marine science and the coast

Veterinarians seek causes of human disease using aquatic models

CORVALLIS, Ore. - Recent graduates of veterinary medicine programs are using common fish species to increase medical understanding and develop prevention protocols for some of the world’s most prevalent and least understood diseases – including cancers, infectious diseases and birth defects.

With funding from the National Institutes of Health, the Oregon State University College of Agricultural Sciences is providing select veterinary school graduates from around the country with broad training in biomedical research relevant to the study of human disease.

The training is not part of traditional curriculums offered in most U.S. veterinary schools, said Robert Tanguay, an OSU associate professor in agricultural sciences and the director of the program. In addition to research experience, trainees who participate in the program have the opportunity to earn advanced graduate degrees.

“We’re taking the skills they have acquired and channeling them toward hypothesis-testing research using powerful aquatic models,” said Tanguay.

The program, which is focused on developing research projects that are applicable to human health, incorporates aquatic research organisms like zebrafish, rainbow trout and medaka to determine the genetic causes of human diseases.

“A surprisingly large number of human diseases can be modeled in fish,” said Tanguay, who also heads the Sinnhuber Aquatic Research Laboratory at OSU. “With about 80 percent of genes in humans also present in these fish, they present an opportunity to better understand risks to human health.”

The NIH awarded Tanguay about $850,000 to be spread over five years for the initiative.

“The work being done in the program focuses on moving the research from the science bench to the patient bedside,” said Tanguay. “Our group uses the zebrafish model because they’re really similar to us and are vertebrates and offer many unique advantages to rapidly unravel disease mechanisms.”

Zebrafish are small, striped tropical fish often sold in pet stores. They are unique from other animal species in that the embryo of the fish is transparent, allowing for direct observation of the fish at early developmental stages. In addition, like the human genome, the zebrafish genome has been fully sequenced allowing for direct comparison between fish and man at the genetic level.

“There are unique opportunities and challenges in using aquatic models to improve human health,” said Tanguay. “The exponential worldwide increase in the use of these models for biomedical research has led to a significant shortage of qualified scientists who have experience using these powerful tools. Training veterinarians in their use addresses an ever-growing need in the biomedical research community.”


Robert Tanguay, 541-737-6514

OSU scientists to study whale-deterring sounds

NEWPORT, Ore. – Scientists from Oregon State University’s Marine Mammal Institute will begin a project in December to test whether a low-power acoustic deterrent device can prevent migrating whales from entering a 500-meter-radius area of the near-shore ocean that may eventually contain wave energy platforms and cables.

Funded by the U.S. Department of Energy, the project is the first step toward reducing potential risks of wave energy to marine mammals, said Bruce Mate, director of the OSU institute and an internationally recognized expert on whales.

“This won’t answer all of the questions,” Mate said, “but it will give us a better idea if low-level acoustics can be used as a tool to help protect the whales by moving them small distances out of harm’s way.”

In an effort to inform citizens, fishermen and other ocean users about the project, OSU’s Hatfield Marine Science Center will host a community forum on Wednesday, May 12, from 7 to 8:30 p.m. in the Hennings Auditorium. Speakers will describe the study’s methodology and outline the type and frequency of the sounds that will be used in the project. There will be time for questions and dialogue.

Mate said that many of the concerns voiced about wave energy’s potential impact on whales involve entanglement in cables, but that risk is minimal because the cables would be rigid and have tens of thousands of pounds of pressure on them. However, migrating whales travel at a speed of about four miles an hour and running into a four-inch to six-inch thick cable – or mooring platform – could cause traumatic injury, he pointed out.

“If an acoustic device can successfully reroute whales in a minor way on their migration, the implications go beyond wave energy,” Mate said. “The technology could be used to prevent whales from entering waters with environmental risks, for example, such as oil spills.”

Mate has spent much of his 41-year career studying endangered and threatened whales and pioneered the use of satellite tags to help track marine mammals. His research on different whale species’ migration routes, diving patterns, and breeding and calving locations has greatly enhanced the ability of resource managers to protect the animals.

The four-month pilot project, which begins in late December, will target gray whales, which are the predominant large whale species in Oregon’s near-shore waters. A 2008 study by Mate and Joel Ortega found that 61 percent of migrating gray whales sighted off the coast passed within Oregon’s Territorial Sea, which is within three nautical miles of the shore.

The scientists will place an acoustic device on a mooring just west of Yaquina Head near Newport which will emit a low-pitched one-second “whoop” sound three times a minute during a six-hour stretch each day. The sound energy will be less than 1 percent of sonar emitted from a single fishing boat, the scientists say, but hopefully it will be enough to subtly influence whale movement, Mate said.

“We do not even expect gray whales to react to the sound unless they are within 500 to 750 meters of the mooring location,” Mate said. “We’re not talking about much sound here. Although baleen whales, including grays, don’t have sophisticated sonar, they are good listeners, so we hope it will alert them to be more aware.”

The researchers have applied for a permit from the National Marine Fisheries Service for the project to test the acoustic devices – the same level of permit required for flying an airplane over the water to count whales, or photographing whales during a ship-based survey.

Mate said the acoustic device would emit one-eighth of one watt, which they hope will make the whales alter their paths about 500 meters from the noise.

Gray whales generally migrate past Yaquina Head twice a year. In December, whales begin heading south toward breeding and calving areas and tend to be farther offshore. They return in two “waves” – singles in March and April, and then north-bound mothers with calves in May, usually within a half mile of shore. The researchers will conduct their north-bound acoustic tests on the single whales and not the mother-calf pairs that travel closer to shore, Mate said.

“Ideally, we’d like to see the whales respond to these pings by moving about 500 meters around the device, which adds just a tiny bit – one hundredth of one percent – to their migration distance,” Mate said.

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Bruce Mate, 541-867-0202

May 10 Science Pub to explore world of seals and sea lions

CORVALLIS, Ore. – Seals, sea lions and other “pinnipeds” are vital cogs in many marine ecosystems, yet they face an uncertain future and threats from fisheries, climate change and marine debris – as well as from other top predators.

While their populations are healthy and near carrying capacity in the Pacific Northwest, populations of seals and sea lions have declined to historically low levels in western Alaska and the Bering Sea.

Markus Horning, a pinniped expert from Oregon State University’s Marine Mammal Institute, will discuss the reasons for these differences this Monday, May 10, in a Science Pub presentation at the Old World Deli, 341 S.W. 2nd St. in Corvallis. His talk, “Consummate and Consumed Predators: Threats to Seals and Sea Lions in a Changing Ocean,” begins at 6 p.m.

Science Pub Corvallis is free and open to the public; attendees are encouraged to arrive early, as space and seating are limited.

Pinnipeds are effective marine predators and their consumption of salmon has raised the ire of some Northwest fishing enthusiasts – even though salmon and seals have co-existed for thousands of years. Yet their protected status has also created challenges for resource managers, who must balance the recovery of multiple threatened species.

In his talk, Horning will discuss the roles and impact of research, rescue and rehabilitation programs on these “charismatic, yet difficult to monitor” marine mammals. He also will touch on recent high-profile rescues of sea lions in Florence and Newport that were threatened by entanglement with marine debris.

And he will discuss how climate change, killer whales and other factors affect marine mammals.

One reason for the decline of Steller sea lions in Alaska may be predation. Horning is principal investigator in an ongoing study that uses lifelong monitors implanted inside the sea lions to track the animals’ temperature rates – and provide clues to the cause of their eventual deaths. Preliminary results suggest greater-than-expected predation of these protected marine mammals by orcas.

In another study, Horning is learning more about the extraordinary physical capabilities of Weddell seals in Antarctica. When these seals dive, he says, they have the ability to reduce the flow of blood to many of their organs, including their skin, liver and kidneys, while keeping their hearts, brains and swimming muscles supplied with blood and oxygen. That allows them to reduce their heart rate from about 100 beats per minute to 40 beats – and sometimes as low as five beats per minute – and remain underwater in search of prey.

Horning’s research is funded by NOAA and the National Science Foundation. He is one of the leading scientists affiliated with OSU’s internationally recognized Marine Mammal Institute, which is headquartered at the university’s Hatfield Marine Science Center in Newport.

For more information on the lecture series, call 541-737-4611 or visit Corvallis Science Pub on Facebook.

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Markus Horning, 541-867-0270

Freeing Willy: OSU-led team uses novel cage to disentangle sea lion

NEWPORT, Ore. – Less than one month after deploying a “capture cage” in an experimental effort to catch and rescue sea lions caught in man-made debris, a team led by Oregon State University used the floating enclosure to confine and free an adolescent California sea lion from a plastic packing band that had been caught around its neck for more than a year.

The animal had become a familiar sight in Newport since first being spotted in September 2008, with area residents and tourists often calling the OSU-based Marine Mammal Stranding Network in hope of seeing it freed. Locals nicknamed the animal “Willy” and often expressed dismay at the tight, white band that over time had cut through the animal’s skin and blubber and embedded itself into muscle tissue, said OSU’s Jim Rice, who coordinates the stranding network.

“The animal was coping with the problem well, despite the ugliness of the wound, but there was the potential that it could have caused systemic infection that might have killed him,” said Rice, who works out of OSU’s Hatfield Marine Science Center in Newport. “It was a very ugly wound.”

On Wednesday, however, the animal was spotted along with six other sea lions inside the capture cage. Dan Lewer, a Newport veterinarian; Jim Burke, director of husbandry at the Oregon Coast Aquarium; Rice and several others rushed to the cage in a skiff, where they were able to close its door, confining five of the animals inside.

Though initially alarmed, the animals soon quieted enough for the tangled animal to be lightly sedated, using a syringe affixed to a pole. Team members were then able to reach through the cage with a second pole device to cut and finally remove the band. A reversal agent was administered to counter the sedation, and the animal was back in the water shortly thereafter.

“As far as I know, this was the first use of a capture cage for this purpose, so it was very exciting,” said Rice, who will present findings on the cage work at a conference next week. “Most of the work I do, quite frankly, revolves around dead animals. So this has been a wonderful opportunity to actually help an animal in distress.”

The rescue comes less than two weeks after Rice and others successfully freed a Steller sea lion from a trawl net that had trapped it on coastal rocks inside the Sea Lion Caves in Florence. That rescue, the first ever performed at the caves, attracted national media attention.

Entanglements are a significant and growing problem, with hundreds of sea lions and seals thought to be caught in debris at any given time along the U.S. West Coast. Sightings of tangled animals have become increasingly common in coastal areas from San Francisco to Alaska, where humans are in close proximity to these marine mammals.

In early March, Rice and colleagues deployed the capture cage on the Newport bayfront at Dock 1, where coastal visitors frequently see the animals sunning themselves on the floating dock. Built by Mulder Sheet Metal, Inc., in Newport, the cage is a modified floating dock enclosed on four sides by a galvanized steel structure, with sliding doors on two sides. It is designed primarily to serve as an additional “haul out” area for sea lions to use freely, with its doors locked in the open position so animals can comfortably come and go as they choose.

This project has been the result of a collaborative partnership involving OSU’s Marine Mammal Institute, the Oregon Department of Fish and Wildlife, Oregon Coast Aquarium, the Animal Medical Care veterinary practice of Newport, and the Port of Newport, which provided the skiffs and allows the capture cage at its docks.. ODFW has used capture cages for years to study and monitor sea lion populations, and its cage design was used to model the cage now in use for disentanglement purposes.

Lewer and Steve Brown of the Animal Medical Care veterinary practice landed a grant to allow for the construction of the capture cage.

Disentanglement efforts have not had formal funding so the Marine Mammal Stranding Network is soliciting donations and sponsorship to enhance the project, including the purchase of a special Web camera for rescuers to continuously monitor the capture cage.

Donations for the project may be made to the Marine Mammal Stranding Fund at the OSU Foundation (800-354-7281). To make a gift online, go to http://bit.ly/aStaCr



Jim Rice, 541-867-0446

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An Oregon State University-led team helped rescue a sea lion in Newport that was entangled in plastic.

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An Oregon State University-led team helped rescue a sea lion in Newport that was entangled in plastic.

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An Oregon State University-led team helped rescue a sea lion in Newport that was entangled in plastic.

OSU team performs historic rescue of entangled animal at Sea Lion Caves

Editor's note: Video footage of this rescue and an interview with Jim Rice are available at http://bit.ly/aZb7Sn. A high-resolution, broadcast version of the same footage is available at http://files.me.com/universitymarketing/w63sto.mov. Finally, an embeddable file of the footage is available through the OSU You Tube channel at http://www.youtube.com/watch?v=160GaUQBD2U.

FLORENCE, Ore. -  An Oregon State University team worked quickly with the owners of Sea Lion Caves and federal authorities late Thursday to rescue a Steller sea lion tangled in a trawl net and trapped among coastal rocks.

The Marine Mammal Stranding Network rescuers removed the netting and set the 250-pound animal free, preventing its likely death from starvation or trauma. Within minutes, the sub-adult sea lion, likely a female estimated to be about 4 years old, was swimming with dozens of other sea lions in the churning water at the entrance to Sea Lion Caves, one of Oregon’s most popular coastal tourist destinations.

“There was a fair amount of net wrapped around its face and neck, and several feet of trailing net were trapped between rocks. The animal only had about a 10-foot radius of movement,” said Jim Rice, who coordinates the network as part of the OSU Marine Mammal Institute. “It had been stuck there for about a day, and we estimate it had been tangled in the net for a few days, maybe a week. It would not have been able to forage or eat where it was stuck, and eventually, the net would have cut into the face and neck, causing serious tissue damage.”

While the OSU performed the rescue, cooperation from the Sea Lion Caves and quick assistance from the National Oceanic and Atmospheric Administration made it possible. Sea Lions Caves managers rarely allow anyone into the cordoned off areas where the animals congregate; patrons view the sea lions from a spectator platform separated by a short wall and fence from the cave interior.

“I’ve been there for 50 years, and this is the first time we’ve ever had an animal trapped like that and the first time for a rescue, so it’s very exciting,” said Steve Saubert, a co-owner of the Caves. “Our goal at Sea Lion Caves is to preserve nature – not just sea lions, but birds, ground squirrels, deer. We have a lot of wildlife around here. So being able to save this animal was very important to us.”

While the Caves were quick to close the attraction early Thursday so rescuers could get to the animal with minimal disruption, the OSU team also needed approval from NOAA, which oversees any human interaction with sea lions in such situations. NOAA gave its approval “almost immediately,” said Rice, making the daylight operation possible.

That didn’t, however, mean that the sea lions would appreciate having strangers among them. Though juveniles and females primarily populate the Caves, the animals can be aggressive. In addition to damaging tissue, a sea lion bite can cause serious infection from organisms typically living in their mouths.

To create a barrier between rescuers and the sea lion, the team used plywood “crowder boards,” which proved valuable when the animal tried to bite them. Still, only light sedation, administered by a veterinarian was part of the rescue team, was necessary to subdue the sea lion while the netting was removed.

“Once the netting was released, the tissue in the neck bounced back and regained its normal appearance, virtually immediately,” said Rice, who called it lucky that the animal had become stuck at the Caves. “It was because she was basically immobilized at the Cave that we had the opportunity to approach her. We typically don’t have this opportunity with entangled animals – they’re typically able to flee and escape a would-be rescuer.”


Markus Horning, 541-867-0270

Jim Rice, 541-867-0446

Steve Saubert, 541-999-8095

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jim rice Jim Rice

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net4 Net around sea lion

Delaney to present inaugural lecture commemorating hydrothermal vents discovery

CORVALLIS, Ore. – A leading oceanographer who has discovered numerous hydrothermal vents off the coasts of Oregon and Washington will give the inaugural lecture in a new series at Oregon State University commemorating the original discovery of undersea vents by OSU researchers.

John Delaney, from the University of Washington, will give a free public lecture at OSU on Friday, Feb. 19, which is the 33rd anniversary of the first discovery. His talk, “At the Leading Edge of a Global Environmental Renaissance: Next Generation Science in the Oceans,” begins at 4 p.m. in Gillfillan Auditorium (located on 26th Street just west of Monroe Avenue).

In February of 1977, a research expedition to the Galapagos led by OSU’s Jack Corliss first discovered undersea hydrothermal vents and an entire colony of marine creatures – many of which had never been observed.

“The discovery marked a turning point in the understanding of life on Earth and has been described as one of the most important discoveries in oceanography,” said Robert Collier, an OSU oceanographer who was aboard the ship 33 years ago.

Also along on that pioneering expedition were OSU oceanographers Lou Gordon and Jack Dymond, and long-time San Francisco Chronicle science writer David Perlman.

Delaney is the Jerome M. Paros Endowed Chair in Sensor Networks at the University of Washington, where he has earned a reputation as a passionate and tenacious advocate for ocean science and education. With Delaney’s leadership and encouragement, the National Science Foundation launched the RIDGE research initiative in 1989, which has proven to be a model of community-driven seafloor exploration for two decades.

He was an early proponent for the Neptune cabled observatory effort, and is a principal investigator for the NSF’s Ocean Observing Initiative, partnering with several OSU researchers.

The new Hydrothermal Vent Discovery Day Lecture Series is sponsored by OSU’s College of Oceanic and Atmospheric Sciences.

Story By: 

Marty Fisk, 541-737-1458

New study finds surprisingly high rate of steelhead mortality in estuary

CORVALLIS, Ore. – A new study by researchers at Oregon State University found that up to nearly half of the ocean-bound juvenile steelhead surveyed in two Oregon river systems appear to have died when they reached the estuaries – before they could reach the ocean.

The scientists aren’t sure if such a mortality rate in the estuary is typical or elevated due to increased predation – most likely by marine mammals or seabirds. One goal of their research is to begin establishing better baseline data on juvenile salmon and steelhead mortality so resource managers can make more accurate predictions on runs of returning adult fish.

“A female steelhead may lay 2,000 to 5,000 eggs – and in rare cases, more than 10,000 eggs – and for the population to remain stable, at least 2-3 percent of the juveniles migrating to the ocean have to survive and return as adults,” said Carl Schreck, a professor of fisheries and wildlife at OSU and leader of the Oregon Cooperative Fish and Wildlife Research Unit on campus. “If you get much more than that, it’s a banner year.

“But it’s hard to predict adult returns if you don’t have good data on outgoing juveniles,” Schreck added, “and this study is an effort to make that monitoring more precise.”

Declining salmon and steelhead runs have been blamed on everything from habitat loss through logging to housing developments on coastal rivers, but the consensus has been that ocean conditions are perhaps the single most important element in how robust the populations may be in a given year. Yet the OSU study found that mortality is significant before the fish even make it to the Pacific Ocean, said David Noakes, a professor of fisheries and wildlife at OSU and one of the principal investigators in the study.

“Steelhead will live in the fresh water for one to two years and then migrate out to the ocean where they’ll spend another two or three years,” Noakes said. “If only 2-3 percent survive, it would be interesting to know what the keys to survival may be for the select few. Are the biggest juveniles more likely to survive? The fastest? Those that have the fewest parasites?  Is there something in their genetics that better helps some of them adapt to the new salt water environment?

“We need to determine what the so-called ‘normal’ predation rates are in the estuary, and get a better handle on what is killing the fish,” he added.

In their study, the OSU researchers inserted small ultrasonic transmitters into 280 juvenile steelhead over a two-year period. The dollar bill-sized fish were captured in traps at sites on the middle stretches of the Alsea and Nehalem river systems, tagged and measured, and then released back into the rivers and tracked on their way to the ocean. About nine out of 10 fish made it safely from the release point to tidewater, and then the ultrasound transmissions from 50 to 60 percent of those survivors abruptly stopped when they reached the estuary.

The scientists received enough signals from surviving fish to know that it wasn’t a failure in signal transmission. And, Schreck says, during an earlier study using tags that broadcast a radio frequency, they recovered transmitters from a cormorant rookery near the mouth of the Nehalem River, and have tracked signals from the tags to a burgeoning seal population – also near the Nehalem’s mouth..

“There are a lot of seals right near the mouths of both rivers and seals can eat a lot of young fish,” Schreck said. “It’s why the steelhead need thousands of eggs to keep the population going.”

One other possible explanation for the high mortality, Noakes said, is that the young fish couldn’t handle the transition from fresh to salt water. Salmon, steelhead and other “anadromous” fish have a complex life cycle and for centuries have utilized both the ocean and river systems. But a high mortality rate might be normal and a way to weed out weak fish that can’t make the adaptation to a new environment.

 “We know that fish need a number of things to trigger their migration to the ocean, including the amount of seasonal light, certain temperatures, enough water flow, etc.,” Noakes said. “But we don’t know why some fish remain in the river for one year before heading out to sea, and others stay for two years. Just preparing to go from fresh water to a salt water environment requires an enormous adjustment.

“There may be something about that adaptation that contributes to the mortality,” he added.

If the mortality rate of juvenile steelhead is atypical, it could be increasing because of some environmental factor – warmer water, more parasites, chemical contaminants, or higher acidification of ocean waters coming into the estuary, for example.

Or predation may be higher because of more seals, sea lions and seabirds.

Much of the research about steelhead migration, spawning behavior and basic biology is emerging from studies done at the Oregon Hatchery Research Center, a joint venture between OSU’s Department of Fisheries and Wildlife, and the Oregon Department of Fish and Wildlife. Located on Fall Creek, a tributary of the Alsea River, the research center is giving fish biologists unprecedented new looks at the physiology and behavior of steelhead.

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David Noakes, 541-737-1953

Oregon Sea Grant delivers federal dollars for ocean research, outreach efforts

CORVALLIS -  An ambitious plan to research, understand and inform the public about marine issues ranging from climate change to invasive species will receive nearly $14 million in federal and state dollars via the Oregon Sea Grant Program over the next four years.

“We're proud to be able to continue supporting an integrated program of coastal science serving Oregon,” said Stephen Brandt, director of the Oregon Sea Grant Program headquartered at Oregon State University. “The research projects, in particular, address some of the critical issues facing Oregon and the coast, and reflect our ongoing commitment to supporting research that addresses current issues of human health and safey, social progress, economic vitality and ecosystem sustainability.”

Oregon Sea Grant recently received the first of four $2.3 million biennial grant installments from its parent agency, the National Oceanic and Atmospheric Administration. Half of that money will go to support  the 10 research proposals – among 60 submitted - that made it through Sea Grant's  rigorous, competitive grant program for 2010-2012. The federal dollars are expected to leverage at least $1.2 million a year in state matching funds.

Grant proposals were reviewed both for their scientific strength and importance and their relevance to Oregonians, said Brandt. Reviewers included scientific peers from across the county as well as members of Sea Grant's citizen advisory council, representing a range of coastal interests.

Nine of the funded research teams are based at OSU; the tenth involves scientists at Western Oregon University. Several involve state and federal research collaborators. The grants will support research into such issues as:

  • The implications of climate change in shifting populations of marine organisms, from tiny organisms that threaten the survival of wild salmon to predatory Humboldt squid.
  • The identification of bioactive compounds, which might have use in human medicine, from organisms in deep-sea hydrothermal vents.
  • Development of a means of predicting oxygen-starved “dead zones,” and their implications for the ocean food web and commercial fisheries.
  • Improved methods of forecasting near-shore waves and their effects on Oregon's coast, and, in a separate project, a look at how local variations in sea-floor geography, river currents and other factors might amplify or reduce the damaging effects of tsunami waves.
  • The use of Oregon's proposed marine reserves as a laboratory for developing a new framework for assessing the human costs and benefits of such zones, taking into account  ecosystem benefits as well as economic costs.
  • A predictive method for analyzing the risks and economics of early detection and rapid-response efforts to control the spread of invasive species.
  • Continued support for ongoing research into oyster disease and salmon habitat restoration, areas pioneered by earlier Sea Grant funding.

Although the grants – ranging from $35,000 to $117,000 per year - are modest by some standards, Sea Grant's steady support of timely, relevant marine research in Oregon over more than 40 years has made the program “an incredibly powerful force,” said John Cassady, OSU's vice president for research.

“Through their vision and foresight, they seeded early studies on wave energy and on the ecological impacts of invasive species. With its educational and research programs, Oregon Sea Grant has increased the awareness of coastal hazards and of ways to mitigate those hazards. They have been a hugely valuable resource to Oregon's fishing communities,” Cassady said. “In innumerable other ways, Sea Grant has, time and again, demonstrated that its programs return value to the state that is many times greater than the initial investment."

The balance of the NOAA funds will support Sea Grant's ongoing education, outreach and public engagement activities on the coast and throughout the region, from marine education programs at OSU's Hatfield Marine Science Center to engaging and informing coastal communities and policy makers on the scientific underpinnings of issues such as marine reserves  and community preparedness for tsunamis. A number of graduate student fellowships in marine science and policy will also be funded under the Sea Grant Scholars program.

Oregon Sea Grant is one of 32 National Sea Grant College Programs, all based at universities in coastal and Great Lakes states and funded under NOAA. The Oregon program, in operation since 1968, has long supported research at OSU and other institutions of higher education in Oregon; it also conducts marine Extension and education programs, and manages the Visitor Center at OSU's Hatfield Marine Science Center in Newport.

For more news about science, marine education and related activities on the Oregon coast, subscribe to “Breaking Waves,” the Oregon Sea Grant news blog, at: http://seagrant.oregonstate.edu/blogs/.

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Stephen Brandt, 541-737-3396


CORVALLIS, Ore. - If increased precipitation and sea surface heating from global warming disrupts the Atlantic Conveyer current - as some scientists predict - the effect on the ocean food chain in the Atlantic and other oceans could be severe, according to a new study just published in Nature.

In a worst case scenario, global productivity of phytoplankton could decrease by as much as 20 percent and in some areas, such as the North Atlantic, the loss could hit 50 percent. The study was conducted by Andreas Schmittner, an assistant professor in the College of Oceanic and Atmospheric Sciences at Oregon State University.

In his sophisticated computer model, Schmittner does not predict that the Atlantic Conveyer current, which drags warm water from the southern tropics into the North Atlantic and warms Europe, will be disrupted. Rather, his study is one of the first to examine what would happen to the ocean food chain if such a disruption did take place.

"Phytoplankton are the basis of the entire marine food web," Schmittner said. "They ultimately affect everything from zooplankton to the larger fish that people consume."

The Atlantic Conveyer current has the strongest impact in the North Atlantic, but it is a global phenomenon, Schmittner said. Surface waters from the Pacific Ocean, the Indian Ocean, the Arabian Ocean and the southern Atlantic are pulled northward where they are cooled by the atmosphere in the North Atlantic. As the water cools, it sinks 2,000 to 3,000 meters and begins flowing southward. The upwelling from the mixing of waters constantly replenishes the supply of phytoplankton at the surface, forming a rich nutrient source at the bottom of the marine food web.

There is growing concern by a number of scientists, however, that higher levels of human-generated carbon dioxide could increase water and air temperatures and decrease salinity in the North Atlantic at a rate significant enough to prevent the sinking and ultimate mixing of the water. That would not only disrupt the Atlantic Conveyer current, Schmittner said, it would prevent nutrient-rich waters from triggering phytoplankton growth.

"When the Atlantic Conveyer current works, the dead plankton sink to the bottom and are replaced at the surface with nutrient-rich water that encourages further production," Schmittner said. "When the current is disrupted, and the mixing slows, that production also is disrupted."

The shutdown of the Atlantic Conveyer current isn't just idle speculation. A growing body of evidence suggests that it switched on and off 20 to 25 times during the last ice age.

"During the last ice age, from about 100,000 years before present to 20,000 years B.P., thick ice sheets over Canada sporadically dropped armadas of icebergs into the North Atlantic where they melted, sufficiently freshening the water to disrupt the conveyer," Schmittner said.

"There is some evidence backing that up," he added. "Deep ocean sediment core samples show pebbles from land delivered by the floating icebergs."

Schmittner said scientists also have examined ice cores from Greenland and measured isotopes that show rapid temperature changes, which coincide with changes in ocean nutrient concentrations measured in deep-sea sediment cores.

"One full oscillation of these switches took 1,500 years," Schmittner said, "but the individual transitions happened surprisingly fast. The climate went from a cold state to a warm state in as little as 20 to 50 years. Surface temperatures in Greenland increased 20 to 30 degrees Fahrenheit and water temperatures increased 10 to 20 degrees."

Schmittner said the impact of the current on the Pacific Ocean generally isn't as great, even though the system is a global one. Still, he added, plankton production would also decrease in the Pacific if the current was reduced.

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Andreas Schmittner, 541-737-9952

Aquaculture: not an easy answer to overfishing

CORVALLIS, Ore. - A new report in the journal Science suggests that some types of aquaculture, a fish-farming concept that once seemed to be the solution to overfishing of the world's oceans, may in fact be causing some of the same problems it was meant to resolve.

Shrimp and salmon aquaculture, in particular, were indicted for depleting fisheries, disrupting coastal ecosystems, polluting the ocean with excess nutrients and pesticides, and using almost triple the quantity of wild-caught fish for "fish food" as the system produces in marketable shrimp or salmon.

"Aquaculture is often seen as a panacea, the solution to relieve fishing pressure on the oceans and feed the world," said Jane Lubchenco, a distinguished professor of zoology at Oregon State University and co-author of the report.

"What we're finding is that, unless it is done right, some aquaculture is causing more problems than it solves and doing nothing to increase the world's overall food supply."

Lubchenco and nine other international experts in aquaculture, fisheries, ecology and economics suggested that improved practices are needed to make salmon and shrimp aquaculture more sustainable. For example, the amount of fish required to make feed for salmon and shrimp should be reduced, pollution from aquaculture operations should be minimized and habitat destruction prevented.

Both the industry and government should consider new regulations, pollution taxes, or reduction of financial subsidies for the most harmful types of aquaculture until some of the problems are addressed, the researchers said.

According to the report, some of the worst problems with aquaculture develop with species such as shrimp and salmon that are carnivores and require high levels of fish meal and fish oil in their diets. Instead of becoming a substitute for ocean fishing, they actually draw down the ocean resources that support all fish production, the report said.

And the issues involved are increasingly a big business. Farmed shrimp is now produced in 50 countries, most of them developing nations in the tropics, with a global value of $6 billion a year. The salmon produced largely in temperate zones are a $2 billion crop which has expanded rapidly since the late 1970s due to improved technology, high profits and government subsidy.

Global aquaculture now accounts for one-fourth of all fish consumed by humans. Almost half of the salmon and nearly one fourth of the shrimp consumed worldwide now comes from farms.

Among the problems caused by shrimp and salmon aquaculture:


  • Shrimp aquaculture ponds can destroy mangroves and other nursery areas that support ocean fisheries, provide livelihoods for indigenous peoples and protect coral reefs.


  • Fish farming discharges nutrients, pesticides and antibiotics into coastal waters.


  • Exotic fish species are sometimes introduced outside their native habitat.


  • The ocean's capacity to assimilate wastes, provide feed and stock, and maintain viable fish populations is being challenged.


  • The viability of tropical ponds used to rear shrimp often collapses after 5-10 years of use from disease, chemical and biological pollution, creating a "boom and bust" economic cycle and disruption of local communities.

A big part of the problem, the report said, are the huge amounts of fish needed to produce fish meal and oil for the "delicacy" species such as shrimp and salmon that bring top prices in the market. It can take 1.8 million tons of wild fish to produce 644,000 tons of salmon.

Meanwhile, salmon netpens send volumes of feces and uneaten food directly into coastal waters. One analysis of the Nordic salmon farming industry showed that it discharged quantities of nitrogen equal to the amount in untreated sewage from a population of 3.9 million people. And there are concerns that escaped, farmed salmon may lead to genetic degradation of wild salmon populations.

"Rapid growth in shrimp and salmon farming has clearly caused environmental degradation, while contributing little to world food security," the researchers said in the report. "These industries provide food mainly for industrialized countries, consume vast quantities of wild fish as feed, and generally do not generate long-term income growth in impoverished communities."

According to Lubchenco, salmon aquaculture in the Pacific Northwest faces similar issues.

"Now that some of these problems are being recognized, they can begin to be addressed," she said. "Incentives which reward good practices should be established, which could operate at local to international levels."

In the Science report, the researchers suggested that a good mechanism to improve production practices might be trade restrictions through the World Trade Organization that addressed the processes of production, not just quality of products.

Story By: 

Jane Lubchenco, 541-737-5337