marine science and the coast

Scientists Eye Possible Link Between Cascadia Zone, San Andreas Fault

CORVALLIS, Ore. – A new comparison of earthquakes that have taken place along the West Coast during the past 10,000 years suggests that seismic activity in the Cascadia Subduction Zone off Oregon and Washington may actually have triggered earthquake events in the San Andreas Fault in the San Francisco Bay area.

The analysis also concludes that major earthquakes occur much more frequently in the southern part of Cascadia – in a range of 270 to 525 years depending on location – rather than every 500-600 years as is known for northern Cascadia.

The study is being published in the April issue of the Bulletin of Seismological Society of America.

A research team led by Chris Goldfinger, an associate professor of marine geology at Oregon State University, sampled marine sediments along the northern California coast to look for evidence of historic seismic activity along the San Andreas Fault. The researchers were looking for “turbidites,” which are coarse sediments that accumulate in the abyssal plain during major earthquakes.

“The turbidites stand out from the finer particles that accumulate on a regular basis between major tectonic events and provide a nice timeline for seismic activity,” Goldfinger said.

The core sampling revealed 15 separate turbidite layers that were deposited over the last 3,000 years and correspond to evidence from the terrestrial paleoseismic record along the northern San Andreas Fault. But what surprised scientists was the discovery that 13 of those earthquakes occurred in close conjunction with major earthquakes in the southern Cascadia Subduction Zone.

“It’s either an amazing coincidence,” Goldfinger said, “or one fault triggered the other. It looks like when Cascadia is hit by a major earthquake, another will occur in the San Andreas region – on average, within several decades, but possibly less.

“They could be separated by decades or years,” he added, “but it is possible that it could be days or hours.”

Cascadia earthquakes are generally larger, Goldfinger pointed out, and the timing suggests that earthquakes in Cascadia would be more likely to be the triggering mechanism to San Andreas activity than vice versa. This conclusion is supported by stress modeling, including work outlined in a paper by Roland Burgmann and Kelly Grijalva of the University of California at Berkeley.

In previous research, Goldfinger has documented 34 major earthquakes in the Cascadia Subduction Zone during the past 10,000 years, including at least 19 quakes that ruptured along the entire length of the zone. Such a major event would have required an earthquake of magnitude 8.5 or larger, he says.

Going back farther than 10,000 years into the geologic record has been difficult because the sea level used to be lower and West Coast rivers emptied directly into offshore canyons, making it difficult to isolate the turbidites from storm debris.

The new study also identified the boundaries for the Cascadia Zone earthquakes that did not rupture the entire fault line. The evidence of these quakes, which could still be of significant magnitude, suggest that recurrence intervals for Cascadia earthquakes are much shorter than for the rest of the margin – a range of 270 to 525 years, and even less along the southern boundary of Cascadia, about 220 years during the last 3,000-year period.

The paper published in the Bulletin of Seismological Society of America was part of a special section on the 1906 San Francisco earthquake. The lead author was Goldfinger.


Story By: 

Chris Goldfinger,

Salmon Decline Linked Mostly to Ocean Conditions, Scientists Says

NEWPORT, Ore. – The finger of blame for declining runs of Pacific Northwest salmon has been pointed broadly: habitat loss from logging and development, an abundance of predatory sea lions, power-generating dams, terns and other coastal birds that prey on juvenile fish, and over-fishing by commercial and sport fishermen.

But no factor is more critical to salmon prosperity than ocean conditions, experts say, and the complex interaction between biologically distinct groups of salmon and changing ocean habitats has created a nightmare for resource managers.

At the same time a projected huge run of spring chinook salmon are entering the Columbia River, fishing on one of its major tributaries – the Willamette River – has been closed because of a shockingly low estimate of returning fish. And offshore salmon seasons are in jeopardy along the entire West Coast this spring and summer because of a projected historic low return of fish to the Sacramento River basin.

The common denominator in the good and bad runs is the ocean.

Bill Peterson, a fisheries biologist with NOAA who is based at Oregon State University’s Hatfield Marine Science Center, says this year’s salmon debacle can be traced back to unusual ocean conditions in 2005. A delay in the ocean upwelling caused ocean conditions “to collapse.”

“The delayed upwelling off the Oregon coast meant that in the critical time when juvenile salmon were entering the ocean, there was nothing for them to eat – and most of them died,” said Peterson, who is a courtesy professor in OSU’s College of Oceanic and Atmospheric Sciences. “But you don’t see the impact until two or three years later, when the fish should first begin returning as adults.”

Wind-driven upwelling brings nutrients from deeper water to the surface and fuels phytoplankton blooms. Lipid-rich copepods and other zooplankton feed on the tiny plants, and in turn are consumed by anchovies, sardines, herring and other small fish that are staples in the diet of salmon and other fish. The delay in upwelling was caused by late arrival of seasonal winds, according to researchers at OSU, who published their findings in the Proceedings of the National Academy.

The delayed upwelling can explain why most fish runs are plummeting, yet fisheries managers are predicting a huge number of spring chinook bound for the Columbia River this year. Why? The answer, Peterson says, can be found by tracing where juveniles from different river systems go once they enter the ocean.

For the past 10 years, Peterson has participated in a research project funded by the Bonneville Power Administration that analyzes the distribution of juvenile salmon off the West Coast and uses genetic tracking to determine their river origin http://www.nwfsc.noaa.gov/research/divisions/fed/oeip/a-ecinhome.cfm. Juvenile fish from many of Oregon’s coastal rivers, along with those from the Willamette River and the Sacramento River, congregate just off the Oregon coast once they leave their river systems.

When the ocean collapse came in 2005, most of those fish starved.

“But Columbia River spring chinook don’t stay off the Oregon coast,” Peterson said. “In our 10 years of sampling, we’ve only caught a few Columbia River juveniles just off our coast, so it’s obvious they go somewhere else. If you look this year at chinook salmon in Alaska, they’re doing well. So it’s possible that Columbia River juveniles head to the same place as Alaska juveniles.”

Peterson speculates that perhaps young Columbia River salmon may migrate toward a unique ecosystem several hundred miles off the Northwest coast. In that deep, cold water, lipid-rich fishes known as myctophids, or “lantern-fish,” provide a bountiful diet for a variety of marine life. These fishes are “very abundant” in the mesopelagic zone, he added, and could provide a rich forage base for young chinook salmon.

“It’s just a theory at this point,” he said. “We need to go out there and sample for juvenile salmon. But the situation this year underscores how fascinating research on salmon can be. We used to have a lot more genetic diversity in our salmon runs. They used to spawn at different times and hang out offshore at different times. We may be paying for the loss of that diversity.”

Ocean conditions off Oregon in 2006 and 2007 were somewhat better for salmon survival, but still were less than ideal. The good news, Peterson says, is that the influence of La Niña over the winter has created what appear to be excellent ocean conditions thus far in 2008. But, he added, it’s premature to celebrate.

“The system can’t recover from a near-complete collapse in one year,” Peterson warned. “There may not be enough adults in the streams to repopulate the runs. We need three or four years of good conditions before we can breathe a little easier.”

Story By: 

Bill Peterson,

Research Aimed at Protecting Salmon in Jeopardy – Because of Lack of Salmon

NEWPORT, Ore. – Commercial fishermen and scientists from Oregon, California and Washington have agreed to collaborate on a critical coast-wide study to learn more about salmon distribution, migration and behavior in the Pacific Ocean, but an alarming projected shortage of fish this year is putting their research in jeopardy.

Ironically the study, which expands a two-year pilot program began by Oregon State University researchers, is designed to help protect weak salmon stocks.

“We’ve got the funding, we’ve got the science and we’ve got the interest and cooperation of the fishing industry,” said Gil Sylvia, director of the Coastal Oregon Marine Experiment Station at OSU’s Hatfield Marine Science Center in Newport, Ore. “Now, we just need some salmon.”

During the pilot project, the OSU scientists found they could trace genetic markers of salmon caught in the ocean through small samples of fin or tissue and within 24 hours pinpoint an individual salmon’s river basin of origin. The hope, Sylvia says, is that an expanded study will allow the scientists to learn more about fish behavior in the ocean and whether salmon from, say, the Sacramento River or the Klamath River travel in clusters and feed in certain areas.

“This is ground-breaking research that could allow resource managers to keep much of the ocean open for fishing, yet protect weakened runs of fish,” Sylvia said. “There are preliminary indications that salmon destined for certain river systems do behave differently, but we need more data from a broader sampling before any management implications become clear.”

The Pacific Fisheries Management Council last month outlined three potential options for ocean chinook salmon fishing south of Cape Falcon (near Garibaldi, Ore.). The most optimistic scenario is a shortened season from April 15 to May 31 that would allow fishermen to catch a quota of fish and also share fins and tissue samples with scientists for genetic identification. A second option would preclude commercial fishing, but allow the scientists to catch and release a select number of salmon, maintaining only a piece of the tail fin for research.

The third, most dire option would close the ocean to all chinook fishing and not allow the take of any fish – even catch-and-release – for research.

The council is seeking to protect what may be a historic low return of salmon to the Sacramento River, a stock of fish that spend much of their time off the Oregon coast. The group will meet April 6-12 in Seattle, Wash., where it will decide on one of the three options – or another approach.

For the past two years, the Collaborative Research on Oregon Ocean Salmon project, or CROOS. has paired Oregon State University scientists and the state’s commercial fishing industry in a study to improve scientific knowledge about salmon behavior in the ocean. More than 190 salmon fishermen from 11 Oregon counties were trained in sampling protocols as part of the project, which was funded by the Oregon Watershed Enhancement Board.

The fishermen clipped fins and took tissues samples from the salmon before processing them, and logged when and where the fish were caught using a handheld GPS unit. The scientists brought the samples back to Hatfield Marine Science Center laboratories and conducted the genetic studies.

In the first year of the project, the scientists were able to match 2,100 salmon caught to a river, basin or specific region with 90 percent probability, according to Michael Banks, an OSU geneticist and director of the scientific portion of the project. Not all samples work flawlessly, Banks said, and genetic markers for some river systems are similar to others. Still, the scientists were able to confidently pinpoint the origin of roughly four out of every five salmon they tested.

Of those fish, 42 carried coded wire tags from hatcheries that identified where the fish were from. Without knowing that nugget of information, the scientists ran their genetic protocols and found they hit the mark on 41 of the 42 fish, Banks pointed out.

“That was pretty good validation that our methods work,” Banks said.

Buoyed by the results, the CROOS leaders sought to expand their studies in 2008. The two years of field study focused solely on the ocean off Oregon – and much of the study was concentrated off the central Oregon coast. Broadening the scope of the research to include Washington and California is critical, Sylvia says, because of the migratory nature of the salmon.

The CROOS project leaders have engaged the Oregon Salmon Commission, the California Salmon Commission and the Washington Department of Fish and Wildlife in the project, as well as NOAA’s National Marine Fisheries Service, and they are awaiting the final word from the Pacific Fisheries Management Council on the April decision.

Washington has used genetic identification methods to estimate fisheries stock composition for several years, but has not yet paired that with ocean sampling to determine at-sea stock distribution, the researchers say. California began its own genetic tracking project in 2006 and continued last year, although on a much smaller scale than Oregon.

Having the three states join forces will give scientists a much better idea of West Coast salmon migration, the researchers pointed out.

“The research is particularly important because some of the preliminary results suggest interesting patterns in salmon behavior that need to be validated,” said Renee Bellinger, an OSU faculty research assistant who is coordinating the three-state research effort. “We recorded ‘pulses’ of fish that would move at one time – from the Rogue River, for example – but we couldn’t gauge the range of movement or duration because the sampling period wasn’t long enough.”

If approved, scientists in all three states will work with commercial fishermen in their respective regions to collect the samples that they will test, using the CROOS protocols. They hope to look at different sampling blocks over time and space, covering the Pacific Ocean from northern Washington to the San Francisco Bay area.

In addition to their genetic studies, the scientists also are monitoring ocean conditions – including temperature, salinity, dissolved oxygen content and other factors – to determine their effect on salmon distribution, Sylvia said. Some of that information is collected by the fishermen, though most is supplied by unmanned undersea gliders that can be programmed to roam the same stretches of ocean where the fishermen are working.

“There is a tremendous amount of interest from the fishing industry in this project,” Sylvia said. “This is a case where science may help provide solutions to a complex and difficult management problem.”

Specific goals of the Oregon-based CROOS project include:

• Broadening the genetic stock identification (GSI) research to test different hypotheses on location and migration of salmon, and determine if hatchery fish behave differently than wild fish;

• Use data from vessels and undersea gliders to monitor ocean conditions that can be tied to biological data to determine if temperature, salinity or other factors influence migration;

• Sample tissues from harvested salmon to test for parasites that previously have infected Klamath basin fish;

• Evaluate different digital data logging instruments that can be used in real time on small fishing vessels;

• Track commercially harvested salmon through a barcode system from vessel to market and develop websites that allow consumers to learn more about their purchase;

• Design a “real time” genetic stock identification-based website to share data with multiple audiences;

• Develop potential management simulation scenarios based on the data to see if what the researchers learn through their data collection is sufficient to influence the in-season decision-making process.


Story By: 

Gil Sylvia,

Public Invited to Preview OPB film, learn about invasive species

CORVALLIS, Ore. -- Scotch broom, Japanese eelgrass, Quagga mussels, and Oregonians: How are they related? While the first three are non-native, invasive species of plants and animals, Oregonians often unknowingly spread these and a growing number of other invaders in the state -- and can also stop invasive species before they spread.

A statewide educational effort to prevent the spread of invasive species ramps up this month, highlighted by a media campaign whose centerpiece is a new documentary film produced by Oregon Public Broadcasting. The hour-long documentary, “The Silent Invasion,” has its OPB broadcast premiere on Earth Day, April 22, at 8 p.m. -- but because of faculty involvement in the production, Oregon State University (OSU) will host special advanced screenings, Wednesday, April 9, in Corvallis, and Thursday, April 17, in Newport. The public is invited.

The Corvallis special event begins at 5 p.m. with a reception and refreshments, followed by an introduction to the film, and then the showing itself at 5:30. Time for discussion follows. All Corvallis events are at the CH2MHill Alumni Center on the campus, across from Reser football stadium.

The Newport screening is at the OSU Hatfield Marine Science Center, in the public auditorium within the Visitor Center, starting at 6 p.m.

Copies of a new guidebook published by Oregon Sea Grant, “On the Lookout for Aquatic Invasive Species,” will be available in limited quantities for free. Oregon Sea Grant leads public education activities in Oregon related to aquatic invasives.

Additional information for media: Oregon Sea Grant faculty at OSU have been playing a critical role in the development of the media campaign. Sam Chan, Sea Grant Extension invasive species specialist, is part of a team of advisors to OPB’s Oregon Field Guide production crew, led by producer Ed Jahn. Chan arranged for the OPB crew to be invited along on an exploratory research visit to China last year, and that experience of the interconnected global nature of the invasives problem and potential solutions figures prominently in the OPB documentary. Chan represents Oregon Sea Grant on the state’s Oregon Invasive Species Council, which is another key partner in the public education campaign. Chan and Jahn will be the main presenters at the Corvallis screening.

At the same time, Chan and other Sea Grant colleagues have been conducting social science research to guide the development of the campaign. “Focus group” interviews were conducted with several groups whose activities impinge on invasive species, including boaters, hunters and gardeners. And Sea Grant has also supported the development of a statewide public opinion survey with the Oregon Invasive Species Council about invasives, led by Sea Grant professor of free-choice learning, Lynn Dierking, Chan, and communications leader Joe Cone.

In addition to the new identification field guide, “On the Lookout for Aquatic Invaders,” which will be available at the April 9 screening, Sea Grant’s own award-winning documentary about aquatic invasive species, “You Ought to Tell Somebody!” is online at www.seagrant.oregonstate.edu.

Along with its feature documentary, OPB has planned a year-long campaign called “Stop the Invasion” to counter the environmental and economic threat of invasive species. The campaign will also include a series of television awareness spots, an online invasive species 'reporting' hotline, a “GardenSmart Oregon” guide to non-invasive plants for your garden, a statewide volunteer Take Action calendar, and other educational materials aimed at giving Oregonians the resources they need to join the fight to protect Oregon's natural environment. Other participants in the educational campaign include SOLV, the Nature Conservancy, the Oregon Invasive Species Council, the City of Portland, and Portland State University.



Sam Chan,

Marine Biologist to Give Lecture Friday at OSU

CORVALLIS, Ore. – Marine biologist Boris Worm, from Dalhousie University in Halifax, Nova Scotia, will give a free public lecture this Friday, April 11, at Oregon State University beginning at 4 p.m. in Gilfillan Auditorium.

His talk, “Ecosystem Consequences of Fishing Large Marine Predators,” is free and open to the public.

In his talk, he will discuss conservation concerns that arise from declining numbers of large predators, including some tuna and billfishes, sharks and turtles. The decline, and potential extinction of such species, can trigger cascading effects on the ecosystem, he says.

Worm is an expert on ocean biodiversity and the effects of fishing on the marine ecosystem. He has documented the effect of over-fishing at both the local and global scales, and is studying the consequences of changes in marine biodiversity.

Among his research projects is an effort to document large-scale patterns of species diversity in the open ocean. He also is working to document species’ response to habitat change and fishing over the last 50 years.


Story By: 

Andreas Schmittner,

Latest Earthquake Swarm off Coast Puzzles Scientists

NEWPORT, Ore. – Scientists at Oregon State University’s Hatfield Marine Science Center have recorded more than 600 earthquakes in the last 10 days off the central Oregon coast in an area not typically known for a high degree of seismic activity.

This earthquake “swarm” is unique, according to OSU marine geologist Robert Dziak, because it is occurring within the middle of the Juan de Fuca plate – away from the major, regional tectonic boundaries.

“In the 17 years we’ve been monitoring the ocean through hydrophone recordings, we’ve never seen a swarm of earthquakes in an area such as this,” Dziak said. “We’re not certain what it means. But we hope to have a ship divert to the site and take some water samples that may help us learn more.” The water samples may indicate whether the process causing the earthquakes is tectonic or hydrothermal, he added.

At least three of the earthquakes have been of a magnitude of 5.0 or higher, Dziak said, which also is unusual. On Monday (April 7), the largest event took place, which was a 5.4 quake. Seismic activity has continued through the week and a 5.0 tremor hit on Thursday. Numerous small quakes have continued in between the periodic larger events.

Few, if any, of these earthquakes would be felt on shore, Dziak said, because they originate offshore and deep within the ocean.

The earthquakes are located about 150 nautical miles southwest of Newport, Ore., in a basin between two subsurface “faulted” geologic features rising out of the deep abyssal sediments. The hill closest to the swarm location appears to be on a curved structure edging out in a northwestern direction from the Blanco Transform Fault toward the Juan de Fuca ridge, Dziak said.

Analysis of seismic “decay” rates, which look at the decreasing intensity of the tremors as they radiate outward, suggest that the earthquakes are not the usual sequence of a primary event followed by a series of aftershocks, Dziak said.

“Some process going on down there is sustaining a high stress rate in the crust,” he pointed out.

Dziak and his colleagues are monitoring the earthquakes through a system of hydrophones located on the ocean floor. The network – called the Sound Surveillance System, or SOSUS – was used during the decades of the Cold War to monitor submarine activity in the northern Pacific Ocean. As the Cold War ebbed, these and other unique military assets were offered to civilian researchers performing environmental studies, Dziak said.

Hatfield Marine Science Center researchers also have created their own portable hydrophones, which Dziak has deployed in Antarctica to listen for seismic activity in that region. The sensitive hydrophones also have recorded a symphony of sounds revealing not only undersea earthquakes, but the movement of massive icebergs, and vocalizations of whales, penguins, elephant seals and other marine species.

This isn’t the first time the researchers have recorded earthquake swarms off the Oregon coast, Dziak said. In 2005, they recorded thousands of small quakes within a couple of weeks along the Juan de Fuca Ridge northwest of Astoria. Those earthquakes were smaller, he pointed out, and located along the tectonic plate boundary.

This is the eighth such swarm over the past dozen years, Dziak said, and the first seven were likely because of volcanic activity on the Juan de Fuca ridge. The plate doesn't move in a continuous manner and some parts move faster than others. Movement generally occurs when magma is injected into the ocean crust and pushes the plates apart.

“When it does, these swarms occur and sometimes lava breaks through onto the seafloor,” Dziak pointed out. “Usually, the plate moves at about the rate a fingernail might grow – say three centimeters a year. But when these swarms take place, the movement may be more like a meter in a two-week period."

But this eighth swarm may be different.

“The fact that it’s taking place in the middle of the plate, and not a boundary, is puzzling,” Dziak admitted. “It’s something worth keeping an eye on.”


Story By: 

Bob Dziak,

Multimedia Downloads

Earthquake Swarm

This earthquake swarm (with red, yellow, brown, purple dots representing different days) is located on a basin between two faulted basement highs that rise above the surrounding, deep abyssal sediments. The swarm, located using the SOSUS hydrophone arrays, has produced more than 600 earthquakes in the past 10 days. (image courtesy of Hatfield Marine Science Center)

New Study Finds Increasing Acidification of Pacific Ocean’s Continental Shelf

CORVALLIS, Ore. – An international team of scientists surveying the waters of the continental shelf off the West Coast of North America has discovered for the first time high levels of acidified ocean water within 20 miles of the shoreline, raising concern for marine ecosystems from Canada to Mexico.

Researchers aboard the Wecoma, an Oregon State University research vessel, also discovered that this corrosive, acidified water that is being “upwelled” seasonally from the deeper ocean is probably 50 years old, suggesting that future ocean acidification levels will increase since atmospheric levels of carbon dioxide have increased rapidly over the past half century.

Results of the study were published this week in Science Express.

“When the upwelled water was last at the surface, it was exposed to an atmosphere with much lower CO2 (carbon dioxide) levels than today’s,” pointed out Burke Hales, an associate professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and an author on the Science study. “The water that will upwell off the coast in future years already is making its undersea trek toward us, with ever-increasing levels of carbon dioxide and acidity.

“The coastal ocean acidification train has left the station,” Hales added, “and there not much we can do to derail it.”

Scientists have become increasingly concerned about ocean acidification in recent years, as the world’s oceans absorb growing levels of carbon dioxide from the atmosphere. When that CO2 mixes into the ocean water, it forms carbonic acid that has a corrosive effect on aragonite – the calcium carbonate mineral that forms the shells of many marine creatures.

Certain species of phytoplankton and zooplankton, which are critical to the marine food web, may also be susceptible, the scientists point out, although other species of open-ocean phytoplankton have calcite shells that are not as sensitive.

“There is much research that needs to be done about the biological implications of ocean acidification,” Hales said. “We now have a fairly good idea of how the chemistry works.”

Increasing levels of carbon dioxide in the atmosphere are a product of the industrial revolution and consumption of fossil fuels. Fifty years ago, atmospheric CO2 levels were roughly 310 parts per million – the highest level to that point that the Earth has experienced in the last million years, according to analyses of gas trapped in ice cores and other research.

During the past 50 years, atmospheric CO2 levels have gradually increased to a level of about 380 parts per million.

These atmospheric CO2 levels form the beginning baseline for carbon levels in ocean water. As water moves away from the surface toward upwelling areas, respiration increases the CO2 and nutrient levels of the water. As that nutrient-rich water is upwelled, it triggers additional phytoplankton blooms that continue the process.

There is a strong correlation between recent hypoxia events off the Northwest coast and increasing acidification, Hales said.

“The hypoxia is caused by persistent upwelling that produces an over-abundance of phytoplankton,” Hales pointed out. “When the system works, the upwelling winds subside for a day or two every couple of weeks in what we call a ‘relaxation event’ that allows that buildup of decomposing organic matter to be washed out to the deep ocean.

“But in recent years, especially in 2002 and 2006, there were few if any of these relaxation breaks in the upwelling and the phytoplankton blooms were enormous,” Hales added. “When the material produced by these blooms decomposes, it puts more CO2 into the system and increases the acidification.”

The research team used OSU’s R/V Wecoma to sample water off the coast from British Columbia to Mexico. The researchers found that the 50-year-old upwelled water had CO2 levels of 900 to 1,000 parts per million, making it “right on the edge of solubility” for calcium carbonate-shelled aragonites, Hales said.

“If we’re right on the edge now based on a starting point of 310 parts per million,” Hales said, “we may have to assume that CO2 levels will gradually increase through the next half century as the water that originally was exposed to increasing levels of atmospheric carbon dioxide is cycled through the system. Whether those elevated levels of carbon dioxide tip the scale for aragonites remains to be seen.

“But if we somehow got our atmospheric CO2 level to immediately quit increasing,” Hales added, “we’d still have increasingly acidified ocean water to contend with over the next 50 years.”

Hales says it is too early to predict the biological response to increasing ocean acidification off North America’s West Coast. There already is a huge seasonal variation in the ocean acidity based on phytoplankton blooms, upwelling patterns, water movement and natural terrain. Upwelled water can be pushed all the way onto shore, he said, and barnacles, clams and other aragonites have likely already been exposed to corrosive waters for a period of time.

They may be adapting, he said, or they may already be suffering consequences that scientists have not yet determined.

“You can’t just splash some acid on a clamshell and replicate the range of conditions the Pacific Ocean presents,” Hales said. “This points out the need for cross-disciplinary research. Luckily, we have a fantastic laboratory right off the central Oregon coast that will allow us to look at the implications of ocean acidification.”

The study, funded by the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA), was the first in a planned series of biennial observations of the carbon cycle along the West Coast of the continent. In addition to Hales, principal investigators for the study included Richard A. Feely and Christopher Sabine of the NOAA Pacific Marine Environmental Laboratory; J. Martin Hernandez-Ayon, the University of Baja California in Mexico; and Debby Ianson, of Fisheries and Oceans Canada, Sidney, B.C.


Story By: 

Burke Hales,

New Mechanism Identified for Action of Possible Carcinogen

CORVALLIS, Ore. – Toxicologists at Oregon State University have identified a new biological mechanism by which a possible carcinogen – a chemical compound that’s widely used in everything from food wrappings to stain-resistant clothing – might increase cancer risk.

The findings were just reported in Environmental Health Perspectives, and relate to perfluorooctanoic acid, or PFOA. Commonly used for decades in many industrial processes, PFOA tends to persist in the environment and can be easily found in the blood of humans or many other animals all over the world.

The EPA is studying concerns about its possible role in developmental toxicity, cancer and other issues. Although in 2006 an EPA science advisory board voted to approve a recommendation that PFOA should be considered a “likely carcinogen,” the agency has made no final conclusions about its safety.

The new OSU study, done at the Sinnhuber Aquatic Research Laboratory with rainbow trout, concluded that PFOA significantly increased the incidence of liver tumors in a manner similar to the natural hormone estrogen – a very different mechanism than the way it had been shown to cause cancer in rodents.

“Laboratory rodents make very good animal models for many cancer studies, but this may not be one of them,” said Abby Benninghoff, a toxicologist with the OSU Department of Environmental and Molecular Toxicology and the Linus Pauling Institute . “The response of rodents and humans to PFOA exposure is most likely not the same. We have reason to believe that trout, which have been used to study cancer for 40 years, may react to PFOA exposure much more like humans do, and therefore provide more useful results.”

In rodents, Benninghoff said, exposure to high levels of PFOA causes a proliferation of “peroxisomes,” which are a part of normal cells that are involved in fat metabolism. Too much activity in these peroxisomes can increase oxidative stress, produce DNA damage and ultimately lead to cancer, researchers believe.

However, this “peroxisome proliferation” is much less of an issue with humans – or trout – perhaps because both humans and trout have fewer receptors that turn on the process of peroxisome proliferation. Because of that, it has been difficult to extrapolate to humans the findings about PFOA that were made with rodents.

By using microarrays that were able to study hundreds of genes in rainbow trout, scientists at OSU were able to identify a different way in which PFOA might cause cancer – it appears to mimic the action of the natural hormone estrogen. The researchers called it a “novel mechanism of carcinogenicity” for this chemical that merits further study.

In humans, several cancers have been linked to estrogen levels, including breast, uterine and ovarian cancer. Some cancer drugs are effective by blocking estrogen. Trout, as well as humans, are very sensitive to tumor promotion by estrogenic compounds.

“This does not, in itself, show that PFOA is a human carcinogen,” Benninghoff said. “However, it gives us an alternative way to understand how it might have those effects, and will provide direction for future research.”

PFOA is a member of a class of perfluorinated compounds that are widely used in many consumer products, such as lubricants, textile coatings, food wrappings, flame retardants, and other applications. PFOA has unusual chemical stability and tends to be found widely in animals, water supplies, and other areas. Some perfluorinated chemicals have been voluntarily removed from the market by manufacturers, but others – including PFOA – are still widely used.


Story By: 

Abby Benninghoff,

Wright Named to Ocean Studies Board

CORVALLIS, Ore. - Dawn Wright, a professor of geography and oceanography at Oregon State University, has been appointed to the Ocean Studies Board of the National Academies.

The Ocean Studies Board advises the federal government on issues of ocean science, ocean policies and ocean infrastructure needed to understand and protect coastal and marine environments and resources.

Wright does research and analysis in such fields as benthic terrain and habitat characterization, tectonics of mid-ocean ridges, high-resolution bathymetry, underwater videography/photography, and geographic information science. She has served on several other committees of the National Research Council.

Two other OSU scientists, Anne Trehu and Rob Holman, professors of marine geology and geophysics, are also members of the Ocean Studies Board. Both are in OSU’s College of Oceanic and Atmospheric Sciences.


Story By: 

Susan Roberts,
Ocean Studies Board, 202-334-2714

New Studies Highlight Concern over Rising Jellyfish Populations

CORVALLIS, Ore. – Jellyfish populations appear to be increasing along the West Coast and in the Bering Sea and scientists studying the phenomenon are concerned because jellyfish may feed on the same plankton species targeted by herring, sardines and anchovies, juveniles salmon and other fishes.

Compounding the situation, the scientists say, is that there are few predators for adult jellyfish.

“A few birds and fish will eat the jellies in their larval or juvenile stages,” said Richard D. Brodeur, a NOAA biologist and adjunct professor in the College of Oceanic and Atmospheric Sciences at Oregon State University. “But once the medusae reach a certain size, not much eats them.”

Newly published studies by Brodeur, OSU oceanographer Lorenzo Ciannelli and others are looking at the link between climate change and jellyfish populations and they have found this relationship is complex. The prevailing school of thought has been that as ocean waters warm, jellyfish populations will increase. But they have discovered that food sources, reproduction dynamics and ocean currents all play a role in jellyfish populations.

In a paper just published in Progress in Oceanography, the scientists describe a steep increase in jellyfish populations in the Bering Sea through the 1990s, peaking in the summer of 2000. But during the years of 2001 through 2005, when scientists recorded some of the warmest temperatures ever in the Bering Sea, jellyfish populations declined.

“They were still well ahead of their historic averages for that region,” said Ciannelli, an assistant professor in OSU’s College of Oceanic and Atmospheric Sciences. “But clearly jellyfish populations are not merely a function of water temperature.”

One key to learning more about jellyfish expansion has been Ciannelli’s work looking into the organisms’ complex life cycle. Adult males release their sperm into the water column and fertilize the eggs that female adults have released. From each fertilized egg, a larva is produced that attaches itself to a rock or some other solid surface and produces a polyp. These polyps reproduce asexually and eventually the young medusae detach themselves and begin the life cycle anew.

The researchers’ preliminary findings suggest that warmer ocean waters may enhance the stage where polyps transform into colonies, but that hypothesis is based on lab work, not field research. The reason, Ciannelli says, is that polyps are notoriously difficult to locate because of their small size.

“We think that higher temperatures lead to a higher metabolic rate and faster division of cells,” he said. “It accelerates the whole system. But finding polyps in the Bering Sea is like trying to do research on the dark side of the moon.”

Ciannelli and his colleagues are funded by the National Science Foundation to better understand how these polyps are distributed. One hypothesis is that there is a single unique source that produces the small jellyfish in the Bering Sea and their expansion is a product of currents. An alternative theory is that the jellyfish are using pockets of warm water to establish new colonies, which would be consistent with global warming scenarios, he said.

“What we’re trying to figure out is where the energy of the food web is going,” Ciannelli pointed out. “If it is going to the jellyfish, which are eating the plankton, it creates an overall sink because they have few predators. It is diverting the energy of the ocean from the pelagic to the benthic system.”

Scientists have begun looking more closely at food sources for jellyfish off the West Coast of the United States and their findings are surprising. In a paper published in the April 2008 issue of the Marine Ecology Progress Series, a team of scientists including Brodeur quantified diet and predation rates for large jellyfish from an upwelling region in the northern California Current. They found that in an area north of Cape Blanco, Ore., abundant populations of jellyfish ate an average of one-third of all the euphausiid – a type of zooplankton – eggs available each day. Consumption of other taxa reached 10 to 12 percent of the standing stocks.

On the other hand, copepods, important components of the marine food web, were consumed at relatively low levels – less than 1 percent a day. Lead author on that study was Cynthia L. Suchman, who conducted her research out of OSU’s Hatfield Marine Science Center Hatfield Marine Science Center in Newport, Ore., where Brodeur works.

Few scientists are conducting long-term jellyfish studies and the authors suggest that zooplankton studies and predation impacts by jellyfish should be incorporated into long-term studies and ecosystem models. “Unfortunately,” Brodeur said, “there hasn’t been a great deal of funding for jellyfish studies, so we don’t know as much as we should about their impact.”

Trawl surveys by Brodeur and his colleagues found that the spatial overlap between jellyfish and most pelagic fishes, including salmon, was relatively small. But in a forthcoming article in Marine Biology, the researchers point out that the overlap with “planktivorous” fishes that consume copepods and euphausiid eggs – including Pacific sardines, the northern anchovy, Pacific saury, and Pacific herring – was considerable. These prey species also are critical to the diets of salmon and other species in the ocean.

“We’ve been collecting data now for about nine years and it appears, at least on a preliminary basis, that when cold water regimes are prevalent, jellyfish numbers increase,” Brodeur said. “During the warmer years, when food sources are scarcer, there may be fewer jellyfish, but they grow quickly – whether because of elevated metabolic rates or less competition, we don’t know.”

This summer Brodeur will be involved in a series of cruises off the Oregon coast to sample jellyfish populations and see what effect this year’s cold-water La Niña phenomenon may have had.

“It won’t be a good sign for the ecosystem if we get a lot of jellies out there,” he said.

Their research has been supported by the National Science Foundation, NOAA and the National Marine Fisheries Service.


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Ric Brodeur,

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