OREGON STATE UNIVERSITY

marine science and the coast

Beaches Ravaged by Tsunami Still Eroding

CORVALLIS, Ore. – The catastrophic damage of the 2004 Indian Ocean earthquake was mostly done within a few hours, but that was just the beginning of a different process that may take up to a decade or more to complete – the stabilization of new beaches and landforms in areas ravaged by this disaster.

In continued studies, researchers at Oregon State University and the U.S. Geological Survey are finding that the beaches may continue to shift and change for several more years, as the lands adjust both to the tsunami impacts and the sudden drop of some nearby land by three to six feet.

Meanwhile, some roads constructed in the push for recovery after the disaster already are being threatened by eroding beaches and lapping water. Houses have been rebuilt on stilts in areas that properly should now be considered ocean, not land. And beach experts are closely studying this process – not only to learn more, but to make sure that when the Pacific Northwest tries some day to recover from its own massive tsunami, the decisions will be informed by good science.

“In Banda Aceh, the city most severely hit by the tsunami, some people are using fill, raised roadbeds and stilts to build their homes in what is essentially an intertidal zone,” said Peter Ruggiero, an OSU assistant professor of geosciences. “It’s amazing the energy they are putting into this, but it is apparent that much of this land may just disappear. You can see palm trees in the ocean, on what used to be dry land. Right now some areas look like a little Venice.

“And with some regularity, when we were looking at a new highway in Indonesia that already needs rip-rap to prevent the ocean from claiming it, I was visualizing Highway 101 on the Oregon Coast,” Ruggiero said. “Our input may be too late to help the Indonesians in their recovery from this disaster, but hopefully we may learn a lot here that will some day help the U.S. recover from the tsunami in our future.”

There’s little realization, Ruggiero said, that after a tectonic and geologic event the magnitude of the one in Indonesia, the ocean will take years to adjust to a new equilibrium, one in which shorelines are largely stable and neither eroding or building. And predicting exactly what the ocean will give, and what it will take away, is a very new science – one that will get a major boost from what is now being learned during the Indonesian recovery. The research is being funded by the U.S. Geological Survey.

“Never before with modern scientific monitoring tools have we been able to so rigorously study a tsunami disaster such as this, literally on film from the moment it occurred to many years later,” Ruggiero said. “There have already been some surprises in places, where we’ve found the sand being moved and then re-distributed, and we’ll find out more as we go. But this process is nowhere near complete yet.”

On Dec. 26, 2004, a 9.2 magnitude earthquake triggered one of the deadliest natural disasters in modern world history, which included tsunami waves that reached up to 100 feet high. The waves scoured the ocean floor with their enormous energy and deposited huge amounts of sand and debris some distances inland, while other material was stripped away and washed out to sea. More than 225,000 people died in 11 countries.

“We have been able to study both the ocean floor and the inland effects, and are monitoring changes through time,” Ruggiero said. “We’ve discovered sandbars created by the tsunami in some shallow ocean waters that otherwise would not be there, and they appear to be gradually rebuilding some of the beaches.”

But receiving less attention at the time of the disaster, Ruggiero said, was the subsidence of some nearby areas by three to six feet – a result of land that had been “pushed up” by a subduction zone for centuries, only to drop back down suddenly during the earthquake. This resulted in an instant change of sea level over broad areas of coastal Indonesia that is still working itself out.

“As a result of the coastal subsidence, we’re still seeing beaches in retreat, which may continue for some time,” Ruggiero said. “Spits and inlets will form. We’re going to try to understand the forces at work and make predictions about where the ultimate shoreline will be, then come back in later years and see if we were right or not. We should learn a lot from this process.”

That knowledge, he said, may help scientists not only to better understand past tsunamis, but also to assist in recovery from those yet to occur. And one of the prime candidates for such an event is the Pacific Northwest coast of the United States and Canada, where the Cascadia Subduction Zone is nearly a geologic twin to its Indonesian counterpart. It’s believed that this zone has had several subduction zone earthquakes in the past 1,000 years, the last of which may have occurred in 1700.

“We’re already learning, just from what we’ve observed in Indonesia, that you must be very cautious what setbacks to allow for new construction and rebuilding after a major tsunami or land subsidence,” Ruggiero said. “Hopefully we’ll be able to develop computer models that will allow us to predict the final shape of the shorelines with more accuracy. And those shores may be dramatically different that the ones we now have.”

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Peter Ruggiero,
541-737-1239

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Indonesia ravaged by the 2004 tsunami.

Stumps of dead trees slowly decay in what used to be the shoreline, rather than ocean, of parts of Indonesia ravaged by the 2004 tsunami.

Study Finds 2004 Oregon Quakes Were in “Locked” Area of Tectonic Plate Boundary

CORVALLIS, Ore. – A pair of modest earthquake clusters that occurred off the Oregon coast in 2004 may be more significant than scientists initially realized after detailed analysis of the main shocks by researchers at Oregon State University.

The newly published study found that the quakes probably occurred on the fault that forms the boundary between the North American and Juan de Fuca plates at a depth where the fault is thought to be “locked.” While earthquakes occur frequently in the upper and lower plates in the Cascadia subduction zone, there haven’t been any instrumentally recorded quakes on this boundary, according to Anne Trehu, a professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and lead author.

Results of the study were announced this week in the journal Geology, published by the Geological Society of America.

“We don’t really know what they mean,” Trehu said of the clusters. “But this is an area with a great deal of paleoseismic evidence for very large earthquakes, so documenting such activity is significant. As we learn more about seismic behavior and associate that with the structure of the plates and faults, we will be in a better position to develop models for what might happen and when.”

Research by one of Trehu’s colleagues, OSU’s Chris Goldfinger, suggests that there may have been as many as 23 major earthquakes in the Cascadia subduction zone over the past 10,000 years. The last known major plate boundary earthquake took place on Jan. 26 in the year 1700, rupturing the entire subduction zone. Scientists know a fair amount about that earthquake, estimated at magnitude 9.0, because of written records of a corresponding tsunami in Japan, as well as plentiful geologic evidence.

The moderate 2004 earthquakes off the central Oregon coast were felt as far east as the Willamette Valley, but did little if any damage to coastal communities. The first, of magnitude 4.9, occurred on July 12 just off Newport. It was followed on Aug. 19 by a magnitude 4.8 earthquake just to the south, near Waldport. Smaller earthquakes occurred near the same spots in August of 2007.

The research by Trehu and colleagues Jochen Braunmiller and John Nabelek found that they occurred about 10-15 kilometers below the surface, and just 10-15 kilometers off the coast.

Most of the earthquakes in the Pacific Northwest have occurred in the upper plate and some have occurred in the lower plate, Trehu said. But portions of the boundary region – where the Juan de Fuca plate is being subducted beneath the North American plate – have been without recent seismic activity and are thought to be locked.

“These earthquakes are telling us something about the nature of the plate boundary,” Trehu said. “It could be that they result from sudden slips on strong patches of the plate boundary, whereas most of the plate boundary slips without generating earthquakes large enough to be recorded on land. Or they could reflect weak patches on an otherwise locked fault.”

Trehu recently installed a temporary onshore/offshore seismic array to try to determine which of those possibilities has the most merit. Her project was funded by the Marine Geophysics and EarthScope programs of the National Science Foundation.

The subduction of the Juan de Fuca plate beneath the North American plate is a slow and intermittent process. Averaged over geologic time – in this case, many millions of years – the plates move past each other at a rate of about 4.5 centimeters a year, Trehu said.

Beneath the continental margin, where the plate boundary is relatively cold, this motion takes place during infrequent and irregular intervals – as do the large earthquakes that may take place. Where the plate boundary is deeper, the plate motion occurs in slow events that take place at regular intervals in a phenomenon known as episodic tremor and slips, or ETS.

Another objective of the NSF-funded seismic array is to test whether ETS can trigger slips on the shallow part of the subduction fault.

“Evidence in the paleoseismic record shows that these plates tend to get stuck for a while, and then unstuck, resulting in major earthquakes,” Trehu noted. “Just what it is that triggers major quakes, though, is the million dollar question. For seismic researchers, it is the Holy Grail.”

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Anne Trehu,
541-737-2655

Public Urged to Restrain from Touching Seal Pups

NEWPORT, Ore. – Seal pups are beginning to appear on the beaches of Oregon and an Oregon State University marine mammal biologist is urging the public to restrain from trying to “rescue” them.

During this time of year, seal pups are frequently discovered alone on the beach, and “this is perfectly normal,” said Jim Rice, coordinator of the statewide Oregon Marine Mammal Stranding Network headquartered at OSU’s Hatfield Marine Science Center. Newborn pups typically spend several hours each day waiting for the mothers, he pointed out.

“Adult female seals spend most of their time in the water, hunting for food, and only come ashore periodically to nurse their pups,” Rice said. “But the mothers are shy and unlikely to rejoin a pup if there is activity nearby.

“After suckling for 4-6 weeks, weaned pups are left to fend for themselves,” added Rice, who is part of OSU’s Marine Mammal Institute. “They frequently come ashore to rest while learning how to catch their own food.”

In past worst-case scenarios, concerned beach-goers have picked up seal pups and taken them away from the beaches – and their mothers. Even hovering near the pups could prevent their mothers from returning. Without public interference, Rice said, most seal pups will survive their first few months of life, even when left alone for hours at a time on the beach.

“It’s tempting for the public to ‘rescue’ these pups,” Rice pointed out, “but their best chance for survival is to be left alone.”

It’s also a law, Rice pointed out. Federal law prohibits interference with seal pups and other marine mammals on the beach. Bystanders should stay at least 50 yards away and keep their dogs leashed.

Anyone who observes incidents of seal pup harassment, or animals in distress, should call the Oregon State Police at 1-800-452-7888, Rice said.

The Oregon Marine Mammal Stranding Network is an organization comprised of state and federal agencies, universities and volunteers, working together for the well-being of stranded marine mammals, public safety, scientific research and education.

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Jim Rice,
541-867-0446

Sounds of the Antarctic: OPB Field Guide to Feature OSU Researchers

NEWPORT, Ore. – A research team from Oregon State University’s Hatfield Marine Science center, whose trips to Antarctica in 2005-06 resulted in new discoveries about the region’s seismic activity, will be featured on OPB’s Oregon Field Guide this Thursday, Feb. 7. The program airs at 8:30 p.m.

The researchers, led by OSU oceanographer Robert Dziak, used an array of sensitive hydrophones to listen for clues to the Southern Ocean’s unique seismology, ice field movements and biology.

The OSU team found that this remote region in the Bransfield Strait is much more seismically active than scientists previously thought and its ongoing earthquakes – in proximity to massive ice fields – create an unusual relationship that may not occur anywhere else on Earth.

“This is a small subduction zone that supposedly has ceased its tectonic activity, but we recorded an awful lot of earthquakes during the expedition,” Dziak said. “So it may not be ceased after all.”

The project was a component of the National Oceanic and Atmospheric Administration’s Ocean Explorer program. In December of 2005, the researchers deployed several hydrophones – built by OSU technicians at the Hatfield Marine Science Center – that were designed to withstand the frigid temperatures of Antarctic waters. Dziak and his colleagues returned to the region in December of 2006 to retrieve the data from the hydrophones, which had a year’s worth of recordings, and then redeploy them.

What they found in analyzing the data is a symphony of sounds revealing undersea earthquakes, the movement of massive icebergs, and the vocalizations of whales, penguins, elephant seals and other marine mammal species.

The researchers’ activities were documented by Bill Hanshumaker, an outreach specialist at the OSU Hatfield Marine Science Center, on a daily blog. He also interacted with K-12 classes as part of the NOAA-funded project. His reports are available online at: http://hmscblog.blogspot.com/

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Bill Hanshumaker,
541-867-0167

Memorable Ocean Lectures Released on DVD

CORVALLIS, Ore. - Distinguished lectures on hurricanes and climate change, the devastating 2004 Asian tsunami, tracking whales and Oregon coastal erosion were highlights of the John Byrne Lecture Series years at Oregon State University in recent years.

Now a sponsor of the series is making those lectures available on two DVDs so that a broader audience can gain the insights that world-class experts offered on these ocean-related topics.

The lectures are presented uncut and unedited, and the presentations include all the slides and other media used by the presenters, as well as audience questions.

The lectures by OSU coastal geologist Paul Komar, “Living on the Oregon Coast in a Century of Climate Change,” and OSU marine mammal researcher Bruce Mate, “Tracking Whales,” are on one DVD. Lectures by MIT hurricane expert Kerry Emanuel, “Hurricanes and Climate Change,” and by a leader in U.S. tsunami science, NOAA’s Eddie Bernard, “The Dec. 26, 2004 Tsunami: Lessons Learned for Improved Tsunami Preparedness,” are on the second DVD.

Sea Grant and the OSU College of Oceanic and Atmospheric Sciences sponsored the Byrne lectures to promote interest in ongoing issues in marine and atmospheric sciences, particularly on themes of resources, policy and communicating science. The public lecture series was named for former OSU President John Byrne, who also was dean of oceanography, and administrator of the National Oceanic and Atmospheric Administration.

The DVDs are available for $6.95 each from Oregon Sea Grant, 322 Kerr Administration Building, OSU, Corvallis, OR 97331. Order ORESU-V-06-004 (vol. 1, Komar, Mate) or ORESU-V-06-005 (vol. 2, Emanuel, Bernard).

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Oregon Sea Grant,
541-737-0756

Sounds of the Antarctic Revealed: Earthquakes, Icebergs and Pygmy Whales

NEWPORT, Ore. – A team of Oregon State University researchers has returned from Antarctica, where they retrieved an array of sensitive hydrophones they are using to listen for clues to the unique seismology, ice field movements and biology of the region.

Their preliminary findings suggest that this remote region in the Bransfield Strait is much more seismically active than scientists previously thought and its ongoing earthquakes – in proximity to massive ice fields – create an unusual relationship that may not occur anywhere else on Earth.

“This is a small subduction zone that supposedly has ceased its tectonic activity, but we recorded an awful lot of earthquakes during the expedition,” said Robert Dziak, an Oregon State oceanographer based at OSU’s Hatfield Marine Science Center in Newport, Ore. “So it may not be ceased after all. There isn’t a lot known about the seismicity – or biology, for that matter – of this region because it supposedly has some of the worst weather in the world and it’s fairly remote.

“But what we are able to learn from the deployment of these hydrophones suggests that this is truly a unique area that deserves a lot more research,” Dziak added.

The project is a component of the National Oceanic and Atmospheric Administration’s (NOAA) Ocean Explorer program. In December of 2005, the researchers deployed several hydrophones – built by OSU technicians at the Hatfield Marine Science Center – that were designed to withstand the frigid temperatures of Antarctic waters. Dziak and his colleagues returned to the region in December of 2006 to retrieve the data from the hydrophones, which had a year’s worth of recordings, and then redeploy them.

What they have found thus far in analyzing the data is a symphony of sounds revealing undersea earthquakes, the movement of massive icebergs, and the vocalizations of whales, penguins, elephant seals and other marine mammal species.

The scientists were particularly intrigued by the humming sounds recorded from the movement of icebergs following the earthquakes. Icebergs that are grounded on the seafloor often get slowly pushed by currents and wind, causing them to vibrate like a tuning fork and make a loud hum.

“With the big Antarctic ice sheets, you can pick up the hum they make as far away as Tahiti,” Dziak said. “That has been well-documented. But we also picked up the same humming sounds right after earthquake activity, suggesting that the undersea seismic activity may play a role in the breakup of ice sheets, or at least the movement of existing icebergs.”

This relationship between earthquakes and ice fields is a new idea and unique to the region, Dziak pointed out.

“This is the only place at either pole where large earthquakes occur in proximity to ice sheets,” he said. “In fact, while our instruments were deployed here, a magnitude 7.5 quake hit the region, generating a small tsunami. It’s a very active area.”

This region of the Antarctic is near the South Sandwich Islands, which are active volcanoes that are monitored primarily through satellite observation because of their remoteness. The researchers worked from Deception Island, which also is volcanically active, having erupted in 1970.

Though their research is primarily designed to study the seismic activity of the region through the use of hydrophones, the scientists also used a remotely operated vehicle to explore the comparatively shallow waters of Deception Island’s caldera, hoping to discover hydrothermal vents. They were unable to locate the vents because of equipment problems, but did document “an array of underwater creatures, including a ton of brittle stars and urchins, as well as unusual plant life that has rarely if ever been seen, Dziak said.

“There was a real sense of accomplishment in even being able to conduct our deep-water survey in this incredibly hostile environment,” Dziak said. “We got somewhat lucky with the weather.”

In addition to the sounds of earthquakes and moving icebergs, the hydrophones picked up the sounds of numerous marine mammals and birds. Kate Stafford, a University of Washington biologist on the trip, identified the vocalization of a pygmy blue whale, which wasn’t known to frequent the area.

Whales have unique “voices” that can not only be differentiated by species, the researchers say, but by geographic dialect. In other words, blue whales from one part of the world have a different “accent” than blue whales from the other side of the globe.

The researchers’ activities were documented by Bill Hanshumaker, an outreach specialist at the OSU Hatfield Marine Science Center, on a daily blog. He also interacted with K-12 classes as part of the NOAA-funded project. His reports are available online at: http://hmscblog.blogspot.com/

For video, go to:

http://oregonstate.edu/media/smbxt

http://oregonstate.edu/media/ccrkvk

http://oregonstate.edu/media/wzfsx

 

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Bob Dziak,
541-867-0175

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Marion Cove, King George, Antarctica
Marion Cove, King George Island, Antarctica
Iceberg, Antarctica

Picture of an iceberg taken from deck of the research vessel.

New Edition of DVD Commemorates 50th Anniversary of Celilo Falls Inundation

CORVALLIS, Ore – The Oregon Sea Grant program based at Oregon State University has released a new edition of a popular DVD that examines a turning point in the history of the Pacific Northwest.

The documentary DVD, “Celilo Falls and the Remaking of the Columbia River,” provides a glimpse of life at Celilo Falls as it once was and considers the cultural, social and political forces that brought about its end, signaling a new era in the relationship between people and nature.

For millennia Celilo Falls was the great Indian fishery on the mid-Columbia River, and it drew native peoples from throughout the West to trade for salmon. But on March 10, 1957, the federal government began operation of a giant hydroelectric dam at The Dalles that drowned Celilo Falls and ended the fishery there.

The new edition of the DVD contains approximately five minutes of additional color footage of the falls obtained from the U.S. Army Corps of Engineers and presented separately from the 30-minute Sea Grant documentary. The latter has been broadcast on Oregon Public Broadcasting and the Oregon Public Affairs Network and has been shown in a series of public education events, “Celilo Stories,” hosted by Columbia River-area libraries and sponsored by the Center for Columbia River History.

“Celilo Falls and the Remaking of the Columbia River” was written, edited and produced by Joseph Cone, assistant director of Oregon Sea Grant and author of “A Common Fate: Endangered Salmon and the People of the Pacific Northwest.”

Cone will present and discuss the documentary at a conference in The Dalles on March 17 at the Columbia Gorge Discovery Center. This conference will bring together more than 20 anthropologists, archeologists, historians, linguists, artists, poets and scholars for panel discussions and informal conversations on the many meanings of Celilo Falls.

The DVD is available from Oregon Sea Grant, 322 Kerr Administration, OSU, Corvallis, OR 97331-2131. Price is $19.95 plus shipping ($2 first copy; $1 each additional copy).

PNAS: Ocean Upwelling Delay Gives Scientists Sneak Preview of What Future May Hold

CORVALLIS, Ore. – A one-month delay in the annual spring “upwelling” of the California current in 2005 provided scientists with a sneak preview of what conditions may be like if global climate change models prove accurate.

And those results, published this week online by the Proceedings of the National Academy, include numerous anomalies affecting West Coast marine ecosystems.

Though the scientists stop short of saying the upwelling delay and its associated impacts were caused by global warming, they acknowledge that the changes are consistent with what most climate change models predict will happen.

“Delays in the onset of upwelling and strong late-season upwelling are consistent with regional climate change models and that’s exactly what we saw in 2005 off the West Coast of the United States,” said Jack Barth, a professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and lead author on the study. “The winds were late in arriving by one month, resulting in the lowest upwelling-favorable ‘wind stress’ in the region during the past 20 years.

“The winds eventually picked up and triggered strong upwelling late in the season, but for some species that depend on those nutrients being there, it was too late,” Barth added. “The juvenile recruits for both barnacles and mussels, for example, were down considerably.”

Mussel recruits were down 83 percent, while barnacle recruits were only 66 percent of normal, the study pointed out.

During the spring of 2005, upwelling didn’t begin until June – a month later than usual. During that time, nearshore waters were two degrees (Celsius) warmer than normal, while chlorophyll levels in the surf zone were only half of normal, and nutrient levels were about 30 percent lower.

Barth said the one-month delay was associated with 20- to 40-day wind oscillations that accompanied a southward shift of the Jet Stream in 2005. In recent years, the Jet Stream has experienced “wobbles” that can warm the waters of the Pacific Ocean of the Northwest coast and hamper upwelling when the shift is to the south, or it can accelerate upwelling when it shifts northward.

What causes these shifts isn’t clear to scientists, but the influence of the enormous mountain ranges in Asia and North America on wind patterns may play a role.

“One major change has been the appearance of persistent wind patterns of 3-5 weeks overriding what used to be patterns that lasted more like two to five days,” Barth said. “The shorter time frame was healthy for the upwelling system; the winds could trigger upwelling and when they died down the shelf would be a great incubator for growth.

“With wind patterns lasting a month or more, you can get a major delay in upwelling,” Barth pointed out, “or you can long windy periods that result in super-charged upwelling like we had in 2006, when the ocean production was so great it created a major hypoxic event along the Pacific Northwest coast.”

Although the researchers’ PNAS study focused only on the 2005 delay, the last decade has seen significant variability outside the norm. The swing began in 1997-98 with one of the most powerful El Nino episodes on record, as ocean waters off the West Coast grew warmer, nutrients decreased, biological production was reduced, and species from zooplankton to salmon disappeared, were drastically reduced or moved from their typical habitats. The El Niño capped what had been a series of years through the 1990s characterized by warm waters and weak upwelling.

That regime ended abruptly in late 1998, and the California Current system entered a four-year period of cold ocean conditions that led to strong phytoplankton and zooplankton productions and a rebound in salmon runs. The final hurrah of that cold-water period came during the summer of 2002, when the system received an influx of sub-arctic water that triggered massive phytoplankton production in the surface waters. As the organisms decayed and sank to the bottom, they sucked oxygen out of the lower water column, leading to hypoxia and marine die-offs of crabs and other species that were unable to move out of the area.

And though the ocean waters warmed over the next four years, the West Coast has experienced hypoxia events every summer, according to Francis Chan, a senior research assistant professor at Oregon State University and one of the authors of the PNAS study.

“When it comes to upwelling and phytoplankton production, there can be too much of a good thing,” Chan said. “Although the low-oxygen zone has varied in intensity from year to year, 2006 saw an unexpected expansion and degradation in oxygen conditions. At least 3,000 square kilometers of the continental shelf along the Oregon coast were affected.”

OSU’s Jane Lubchenco, who organized a symposium on West Coast variability for the annual American Association for the Advancement of Science meeting, said the bottom line is that the dramatic events of the past few years have shown how vulnerable our oceans are to changes in overall climate – and how quickly ecosystems respond.

“Wild fluctuations in the timing and intensity of the winds that drive the system are wreaking havoc with the historically rich ocean ecosystems off the West Coast,” Lubchenco said. “As climate continues to change, these arrhythmias may become more erratic. Improved monitoring and understand of the connection between temperatures, winds, upwelling and ecosystem responses will greatly facilitate capacity to manage those parts of the system we can control.”

Researchers in the study included Barth, Chan and Lubchenco, as well as OSU colleagues Bruce Menge, Anthony Kirincich and Stephen Pierce; John Bane, of the University of North Carolina at Chapel Hill; Margaret McManus, University of Hawaii at Manoa; Karina Nielsen, Sonoma State University; and Libe Washburn, University of California at Santa Barbara.

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Jack Barth,
541-737-1607

New Study: Iron in Northwest Rivers Fuels Phytoplankton, Fish Populations

CORVALLIS, Ore. – A new study suggests that the iron-rich winter runoff from Pacific Northwest streams and rivers, combined with the wide continental shelf, form a potent mechanism for fertilizing the nearshore Pacific Ocean, leading to robust phytoplankton production and fisheries.

The study, by three Oregon State University oceanographers, was just published by the American Geophysical Union in its journal, Geophysical Research Letters.

West coast scientists have observed that ocean chlorophyll levels, phytoplankton production and fish populations generally increase in the Pacific Ocean the farther north you go (from southern California to northern Washington). No one has a definitive explanation for the increase, the OSU scientists say, though some researchers have suspected river runoff may play a role. That theory has generally been discounted, they added, because river flows are low in the summer when phytoplankton blooms occur.

In their study, however, the OSU scientists found that Northwest rivers churn out huge amounts of iron in the winter and deposit it on the continental shelf, where it sits until the spring and summer winds begin the ocean upwelling process. The authors studied the relationships between phytoplankton, river runoff and shelf width all along the West Coast.

“If we consider just river flows or shelf width by themselves, they explain part of the northward increase in productivity,” said Zanna Chase, an assistant professor in OSU’s College of Oceanic and Atmospheric Sciences and lead author of the study. “But if we analyze both together, they provide a more complete picture. The shelf increases in width as you move north. If the shelf wasn’t there, the iron from rivers would be lost to the open ocean.

“Our shelf acts as a ‘capacitor,’” she added, “storing the iron for the high-productivity upwelling season.”

In their studies, the OSU scientists sampled water from Oregon rivers in the winter and found iron concentrations that were roughly 1,000 times higher than that found in samples of sea water taken from the Pacific Ocean off Oregon. And though previous studies, based on East Coast rivers, have suggested that almost all of the iron in rivers gets trapped in estuaries, this latest study found very different results for Oregon rivers in winter.

The researchers measured iron, ammonium, silicate and salinity levels at the mouth Alsea River during the winter, and tracked how much of it went into the ocean, said Burke Hales, an OSU associate professor of oceanic and atmospheric sciences.

The answer: more than half.

“Iron just doesn’t like to be dissolved,” Hales said, “especially in sea water. When fresh water meets salt, almost all of the iron sticks to particles that sink to the floor of the continental shelf, waiting for the winds to trigger upwelling. In contrast, Monterey, Calif., has a very narrow shelf and if you step off the beach it almost immediately goes to 6,000 feet deep.”

Chase said there doesn’t seem to be a direct relationship between the amount of winter runoff in Northwest streams and the level of phytoplankton production the following summer, indicating the broad Northwest shelf is storing more iron than the phytoplankton need in any given year. As a result, she added, phytoplankton production off the Oregon coast doesn’t seem to be limited by a lack of iron, whereas their cousins off central California – where river flow and shelf width are much less than off Oregon – are “iron-starved” in comparison.

The iron from the Northwest’s winter runoff is trapped on the continental shelf in the winter by downwelling winds that create an oceanographic circulation barrier that prevents the iron from being transported into the open ocean. The Columbia River also plays a role, spilling out into the Pacific and turning north in the winter, further pinning the iron deposits in Washington’s nearshore waters.

Further research is needed to test how much iron is stored in the sediments on Oregon’s continental shelf, the scientists say, and how much gets used during a typical season of upwelling.

“We probably have several years of iron stored out there,” Hales pointed out, “but we don’t know whether ‘several’ means five, 10 or 50 years.”

The importance of iron as a catalyst for ocean productivity invariably raises the question of whether humans can ‘fertilize’ the oceans to boost phytoplankton growth. All three of the authors have been involved in research in the Southern Ocean off Antarctica that tested that concept.

“It’s more complex than simply adding iron to seawater,” said Pete Strutton, an OSU assistant professor of oceanic and atmospheric sciences. “Experiments so far have generally shown an increase in productivity that was less than expected – and it didn’t last long. Adding iron also changes the type of phytoplankton that grew, which might have important ecological consequences we don’t yet understand.”

The Northwest’s system of iron-rich winter river water, a wide continental shelf, and summer upwelling has the overall effect of making this part of the Pacific Ocean a net “carbon sink” – or sequestering more carbon dioxide than the region produces. The ocean off central California, by contrast, “seems to be poised between a carbon source and a sink, depending on the year,” Strutton said.

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Pete Strutton,
541-737-2065

OSU Extension Classes Prepare Fishermen, Scientists to Survive At Sea

NEWPORT, Ore. – A series of one- and two-day classes starting in March aims to prepare fishermen, scientists and others who work at sea to survive the worst of what the marine environment can throw at them.

Organized by Oregon State University’s Sea Grant Extension program and taught by the U.S. Coast Guard, the workshops will also help commercial fishing vessels meet federal regulations requiring them to have at least one crew member on board certified in conducting at-sea safety and survival drills.

The classes are the latest in Sea Grant’s more than 20-year tradition of helping Oregon’s fishing fleet stay safer while at sea.

“The fishing community has always welcomed these kinds of opportunities for safety training,” said Kaety Hildenbrand, Sea Grant Extension agent in Lincoln County. “In recent years, other employers – universities, regulatory agencies, aquariums – have started to realize that when they send their people to sea, they need some basic safety and survival training, too.”

Commercial fishing has long been recognized as one of the most hazardous occupations in the United States. The cold waters of the Pacific Ocean can be lethal when a crew member falls overboard or a vessel capsizes. While safety initiatives have improved the odds, Coast Guard estimates indicate that the fatality rate for commercial fishing vessels remains more than five times higher than that for other domestic commercial vessels.

In an effort to reduce injuries and deaths, federal vessel safety rules and guidelines have been revised and strengthened in recent years – with industry cooperation – to require fishing crews to conduct regular on-board drills in the use of safety procedures and equipment that can save their lives.

The two-day classes, taught by four instructors from the Coast Guard’s District 13 office in Portland, aim at preparing crew members to conduct those drills, and giving them hands-on experience working with a variety of safety equipment and procedures, from abandoning ship safely to how to don and wear the insulated immersion suits meant to keep capsized crew alive and afloat in frigid waters.

While there is a $50 deposit to reserve a spot in the commercial vessel safety classes, it is returned in full when the class is completed.

A second set of classes, each one day long, is directed at marine scientists, graduate students, aquarium specimen collectors and others who work at sea, but who likely have not had the formal training available to fishermen. The Coast Guard will teach these classes, too, for the first time; in the past, they’ve been conducted by community members.

“This is a less-intense version of the two-day course, but it still covers what they need to know to survive an emergency,” said Hildenbrand. “A lot of researchers haven’t had this kind of training, and universities and other employers are starting to require it.”

Two-day classes for commercial fishermen are scheduled March 8-9 in Newport, and March 20-21 in Tillamook. Pre-registration is required, along with a $50 deposit, refundable on completion of the course.

One-day classes for researchers, student research assistants and others will take place March 7, April 14, May 14, May 31 and June 20 in Newport. Pre-registration is required, along with a $25, non-refundable deposit.

To register or get more information about any of the classes, contact Kaety Hildenbrand at the Lincoln County Extension office in Newport, 541-574-6537 Ext. 27, or by e-mail to Kaety.Hildenbrand@oregonstate.edu.

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Kaety Hildenbrand,
541-574-6537, Ext. 27