could break down MPn and thus it could be a potential source of phosphorus, which is a critical mineral essential to every living organism.

However, Trichodesmium are rare in the marine environment and unlikely to be the only source for vast methane deposits in the surface waters.

So White turned to Steve Giovannoni, a distinguished professor of microbiology at OSU, who not only maintains the world’s largest bank of SAR11 strains, but who also discovered and identified SAR11 in 1990. In a series of experiments, White, Giovannoni, and graduate students Paul Carini and Emily Campbell tested the capacity of different SAR11 strains to consume MPn and cleave off methane.

“We found that some did produce a methane byproduct, and some didn’t,” White said. “Just as some humans have a different capacity for breaking down compounds for nutrition than others, so do these organisms. The bottom line is that this shows phosphate-starved bacterioplankton have the capability of producing methane and doing so in oxygen-rich waters.”

SAR11 is the smallest free-living cell known and also has the smallest genome, or genetic structure, of any independent cell. Yet it dominates life in the oceans, thrives where most other cells would die, and plays a huge role in the cycling of carbon on Earth.

These bacteria are so dominant that their combined weight exceeds that of all the fish in the world's oceans, scientists say. In a marine environment that's low in nutrients and other resources, they are able to survive and replicate in extraordinary numbers – a milliliter of seawater, for instance, might contain 500,000 of these cells.

"The ocean is a competitive environment and these bacteria apparently won the race," said Giovannoni, a professor in OSU’s College of Science. "Our analysis of the SAR11 genome indicates that they became the dominant life form in the oceans largely by being the simplest.”

“Their ability to cleave off methane is an interesting finding because it provides a partial explanation for why methane is so abundant in the high-oxygen waters of the mid-ocean regions,” Giovannoni added. “Just how much they contribute to the methane budget still needs to be determined.”

Since the discovery of SAR11, scientists have been interested in their role in the Earth’s carbon budget. Now their possible implication in methane creation gives the study of these bacteria new importance.

Media Contact: 
Source: 

Angel White, 541-737-6397; awhite@coas.oregonstate.edu; Steve Giovannoni, 541-737-1835, steve.giovannoni@oregonstate.edu

ODFW, OSU to survey hunters about use of lead ammunition

CORVALLIS, Ore. – The Oregon Department of Fish and Wildlife and Oregon State University are collaborating on an effort to survey Oregon hunters about their use and knowledge of lead ammunition.

The random sample of 4,200 Oregon hunters will begin later this month and those selected should receive a letter from ODFW within the next two weeks. Oregon has approximately 250,000 hunters and the survey will include hunters from each geographic region of the state.

The use of lead ammunition has become a national issue because of impacts to wildlife and human health concerns, according to Ron Anglin, ODFW Wildlife Division administrator. Last year, California passed a law banning the use of lead ammunition for all hunting in the state beginning in 2019; other states have adopted voluntary measures encouraging the use of ammunition made from alternative compounds.

“There is no proposal to ban or limit use of lead ammunition in Oregon, but developments outside of Oregon could affect the use of lead ammunition within the state,” Anglin said. “The Environmental Protection Agency was petitioned to ban the use of lead in ammunition on a nationwide basis and there is the potential of condors being restored in northern California.”

The California legislature passed a law banning lead ammunition to protect endangered California condors, according to Dana Sanchez, an OSU Extension wildlife specialist and one of the project leaders. Condors can become ill after scavenging on animals that have been killed by lead bullets. The birds ingest lead fragments and can become sick or die, she said.

“Historically, Oregon has had condors, though none are known to live here now,” Sanchez pointed out. “However, there are efforts to re-establish populations in northern California and if they are successful, it is only a matter of time before condors begin frequenting the southern portions of Oregon.

“Once condors appear in Oregon, they would be subject to federal protection under the Endangered Species Act,” she added.

Sanchez said some conservation organizations in the state are monitoring lead levels in birds of prey brought into wildlife rehabilitation centers. There is increasing concern that lead exposure may be causing impacts to raptors and eagles in some areas, she said.

“This could lead to an initiative or other efforts to eliminate or restrict the use of lead ammunition,” Sanchez said.

The survey was developed by the OSU Survey Research Center, which will collect the data for ODFW and the OSU Wildlife Extension program. Survey results will be used to inform discussions among agencies, groups and others about any potential restrictions in the use of lead ammunition.

The purpose of the survey, Anglin said, is to gather information from the group of stakeholders who would be most affected by any restrictions on lead ammunition – Oregon hunters.

“Ideally, we would like to survey all Oregon hunters, but that is expensive,” Anglin said. “However, by selecting a random sample of hunters from regions across the state, we should get a clear picture of how Oregon hunters feel about lead ammunition and possible alternatives.”

Persons not chosen for the survey are welcome to provide comments on lead ammunition directly to the Oregon Department of Fish & Wildlife at a special email address: ODFW.wildlifeinfo@state.or.us

Anglin said the ODFW/OSU project team plans to conduct a similar survey of non-hunting Oregonians in the future.

Media Contact: 
Source: 

Ron Anglin, 503-947-6301; ODFW.wildlifeinfo@state.or.us; Dana Sanchez, 541-737-6003; dana.sanchez@oregonstate.edu

Sea star disease epidemic surges in Oregon, local extinctions expected

CORVALLIS, Ore. – Just in the past two weeks, the incidence of sea star wasting syndrome has exploded along the Oregon Coast and created an epidemic of historic magnitude, one that threatens to decimate the entire population of purple ochre sea stars.

Prior to this, Oregon had been the only part of the West Coast that had been largely spared this devastating disease.

The ochre sea star, which is the species most heavily affected by the disease in the intertidal zone, may be headed toward localized extinction in Oregon, according to researchers at Oregon State University who have been monitoring the outbreak. As a “keystone” predator, its loss could disrupt the entire marine intertidal ecosystem.

Researchers say this is the first time that die-offs of sea stars, more commonly known as starfish, have ever been identified at one time along such a wide expanse of the West Coast, and the sudden increase in Oregon has been extraordinary.

The best information is from the intertidal zone, which is easier to access for monitoring. In this area, less than 1 percent of the ochre sea stars in Oregon were affected in April, and only slightly more than that by mid-May.

Today, an estimated 30-50 percent of the Oregon populations of this sea star species in the intertidal zone have the disease. The highest losses are at Fogarty Creek, where about 60 percent are affected. Researchers project that the epidemic will intensify and, at some sites, nearly 100 percent of the ochre sea stars could die.

“This is an unprecedented event,” said Bruce Menge, the Wayne and Gladys Valley Professor of Marine Biology in the Department of Integrative Biology of the OSU College of Science. “We’ve never seen anything of this magnitude before.

“We have no clue what’s causing this epidemic, how severe the damage might be or how long that damage might last,” he said. “It’s very serious. Some of the sea stars most heavily affected are keystone predators that influence the whole diversity of life in the intertidal zone.”

Colleagues from the Oregon Coast Aquarium are monitoring subtidal sites in Yaquina Bay, where wasting was first observed in April. Photos and video of that work are available at http://bit.ly/1kMlG9s

Altogether, mortality has been documented in 10 species of sea stars on the West Coast. No definitive cause has yet been identified, and it could include bacterial or viral pathogens. Researchers around the nation are working on the issue. More information, including an interactive map of all observations, and opportunities for interested citizens to participate in the observation effort are available online at http://bit.ly/1o5bWNi

Sea star wasting syndrome is a traumatic process in which, over the course of a week or less, the sea stars begin to lose legs, disintegrate, ultimately die and rot. They sometimes physically tear their bodies apart. Various epidemics of the syndrome have been observed in the past, but none of this extent or severity.

In a healthy ecosystem, sea stars are beautiful, but also tenacious and important parts of the marine ecosystem. In particular, they attack mussels and keep their populations under control. Absent enough sea stars, mussel populations can explode, covering up algae and other small invertebrates. Some affected sea stars also eat sea urchins. This could lead to increased numbers of sea urchins that can overgraze kelp and sea grass beds, reducing habitat for other fish that use such areas for food and refuge.

The very ecological concept of “keystone predators,” in fact, originated from work in 1969 at the University of Washington using this same purple ochre sea star as a model.

“Parts of California, Washington, and British Columbia had already been affected by this outbreak of the wasting syndrome,” said Kristen Milligan, program coordinator at OSU for the Partnership for Interdisciplinary Studies of Coastal Oceans, or PISCO, which is a collaboration of OSU, the University of California/Santa Cruz, UC/Santa Barbara and Stanford University.

“It wasn’t clear why those areas had been hit and Oregon had not,” Milligan said. “We were hoping that Oregon’s coast would be spared. Although it was hit late, we are obviously being hit hard by this potentially devastating syndrome.”

A group of OSU undergraduate students have assisted in recent monitoring of the OSU outbreak, studying conditions at 10 sites from south of Cape Blanco to north of Depoe Bay. Researchers say this is one of the best documented outbreaks of marine disease ever undertaken in North America.

Besides OSU and PISCO, other collaborators in this Oregon initiative include the Oregon Department of Fish and Wildlife, the Oregon Coast Aquarium, OSU Hatfield Marine Science Center, Oregon Coast Watch, Haystack Rock Awareness Program in Cannon Beach, and the Multi-Agency Rocky Intertidal Network. Oregon Sea Grant provides funding for volunteer surveys in the intertidal zone, and the David and Lucile Packard Foundation provides support to PISCO.

In some past cases, ecosystems have recovered from severe losses of sea stars, but in others damage has been long-lasting.

In the past, some of the outbreaks were associated with warm-water conditions during El Nino events, but currently the water temperatures in Oregon “are only at the high end of a normal range,” Menge said.

 

Media Contact: 
Source: 

Kristen Milligan, 541-737-8862

Multimedia Downloads
Multimedia: 

Dying sea star

Dying sea star


Sea star monitoring

Oregon Coast Aquarium diver monitoring


Monitoring sea star epidemic

OSU students monitoring


YouTube video
http://bit.ly/1mazKuT

Tracking potato famine pathogen to its home may aid $6 billion global fight

CORVALLIS, Ore. – The cause of potato late blight and the Great Irish Famine of the 1840s has been tracked to a pretty, alpine valley in central Mexico, which is ringed by mountains and now known to be the ancestral home of one of the most costly and deadly plant diseases in human history.

Research published today in the Proceedings of the National Academy of Sciences, by researchers from Oregon State University, the USDA Agricultural Research Service and five other institutions, concludes that Phytophthora infestans originated in this valley and co-evolved with potatoes over hundreds or maybe a few thousand years, and later spread repeatedly to much of the world.

Knowing the origin of the pathogen does more than just fill in a few facts in agricultural history, the scientists say. It provides new avenues to discover resistance genes, and helps explain the mechanisms of repeated emergence of this disease, which to this day is still the most costly potato pathogen in the world.

Potato late blight continues to be a major threat to global food security and at least $6 billion a year is spent to combat it, mostly due to the cost of fungicides and substantial yield losses. But P. infestans is now one of the few plant pathogens in the world with a well-characterized center of origin.

“This is immensely important,” said Niklaus Grunwald, who is a courtesy professor in the Department of Botany and Plant Pathology in the College of Agricultural Sciences at Oregon State University, a researcher with the USDA Agricultural Research Service, and lead author on the study.

“This is just a textbook example of a center of origin for a pathogen, and it’s a real treat,” Grunwald said. “I can’t think of another system so well understood. This should allow us to make significant headway in finding additional genes that provide resistance to P. infestans.”

Finding ways to genetically resist the potato late blight, scientists say, could help reduce the use of fungicides, and the expense and environmental concerns associated with them.

There had been competing theories about where P. infestans may have evolved, with the leading candidates being the Toluca Valley near Mexico City, or areas in South America where the potato itself actually evolved thousands of years ago.

Gene sequencing technology used by this research group helped pin down the Toluca Valley as the ancestral hot spot. The P. infestans pathogen co-evolved there hundreds of years ago with plants that were distant cousins of modern potatoes, which produced tubers but were more often thought of as a weed than a vegetable crop.

Today, the newly-confirmed home of this pathogen awaits researchers almost as a huge, natural laboratory, Grunwald said. Since different potato varieties, plants and pathogens have been co-evolving there for hundreds of years, it offers some of the best hope to discover genes that provide some type of resistance.

Along with other staple foods such as corn, rice and wheat, the potato forms a substantial portion of the modern human diet. A recent United Nations report indicated that every person on Earth eats, on average, more than 70 pounds of potatoes a year. Potatoes contain a range of vitamins, minerals, phytochemicals, fiber and – for hungry populations – needed calories.

It’s believed that the potato was first domesticated more than 7,000 years ago in parts of what are now Peru and Bolivia, and it was brought to Europe by Spanish explorers in the late 1500s. A cheap and plentiful crop that can grow in many locations, the ability to increase food production with the potato eventually aided a European population boom in the 1800s.

But what the New World provided, it also took away - in the form of a potato late blight attack that originated from Mexico, caused multiple crop failures and led, among other things, to the Irish potato famine that began in 1845. Before it was over, 1 million people had died and another 1 million emigrated, many to the U.S.

That famine was exacerbated by lack of potato diversity, as some of the varieties most vulnerable to P. infestans were also the varieties most widely cultivated.

Collaborators on the research were from the University of Florida, the James Hutton Institute in Scotland, the University of the Andes in Colombia, Cornell University, and the International Potato Center in Beijing. It was supported by the U.S. Department of Agriculture and the Scottish government.

Media Contact: 
Source: 

Niklaus Grunwald, 541-738-4049

Multimedia Downloads
Multimedia: 

Toluca Valley

Toluca Valley


Potato relative

Potato relative


Infected potato plant

Infected plant

Study finds Oregon’s most common fish at least three distinct species

CORVALLIS, Ore. – A new study has found that the most common fish species in Oregon – the speckled dace – is actually at least three separate and distinct species.

The findings suggest that Oregon may have greater biological diversity in its native fish populations than previously recognized, said researchers at Oregon State University who led the study. The management implications for the discovery are not yet known.

Results of the study are being published this week in the journal Molecular Phylogenetics and Evolution.

The speckled dace is a small minnow that appears in ponds, rivers, springs, lakes and other waterways from Canada to Mexico. It is the most common fish in Oregon, meaning that it appears in more bodies of water than any other fish, the researchers say, yet little is known about its genetic makeup.

“For some reason, the speckled dace has never been fully investigated,” said Kendra Hoekzema, a faculty research assistant in OSU’s Department of Fisheries and Wildlife and lead author on the study. “Yet it varies greatly in genetics and morphology and now we’re finding that more than one species is out there in a small corner of Oregon.

“Who knows how many other species there might be?” she added. “The Great Basin has a lot of springs.”

The study began as a review of the Foskett Spring speckled dace which, as a listed federally threatened subspecies, must be investigated every five years. This particular dace has only been found in a single spring within Warner Valley in southeast Oregon, and as part of her study, Hoekzema collected speckled dace from surrounding basins, including the Warner system, Goose Lake, Lake Abert, Silver Lake and the Malheur River system, as well as Stinking Lake Spring on the Malheur National Wildlife Refuge.

DNA analysis led Hoekzema and co-author Brian Sidlauskas, an assistant professor in the Department of Fisheries and Wildlife at OSU, to determine that there are three “highly divergent” evolutionary lineages of speckled dace that warrant species-level status – the Malheur stream dace, Stinking Lake Spring dace, and dace from the other four basins combined.

“The speckled dace has been on the books for decades as one species and yet when we look at one small corner of Oregon, we find three distinct species,” Sidlauskas said. “Typically, when we think about new species being discovered, we think about some isolated part of the tropics. This is in our own backyard.”

“It goes to show both how much diversity may exist,” he added, “and how little we know about it.”

Hoekzema said the Stinking Lake Spring dace appeared to have branched off genetically some 2.5 million years ago, while the Foskett Spring dace – and perhaps others – became isolated just 10,000 years ago.

The researchers also recommended that the Foskett Spring dace should be listed as an “Evolutionarily Significant Unit” (ESU) and not a subspecies, a technical status change that would not necessarily affect how it is protected.

Paul Scheerer, a biologist with the Oregon Department of Fish and Wildlife, has been working at Foskett Spring since 2005 evaluating population status, trends and habitat conditions. He and his colleagues became concerned, Scheerer said, that the speckled daces’ population was declining and that their habitat was shifting from open water vegetated habitat to emergent marsh.

The Bureau of Land Management, ODFW and the U.S. Fish and Wildlife Service conducted controlled burns of some of the vegetation in 2009 and then excavated new pools fed by the spring.

“Foskett speckled dace quickly expanded into the new pools,” Scheerer said, “and since then we’ve experienced a seven-fold increase in the speckled dace to about 13,000 fish. We also introduced dace into nearby, recently restored ponds to expand their abundance and reduce the risk of catastrophic loss.

“The OSU study results suggest there are more dace species out there than we previously knew,” he added. “It will allow us to adequately protect and enhance these unique fish into the future. The work by OSU is invaluable and will allow us to better understand the diversity of the fish fauna that has evolved in these isolated desert basins.”

The management implications on a broader scale are unclear, Sidlauskas said, because while the new species have been recognized as genetically distinct, their full geographic ranges are unknown. Nevertheless, the discovery of a distinct, unrecognized and possibly endemic species within the Malheur refuge underscores the importance of such areas, he added.

“This suggests that the refuge may harbor even more diversity than we knew and highlights the importance of preserving and valuing such wild places,” Sidlauskas said.

Although the minnows, which grow to a length of about three inches, don’t carry the iconic status of Northwest salmon or steelhead, they are important parts of the food web in many areas. Many species of fish-eating fish love them.

“Speckled dace are the bon-bons of the fish world for piscatorial fish,” Sidlauskas said, “and they are likely important prey for birds and other animals as well.”

The study was funded by the Bureau of Land Management, Oregon Department of Fish and Wildlife, the OSU College of Agricultural Sciences, and the OSU Research Office.

Media Contact: 
Source: 

Kendra Hoekzema, 541-737-6035, Kendra.hoekzema@oregonstate.edu; Brian Sidlauskas, 541-737-6789, brian.sidlauskas@oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

 

 

 

 

 

 

 

 

speckled dace photo

speckled dace

 

Seining for dace

Collecting dace

 

MobileTissuingLab

Mobile lab

 

ColemanLake

Coleman Lake

Study of marine life near Newport finds no red flags for toxicity

NEWPORT, Ore. – Oregon State University scientists have examined a variety of coastal marine species near Newport, Ore., for concentrations of heavy metals and organic pollutants and found only trace amounts with no bioaccumulation of significant concern.

Their report is being presented May 19 to the City of Newport, which commissioned the study. It is available online at: http://www.thecityofnewport.net/

Newport city officials were concerned that effluent from a Georgia-Pacific containerboard plant outfall pipe, located some 4,000 feet off Nye Beach, may be exposing some marine life to contaminants. A 2010 study by CH2M-Hill looked for heavy metals in the surrounding water and sediments and found little with which to be concerned. Their study did not investigate marine organisms, however.

“There was some concern that metals and organic pollutants may be bioaccumulating in nearby marine life,” said Sarah Henkel, a marine ecologist at OSU’s Hatfield Marine Science Center and primary investigator on the study. “We tested for 137 different chemicals and only detected 38 of them – none at levels that remotely approach concern for humans.”

The City of Newport had asked the OSU researchers to look at a variety of species, including flatfish (speckled sand dab), crustaceans (Dungeness crab and Crangon shrimp), and mollusks (mussels and olive snails) because they could bioaccumulate metals and organic pollutants at different rates. The researchers collected a variety of samples in 2012 near the G-P outfall, as well as at sites north of Yaquina Head and south of Yaquina Bay. In fall of 2013, they also collected and analyzed rock scallops.

The organisms were analyzed for trace metals including copper and lead, polychlorinated biphenyls (PCBs) and congeners, polybrominated diphenyl ethers (PBDEs), which are used in flame-retardant materials, and other potentially carcinogenic compounds. They also were analyzed for organic-based compounds, which are commonly derived from pesticides.

Not a single organism was found with a bioaccumulation of metals or organic pollutants that approached levels of concern for humans established by the U.S. Food and Drug Administration, the researchers reported.

“The system is pretty darn clean,” said Scott Heppell, a biologist with the OSU Department of Fisheries and Wildlife and co-primary investigator on the study.  “I was certainly interested personally going into the study because my family goes crabbing in some of the places we sampled. If we had found anything, we would have had to come up with a new place. But we found nothing approaching the level of intervention for humans and that’s reassuring.”

The OSU researchers did find one area of potential future concern – trace levels of arsenic in mussels at sites both north and south of Yaquina Bay. The arsenic levels were still below the FDA level of concern for human consumption (86 parts per million), Heppell said, but in some cases exceeded the established level of concern for impacts to the mussels themselves, which is 3.6 ppm. Some of the samples analyzed by the researchers reached 5.0 ppm.

“It is still 15 times lower than the threshold for human concern, but there is potential for damage to the mussels themselves,” Heppell said. “It is also worth noting because the arsenic was in virtually all of the mussel samples we collected on beaches from Seal Rock to north of Yaquina Head. There is no way to draw a link to the G-P outfall.

“But because it was so common, it may be a good idea to study mussel populations up and down the entire coast to see what arsenic levels are at beyond our study area.”

Arsenic is often used in pressure-treated lumber and wood preservatives, the researchers noted.

Among other findings:

  • The researchers found three derivatives of dichlorodiphenyltrichloroethane, or DDT, a pesticide that has been banned for 40 years. Although it was detected at very small amounts, “the fact that it is still present in organisms four decades later shows why it was banned,” Henkel said.
  • No significant bioaccumulation could be attributed to the G-P outfall. In fact, fish, crabs and shrimp collected from subtidal sites away from the outfall often had higher concentrations of metals than those adjacent to the pipe, though still at levels safe for human consumption.
  • Two DDT derivatives (2,4’-DDE and 4,4’-DDD) were found in a single crab sample. Another, hexochloro-benzene, was detected in just two crab samples – at concentrations some 10,000 times less than the toxicity level listed as potentially affecting the crabs themselves.

“It is worth noting that the instrumentation today is so sensitive it can detect trace amounts of compounds at concentrations not possible just a few years ago,” Heppell said.

The OSU researchers praised the City of Newport for seeking data that potentially could have been damaging, yet was important to know.

“This is one of those reports that, thankfully, turns out to be rather boring,” Henkel said.

Other researchers on the project included Selina Heppell, a biologist with the OSU Department of Fisheries and Wildlife; and OSU faculty research assistants Kristin Politano and Vincent Politano.

Media Contact: 
Source: 

Sarah Henkel, 541-867-0316, sarah.henkel@oregonstate.edu; Scott Heppell, 541-737-1086, scott.heppell@oregonstate.edu

OSU scientists part of national APLU report outlining research challenges

CORVALLIS, Ore. – The national Association of Public and Land-grant Universities released a report today outlining six “grand challenges” facing the United States over the next decade in the areas of sustainability water, climate change, agriculture, energy and education.

The APLU project was co-chaired by W. Daniel Edge, head of the Department of Fisheries and Wildlife at Oregon State University. The report is available online at: http://bit.ly/1ksH2ud

The “Science, Education, and Outreach Roadmap for Natural Resources” is the first comprehensive, nationwide report on research, education and outreach needs for natural resources the country’s university community has ever attempted, Edge said.

“The report identifies critical natural resources issues that interdisciplinary research programs need to focus on over the next 5-10 years in order to address emerging challenges,” Edge noted. “We hope that policy-makers and federal agencies will adopt recommendations in the roadmap when developing near-term research priorities and strategies.”

The six grand challenges addressed in the report are: 

  • Sustainability: The need to conserve and manage natural landscapes and maintain environmental quality while optimizing renewable resource productivity to meet increasing human demands for natural resources, particularly with respect to increasing water, food, and energy demands.
  • Water: The need to restore, protect and conserve watersheds for biodiversity, water resources, pollution reduction and water security.
  • Climate Change: The need to understand the impacts of climate change on our environment, including such aspects as disease transmission, air quality, water supply, ecosystems, fire, species survival, and pest risk. Further, a comprehensive strategy is needed for managing natural resources to adapt to climate change.
  • Agriculture: The need to develop a sustainable, profitable, and environmentally responsible agriculture industry.
  • Energy: The need to identify new and alternative renewable energy sources and improve the efficiency of existing renewable resource-based energy to meet increasing energy demands while reducing the ecological footprint of energy production and consumption.
  • Education: The need to maintain and strengthen natural resources education at our schools at all levels in order to have the informed citizenry, civic leaders, and practicing professionals needed to sustain the natural resources of the United States.

 

Three other OSU researchers were co-authors on the report, including Hal Salwasser, a professor and former dean of the College of Forestry; JunJie Wu, the Emery N. Castle Endowed Chair in Resource and Rural Economics; and George Boehlert, former director of OSU’s Hatfield Marine Science Center.

Wu played a key role in the climate change chapter in identifying the need to better understand the tradeoffs between investing now in climate change adaptation measures versus the long-term risk of not adopting new policies.

Edge and Boehlert contributed to the energy chapter, which focuses primarily on renewable energy.

“The natural resources issues with traditional sources of energy already are well-understood,” Boehlert said, “with the possible exception of fracking. As the country moves more into renewable energy areas, there are many more uncertainties with respect to natural resources that need to be understood and addressed. There are no energy sources that do not have some environmental issues.”

Salwasser was an author on the sustainability chapter that identifies many issues associated with natural resource use, including rangelands, forestry, fisheries and wildlife and biodiversity. The authors contend the challenge is to use these resources in a sustainable manner meeting both human and ecosystem needs.

The project was sponsored by a grant from the U.S. Department of Agriculture to Oregon State University, which partnered with APLU and authors from numerous institutions.

-30-

Media Contact: 
Source: 

Dan Edge, 541-737-2810; Daniel.edge@oregonstate.edu