OREGON STATE UNIVERSITY

marine science and the coast

New, complex call recorded in Mariana Trench believed to be from baleen whale

CORVALLIS, Ore. – A sound in the Mariana Trench notable for its complexity and wide frequency range likely represents the discovery of a new baleen whale call, according to the Oregon State University researchers who recorded and analyzed it.

Scientists at OSU’s Hatfield Marine Science Center named it the “Western Pacific Biotwang.”

Lasting between 2.5 and 3.5 seconds, the five-part call includes deep moans at frequencies as low as 38 hertz and a metallic finale that pushes as high as 8,000 hertz.

“It’s very distinct, with all these crazy parts,” said Sharon Nieukirk, senior faculty research assistant in marine bioacoustics at Oregon State. “The low-frequency moaning part is typical of baleen whales, and it’s that kind of twangy sound that makes it really unique. We don’t find many new baleen whale calls.”

Recorded via passive acoustic ocean gliders, which are instruments that can travel autonomously for months at a time and dive up to 1,000 meters, the Western Pacific Biotwang most closely resembles the so-called “Star Wars” sound produced by dwarf minke whales on the Great Barrier Reef off the northeast coast of Australia, researchers say.

The Mariana Trench, the deepest known part of the Earth’s oceans, lies between Japan to the north and Australia to the south and features depths in excess of 36,000 feet.

Minke whales are baleen whales – meaning they feed by using baleen plates in their mouths to filter krill and small fish from seawater – and live in most oceans. They produce a collection of regionally specific calls, which in addition to the Star Wars call include “boings” in the North Pacific and low-frequency pulse trains in the Atlantic.

“We don’t really know that much about minke whale distribution at low latitudes,” said Nieukirk, lead author on the study whose results were recently published in the Journal of the Acoustical Society of America. “The species is the smallest of the baleen whales, doesn’t spend much time at the surface, has an inconspicuous blow, and often lives in areas where high seas make sighting difficult. But they call frequently, making them good candidates for acoustic studies.”

Nieukirk said the Western Pacific Biotwang has enough similarities to the Star Wars call – complex structure, frequency sweep and metallic conclusion – that it’s reasonable to think a minke whale is responsible for it.

But scientists can’t yet be sure, and many other questions remain. For example, baleen whale calls are often related to mating and heard mainly during the winter, yet the Western Pacific Biotwang was recorded throughout the year.

“If it’s a mating call, why are we getting it year round? That’s a mystery,” said Nieukirk, part of the team at the Cooperative Institute for Marine Resources Studies, a partnership between OSU and the NOAA Pacific Marine Environmental Laboratory. “We need to determine how often the call occurs in summer versus winter, and how widely this call is really distributed.”

The call is tricky to find when combing through recorded sound data, Nieukirk explains, because of its huge frequency range. Typically acoustic scientists zero in on narrower frequency ranges when analyzing ocean recordings, and in this case that would mean not detecting portions of the Western Pacific Biotwang.

“Now that we’ve published these data, we hope researchers can identify this call in past and future data, and ultimately we should be able to pin down the source of the sound,” Nieukirk said. “More data are needed, including genetic, acoustic and visual identification of the source, to confirm the species and gain insight into how this sound is being used. Our hope is to mount an expedition to go out and do acoustic localization, find the animals, get biopsy samples and find out exactly what’s making the sound. It really is an amazing, weird sound, and good science will explain it.”

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Steve Lundeberg, 541-737-4039

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dwarf minke whale

Dwarf minke whale

OSU Press publishes first guide to Oregon freshwater fishes

CORVALLIS, Ore. – The first comprehensive guide to Oregon’s freshwater fishes has been published by the Oregon State University Press.

Written by Professor Emeritus Douglas Markle in the Department of Fisheries and Wildlife at Oregon State, the guide includes tips on identifying the state’s 137 known species and subspecies, along with photos and illustrations of native and non-native fish.

“A Guide to Freshwater Fishes of Oregon” is available in bookstores, by calling 1-800-621-2736, or by ordering online at osupress.oregonstate.edu

The guide includes information about Oregon’s most iconic fishes – including Chinook and coho salmon – as well as those species not as well-known, such as sculpins and minnows. Markle notes that the number of introduced, non-native fishes continues to increase and “they often are responsible in part for the decline of native fishes.”

“The book is a great guide for anglers and others who may encounter a fish that they cannot easily recognize,” said Marty Brown, marketing coordinator for the OSU Press. “Many groups of Oregon fishes are difficult to identify because of their size, diversity of forms, or lack of study, and there are ongoing debates about the actual number of species and subspecies of fish in the state.”

The guide covers fish both large and small. The white sturgeon is Oregon’s largest freshwater fish, reaching sizes of up to 19 feet and 1,800 pounds, and it is the most long-lived reaching estimated ages of close to 100 years. Among the smaller fish are minnows, which are the largest family of fishes in Oregon, and include such species as the Oregon chub and Umpqua chub – species only found in this state.

Markle is a long-time faculty member at Oregon State who parlayed a childhood interest in aquarium fish into a career teaching and conducting research on deep-sea fishes, coral reef fish, and a variety of freshwater fishes.

In addition to the many color photographs in “A Guide to Freshwater Fishes of Oregon” are numerous illustrations by well-known fish artist Joseph R. Tomelleri.

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Marty Brown, 541-737-3866, marty.brown@oregonstate.edu;

Doug Markle, 541-737-1970, douglas.markle@oregonstate.edu

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Freshwater Fishes of Oregon

Douglas F. Markle

Douglas Markle

New study shows impact of Antarctic Ice Sheet on climate change

CORVALLIS, Ore. – Scientists have known for decades that small changes in climate can have significant impacts on the massive Antarctic Ice Sheet.

Now a new study suggests the opposite also is true. An international team of researchers has concluded that the Antarctic Ice Sheet actually plays a major role in regional and global climate variability – a discovery that may also help explain why sea ice in the Southern Hemisphere has been increasing despite the warming of the rest of the Earth.

Results of the study are being published this week in the journal Nature.

Global climate models that look at the last several thousand years have failed to account for the amount of climate variability captured in the paleoclimate record, according to lead author Pepijn Bakker, a former post-doctoral researcher at Oregon State University now with the MARUM Center for Marine Environmental Studies at the University of Bremen in Germany.

The research team’s hypothesis was that climate modelers were overlooking one crucial element in the overall climate system – an aspect of the ocean, atmosphere, biosphere or ice sheets – that might affect all parts of the system.

“One thing we determined right off the bat was that virtually all of the climate models had the Antarctic Ice Sheet as a constant entity,” Bakker said. “It was a static blob of ice, just sitting there. What we discovered, however, is that the ice sheet has undergone numerous pulses of variability that have had a cascading effect on the entire climate system.”

The Antarctic Ice Sheet, in fact, has demonstrated dynamic behavior over the past 8,000 years, according to Andreas Schmittner, a climate scientist in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences and co-author on the study.

“There is a natural variability in the deeper part of the ocean adjacent to the Antarctic Ice Sheet – similar to the Pacific Decadal Oscillation, or El Niño/La Niña but on a time scale of centuries – that causes small but significant changes in temperatures,” Schmittner said. “When the ocean temperatures warm, it causes more direct melting of the ice sheet below the surface, and it increases the number of icebergs that calve off the ice sheet.”

Those two factors combine to provide an influx of fresh water into the Southern Ocean during these warm regimes, according to Peter Clark, a paleoclimatologist in OSU’s College of Earth, Ocean, and Atmospheric Sciences and co-author on the study.

“The introduction of that cold, fresh water lessens the salinity and cools the surface temperatures, at the same time, stratifying the layers of water,” Clark said. “The cold, fresh water freezes more easily, creating additional sea ice despite warmer temperatures that are down hundreds of meters below the surface.”

The discovery may help explain why sea ice has expanded in the Southern Ocean despite global warming, the researchers say. The same phenomenon doesn’t occur in the Northern Hemisphere with the Greenland Ice Sheet because it is more landlocked and not subject to the same current shifts that affect the Antarctic Ice Sheet.

“One message that comes out of this study is that the Antarctic Ice Sheet is very sensitive to small changes in ocean temperatures, and humans are making the Earth a lot warmer than it has been,” Bakker said.

Sediment cores from the sea floor around Antarctica contain sand grains delivered there by icebergs calving off the ice sheet. The researchers analyzed sediments from the last 8,000 years, which showed evidence that many more icebergs calved off the ice sheet in some centuries than in others. Using sophisticated computer modeling, the researchers traced the variability in iceberg calving to small changes in ocean temperatures.

The Antarctic Ice Sheet covers an area of more than 5 million square miles and is estimated to hold some 60 percent of all the fresh water on Earth. The east part of the ice sheet rests on a major land mass, but in West Antarctica, the ice sheet rests on bedrock that extends into the ocean at depths of more than 2,500 meters, or more than 8,000 feet, making it vulnerable to disintegration.

Scientists estimate that if the entire Antarctic Ice Sheet were to melt, global sea levels would rise some 200 feet.

Other authors on the study include Nicholas Golledge of Victoria University of Wellington in New Zealand and Michael Weber of the University of Bonn in Germany.

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Peter Clark, 541-737-1247, clarkp@geo.oregonstate.edu;

Andreas Schmittner, 541-737-9952, aschmittner@coas.oregonstate.edu;

Pepijn Bakker, 004942121865435, pbakker@marum.de

Despite evolutionary inexperience, northern sockeye manage heat stress

CORVALLIS, Ore. – Sockeye salmon that evolved in the generally colder waters of the far north still know how to cool off if necessary, an important factor in the species’ potential for dealing with global climate change.

Sockeyes, which spawn in fresh water and spend two to three years in the Pacific Ocean, range from southern Alaska south to the Columbia River.

Research by Oregon State University revealed that sockeyes at the northern edge of that range, despite lacking their southern counterparts’ evolutionary history of dealing with heat stress, nevertheless have an innate ability to “thermoregulate.”

Thermoregulation means that when their surroundings warm up too much, the fish will seek cooler water that precisely meets their physiological needs. A study conducted by an OSU researcher at an Alaska lake during a heat wave shed light on sockeyes’ ability to find the water temperatures they need.

Multiple earlier studies had demonstrated thermoregulation behavior among sockeye salmon at lower latitudes, but northern populations’ behavioral response to heat stress had largely gone unexamined.

While it may seem obvious that any fish would move around to find the water temperature it needed, prior research has shown thermoregulation is far from automatic – even among populations living where heat stress is a regular occurrence.

“Often what’s happened has been counterintuitive, so we had no idea what to expect,” said Jonathan B. Armstrong, assistant professor in the College of Agricultural Sciences’ Department of Fish and Wildlife, the lead author on the study. “About 40 million sockeye return to Bristol Bay every year. These huge salmon runs are a big part of the regional culture and economy, so how these fish respond to climate change will have very real effects on people’s lives. It’s encouraging that the sockeyes showed this innate capacity to respond.”

Results of the research were recently published in Conservation Physiology.

Armstrong and his collaborators at the University of Washington worked in 2013 at Little Togiak Lake – one of five major lakes in the Wood River watershed that drain into Bristol Bay, a fishery that produces nearly 70 percent of all the sockeye salmon caught in the United States. Bristol Bay is close to the 60-degree latitude that marks the northern boundary of the sockeyes’ primary range.

Adult sockeye salmon return to the Wood River system from the Bering Sea in early summer, then mature and develop secondary sexual traits before spawning later in the summer or at the beginning of fall.

During the time between entering fresh water and spawning, the fish group together in their lake’s epilimnion – the upper, warmer level of water in a thermally stratified lake. Usually the fish congregate, or stage, near tributary inlets and along shorelines.

During a staging period of unusually warm weather – maximum daily air temperatures hovered around 80 degrees for a week, the second-warmest heat wave on record – researchers used a seine to capture fish and outfitted 95 of them with devices that logged water temperatures at 20-minute intervals.

What they learned from the 40 recovered temperature loggers was that when the epilimnion temperature rose above about 12 degrees Celsius, or about 53 degrees, the fish thermoregulated by moving to tributary plumes or to deeper water.

By swimming away from the rising temperatures, the fish expended 50 percent less energy during the warmest conditions – 64 to 68 degrees – than they would have had they stayed put.

“The hotter it is, the more energy they burn, but these fish don’t just want the coldest water possible,” Armstrong said. “If they were cars looking for maximum fuel efficiency, they’d just find the coldest water, but instead it’s a Goldilocks sort of thing - they’re looking for not too warm, not too cold.

“They want their system to go fast enough for them to go through maturation before they spawn, where they go from these silver torpedoes to these crazy, exaggerated beasts of sexual selection with a red body and green jaws.”

Armstrong noted the broader message of the study is what it says about the ability of animals to exploit the kinds of diversity of temperature and diversity of habitat found in ecosystems that are intact and not heavily developed.

“There’s all this diversity and connectivity up there,” Armstrong said. “Fish have lots of options for coping with warming or environmental change in general.

“When we develop watersheds, we often simplify habitats and take away these options. In our research we are constantly stumbling across new and interesting ways that fish and wildlife thrive by exploiting diversity in temperatures, often at small spatial scales that would be very easy to overlook. This study is one more example of how all the little details matter, and they could be what save animals from climate change, or at least reduce the impacts.”

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Steve Lundeberg, 541-737-4039 

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Sockeye salmon

Marine incentives programs may replace 'doom and gloom' with hope

CORVALLIS, Ore. – Incentives that are designed to enable smarter use of the ocean while also protecting marine ecosystems can and do work, and offer significant hope to help address the multiple environmental threats facing the world’s oceans, researchers conclude in a new analysis.

Whether economic or social, incentive-based solutions may be one of the best options for progress in reducing impacts from overfishing, climate change, ocean acidification and pollution, researchers from Oregon State University and Princeton University say in a new report published this week in Proceedings of the National Academy of Sciences.

And positive incentives – the “carrot” – work better than negative incentives, or the “stick.”

Part of the reason for optimism, the researchers report, is changing awareness, attitudes and social norms around the world, in which resource users and consumers are becoming more informed about environmental issues and demanding action to address them. That sets the stage for economic incentives that can convert near-disaster situations into sustainable fisheries, cleaner water and long-term solutions.

“As we note in this report, the ocean is becoming higher, warmer, stormier, more acidic, lower in dissolved oxygen and overfished,” said Jane Lubchenco, the distinguished university professor in the College of Science and advisor in marine studies at Oregon State University, lead author of the new report, and U.S. science envoy for the ocean at the Department of State.

“The threats facing the ocean are enormous, and can seem overwhelming. But there’s actually reason for hope, and it’s based on what we’ve learned about the use of incentives to change the way people, nations and institutions behave. We believe it’s possible to make that transition from a vicious to a virtuous cycle. Getting incentives right can flip a disaster to a resounding success.”

Simon A. Levin, the James S. McDonnell distinguished university professor in ecology and evolutionary biology at Princeton University and co-author of the publication, had a similar perspective.

“It is really very exciting that what, until recently, was theoretical optimism is proving to really work,” Levin said. “This gives me great hope for the future.”

The stakes are huge, the scientists point out in their study.

The global market value of marine and coastal resources and industries is about $3 trillion a year; more than 3 billion people depend on fish for a major source of protein; and marine fisheries involve more than 200 million people. Ocean and coastal ecosystems provide food, oxygen, climate regulation, pest control, recreational and cultural value.

“Given the importance of marine resources, many of the 150 or more coastal nations, especially those in the developing world, are searching for new approaches to economic development, poverty alleviation and food security,” said Elizabeth Cerny-Chipman, a postdoctoral scholar working with Lubchenco.  “Our findings can provide guidance to them about how to develop sustainably.”

In recent years, the researchers said in their report, new incentive systems have been developed that tap into people’s desires for both economic sustainability and global environmental protection. In many cases, individuals, scientists, faith communities, businesses, nonprofit organizations and governments are all changing in ways that reward desirable and dissuade undesirable behaviors.

One of the leading examples of progress is the use of “rights-based fisheries.” Instead of a traditional “race to fish” concept based on limited seasons, this growing movement allows fishers to receive a guaranteed fraction of the catch, benefit from a well-managed, healthy fishery and become part of a peer group in which cheating is not tolerated.

There are now more than 200 rights-based fisheries covering more than 500 species among 40 countries, the report noted. One was implemented in the Gulf of Mexico red snapper commercial fishery, which was on the brink of collapse after decades of overfishing. A rights-based plan implemented in 2007 has tripled the spawning potential, doubled catch limits and increased fishery revenue by 70 percent.

“Multiple turn-around stories in fisheries attest to the potential to end overfishing, recover depleted species, achieve healthier ocean ecosystems, and bring economic benefit to fishermen and coastal communities,” said Lubchenco.  “It is possible to have your fish and eat them too.”

A success story used by some nations has been combining “territorial use rights in fisheries,” which assign exclusive fishing access in a particular place to certain individuals or communities, together with adjacent marine reserves. Fish recover inside the no-take reserve and “spillover” to the adjacent fished area outside the reserve. Another concept of incentives has been “debt for nature” swaps used in some nations, in which foreign debt is exchanged for protection of the ocean.

“In parallel to a change in economic incentives,” said Jessica Reimer, a graduate research assistant with Lubchenco, “there have been changes in behavioral incentives and social norms, such as altruism, ethical values, and other types of motivation that can be powerful drivers of change.”

The European Union, based on strong environmental support among its public, has issued warnings and trade sanctions against countries that engage in illegal, unregulated and unreported fishing. In the U.S., some of the nation’s largest retailers, in efforts to improve their image with consumers, have moved toward sale of only certified sustainable seafood.

Incentives are not a new idea, the researchers noted. But they emphasize that their power may have been under-appreciated.

“Recognizing the extent to which a change in incentives can be explicitly used to achieve outcomes related to biodiversity, ecosystem health and sustainability . . .  holds particular promise for conservation and management efforts in the ocean,” they wrote in their conclusion.

Funding was provided by OSU and the National Science Foundation.

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Jane Lubchenco, 541-737-5337

lubchenco@oregonstate.edu

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Catch share
Catch share program

Rockfish siblings shed new light on how offspring diffuse and disperse

CORVALLIS, Ore. – A splitnose rockfish’s thousands of tiny offspring can stick together in sibling groups from the time they are released into the open ocean until they move to shallower water, research from Oregon State University shows.

The study conducted in the OSU College of Science sheds new light on how rockfish, a group of multiple species that contribute to important commercial and recreational fisheries in the Northwest, disperse through the ocean and “recruit,” or take up residence in nearshore habitats. Previously it was believed rockfish larvae dispersed chaotically to wherever currents carried them.

“When you manage populations, it’s really important to understand where the young are going to and where the young are coming from – how populations are connected and replenished,” said Su Sponaugle, a professor of integrative biology based at OSU’s Hatfield Marine Science Center. “This research helps us better understand what’s possible about offspring movement. We don’t know fully by what mechanisms the larvae are staying together, but these data are suggestive that behavior is playing a role.”

The findings were published today in Proceedings of the National Academy of Sciences. Primary funding came from the Hatfield Marine Science Center’s Mamie L. Markham Research Award.

The discovery of “spatial cohesion” among the larvae came via the collection of newly settled rockfish in a shallow nearshore habitat off the central Oregon coast. Nearly 500 juvenile fish that had started out up to six months earlier as transparent larvae at depths of a few hundred meters were collected and genetically analyzed, with the results showing that 11.6 percent had at least one sibling in the group.

“That’s much higher than we would have expected if they were randomly dispersing,” Sponaugle said.

Bearing live young – a female can release thousands of able-to-swim larvae at a time – and dwelling close to the sea floor in the benthic zone, rockfishes make up a diverse genus with many species.

Adult splitnose rockfish live in deep water – usually 100 to 350 meters – but juveniles often settle in nearshore habitats less than 20 meters deep after spending up to a year in the open sea. Taking into account dynamic influences such as the California Current, siblings recruiting to the same area suggest they remained close together as larvae rather than diffusing randomly and then reconnecting as recruits.

“This totally changes the way we understand dispersal,” said lead author Daniel Ottmann, a graduate student in integrative biology at the Hatfield Marine Science Center. “We’d thought larvae were just released and then largely diffused by currents, but now we know behavior can substantially modify that.”

Splitnose rockfish range from Alaska to Baja California and can live for more than 100 years. Pelagic juveniles – juveniles in the open sea – often aggregate to drifting mats of kelp, and the large amount of time larvae and juveniles spend at open sea is thought to enable them to disperse great distances from their parental source.

“This research gives us a window into a stage of the fishes’ life we know so little about,” added Kirsten Grorud-Colvert, an assistant professor of integrative biology at OSU’s Corvallis campus. “We can’t track the larvae out there in the ocean; we can’t look at their behavior early and see where they go. But this genetic technique allows us to look at how they disperse, and it changes the conversation. Now that we know that siblings are ending up in the same places, we can consider how to more effectively manage and protect these species.”

Because larval aggregation shapes the dispersal process more than previously thought, Ottmann said, it highlights the need to better understand what happens in the pelagic ocean to affect the growth, survival and dispersal of the larvae.

“Successful recruitment is critical for the population dynamics of most marine species,” he said. “Our findings have far-reaching implications for our understanding of how populations are connected by dispersing larvae.”

In addition, Grorud-Colvert adds, there’s the simple and substantial “gee whiz” factor of the findings.

“These tiny little fish, a few days old, out there in the humongous ocean, instead of just going wherever are able to swim and stay close together on their epic journey,” she said. “These tiny, tiny things, sticking together in the open ocean – it’s cool.”

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Steve Lundeberg, 541-737-4039

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Splitnose rockfish

Kelp forests globally resilient, but may need local solutions to environmental threats

CORVALLIS, Ore. – The first global assessment of marine kelp ecosystems shows that these critically-important habitats have exhibited a surprising resilience to environmental impacts over the past 50 years, but they have a wide variability in long-term responses that will call for regional management efforts to help protect their health in the future.

The findings were published today in Proceedings of the National Academy of Sciences.

Scientists noted that kelp forests have a remarkable ability to recover quickly from extreme damage, but they can still be overwhelmed in some instances by the combination of global and local pressures.

This points to the need for regional management efforts that carefully consider local conditions when trying to offset human-caused impacts from climate change, overfishing and direct harvests, researchers said.

Kelp forests, the largest species of algae in shallow, coastal waters almost everywhere except the tropics, are a globally important foundation species that occupy almost half of the world’s marine ecoregions. Often harvested directly, they help support commercial fisheries, nutrient cycling, shoreline protection, and are valued in the range of billions of dollars annually.

The new research was conducted by an international team of 37 scientists who analyzed changes in kelp abundance in 34 regions of the planet that had been monitored over the past 50 years.

“Kelp forests are cold-water, fast-growing species that can apparently withstand many types of environmental disturbances,” said Mark Novak, an assistant professor of integrative biology in the College of Science at Oregon State University, co-author of the study, and an organizer of the international group at the National Center for Ecological Analysis and Synthesis that conducted this research.

“The really surprising thing in this study was how much region-to-region variation we found, which is quite different from many other ecosystems. Thus, despite global threats like climate change and ocean acidification, the battle to protect our kelp forests of the future may best be fought locally – in the U.S., by states, counties, even individual cities and towns.”

These forests can grow fast, tall, and are highly resilient – but also are often on the coastal front line in exposure to pollution, sedimentation, invasive species, fishing, recreation and harvesting. Even though “they have some of the fastest growth rates of any primary producer on the planet,” the researchers wrote, there are limits to what they can take.

In their study the scientists concluded that of the kelp ecosystems that have been studied, 38 percent are in decline; 27 percent are increasing; and 35 percent show no detectable change. On a global scale, they are declining at 1.8 percent per year.

Where kelp resilience is eroding and leading to declines in abundance, impacts to ecosystem health and services can be far-reaching, the researchers wrote in their report.

This research was supported by the National Science Foundation, the University of California/Santa Barbara, and the state of California.

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Mark Novak, 541-737-3610

mark.novak@oregonstate.edu

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Kelp Forest
Kelp forests

Discovery of new bacteria complicates problem with salmon poisoning in dogs

CORVALLIS, Ore. – Researchers at Oregon State University have identified for the first time another bacterium that can cause symptoms similar to “salmon poisoning” in dogs - and may complicate the efforts of Pacific Northwest pet owners to keep their dogs protected and healthy.

The Pacific Northwest, from northern California to central Washington, is the only region of the world in which dogs face this potentially deadly health threat. It’s caused by a complicated life cycle that includes a common freshwater snail that harbors a fluke worm, and the fluke, in turn, carries the bacterium Neorickettsia helminthoeca. The bacterium is the actual cause of salmon poisoning.

The underlying problem is not new. Dogs that died after eating uncooked, infected salmon were first noted in the Astoria Journal in 1814, not long after Lewis and Clark visited the region.

The conventional wisdom, however, has been that dogs are usually immune to salmon poisoning after they have once been infected, treated with antibiotics and recovered – giving pet owners at least some assurance that it’s a problem they no longer need be concerned about.

The new discovery makes it clear the issue is not that simple.

In the infectious process that leads to salmon poisoning, the fluke is released from snails, which then infect salmon and other freshwater fishes. The life cycle is completed when a mammal eats an infected fish – in this case, dogs get sick from eating raw or undercooked salmon. The possible occurrence of “salmon poisoning” is actually dictated by the geographic distribution of the snail.

Another bacterium called “SF agent,” however, has been found for the first time in a salmonid fish anywhere in the world, researchers report in a recent study in Veterinary Parasitology. The fluke host for this bacterium is Stellanchasmus falcatus.

“SF agent can infect dogs that eat salmon or trout, and it can cause a mild fever in dogs and other symptoms that can resemble salmon poisoning,” said Michael Kent, a professor of microbiology in the OSU College of Science and College of Veterinary Medicine, and co-author of the study. “It can also be treated with antibiotics, but may not offer immunity to dogs that could be later exposed to the actual salmon poisoning bacterium. A pet owner might believe their dog is protected, when it isn’t.”

The larval stages of the worm that carries Neorickettsia helminthoeca were first associated with the disease in 1911, and in 1950 the actual bacterium was confirmed as the cause of salmon poisoning. It’s in the same bacterial family as SF agent – meaning pet owners must now understand their dogs may face two related Neorickettsia pathogens – but one causes only a mild illness, while the other can be deadly.

Veterinary doctors, Kent said, routinely have treated animals based on their [mlk1] clinical signs, because the eggs of the fluke may be hard to find in dog feces, and the bacterium is difficult to culture from dog blood. Left untreated, dogs with salmon poisoning can die in a week to 10 days, often from severe hemorrhaging and internal ruptures. The ultimate fatality rate can approach 90 percent of untreated cases.

The bottom line, he said, is that pet owners should not make any assumptions about whether or not their dogs may have immunity to salmon poisoning. Kent said he has received several reports from local veterinarians documenting dogs contracting salmon poisoning more than once.

With the new awareness that different bacteria can cause similar initial symptoms, pet owners should know that dogs displaying such symptoms may or may not have a serious health problem.

The fluke worm, but not the bacterium, can also infect humans.  Humans do not contract salmon poisoning, but may develop a relatively mild gastrointestinal illness. Either freezing or cooking infected fish will kill the worms.

This research was supported by the National Institutes of Health and done in collaboration with researchers from the University of North Dakota, Georgia Southern University, and the Woodburn Veterinary Clinic in Woodburn, Ore.


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Michael Kent, 541-737-8652

michael.kent@oregonstate.edu

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Salmon poisoning of dogs
Dogs at play

Fall Creek hatchery to hold annual festival on Nov. 5

CORVALLIS, Ore. – The Oregon Hatchery Research Center will host its annual Fall Creek Festival on Saturday, Nov. 5, from 10 a.m. to 4 p.m. at the hatchery, located 13 miles west of Alsea on Highway 34.

The festival, which is free and open to the public, features a day of art workshops – scheduled for 10:30 a.m. and 2 p.m. – as well as children’s activities and tours. Registration is required because space is limited; lunch will be provided for registered participants.

To register, call 541-487-5512 and state workshop preferences, or send an email to oregonhatchery.researchcenter@state.or.us

“It’s a wonderful opportunity to see wild coho and Chinook salmon spawning in Fall Creek,” said David Noakes, an OSU professor of fisheries and wildlife.

The workshops include:

  • Water color painting
  • Fish printing
  • Bird house construction
  • Grocery bag stenciling
  • Wind chime construction
  • Nature journal illustration

The center is jointly operated by the Oregon Department of Fish and Wildlife and Oregon State University’s Department of Fisheries and Wildlife.

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David Noakes, 541-737-1953, david.noakes@oregonstate.edu

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Tsunami-safety panel to oversee construction of Marine Studies building

CORVALLIS, Ore. – Oregon State University President Ed Ray announced today the creation of an oversight committee to monitor construction of a Marine Studies Building and student housing in Newport, Ore.

“This committee will ensure that the design, engineering and construction of these buildings meet or exceed the earthquake and tsunami performance commitments the university has made to the public,” Ray said.

Ray also charged the committee with ensuring that the buildings are operated with the highest level of safety and evacuation procedures, preparation and training. The committee’s charge is available online.

The $50 million center for global marine studies research and education will be built at OSU’s Hatfield Marine Science Center in Newport. The 100,000-square-foot facility is an integral part of OSU’s ambitious Marine Studies Initiative, designed to educate students and conduct research on marine-related issues – from rising sea levels and ocean acidification to sustainable fisheries and economic stability.

Housing to accommodate Oregon State students at the campus will be located near Oregon Coast Community College and located out of the tsunami zone.

“Life safety for the occupants of these buildings, as well as the safety for all Hatfield Marine Science Center faculty, staff, students and visitors, is of the highest priority for OSU,” Ray said.

Scott Ashford, dean of Oregon State’s College of Engineering, will chair the committee, which will report to interim Provost and Executive Vice President Ron Adams. The committee will be made up of eight university leaders and will be advised by two seismic and structural engineers, one of whom will be externally employed and independent of the university.

Committee members include Michael Green, OSU interim vice president for finance and administration; Toni Doolen, dean of the university’s Honors College; Susie Brubaker-Cole, vice provost for Student Affairs; Jock Mills, government relations director; Steve Clark, vice president for University Relations and Marketing; and Roy Haggerty, associate vice president for research. OSU’s Office of General Counsel will serve in an advisory capacity.

The committee will be advised by Chris D. Poland, an independent, third party seismic resilience structural engineer, who is a member of the National Academy of Engineering; and Dan Cox, an OSU professor in civil and construction engineering with expertise in coastal resilience and tsunami impacts.

Ashford said the Marine Studies Building will meet or surpass the new “inundation zone” construction guidelines announced recently by the American Society of Civil Engineers. Faculty researchers within OSU’s College of Engineering and Oregon State’s O.H. Hinsdale Wave Research Laboratory aided in the standards’ formation.

In addition to design, engineering and construction matters, the committee will also oversee safety and evacuation planning, procedures and training for the Marine Studies Building, the HMSC campus and the student housing to be built in Newport.

The committee’s charge also includes keeping stakeholders informed; maintaining transparency of all the university’s work regarding design, engineering, construction and safety operations; and ensuring the buildings are completed within budget and on time.

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Steve Lundeberg, 541-737-4039

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Hatfield Marine Science Center