marine science and the coast

El Nino forecasts could help save coho salmon

CORVALLIS - The ability to forecast the onset of an El Nino would help efforts to stem the decline of coho salmon on the West Coast, suggests a research report issued by scientists at Oregon State University.

The economic value of improved El Nino forecasting to the coho fishery varies from $250,000 to $900,000 a year, depending on the accuracy of the forecast, the interdisciplinary team of scientists found.

The researchers combined biological, statistical and economic models to measure the long-term benefits of incorporating information about El Nino in management decisions for the coho salmon fishery. The research was funded by a grant from the National Oceanic and Atmospheric Administration.

The report supports doubling the number of wild coho allowed to enter coastal streams to spawn and reducing by as much as 75 percent the yearly coho hatchery production. The findings corroborate recommendations of Oregon's Coastal Salmon Restoration Initiative, established by Gov. John Kitzhaber.

"Improved El Nino forecasts would allow fishery managers to make more effective decisions and perhaps reduce the need for drastic short-term measures, such as closing the commercial and recreational coho fishing seasons," said Richard Adams, a professor of agricultural and resource economics who works with the OSU Agricultural Experiment Station.

Coho salmon along Oregon, Washington and California have been in steep decline since the late 1970s. In an attempt to halt the loss of coho, the National Marine Fisheries Service is considering listing coho as an endangered species. The listing would result in lengthy and constant review by federal agencies of many activities that occur in the coastal zone, including public and private land use, release of hatchery fish and regulation of fisheries. El Nino is part of a global climate system called the "southern oscillation" that affects weather throughout the world. In El Nino years, West Coast water temperatures become abnormally warm, which disrupts the upwelling of colder, nutrient-rich water containing the species coho depend on for food.

With their usual food supply unavailable, a larger number of salmon die prematurely. Those that do survive have lower average weights and the females produce fewer eggs.

Although the capability to predict an El Nino already exists, its accuracy is only slightly better than guessing, according to the report. However, forecasting accuracy is likely to improve due to ongoing NOAA data collection and monitoring efforts.

In 1982-83, the West Coast experienced an El Nino now thought to be one of the worst this century. This unanticipated El Nino had a devastating effect on coho salmon and played havoc with the assumptions upon which fishery management policies were based.

For example, fishery experts had predicted that nearly 1.6 million wild coho would return to spawn in Pacific Northwest streams that year. Only an estimated 667,000 showed up, or 42 percent of what had been expected.

"If accurate forecasts of the 1982-83 El Nino had been available and incorporated into fishery management decisions prior to the 1983 event, the effect of El Nino might have been less severe," Adams said. "Incorporating forecasts in subsequent years would also have helped to avoid extreme measures, such as closing the fishing season."

El Ninos may last from a few months to a few years. A recent, lingering El Nino is thought to have contributed to the current low population level of coho that led to the closure of the commercial and recreational ocean coho salmon fishing seasons from 1994-96. Other factors contributing to the decline of coho include dams, destruction of spawning and rearing habitat, high harvest rates, and the introduction of hatchery coho.

El Ninos vary in their intensity. Seven notable El Ninos have occurred in the past 100 years. Very strong ones occurred in 1925-26 and 1982-83, and strong ones took place in 1899-1900, 1932, 1940-41, 1957-58 and 1972-73.

"Historical catch statistics of Oregon salmon indicated that the abundance and average size of coho were below normal during these events," said David Sampson, a fisheries scientist in the OSU Department of Fisheries and Wildlife and member of the El Nino research team.

The impact of an El Nino is not uniform along the Pacific coast, according to the report. Even during strong events, the coho off Washington and British Columbia may not be as susceptible to ocean changes. And research on the abundance of Alaska salmon shows no appreciable connection between coho abundance and El Nino.

The primary indicator of an El Nino is the southern oscillation index, a measurement of the difference in the atmospheric pressure between Easter Island and Darwin, Australia. These differences usually occur 12-18 months before an El Nino occurs on the West Coast of the United States.

NOAA makes El Nino forecasts on an annual basis. Because these forecasts are available 12-18 months ahead of time, the researchers recommend that harvest rates and hatchery releases be adjusted in anticipation of the El Nino. Their research showed that, over time, a strategy of incorporating this information would yield higher benefits to society.

They also recommend changes in the number of wild coho allowed to migrate to their native streams to spawn.

"Current coho management policies call for 200,000 wild coho to return and spawn each year," Sampson said. "We concluded that the optimal level should be around 400,000 fish each year, depending on the predicted strength of the El Nino."

Other scientists on the interdisciplinary team were Andrew Solow, statistician, Woods Hole Oceanographic Institution; Stephen Polasky, OSU agricultural economist; and Christopher Costello, graduate student in the OSU Department of Agricultural and Resource Economics.


Richard Adams, 541-737-1435

Three named to Sea Grant Advisory Council

CORVALLIS - A commercial fisherman, a wildlife biologist and a Seaside tourism official have been named to three-year terms on the Oregon Sea Grant Advisory Council.

The 11-member council meets twice each year to help set research, education and outreach priorities for Oregon Sea Grant, which is part of a nationwide consortium of Sea Grant programs organized under the National Oceanic and Atmospheric Administration.

The new members are:

-Ralph Brown, a commercial fisherman from Brookings who serves on the Pacific Fishery Management Council and helped initiate Oregon's innovative Developmental Fisheries Program;

-Willa Nehlsen, a staff biologist for the U.S. Fish and Wildlife Service in Portland. Formerly on the staff of the Pacific Rivers Council, Nehlsen has written numerous studies on salmon and salmon habitat, and is a member of the state's Salmon Restoration and Production Task Force.

-Sue Pickell, manager of the Seaside Chamber of Commerce, past president of the Tourism Council of Oregon, and a member of Oregon Tourism Commission.

They join present council members Don Barth of Newport, Kirk Beiningen of Portland, Anne Berblinger of Portland, Jerry Dove of Tillamook, Basil Edmunds of Garibaldi, Russ Heggen of Eugene, Nancy Leonard of Lincoln County and Bob Montgomery of Cascade Locks.

Based at Oregon State University, Oregon Sea Grant supports research in a variety of disciplines on subjects ranging from fisheries to seafood, coastal natural hazards and marine biotechnology.

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Jay Rasmussen, 541-867-0370

Survey reveals coast public's views of salmon restoration

CORVALLIS - Oregon coast residents have strong opinions about the decline of coastal salmon and proposed methods to restore the fish, and their views suggest that fishery managers and the state's restoration planners have work ahead to gain public acceptance for salmon recovery efforts.

These are some of the key insights from a new survey of 500 Oregon coast residents conducted by researchers Court Smith and Jennifer Gilden at Oregon State University. The survey is the largest systematic sampling of coastal public opinion about salmon undertaken in recent years. It was funded by Oregon Sea Grant, a marine research and education program at OSU.

"Coastal residents as a whole have not had very much say in the formulation of the state's Coastal Salmon Restoration Initiative," said Smith, an OSU professor of anthropology and the survey leader. "Their views are divided and are often not in synch with values reflected in the Governor's restoration plan."

The Sea Grant study, conducted in November and December, surveyed a random sample of all Oregon coast residents and a smaller group of identified "salmon opinion leaders" - coastal watershed council and elected officials. Surveys were mailed to more than 800 coastal residents and 195 leaders.

Key findings of the study, according to Smith and Gilden, include:

  • The state, rather than the federal government, is favored to lead salmon restoration.
  • The public and fishery managers have widely different views on several issues, including the effect of predators such as seals and sea lions on salmon, the role of hatcheries, and the importance of wild fish.
  • There is strong support for compensating private landowners for protecting and restoring salmon.
  • Nearly half of the respondents (47 percent) are willing to volunteer a half day or more a month on salmon restoration work.
  • The coastal public receives its salmon information mainly from television and radio (62 percent) and by word of mouth (60 percent).
  • The public has no greater than moderate confidence in institutions and organizations dealing with salmon - a confidence level of 3 on a scale of 1 to 5. In general, federal fish and wildlife agencies and the OSU Extension Service fared better than environmental groups and city and county planners (which rated higher than federal courts or Congress).

The distance between public and professional opinion was clear in response to a question which asked the relative importance of certain factors for the future of salmon, Smith said.

While most professionals would argue that reducing predators like seals and sea lions, increasing hatchery production, and eliminating ocean driftnets fall decidedly on the less important end of the scale, the public thinks that reducing marine mammals and stopping ocean driftnetting are very important.

Opinions also contrast on hatcheries. While nearly all salmon biologists now argue that hatchery production should be decreased and changed to avoid harming wild fish runs, only 20 percent of respondents agree. About 38 percent of the rest of the respondents think it's "not important at all" to decrease hatchery production.

"The public apparently views the salmon decline mainly as a production problem," said Smith. "They see hatcheries as at least part of the solution."

In reviewing the 500 responses, Smith and Gilden wanted to see if there was any factor which would help leaders of salmon restoration understand what would motivate coastal people to restore the salmon. They examined variables like age, income, and education but found that the most critical factors in shaping people's opinions about salmon were their values and beliefs.

A key question noted that trade-offs between the environment and the economy could be involved in salmon restoration and asked respondents to place themselves on a scale from favoring the environment to favoring economic considerations. Forty percent of respondents said their priority was "restoring and protecting environmental conditions even if there are negative economic consequences," while 16 percent favored the economy over the environment. Most people, 44 percent, favored an "equal priority."

Those preferences repeatedly shaped other opinions. For example, the majority of those who favored the environment think that endangered species laws don't need changing, while those who favor the economy think that they do. Those on the environmental side are much more willing to volunteer time to help restore salmon than are those who favor the economy.

Such responses have importance for those who are trying to promote salmon recovery efforts, said Gilden.

"Coastal residents will interpret and evaluate plans and information according to their beliefs, " said Gilden. "To the extent that a plan captures the values of coastal residents, acceptance is more likely."

Smith advises salmon recovery planners to think of their task as not "selling the Governor's plan," but rather "addressing resident concerns."

Educating and working with the public to increase their understanding of the issues - a much longer process than merely mounting a public relations or information campaign - is likely to be needed in some cases, said Smith.

Despite the considerable attention on salmon decline in the news media and within government, many coastal residents are not engaged by the issue. This interpretation comes from phone calls to about two-thirds of those who did not respond by mail.

In talking personally with 150 people, Smith identified five groups among those who did not respond: those for whom salmon restoration is simply not a priority concern; people who feel they are not knowledgeable enough to respond to a survey; a "small but vocal" group who oppose or are hostile to "government" and equated the survey with government; and a generally older group who felt that their opinions were not as important as those of a younger generation and such decisions should be deferred to them.

Finally, some non-respondents were thought to be seasonal residents of the coast and simply not at home.


Court Smith, 541-737-3858

New funds will help create Oregon’s most accurate seafloor mapping system

CORVALLIS, Ore. – An allocation from the 2009 Oregon Legislature combined with funding from the National Oceanic and Atmospheric Administration (NOAA) will help researchers from Oregon State University and Northwest companies create the most detailed maps of the seafloor off Oregon ever generated.

With a resolution of a half-meter or better, the maps will cover about 34 percent of State of Oregon waters and 75 percent of its rocky reefs, recording every bump, depression, reef and boulder on the seafloor from a depth of 10 meters out to three miles, the boundary of Oregon’s territorial sea.

“Developing an image of our ocean floor will help us model tsunamis, identify marine habitats, select alternative energy sites, identify geological hazards, and enhance safe and efficient marine transportation,” said Oregon Gov. Ted Kulongoski. “Gov. (Arnold) Schwarzenegger of California, Gov. (Christine) Gregoire of Washington and I set a goal of mapping our three states’ oceans by the year 2020.

“Thanks to the strong partnership between academia, private industry, fishermen, coastal legislators and multiple state and federal agencies, Oregon is on track to reach that goal,” Kulongoski added.

Chris Goldfinger, an associate professor of oceanic and atmospheric sciences at OSU, says the work will begin immediately and focus initially on sites from Cape Perpetua northward, including sites important for tsunami modeling, wave energy and marine reserves proposed at Cape Falcon, south of Cannon Beach; Cascade Head, near Lincoln City; and Cape Perpetua, near Yachats.

“We’ll be hiring local fishing boats and crews to help us with the surveys,” Goldfinger said, “so there will be a real Oregon flavor to the project. We should get about halfway done this summer and finish up next year.”

The project later will focus on others sites that are being evaluated for future marine reserves, including  Cape Arago/Seven Devils, south of Coos Bay, as well other rocky reef areas such as the Rogue and Blanco Reefs.

Goldfinger and his colleagues at OSU will work with David Evans & Associates in Portland on the project. OSU will use an allocation of nearly $1.3 million from the Oregon Legislature, which was part of the settlement from the cleanup of the New Carissa, a ship that wrecked off the southern Oregon coast in 1999 carrying an estimated 135,000 gallons of oil.

David Evans & Associates will be funded by a grant of approximately $4 million from the American Recovery and Reinvestment Act of 2009 through NOAA’s Office of Coast Survey (http://www.nauticalcharts.noaa.gov/), which creates nautical charts and surveys. A second company, Fugro Seafloor Surveys, Inc. of Seattle, has received a separate grant from NOAA to map the southern Oregon coast. The combined project will be funded at about $7.3 million.

The project was spearheaded by coastal legislators, especially Oregon Rep. Deborah Boone, D-Cannon Beach, whose advocacy for the project never waned, despite state and national budget shortfalls.

“They say that the third time is the charm and this was our third attempt to pass legislation to enable Oregon State University ocean scientists to finish the task of mapping the sea floor,” Boone said. “Many thanks should go to all partners for their hard work, diligence and collaboration to achieve the goal of being able to have credible tsunami inundation zone modeling, navigational charts updated, and marine, fisheries habitat and coastal hazards mapping available for multiple uses.”

OSU’s Goldfinger said that the maps have other benefits beyond siting marine reserves and developing tsunami inundation models. The detailed seafloor maps will be beneficial to Oregon fishermen, boaters, and scientists studying sea level rise, potentially catastrophic earthquakes, wave energy and other issues, Goldfinger pointed out.

“The resolution will be on a scale we’ve never had before,” he said. “We’ll be using multi-beam sonar that will give us complete coverage of the ocean floor, and will record ‘backscatter’ data that will tell us how hard the ocean floor is and whether the bottom is comprised of sand, mud or gravel.”

A second ship will follow the survey ship and use additional instruments to “ground truth” the surveys, collecting samples and recording some oceanographic data including dissolved oxygen content. These measurements will help scientists better understand ocean hypoxia – or low oxygen that has led to marine “dead zones” – and harmful algal blooms that lead to domoic acid concentrations in Oregon shellfish.

Goldfinger previously had led an effort to create an interim map of Oregon’s territorial sea and seabed habitats, with sparse existing data that showed water depths and sediment types, and can be overlaid with information about geology, habitat, buoys, seabirds, marine life and kelp beds. The map is available online at (http://pacoos.coas.oregonstate.edu/MarineHabitatViewer/viewer.aspx).

The new maps will provide more detail at a much finer scale, Goldfinger said. It is that precision that will allow scientists and decision-makers to better understand and prepare for earthquakes, tsunamis and sea level rise, as well as better manage marine resources.

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Chris Goldfinger, 541-737-5214

Invading crabs pose serious concern, not chaos

CORVALLIS - The European green crab that has arrived in Coos Bay has the potential to spread fairly rapidly up and down the Pacific Coast, experts say, but may not totally decimate marine ecosystems as some reports have suggested.

This unwanted crab species breeds and spreads rapidly, grows fast, eats almost anything, and has an unusually wide tolerance for variation in both water temperature and salinity, says Sylvia Yamada, an instructor of zoology at Oregon State University and expert on crab predation.

"There's little doubt this crab will spread and cause some problems, and there's not much we can do to stop that," Yamada said. "In some local cases the problems may be severe. But it's also true that other marine species will adapt and survive. Our native marine fauna will not be wiped out."

Yamada just completed a literature review of research on this invasive crab species, which is native to Europe and has been causing problems on the West Coast since showing up in San Francisco Bay in 1989.

Among the findings:


  • A female green crab can produce up to 200,000 eggs per year, and its planktonic larvae, in theory, can travel up to 400 miles in one generation on Pacific Ocean currents.


  • All bays, estuaries and inland seas from Baja California to Alaska may be habitat for the green crab - including Puget Sound - but it won't become abundant on wave-exposed portions of the coast.


  • The green crab is voracious, eating barnacles, clams, oysters, mussels, worms, urchins, young Dungeness or red rock crabs, some plants and small fish.


  • These crabs are smaller than native Dungeness and red rock crabs, but larger than other native crab species that can tolerate low salinity, such as the purple shore crab and hairy Oregon shore crab.


  • Because of its size, fast growth and low-salinity tolerance, the green crab will pose a special problem to commercial shellfish growers as it feeds on young oysters and clams. It may also disturb the ecosystem through its burrowing habits in soft sediments.

A picky eater? No. In lean times the green crab will make dinner out of 104 biological families, 18 genera, five plant and 14 animal phyla. If it's alive, it's lunch.

But in spite of this list of predatory accomplishments, Yamada said the green crab will probably become just another predatory crab species within the marine ecosystem.

"For one thing, it's important to remember that the European green crab will not only be a predator, it will also be a prey," she said. "Especially when young, it will be eaten by other native crabs, fish, otters, seals, the great blue heron, ducks, gulls and other birds. And maybe humans."

The green crab also can't take waves very well - it will confine itself largely to inland waters of one type or another.

"It's very difficult to predict exactly how a new species will establish itself in a given situation," Yamada said. "It will take time for the green crab to build up breeding populations as it spreads, and it will be preyed upon by many other marine species."

If the green crab does form dense enough populations, Yamada said, we can expect some reduction in clam harvests, decrease in the survival of young oysters, an evolutionary "natural selection" for shellfish with thicker shells, a displacement of native species such as the hairy Oregon shore crab from some of their habitats, and a decrease in the survival of young Dungeness crabs.

Silver linings are hard to come by with this crab species. It might make decent fish bait, and in theory it can be eaten - the green crab is harvested and eaten by people in Portugal, Spain, France and England. But due to its small size it won't compare favorably to a succulent Dungeness crab.

"It's very unfortunate this species has arrived," Yamada said. "In all likelihood we'll just have to learn to live with it. And that's exactly what the other marine species will do."

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Sylvia Yamada, 541-737-5345

OSU marine mammal expert to lead educational whale-watching trip

NEWPORT, Ore. - An educational excursion this Sept. 22-28 to the inland passage of Vancouver Island will offer participants a closeup view of killer whales and other wildlife.

Organized by Oregon State University's Hatfield Marine Science Center, the trip will be led by Bruce Mate, one of the world's most prominent marine mammal experts. Mate holds an endowed chair in marine mammal research at OSU.

Participants will travel on a 70-passenger ship equipped with zodiacs for exploring the area from the San Juan Islands to Johnstone Strait. In addition to whale watching, the tour will explore Princess Louisa Inlet, called one of North America's most beautiful fjords, as well as the San Juan archipelago and the Gulf Islands of British Columbia.

The trip also will include a stop in Victoria to view Butchart Gardens and local museums.

Joining Mate will be a group of naturalists and historians, who will offer a blend of science and history to participants on the expedition.

OSU's Hatfield Marine Science Center in Newport also is offering a trip March 5-13, 1998, to visit breeding and calving lagoons of gray whales near Baja California, and an excursion to the Antarctic in January, 1999.

For more information on any of the trips, or to be put on a mailing list, write to the Marine Mammal Program, Oregon State University, Hatfield Marine Science Center, Newport, OR 97365, or call 541-867-0133 for more information.

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Bruce Mate, 541-867-0202


NEWPORT - Ginny Goblirsch, an Oregon State University Extension Sea Grant agent who works out of Newport, has been recognized as one of three "Highliners of the Year" by National Fisherman, a national publication serving commercial fishermen and other marine professionals.

The magazine cited her both for her work as an extension agent and as a member of a fishing family.

In addition to working as an extension agent with Oregon Sea Grant, Goblirsch supports her family's albacore boat, the EZC out of Newport, specialty marketing their albacore.

"I'm extremely proud of the fact that I am a fisherman's wife," she told National Fisherman. "These guys take an enormous risk, so when I see misinformation out there, whether it's in my local community or statewide, I like to try to clarify issues."

As an extension agent, Goblirsch has been a statewide leader on safety, insurance and other initiatives and works to keep open communication between the commercial fishing industry and various agencies. She also presents information and gives advice about issues of importance to fishermen, and encourages the agencies to understand and actively respond to these concerns.

She shared the "Highliners" honor with Tim Thomas of Edmonds, Wash., and Jamie Ross of Homer, Alaska.

National Fisherman is the most widely read commercial-fishing magazine in the U.S., reaching more than 38,000 readers.




Jay Rasmussen, 541-867-0368

Climate changes may have major impact on salmon

CORVALLIS - Natural climate cycles and the advent of global warming could both have a dramatic impact on already-depleted stocks of Pacific Northwest salmon, one fisheries expert said today.

There's evidence of a natural 40-year cycle in weather patterns, and some people are hoping that conditions in the ocean will follow past patterns, soon improve and help solve the salmon fisheries conservation crisis.

But it's also possible that global warming caused by the greenhouse effect might negate any positive trends and create future conditions on both inland streams and in the ocean that are worse than ever, the researcher said.

A summary of these climatic, ocean, and precipitation trends was made today by Daniel Bottom in a meeting at Oregon State University of the Pacific Division of the American Association for the Advancement of Science.

"The focus in recent years has turned very strongly towards the impact of climate and ocean conditions on salmon growth and survival," Bottom said. "In the past we always emphasized hatcheries, dams, and fishing pressure as the only important factors in salmon conservation. That was shortsighted, this problem involved environmental changes literally Pacific Rim in scope."

Factors such as dams and riparian protection are still very important, Bottom said, but there's now more appreciation of the critical role that long-term climate change can play, as it dictates ocean upwelling and currents, marine food supply, terrestrial temperatures, snowpacks and stream flows.

And when looked at from that perspective, the news is not good.

"There's a lot of variability in the predictions for this region, but the latest climate models based upon a doubling of atmospheric carbon dioxide indicate that large interior basins like the Columbia River may shift from a spring to a winter peak period of flow," Bottom said. "More precipitation may fall as rain and less as snow, with serious impacts on summer stream flows."

And to complete the double whammy, ocean upwelling cycles and nutrient rich currents may continue to resemble those most often observed during recent "El Nino" events, which have been disastrous for salmon health and survival.

Bottom is a research biologist with the Oregon Department of Fisheries and Wildlife, and has managed the salmon conservation program with OSU's Center for the Analysis of Environmental Change.

He and other climatic experts have identified a significant "turning point" in 1976 which seemed to begin a long, downward spiral in the ocean conditions and onshore weather patterns salmon need to thrive in this region.

For about two decades now, a low-pressure system that forms over the Aleutian Islands each winter was often more intense than usual. That seemed, by mechanisms still not clearly understood, to enhance salmon fisheries in Alaska and British Columbia while those in the Pacific Northwest withered.

If historical trends were to continue, Bottom said, this trend might soon reverse itself and begin improving weather and ocean conditions in the Pacific Northwest. Whether that will actually happen is less clear.

"A lot of people don't seem to think that the one or two degree changes we talk about with climate change are a big deal," he said. "But global warming can have a profound ripple effect that changes entire ecosystems, including those necessary to support salmon. It's a very big deal."

As yet another El Nino looms this year, Bottom said, an unusually-frequent occurrence of this global weather phenomenon begins to raise still more questions about links to a changing global climate.

Many people also don't realize, Bottom said, that despite its historic association with salmon, California and the Pacific Northwest are actually on the southern fringe of the natural range of this cold-water fish species.

"Our salmon are already literally living on the edge," Bottom said. "And since future climatic conditions are impossible to predict with certainty, that makes it all the more important to preserve as many different stocks as possible to give us the best chance that some can adapt to new conditions."

The new facts that are being learned about climate, ocean conditions and weather impacts in no way lessen the need to improve salmon survival and habitat in other areas, Bottom said.

In fact, the dubious climatic conditions of the future make it all the more important to give the fish every possible advantage. And it's also important to better understand such climate mechanisms, so that other salmon restoration efforts are not inappropriately given credit for which they may not really be responsible.

"Too often in the past we've managed these fisheries from a perspective of the times always being good and production always high," he said. "Now we must quit deluding ourselves, and manage the fisheries for the lean years."

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Daniel Bottom, 541-737-7631

Natural controls on fish populations analyzed

CORVALLIS, Ore. - Researchers at Oregon State University have demonstrated for the first time one of the natural mechanisms that helps regulate populations of marine fish species, so that the fish neither go extinct or expand their numbers to unsupportable levels.

The study, to be reported Friday in the journal Science, documents how the population of a tropical fish species called damselfish is controlled by combined attacks from predators in the reefs below and the waters above.

The research also confirms a theory about "density dependent" mortality, which suggests that as populations of a fish species grow large, the levels of predation increase; but as populations fall, the "roving" predators lose interest and move away to better hunting grounds, allowing populations to rebound.

"Among other findings, this research suggests that it's important to not overfish these predatory species, since they may play a key role in regulating the populations of other fish," said Mark Hixon, an OSU professor of zoology. "If you were to remove the predatory species, you could seriously destabilize the population and make it far more erratic than it already is."

The findings, Hixon said, help explain on a basic ecological level how the population of at least one fish species may be regulated on a short-term basis, and it probably has applications to a number of other species with related mechanisms. However, these small-scale oscillations in fish population are a different issue than large-scale population changes - such as the salmon crisis in the Pacific Northwest - that may be influenced by overfishing, habitat degradation and marine climate change.

It's commonly known, Hixon said, that many fish populations can vary dramatically, sometimes on a scale of 10-100 times over a period of decades or even a few years. It's been far less clear what prevents this natural variation from getting out of control, although it is widely theorized that some natural mechanism causes a high level of natural mortality when fish populations are too high, and the mortality lessens when the populations are low.

In field research done on tropical reefs in the Bahamas Islands, scientists from OSU and the University of California at Santa Cruz showed that the damselfish - during their particularly vulnerable juvenile stage - were preyed upon by two distinct types of predators, both of which were necessary for this type of "density dependent" population control.

Groupers, and other "resident" fish species living within the same coral reefs the damselfish favored, preyed on them if they ventured too close to the reef. Jacks, another tropical fish species, were "roving" predators that attacked the damselfish from above.

"When damselfish populations became high, the jacks would show up and attack the juvenile fish from above and the groupers would eat them if they ventured into the reefs below," Hixon said. "They were literally caught between the devil and the deep blue sea."

But when damselfish populations dwindled, Hixon said, the jacks would lose interest and move on to other feeding grounds, giving the damselfish time and opportunity to rebuild their populations.

These types of natural population control mechanisms are complex, quite variable, and no doubt operate differently for different fish species, Hixon said. Cod fisheries in the North Atlantic - which have practically collapsed due to overfishing - may have predatory fish similar to the damselfish involved in their population control. But there is speculation that marine bird species and other predators may regulate juvenile salmon in the ocean.

Basic ecological research such as this may help fisheries managers better understand the life cycle and ecology of marine fish, Hixon said, and take steps to protect the natural interaction of different species. For instance, the research suggests that overfishing of important marine predators could seriously disrupt natural population controls on other fish species.

"What we basically need to do is understand how natural systems work and then make sure they are not seriously disrupted by human activities," Hixon said.

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Mark Hixon, 541-737-5364

Oregon seafood processors facing deadline

NEWPORT - Like their counterparts across the nation, Oregon seafood processors face a December deadline to comply with new federal regulations aimed at ensuring that America's seafood supply is safe and fit to eat.

The industry should be ready, an Oregon State University seafood specialist predicts, thanks to the efforts of an alliance of educators, government agencies and trade groups pulled together three years ago by the National Sea Grant College Program.

That alliance is being honored this month with a Hammer Award from Vice President Al Gore, in recognition of its "significant contribution to the nation."

Ken Hilderbrand, an OSU Extension Sea Grant seafood specialist, has been part of the alliance since its inception in 1994, soon after the U.S. Food and Drug Administration announced plans to apply Hazard Analysis and Critical Control Points (or HACCP) standards to seafood.

HACCP lays out seven principles for food processors, intended to ensure food safety from the point of harvest to the consumer's table. Among other things, the system identifies critical points in the processing chain at which potential hazards can be controlled or eliminated.

The principles require careful planning, record-keeping and monitoring, all backed by sound scientific information.

Instead of relying on after-the-fact food inspections to make sure food is wholesome, the new system looks at food processing every step of the way, including shipping, warehousing and overseas imports. FDA Commissioner David Kessler called HACCP "the most fundamental shift in the way we think about inspecting food in the past 50 years."

Federal law set a Dec. 18, 1997, deadline for HACCP to be in use by all processors engaged in interstate seafood commerce. At that point, the local, state and federal agencies which monitor seafood safety will begin checking for HACCP compliance. (Similar plans for the beef and poultry industries are to be phased in by the year 2000)

Putting such a system in place is a massive national - and even international - undertaking. That was evident to seafood specialists with the National Sea Grant College Program, which provides university-based marine research, education and outreach in 29 coastal and Great Lakes states, including Oregon.

The Sea Grant network helped pull together the National Seafood HACCP Alliance, with representation from the U.S. Food and Drug Administration, the U.S. Department of Agriculture's Cooperative Extension services, the National Marine Fisheries Service, the National Fisheries Institute, National Food Processors Association, Interstate Shellfish Sanitation Conference, the Association of Food and Drug Officials, and various state agencies that deal with health, food safety and commerce.

Their goal: To develop a uniform, national HACCP education, training and technical assistance program for the seafood industry and those who are charged with inspecting their products.

Hilderbrand, who serves on the Alliance's steering committee, says most of the pieces of that program are in place, including:


  • A national HACCP training curriculum for seafood safety inspectors. Assembled and distributed by the North Carolina Sea Grant program, the 200-plus page guide has been translated into four languages and more than 6,000 copies have been sold in the U.S. and abroad.


  • An HACCP training and certification program to "train the trainers" who in turn teach HACCP procedures to seafood industry workers, regulators and seafood safety inspectors. The program has already certified more than 400 trainers who have gone on to teach an additional 5,000 people in the industry, regulatory agencies and academia.


  • A list of seafood safety-related questions which need additional scientific attention - "the things we need to know that could help the industry do a better job of implementing their mandated HACCP plans," Hilderbrand said. That list, compiled by an Alliance subcommittee he chaired, has been distributed to various agencies which support ocean and coastal research.


  • A series of "generic" HACCP plans, written by Hilderbrand and other Sea Grant specialists around the country, designed to serve as models for processors who need help drafting their own plans. To speed circulation of the medels, and make it possible to update and refine them quickly, the Alliance has mounted them on its World Wide Web site at
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Ken Hilderbrand, 541-867-0242