marine science and the coast

Zebrafish may hold key to improved cancer research

CORVALLIS, Ore. - A new study has confirmed that research done with zebrafish may be able to play a critical role in learning about the genetic basis of cancer and the mutations that can lead to it - and identified one gene in particular, B-myb, whose function is essential to preventing tumors.

The findings were published in a professional journal, Proceedings of the National Academy of Sciences, by researchers from Oregon State University and two Boston hospitals, the Brigham and Women's Hospital and Children's Hospital.

The research also indicates that zebrafish may be a key to faster, less expensive studies on cancer and carcinogens, as well as a tool to lower the cost for drug development, OSU experts said.

The first comprehensive cancer research studies using this small, striped tropical fish were begun at OSU over 10 years ago, and the species has become an important tool in medical research programs around the world.

"It's increasingly clear that in zebrafish we have an animal model that is inexpensive, easy to work with and extremely useful for study of human cancers," said Jan Spitsbergen, a fish pathologist in OSU's Center for Fish Disease Research. "We've now proven that most of the carcinogens that affect humans are also active in zebrafish and can lead to the same types of cancer, whether it's in the brain, blood, reproductive organs or elsewhere."

The newest finding about the gene B-myb is especially compelling, said Spitsbergen. The B-myb gene has been conserved through hundreds of millions of years of divergent evolution in species ranging from worms to fruit flies, fish and humans.

When it functions normally, B-myb appropriately regulates cell proliferation. When it becomes mutated, either through genetic predisposition or environmental influences, the formation of tumors can dramatically increase, scientists say. The gene appears to be particularly relevant to human leukemias.

OSU's fish disease research programs date back several decades, and the university first developed the rainbow trout as a useful model for cancer research. Those studies, among others, helped to determine that aflatoxin contaminants that can be found in some foods are a powerful carcinogen - and are still a major cause of liver cancer in some developing nations.

Zebrafish, however, are a fascinating species because the fish embryos are literally transparent and can be directly observed at early developmental stages better than almost any other animal species. They had been used for years in studying everything from the immune system to cardiovascular disease and skeletal development. In the mid-1990s, OSU researchers began the use of zebrafish in cancer research.

OSU scientists conducted studies on a wide variety of carcinogens and a complete histologic examination of all major organs, the first work of that type. In recent years collaboration has also been extensive with colleagues at the University of Oregon, where the federally funded Zebrafish International Resource Center archives, propagates and distributes the many mutant lines of zebrafish now developed worldwide to aid research on specific genes in development and disease.

This research has proven that the mechanism of cancer prevention in fish is remarkably similar to that of humans, including the genes involved.

"Zebrafish are now changing the face of cancer research," Spitsbergen said. "They can be managed in a laboratory almost anywhere, they reproduce quickly, lend themselves well to genetic manipulation, can efficiently test high numbers of possible drug therapies, and might tell you in three months what it would take two years to find out with other animal models."

"This low cost, efficient research should speed up drug development, save many millions of dollars and help lead to new cancer therapies."

Using zebrafish, OSU has extensively studied two groups of carcinogens, polyaromatic hydrocarbons, or PAHs, and nitrosamines. Both of these groups can be produced by normal living activities, ranging from preserved foods to smoking and use of wood stoves. University researchers have also been active in studies on dioxin and PCBs, both concerns in the process of carcinogenesis.

"With zebrafish as a model we should be able to better determine what types and levels of environmental carcinogens are a real health concern," Spitsbergen said. "And we should also be able to rapidly test and develop new approaches to treat cancer."

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Jan Spitsbergen, 541-737-5055

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Zebrafish are helping move cancer research forward

OSU Recognized for Coral Reef Research

CORVALLIS, Ore. – The chilly coastal waters of the Pacific Northwest are quite a distance from the closest tropical coral reef, but Oregon State University research programs on these threatened ecosystems have been recognized as among the best in both the United States and the world.

One of OSU’s scientists involved in studies of coral reef ecology, Mark Hixon, was also cited as the leading expert in the Western Hemisphere and third in the world, based on journal publications that were most often cited for their scientific significance. Overall, OSU coral reef research programs ranked sixth in the U.S. and eighth globally.

The report was just made in an analysis of the field of coral reef ecology, surveying 5,060 authors from 1,644 institutions in 103 countries over a 10-year period, made by the Thomson Institute for Science Information. The top two research institutions in this field are in Australia, home of the world’s largest coral reef system, the Great Barrier Reef.

Other leading institutions in the United States include the Smithsonian Institution, University of California at Santa Barbara, University of North Carolina, University of Miami and University of Hawaii.

Research papers in coral reef ecology address such environmental issues as overfishing, global warming, human impacts, population change in reef organisms, ecological modeling and reef geology.

“Many Oregonians don’t understand the relevance of coral reefs to our state,” Hixon said. “In fact, coral reefs are the source of important medicines, and their ongoing demise is a strong warning of the effects of global warming. They are also outdoor laboratories for answering fundamental questions about sea life, such as what specifically causes the birth and death rates of marine fish to vary.”

Coral reefs, found in shallow, tropical marine waters, are renowned for their beauty and often form the basis for major tourist industries. They support an extraordinary level of biodiversity, including over 4,000 species of fish and everything from sponges to spiny lobsters and sea snakes. But threats from pollution, overfishing, ocean acidification and other environmental issues have caused serious concerns, and led to significant research, monitoring and protection initiatives.

In the past few decades, about 20 percent of the world’s coral reefs have died, and it’s estimated that an additional 40 percent are at risk.

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Mark Hixon,

For Salmon and Human Communities, “Resilience” Emerging as Key Concept

CORVALLIS, Ore. - In a world in which instability, whether driven by people or nature, seems to be increasing, “resilience” is emerging as a key concept – a desirable characteristic of both natural and human systems and communities. Scientists define resilience as the ability to tolerate or recover from disturbance.

In the Pacific Northwest, researchers who specialize in salmon have begun to examine the problem of long-term salmon persistence in the region through the lens of resilience. They say that the traditional focus on maintaining production and harvest – which has long dominated discussion of salmon – has diverted attention from the more fundamental concern about the fish’s ability to withstand disturbances and persist.

According to Dan Bottom, a salmon biologist with NOAA Fisheries and a courtesy professor at Oregon State University, “the problem with the way we've managed fisheries in the past is we've tried to force a dynamic system into a static condition that actually, in the long run, makes the system much more unstable.”

“The natural world has adapted to disturbance,” said Bottom, “so, ironically, when you try to stabilize it, for example through raising fish in a hatchery, you make it less stable.”

In the case of hatchery-raised salmon, produced to maintain a stable population size, one consequence is that many of these fish “are not capable of living outside that narrow range of tolerances” in which they were produced in the hatchery.

“Fish raised to a uniform size all released at the same time are likely to be less flexible to the vagaries of nature,” said Bottom. The drive to stabilize populations through artificial production backfires, and to the extent that hatchery production replaces natural re-seeding of salmon habitat in rivers and streams, that population of salmon becomes less resilient to natural disturbances.

“We try to manage natural resources so we can have things nice and predictable,” said Court Smith, an OSU anthropologist who has studied how communities adapt to change. “But we're now facing tremendous changes, in terms of climate, globalization, and other human impacts, so today there are a lot of very dynamic changes going on to which humans have to be really skillful in adapting, and in assisting other organisms, such as salmon, to adapt.”

The Oregon Sea Grant program at OSU has been encouraging development of the resilience concept as it provides another approach to the problem of salmon decline and restoration in the Northwest, said Robert Malouf, program director. Earlier this year, Sea Grant sponsored a conference called Pathways to Resilience that involved more than 125 salmon researchers, social scientists, managers, and policy makers.

Resilience as a goal of salmon management was described by many at the conference as an idea whose time has come. The idea has been gaining currency in both the biological and social sciences since the 1970s, but the approach seems increasingly relevant as both biological and social systems come under stress.

In his keynote address, former Oregon Gov. John Kitzhaber supported such new thinking.

Kitzhaber observed: “Albert Einstein once said ‘You should not use an old map to explore a new world.’ And he was right, because each new generation faces a new world with new challenges--challenges that cannot be met by clinging to the past but only by imagining a different world and a different set of tools through which to build it.”

A theme sounded by many conference speakers was that the old approach to managing salmon has had the unintended effect of leaving both the fish and the human communities dependent on them less resilient.

“Traditional harvest management of salmon has focused on taking maximum yields of the dominant life-history types, while conservation has come to focus on so-called ‘critical habitats’ of those same population components,” noted Michael Healey of the University of British Columbia. “This management approach has narrowed significantly the spectrum of life history traits of salmon, and thereby reduced the resilience of salmon.”

“My definition for resilience would be survival,” said Irene Martin of Ilwaco, Wash., an adviser to the board of Salmon for All, a commercial fishing group. “How do families in an occupational group survive from one generation to the next?

“In the 1990s, when the Endangered Species Act listings of salmon on the Columbia River caused fishing seasons to be curtailed,” she noted, “some commercial fishermen invested in other permits, in Alaska – crab permits, shrimp permits, a variety of other permits. So they developed, basically, portfolios of permits in order to survive in their occupation.”

OSU anthropologist Smith said that the concept of resilience has applications far beyond salmon and fishing. “We should all be interested in resilience, because it adds a little different twist to the way we think about things. We have a human system interacting with a biocomplex system; if humans are going to survive over a long period of time, we need to be able to adapt to change and disturbance, rather than trying to make everything stable, as we have with our current policies.”

Highlights of the resilience conference, including Kitzhaber’s speech and video interviews with Bottom, Smith, Martin, Healey, and others, are now online at the Sea Grant program’s website: http://seagrant.oregonstate.edu/themes/resilience/index.html


Dan Bottom,

OSU Researchers to Study Effect of Floods on Estuaries Through EPA Grant

CORVALLIS, Ore. – A team of Oregon State University researchers will use a $620,000 grant from the U.S. Environmental Protection Agency to study the impacts of large sediment deposits on coastal estuaries during winter flood events and to document the recovery of the benthic communities.

The sediment discharge in Northwest rivers appears to be increasing, scientists say, because of an increasing number of intense precipitation events; changes in the landscape through logging, agriculture and development; the evolution of complex river systems into channels; and the drainage of tidal marshes through diking and other human influences that reduce the buffering capacity of natural systems to absorb sediment load.

The OSU researchers will study the impact of increasing sediment loads on worms, clams and small crustaceans – estuarine species that represent important prey for Dungeness crab, fish and seabirds, according to Anthony D’Andrea, an assistant professor in the OSU College of Oceanic and Atmospheric Sciences and a co-principal investigator on the study.

“This is the first step in assessing the risks to estuaries posed by extreme rain events in the region,” D’Andrea said. “Muddy, rain-swollen rivers are a signature characteristic of the Pacific Northwest, yet the impact of flood sedimentation events on benthic communities is poorly understood.”

The OSU researchers also will track the response of native and non-indigenous species to sedimentation events to see if this type of disturbance allows non-native species to gain a foothold and thrive at the expense of native species.

D’Andrea and co-principal investigator Rob Wheatcroft will stage their experiment at Netarts Bay near Tillamook because it has no river system and the organisms in the tidal flats have not previously been exposed to constant flooding.

“Studying benthic communities in established flood plains is tricky,” D’Andrea pointed out, “because the resident organisms may already be adapted to flood events and have a quicker recovery. Starting from scratch will give us better baseline data and lead to a more accurate predictive model.”

The researchers will add a layer of fine sediment from local watersheds onto study plots in Netarts Bay in December and compare them with nearby control plots. A subset of those plots will be subjected to a second simulated sedimentation event 40 or 50 days later to see if multiple events have different impacts. December and January are peak rainfall months for Tillamook County, which has seen increasing precipitation problems in recent years.

Between 1910 and 1950, the Wilson River entering Tillamook Bay experienced three total peak runoff events. Since 1960, the Wilson has seen 17 peak events, including six in the 1990s alone. Damage from these floods during a six-year period alone topped $60 million.

Likewise, major sedimentation events have been increasing in Pacific estuaries and sediment deposits of up to 12 centimeters thick have been documented.

This is one of the first major experiments looking at major sedimentation impacts on Northwest estuaries. A pioneering study in New Zealand found that many species die due to initial smothering because of sediment deposition and recovery can take many months, even years.

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Anthony D’Andrea,

Climate-change Outreach Project Funded

CORVALLIS, Ore. – The Oregon Sea Grant program at Oregon State University has been awarded special funding to help coastal communities prepare for climate change. The two-year, $290,000 grant is from the Sectoral Applications Research Program of the National Oceanic and Atmospheric Administration.

Leading the project is Joseph Cone, assistant director of Oregon Sea Grant. The project aims to develop and test a model of public outreach about climate change that may ultimately be used by all the members of the national Sea Grant network. Oregon’s project partner is Maine Sea Grant.

Outreach in the two states will be directed toward and involve public and private decision-makers such as city managers, county planners, private developers, bankers, and realtors. Surveys, focus groups, and interviews will be used to determine information needs and strategies. Advisory committees representative of the intended audiences have been formed.

Oregon and Maine have similarities and differences with respect to anticipated climate change effects and the communities and economic interests that will likely be most affected. As a result, collaboration and complementary outreach efforts between the two states are expected to yield insights about critical information needs and effective outreach strategies that may be applicable to other states.

While climate change is grabbing public attention and will be a focus of the project, shorter-term climate variability, over years and decades, is already having an impact on the physical features and habitats of coastal zones. These impacts are worsened by increased development and use of the coast, particularly in low-lying, hazard-prone areas.

Decision-makers and residents need to better understand the challenges of adapting to climate variability locally in order to lessen its effects and make their communities more resilient, Cone said.

Sea Grant Extension faculty will build upon their historic and close ties with coastal communities to lead the outreach efforts. Oregon Sea Grant Extension faculty members involved in the project include Patrick Corcoran, Michael Harte and Shawn Rowe. Nathan Mantua of the University of Washington’s Climate Impacts Group is part of the Oregon team.

Team of Oregon Scientists to Study Harmful Algal Blooms off Coast

CORVALLIS, Ore. – A team of Oregon scientists has received a grant from the National Oceanic and Atmospheric Administration to begin monitoring harmful algal blooms off the coast, and responding to these events as they occur.

The five-year, $2.3 million grant will bring together researchers from Oregon State University, the University of Oregon, and the Oregon Department of Fish and Wildlife to develop a program they hope will better protect the public from two species of toxic algae, and reduce closures of razor clam harvests along the Oregon coast.

The group will work closely with NOAA scientists at OSU’s Hatfield Marine Science Center in Newport, as well as in Seattle and Monterey, Calif., and with the Oregon Department of Agriculture, which tests for toxin levels in coastal shellfish and makes decisions on closures.

“We already have done a lot of the background science that helps us to understand the nature of these harmful algal blooms,” said Peter Strutton, an assistant professor in OSU’s College of Oceanic and Atmospheric Sciences and one of the lead researchers on the project. “Now the goal is to do a full-out response when these blooms occur and to determine what triggers the toxicity in the phytoplankton.

“Ultimately,” he added, “this should allow us to more rapidly detect when these toxic events occur, and hopefully it will lead to the ability to use satellites to identify and track harmful algal blooms in general.”

Phytoplankton blooms are a normal ocean process, critical to maintaining the productive marine food web off the Pacific Northwest coast. Spring and summer winds bring up cold, deep water that is nutrient-rich to the ocean surface in a process called “upwelling.” When that water is exposed to sunlight, it creates blooms of phytoplankton. These tiny plants are a source of food for zooplankton and other marine creatures, which in turn are feasted upon by larger animals.

But certain species of phytoplankton have the ability to produce toxins that can be harmful to humans. One called Pseudo-nitzschia produces domoic acid, which bio-accumulates in the tissues of razor clams, mussels and oysters and causes a syndrome known as amnesic shellfish poisoning in humans. Another species, Alexandrium, produces saxitoxin, which can lead to paralytic shellfish poisoning if ingested.

“Clams and other shellfish take in the toxins when they filter water and the toxin level can vary for a number of reasons,” said Michelle Wood, a professor of biology at the University of Oregon and a member of the research team. “Mussels lose their toxicity quickly, in a matter of days. But razor clams incorporate the toxin in their tissue and remain toxic for weeks, even when they are no longer consuming toxin-producing food.”

Razor clam closures due to these harmful toxins come with a cost. The Oregon Department of Fish and Wildlife estimated that a domoic acid-related closure of razor clamming at Clatsop Beach alone in 2003 cost local communities an estimated $4.8 million.

“That’s probably a conservative estimate,” said Matt Hunter of ODFW, “but it illustrates the scope of the issue.” Harmful algal blooms have resulted in closures of the entire Oregon coast at times over the past few years, he added.

Of course, not all phytoplankton blooms are toxic, Strutton pointed out, and even the species that are potentially toxic don’t always produce toxins.

“We’re not sure what causes phytoplankton to suddenly become toxic,” he said. “Some scientists believe it may be stress from a lack of nutrients; it also has been suggested that the toxins bond to necessary trace elements such as iron as a way for the phytoplankton to ‘capture’ these nutrients. There has been some work on this off of Washington, which we hope to incorporate into this NOAA study.”

As part of the project, the scientists will use programmed undersea gliders to monitor ocean conditions during harmful algal blooms to determine whether temperature, salinity, chlorophyll levels, oxygen levels or other factors may contribute to toxicity. They also will study coastal currents and winds in an effort to better predict when these toxic blooms may come ashore and affect clams and other shellfish.

More information on the project is available online at: www.coas.oregonstate.edu/habs

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Pete Strutton,

Oregon Sea Grant Director Malouf Announces Retirement

CORVALLIS, Ore. – Oregon Sea Grant director Robert E. Malouf has announced his retirement after 16 years leading the marine research, outreach, and education program based at Oregon State University.

Malouf has had overall responsibility for all of Sea Grant's activities, including its competitive grants, the visitor center of the OSU Hatfield Marine Science Center, and active programs in communication, education and extension. Oregon Sea Grant employs more than 40 people on a budget that exceeds $5 million in state and federal funds annually.

The national recruitment and selection process for Malouf’s successor has recently begun, said John Cassady, OSU vice president for research.

Malouf, a native of Montana, began his affiliation with Oregon Sea Grant in the program’s first year, 1968, when he received support as a new OSU master’s student in fisheries. After earning his Ph.D. in fisheries from Oregon State he joined the faculty of the Marine Sciences Research Center of the State University of New York at Stony Brook. While there from 1977 to 1991 he taught courses in marine fisheries, shellfisheries, and aquaculture. In 1987 he was named director of the New York Sea Grant Institute; he held that position until he succeeded Oregon Sea Grant’s original director, William Wick, on Wick’s retirement in 1991.

Under Malouf’s leadership, Oregon Sea Grant has been consistently ranked as the best Sea Grant program in the nation in formal reviews.

The national review panel cited the program as demonstrating several national “best management practices,” including strategic planning, decision-making, and program integration, all articulated and developed by Malouf.

For more than 10 years Malouf served as a member of Oregon’s Ocean Policy Advisory Council and chaired the council's Scientific and Technical Advisory Committee. He has had numerous leadership positions with other state and national organizations.


Robert Malouf,

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Bob Malouf

OSU Teams With Woods Hole, Scripps on Ocean Observatories Initiative

CORVALLIS, Ore. – Oregon State University will receive $20.6 million over the next six years to lead a component of the National Science Foundation’s Ocean Observatories Initiative that will be located in the Pacific Northwest’s coastal ocean.

The university also could receive an additional $29 million over the succeeding five years to continue operating the coastal observatory.

The NSF initiative is coordinated by the Joint Oceanographic Institutions (JOI), a consortium of leading academic institutions. The $331.5 million research facility project will create a distributed, multi-tiered observatory spanning global, regional and coastal scales. It will be linked by a common computer network intended to operate for up to 30 years. The OSU-led coastal observatory will be based off the Pacific Northwest, focusing on the continental shelf off Newport, Ore., in what is one of the most heavily studied marine environments in the world.

Earlier this year, JOI announced awards to the University of Washington to design a regional fiber-optic cabled observatory off Washington and Oregon, and to the University of California at San Diego to direct the system-wide computing infrastructure.

OSU partnered with the Woods Hole Oceanographic Institution and the Scripps Institution of Oceanography on a proposal to develop, install and operate the combined coastal and global observatories. Woods Hole will provide the overall administrative leadership and engineering for the project and will implement a separate coastal observatory on the shelf break off the northeast coast of the United States. Scripps and Woods Hole will combine to implement global scale elements of the observatory.

The Pacific Northwest coastal observatory, led by OSU, will place a series of permanent moorings off the Northwest coast called the Endurance Array, and will include a network of undersea gliders that can be programmed to patrol the near-shore waters and collect a variety of data and transmit it to onshore laboratories.

“The long-term coastal scale observations by the Ocean Observatories Initiative will be a key to understanding and monitoring the impacts of global climate change,” said Mark Abbott, dean of the OSU College of Oceanic and Atmospheric Sciences. “Although the area off the central Oregon coast has been studied at length and has a significant impact on regional and national climate, we’ve simply lacked the infrastructure to monitor conditions on an ongoing basis to see how the ecosystem responds to change. This will allow us to do that.”

The region is particularly important for a number of reasons, said Robert Collier, an OSU professor of oceanic and atmospheric sciences who will serve as deputy project manager at OSU. The California Current System has a major influence on the West Coast and changing ocean conditions may have created a recent series of hypoxic events and harmful algal blooms.

“It is a dynamic area that is the interface between the open Pacific Ocean and the human-populated coast,” Collier said. “It includes rich habitats for marine life, hydrothermal vents, methane fields, storm-induced waves that have caused erosion, and the Cascadia Subduction Zone, which may produce large earthquakes and tsunamis.

“Oregon was an obvious place for locating this portion of the coastal observatory,” Collier added, “in part because of the years that OSU researchers and others have invested in this environment and in part because of its seamless connection to the regional and global observatories offshore.”

During the next year, OSU researchers including Collier, Jack Barth and Ed Dever will help finalize the scientific and engineering plans for creating the array. Once approved by JOI and the National Science Foundation, construction on the permanent moorings and deployment of the gliders can begin.

Between five and seven mooring sites are planned, including several that will be directly connected to the University of Washington’s fiber-optic cable that extends into deeper waters and provides regional scale coverage of the Juan de Fuca tectonic plate offshore. OSU will work closely with UW to integrate these systems, which will provide exceptional power and bandwidth for new instrumentation to study the ocean and seafloor.

Instruments aboard the moorings will take a series of measurements that include temperature, salinity, dissolved oxygen content, optical properties of the water, chlorophyll levels, nutrient levels, and the speed and direction of currents. Each mooring site will include a surface buoy to monitor the atmosphere as well.

The entire region is significant to scientists because of the complex interactions of winds, currents and terrain, said Barth, a professor of oceanic and atmospheric sciences at Oregon State who will serve as project scientist at OSU.

“The Heceta Bank just south of the Endurance Array is one of the most important locations along the coast because it deflects the waters flowing from the north and creates a quiet pool of water that serves as an incubator for the phytoplankton that feed the rich marine food web found there,” Barth said. “That’s also the location of the most intense hypoxia events we’ve experienced.

“Oregon is situated at a point where changes in the atmospheric Jet Stream have a major impact on local weather conditions and the ocean’s response to them,” he added. “This coastal observatory will help us better understand and monitor the complex interactions that affect us every day.”

Collier said the Ocean Observatories Initiative will have strong public outreach and educational value, and scientific data compiled at the different sites will be available to scientists and the public alike in real-time on the Internet.

“Fishermen and crabbers may apply the data we gather on the ocean,” he said, “because they can readily see an application that directly influences their livelihood. The potential also exists for improving scientific literacy in general, and ocean literacy in particular, through involving high school students and others in education initiatives.”

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Bob Collier,

Ocean Biology, Productivity Driven by Jet Stream

CORVALLIS, Ore. – The biological productivity and summer “upwelling” on the Pacific Northwest coast appears to be strongly correlated to oscillating jet stream patterns, according to a new study that draws definitive links between short-term ocean effects and larger climatic patterns.

In normal summer patterns, the research found, there is a 20-day oscillation of the jet stream – a strong air flow about seven miles high – that moves north and south, and is tightly linked to normal upwelling activity and the growth of phytoplankton and zooplankton, the basis of the marine food chain.

It’s less clear, scientists say, how long-term climate changes, such as El Nino events or global warming, may be affecting the jet stream. But the clear connection between the jet stream and underlying marine productivity is significant in itself, they said.

The study was published this week in the online version of Proceedings of the National Academy of Sciences, a professional journal, by researchers from Oregon State University, the University of North Carolina, and the National Marine Fisheries Service.

“We’ve known for some time that winds play a fundamental role in controlling upwelling and biological productivity,” said Ricardo Letelier, an associate professor of oceanography at OSU. “But now we can better define the larger patterns that force this action and the short-term biological fluctuations that result.”

Yvette Spitz, an OSU associate professor of oceanography, also said that in the ocean off central Oregon, there appears to be a very strong and well-defined 18-year cycle of upwelling intensity, and an “upwelling index” in the region is now at almost its highest value since the early 1990s – a time when, among other things, summer upwelling seems to be delayed longer than usual, but then becomes very intense.

It’s possible this is relevant to the recent hypoxic events that have been observed in this region, they said, but more research needs to be done before that linkage can be drawn. There are probably multiple forces that are part of the hypoxia issue.

“The correlation between movements of the jet stream and the underlying biological action in the ocean is really quite strong,” said Spitz.

When the system is operating in a healthy and productive pattern, the scientists found, the jet stream oscillates north and south, causing shifts in the wind patterns beneath it, and causing an ebb and flow of nutrient enriched water on the near-shore coast. This forms the basis for one of the world’s more productive fisheries.

This situation exists most of the time, although the study documented two years out of 12 when the process broke down.

Other parts of the Pacific Ocean coast off North America and Mexico have coastal upwelling also, the study noted, but it is often less intense and more stable because the jet stream is more distant and has less impact on these areas.

It’s not certain what effect global warming or other changes in ocean processes may have on these patterns, the researchers said.

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Yvette Spitz,

New invasive parasite raises concern for West Coast estuaries

NEWPORT, Ore. - Scientists have identified a prolific parasite that preys on mud shrimp - a native species of West Coast estuaries - and threatens to decimate mud shrimp populations, raising concern for the fragile, complex ecosystems of these coastal inlets.

This bopyrid isopod, known as Orthione griffenis (or Griffen's isopod) is a form of aquatic crustacean that enters the shrimp gill chamber under the carapace. It destroys the shrimp's ability to reproduce by sucking their blood or nutrients. Oregon State University's John Chapman, an invasive species expert, thinks the parasite is a non-native species, probably introduced to West Coast waters through ballast water released from ships.

"If we're right," Chapman said, "this may be the most significant ballast water introduction of a non-native species yet discovered on the West Coast."

The zebra mussel, the most well-known invasive aquatic species in the United States, has thus far been restricted to the East Coast and Great Lakes, where it has caused millions of dollars in damages to dams, ships and structures.

A professor of fisheries and wildlife at OSU, Chapman heads the Biological Invasions Program at the university's Hatfield Marine Science Center in Newport. He and his colleagues already have found the parasite in Yaquina Bay, Alsea Bay, Siletz Bay and Tillamook Bay in Oregon, as well as in Willapa Bay in Washington. There also are reports of the isopod as far south as Santa Barbara, Calif., and as far north as British Columbia, he added.

Chapman says the parasite's impact on mud shrimp populations is difficult to estimate. In 1999 and 2001, Ted DeWitt, an HMSC ecologist with the Environmental Protection Agency, conducted mud shrimp surveys in Yaquina Bay. This summer, Chapman and colleagues are working with Lincoln County natural resource crews on new surveys that will give them an idea of the early impact of the parasite on mud shrimp numbers, though the effect of limited reproduction may take time to complete.

"Nothing we know already provides reason to be optimistic," said Chapman, who added that all of the mud shrimp populations they've investigated this summer have been infested with the parasite.

The researchers estimate an overall parasite infestation rate as high as 45 percent and believe that 80 percent or more of the breeding-sized adults may be infested. Once infested, reproduction - almost without exception - is halted.

Humans use mud shrimp primarily as fishing bait, but they are valuable prey for birds, fish, and other animals in estuaries. The mud shrimp are a dominant species in many Oregon estuaries, comprising the greatest biomass in many intertidal mudflats. Mud shrimp feeding may filter as much as 80 percent of the water per day in some estuaries.

Chapman says removing a dominant species from any ecosystem can have large impacts.

"It's hard to guess what the removal of mud shrimp would mean to the estuary," Chapman said, "but because they are so abundant and filter so much of the water, we have to be concerned. Mud shrimp also are important in the sediment dynamics of estuaries and their loss could conceivably lead to greater erosion. There also are signs that where mud shrimp are disappearing, populations of sand shrimp increase. Both species cause problems for oyster growers, but sand shrimp may be worse."

Chapman and Brett Dumbauld, a U.S. Department of Agriculture ecologist working out of OSU's Hatfield Marine Science Center, recently examined 42 female mud shrimp from Yaquina Bay during the winter breeding season and found that only eight of them had eggs. The rest were infested with the parasite. Only one of the eight females that had eggs was infested - and she had just 15 eggs. Normally, females produce 1,800 to 11,000 eggs.

The message, Chapman said, is that infestation cuts off reproduction. He is working to find out why. "Mud shrimp don't begin to reproduce until their carapaces are about 20 millimeters long, and these parasites seem to have targeted them by that time," he said.

Chapman said this parasite is huge compared to previously discovered species. At eight-tenths of an inch, Griffen's isopod is the largest bopyrid isopod ever seen on the West Coast.

"Over the past 140 years, virtually every new parasitic isopod species discovered has been smaller than previously known species," he said. "In comparison, this recently discovered species is a monster. Because of its great abundance, large size and it occurrence also in Japan, we are sure this is an introduced species, and not an overlooked native species.

"If you had a water buffalo in your back yard," he said, wryly, "you would notice it."

The parasitic isopod primarily targets the mud shrimp, Upogebia pugettensis, but doesn't seem to affect sand shrimp. Though the two species appear to be similar, sand shrimp are burrowing animals that get their nutrients from the sand, while mud shrimp draw water down into their mud tubes and filter it through their feeding baskets.

Chapman said this parasite wasn't fully identified until this past winter. Since then, he and other scientists have been scrambling to learn more about it. They have been able to trace its appearance on the West Coast back about 20 years by combing through references in scientific literature, examining samples and/or photos of mud shrimp used in other studies, and working with biological museums. Its numbers, however, have been very small.

Something caused the population to "take off" over the last few years, Chapman said, and scientists aren't sure why. Unusual ocean conditions, characterized by changes in upwelling, may have played a role by maximizing their growth and reproduction at a time when other species have suffered. Or more of them may have been introduced to West Coast waters in recent years.

Chapman said the origins of the parasitic isopod may be in Asia. Japanese taxonomist Gyo Itani of the Center for Marine Environmental Studies at Ehime University found a Japanese bopryid isopod that is morphologically identical to Orthione griffenis.

How the parasite arrived at the West Coast is a matter of guesswork. More important, Chapman said, is trying to understand how prevalent it is and what impact it may have.

Dumbauld has been working with oyster growers in Willapa Bay for years studying the impact of mud shrimp on the industry. Some local populations of the shrimp there have almost completely disappeared, and the researchers suspect the parasite is to blame. The few remaining Willapa Bay mud shrimp are heavily infested.

Chapman said it doesn't appear that the isopod invasion will disappear soon. Water samples from the bay are full of the parasites at their early stages of life.

Female Orthione griffenis brood their young and may release as many as 60,000 epicarid offspring. These epicarids migrate out of the estuaries and into the ocean, where ey attach themselves to copepods and parasitize them before moulting into their final dispersal phase, known as "cryptoniscans." These cryptoniscans return to estuaries and apparently seek out mud shrimp as final hosts. Their abundance in the seawater covering mud shrimp communities is surprising, Chapman said.�

"We collected water samples from Yaquina Bay and thought finding them would be like the proverbial needle-in-the-haystack," Chapman said, "But on our first scoop of the net, we found a bunch of them. And then we found a bunch in the second scoop, and the third scoop, and so on. It didn't matter whether it was day or night, the bay is full of them."

Chapman said the parasites live at least two years and when they return to the estuaries, they "simply suck the life out of the mud shrimp. They may not kill them right away, but the shrimp lose their ability to reproduce, and they may just be lying there, living out the rest of their lives.

"They are zombies," he added, "And there aren't many healthy breeders left to keep the species going."


Story By: 

John Chapman, 541-867-0235

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An invasive parasite is threatening local shrimp