Winds of Change

Scientists link air and water currents as shifting conditions take their toll on the Oregon coast
Jack Barth

OSU oceanographer Jack Barth and colleague Patricia Wheeler discovered a Jet Stream “wobble” that may be responsible for changes in wind patterns and ocean productivity. What’s behind the phenomenon is unclear. (Photo: Jim Folts)

In his 32 years as a crab fisherman off the central Oregon coast, Al Pazar has pulled up a lot of strange things in his pots: wolf eels, skates, huge starfish, fossilized rocks, octopi, fish that rarely stray south of Alaska, and others that prefer the warm subtropical waters off Mexico. But until July 2002, he had never yanked up a pot full of dead Dungeness crabs.

“At that moment,” he says, “I was absolutely shocked.”

At first Pazar blamed himself, figuring he had done something wrong in baiting or placing his pots, though he couldn’t come up with a rational cause. By the time he pulled up a second pot of dead Dungeness, his shock gave way to anger. His thought? Someone must have soaked a forest in herbicides and the toxin had floated down the Alsea River and out to sea, poisoning one of his favorite crabbing spots.

By the end of the day, Pazar’s anger had been replaced by recognition that something was happening out there. He admits a feeling of fear as he contemplated his livelihood. Dungeness crabs, he says, are the lifeblood of Oregon’s fishing industry. Coastal communities already rocked by closures and restricted seasons for salmon and groundfish would blow away in the Pacific wind without the economic stability provided by the tasty Dungeness.

That night, Pazar called state officials to report his find.

Terra Up Close

Feast or Famine

Gray whales have roamed the world’s oceans for some 30 million years. The species hasn’t survived that long without adapting to changes, such as those in the California Current over the past decade.
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The System Shifts

For eons, ocean conditions have literally changed with the wind, but in the last decade, marine scientists have seen extraordinary shifts off the West Coast. From a powerful El Niño in 1997-98 that warmed near-shore waters and starved the marine food web to the “super-charged” upwelling event of 2006 that nearly choked the system with blooms of plankton, the waters off Oregon have become a unique laboratory drawing international attention.

The central Oregon coast has been plagued by hypoxia, or extremely low levels of oxygen in the water, for each of the last five years. The die-off of bottom-dwelling creatures Pazar first experienced in 2002 has continued each summer, with last year’s episode the largest yet.

At the 2007 national meeting of the American Association for the Advancement of Science, Oregon State University Professor Jack Barth told the assembled scientists that these changes are consistent with global warming models. “But,” he said, “it’s still too early to say what we’ve experienced is the result of climate change. There are a lot of natural cycles out there that we don’t fully understand.

“On the other hand,” Barth added, “we’ve never before seen such dramatic change in such rapid fashion.”

A physical oceanographer in OSU’s College of Oceanic and Atmospheric Sciences, Barth has specialized in the California Current, a complex system that extends from Oregon to Baja. Reaching more than 600 miles offshore, it comprises surface waters that flow south, deep water that flows north and meandering eddies that have puzzled researchers for decades.

The bountiful Pacific provides us with salmon, halibut and tuna from the “upper trophic” level of a biological food web that is maintained through complex physical oceanic and atmospheric processes. The key ingredient in this recipe for productivity is the wind. But the process for fueling this dynamic begins with another Oregon staple — rain.

When Oregon rivers rise during winter rains, they leach iron from surrounding rocks and transport it to the ocean where it fertilizes the marine food system. OSU oceanographer Zanna Chase and her colleagues have sampled water from Oregon rivers in the winter and found iron levels roughly 1,000 times higher than in samples of seawater. This river-born iron gets pushed out onto the continental shelf, which acts as a “capacitor,” Chase says, storing the element for the upwelling season.

“Oregon has more rain, more rivers and a wider continental shelf to store the iron than California. That explains why our stretch of ocean is so much more biologically productive than theirs. Our productivity isn’t limited by a lack of iron, whereas the waters off central and southern California are iron-starved by comparison,” Chase explains.

Scientists who study marine food webs may look at Oregon with a sense of iron-envy. A lack of iron in many parts of the world’s oceans, particularly in the open seas, is a limiting factor in biological productivity. Still, experiments “fertilizing” the seas with iron have met with mixed results.

In Oregon, such additions are hardly necessary. When north winds begin blowing in the spring, they drive the surface water offshore, a process that pulls deep nutrient-rich water to the surface near the coast. Thus the season of “upwelling” begins with fertilization of the upper water column. In the presence of sunlight, nutrients trigger blooms of microscopic plant life (phytoplankton), which in turn are eaten by a variety of miniscule animals (zooplankton), which are consumed by sardines, herring and candlefish. Waiting in line are the higher echelon predators, including salmon and tuna.

As the phytoplankton and zooplankton die, their remains sink to the bottom and provide additional fertilizer for the ocean system to replenish itself. Sometimes, however, that system can break down.

When Things Go Haywire

In 1997-98, a powerful El Niño raised water temperatures along the West Coast. Nutrient levels decreased, biological production dropped, and species from zooplankton to salmon either disappeared, were drastically cut back 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 “warm-water regime” ended abruptly in 1998, and the California Current shifted into another extreme. For the next four years the waters off the West Coast were much colder than usual. Upwelling was strong, biological productivity was healthy, and salmon runs began rebounding. At the end of 2002, an unprecedented surge of cold, nutrient-rich sub-Arctic water flowed southward into the region.

Videos

OSU oceanographer Jack Barth talks about how our oceans are changing. (Produced by Larry Pribyl, University Advancement)

Ten years of change in the California Current (0:42)
Ocean waters are changing around the world (1:09)
Forecasting ocean weather (0:46)
Ocean observing systems (1:01)

“It triggered massive phytoplankton production in surface waters,” Barth says, “and as the organisms decayed and sank to the bottom, they sucked the oxygen out of the lower water column. That was our first experience with hypoxia leading to die-offs of crabs and other marine life.”

In that pivotal year of 2002, OSU was leading a four-institution research effort called the Partnership for Interdisciplinary Studies of Coastal Oceans, or PISCO, that was funded primarily by the Packard and Moore foundations and OSU alumnus Robert Lundeen to look at near-shore processes. Barth and OSU colleagues Jane Lubchenco, Bruce Menge and Francis Chan (Department of Zoology) came to the same realization that Pazar had — something was happening out there.

With the flexibility of private funding, they assembled an interdisciplinary team to closely monitor the physical conditions of the hypoxic zone in a region that extends into the Pacific from Lincoln City to Florence along the central Oregon coast. The researchers used moorings and ship-based instruments to record measurements of temperature, salinity, dissolved oxygen and water chemistry. They used satellite images to look at the ocean’s “skin,” or surface, to analyze the blooms of phytoplankton. Technology was an ally.

During the next two years the research team identified milder hypoxic events, and the scientists felt they were beginning to understand how the system worked. And then in 2005, things went haywire once again. The winds that trigger spring upwelling were late in arriving by a month. Near-shore waters were 2 degrees warmer than usual, and chlorophyll levels in the surf zone went down by 50 percent.

“It was the lowest ‘wind stress’ for favorable upwelling in the region in at least 20 years,” Barth says. “The winds eventually picked up and upwelling began, but it was too late for some species that depended on those nutrients. The lesson we learned is that it isn’t just the direction and strength of the wind that matters; timing is critical, too.”

Their focus on the wind led to two key discoveries. The first was that wind patterns have been shifting over the past few years. Two decades ago, for example, it was typical to see two to five days in a row of persistent winds, followed by a similar period of calm. During the past decade, however, those oscillations have been on the order of 20 to 40 days, Barth says.

“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.”
Jane Lubchenco

These longer wind patterns can lead to a major delay in upwelling, as in 2005, or a “super-charged” upwelling, as happened in 2006. Last year, the upwelling winds were so favorable that the system became choked, according to Chan. Phytoplankton blooms were everywhere. And eventually, the organisms had to sink to the bottom, where their decay led to the largest hypoxic event the West Coast had yet seen. Some 3,000 square kilometers of the continental shelf along the Oregon coast were affected.

“It was literally too much of a good thing,” Chan says. “And one of the most eye-opening aspects was how long it lasted. We used to think we knew how fast hypoxia dissipated — until last year. The winds just didn’t have a southern component, so we got all upwelling and no downwelling. The pool of low-oxygen water just kept growing and growing, and it took weeks for it to flush itself out.”

The multi-week wind patterns had struck again, leading the researchers to confirm their second discovery. Barth and a colleague, OSU Distinguished Professor Patricia Wheeler, had led a recently completed National Science Foundation study off central Oregon that identified a “wobble” in the Jet Stream that they suspected was leading to these new longer wind patterns. This high-altitude air stream circles the globe and flows toward the West Coast of the United States. In recent years, Barth says, its path has begun shifting, and when it migrates slightly to the south, it delays the upwelling. A shift to the north may lead to stronger upwelling and potentially severe hypoxic events, as well. Barth and his team are working to confirm evidence that in 2006 it migrated north and led to one of the strongest upwelling events they have seen — and the largest hypoxic event, as well.

Why the wobble?

“That’s one reason we need to continue studying our oceans and atmosphere,” Barth says. “We don’t have all the answers yet.”

Terra Up Close

Salmon Survival

Ocean conditions play a key role in the health of Northwest salmon runs, and scientists at OSU’s Hatfield Marine Science Center are trying to pinpoint why. Clearly there are more salmon during cold-water regimes, when strong and persistent upwelling fertilizes the marine food web.

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More Eyes and Ears

Al Pazar isn’t convinced that the ocean is broken. In each of the years following hypoxic events, the chairman of the Oregon Dungeness Crab Commission has returned to his crabbing grounds and enjoyed strong harvests. He says there is much we don’t know about the ocean’s natural cycles and points to the surprising return of sardines to Oregon, where they have mostly been absent for the past 75 years.

“I don’t believe all the doom and gloom I see in the press,” Pazar says. “I’ve fished through all of the ‘dead zones,’ and had better-than-average years after each one. Crabs aren’t stupid. They have legs. And they’ll use them to get the hell out of there if they can.”

Then he paused. And sighed.

“There is still a lot we don’t know,” he admits. “Do you know that the state of Oregon doesn’t even have a crab biologist? We need to study the Dungeness and see where they go and how they respond when this stuff happens.”

The OSU researchers agree and say scientific observations need to be expanded well beyond Dungeness crab. Since West Coast conditions turned extreme a decade ago, sea birds have died, salmon runs have yo-yoed up and down, mussel and barnacle juvenile recruitment has suffered, and the entire system of ocean productivity seemingly changes from year to year.

“The ocean may be losing its ability to replenish itself, to re-cleanse itself. There is real potential we may push it too far before we realize what we’re doing.”

Jack Barth

More than the marine food web is at stake. The Pacific Ocean plays a major role in balancing the Earth’s carbon dioxide, says OSU oceanographer Burke Hales.

“The ocean off Oregon alone annually negates the effects of about 100 million tanks of gasoline feeding greenhouse gas discharges into the air,” Hales says. “Phytoplankton blooms draw the CO2 out of the atmosphere and consume it, then sink to the bottom and die. We think they are transported to the deep ocean, in which case the carbon dioxide will stay there for a thousand years.

“But if they decompose on the shelf,” he adds, “the CO2 will just return to the atmosphere, and we don’t have the carbon ‘sink’ we think we do.”

The bottom line, Barth says, is that Oregon needs a coordinated, comprehensive ocean observing system instead of a piecemeal approach. He and colleague Kipp Shearman operate three undersea gliders that cost $100,000 apiece. “We need 10 to cover the near-shore from Brookings to Astoria,” he says.

The gliders complement moorings, buoys, satellites and ships, Barth says, but the state needs more instruments, more coordination and more human resources to keep its collective eyes and ears on the ocean. The beneficiaries will be commercial and recreational fishermen, boating enthusiasts, Coast Guard rescue teams, coastal residents and others, he adds.

OSU is uniquely positioned to lead the effort. Scientists in four OSU colleges conduct marine research, and the College of Oceanic and Atmospheric Sciences alone competed successfully for $24.3 million in research grants in FY2006. Marine science facilities at the Hatfield Marine Science Center in Newport include two research ships, the Wecoma and the Elakha. The Corvallis campus hosts the world’s largest tsunami wave tank and a premier marine supercomputing network. In a regional project, Oregon Sea Grant is working with Sea Grant programs in California and Washington on a first-ever marine resource management plan for the West Coast.

If the dramatic changes continue in our section of the Pacific Ocean, those assets will become invaluable.

“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,” Jane Lubchenco said at the 2007 AAAS meeting. “As climate continues to change, these arrhythmias may become more erratic. Improved monitoring and understanding of the connection between temperatures, winds, upwelling and ecosystem responses will greatly facilitate capacity to manage those parts of the system we can control.”

“We’re seeing more and more ecosystem effects,” Barth adds. “As the system swings from one extreme to another, it may become less resilient. The ocean may be losing its ability to replenish itself, to re-cleanse itself. There is real potential we may push it too far before we realize what we’re doing.

“And the only way to prevent that,” he argues, “is by observing what is happening out there. When the world wanted to understand El Niño, it put a massive array of instruments on the equator. If we put the same amount of resources and will into studying our coastal ocean’s productivity and carbon, we can make real progress.”

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