OREGON STATE UNIVERSITY

marine science and the coast

Study finds prey distribution, not biomass, key to marine food chain

CORVALLIS, Ore. – A new study has found that each step of the marine food chain is clearly controlled by the trophic level below it – and the driving factor influencing that relationship is not the abundance of prey, but how that prey is distributed.

The importance of the spatial pattern of resources – sometimes called “patchiness” – is gaining new appreciation from ecologists, who are finding the overall abundance of food less important than its density and ease of access to it.

Results of the study are being published this week in the Royal Society journal Biology Letters.

Kelly Benoit-Bird, an Oregon State University oceanographer and lead author on the study, said patchiness is not a new concept, but one that has gained acceptance as sophisticated technologies have evolved to track relationships among marine species.

“The spatial patterns of the resource ultimately determine how the ecosystem functions,” said Benoit-Bird, who received a prestigious MacArthur Fellowship in 2010. “In the past, ecologists primarily used biomass as the determining factor for understanding the food chain, and the story was always rather muddled. We used to think that the size and abundance of prey was what mattered most.

“But patchiness is not only ubiquitous in marine systems, it ultimately dictates the behavior of many animals and their relationships to the environment,” she added.

Benoit-Bird specializes in the relationship of different species in marine ecosystems. In one study in the Bering Sea, she and her colleagues were estimating the abundance of krill, an important food resource for many species. Closer examination through the use of acoustics, however, found that the distribution of krill was not at all uniform – which the researchers say explained why two colonies of fur seals and seabirds were faring poorly, but a third was healthy.

“The amount of food near the third colony was not abundant,” she said, “but what was there was sufficiently dense – and at the right depth – that made it more accessible for predation than the krill near the other two colonies.”

The ability to use acoustics to track animal behavior underwater is opening new avenues to researchers.  During their study in the Bering Sea, Benoit-Bird and her colleagues discovered that they could also use sonar to plot the dives of thick-billed murres, which would plunge up to 200 meters below the surface in search of the krill.

Although the krill were spread throughout the water column, the murres ended up focusing on areas where the patches of krill were the densest.

“The murres are amazingly good at diving right down to the best patches,” Benoit-Bird pointed out. “We don’t know just how they are able to identify them, but 10 years ago, we wouldn’t have known that they had that ability. Now we can use high-frequency sound waves to look at krill, different frequencies to look at murres, and still others to look at squid, dolphins and other animals.

“And everywhere we’ve looked the same pattern occurs,” she added. “It is the distribution of food, not the biomass, which is important.”

An associate professor in the College of Earth, Ocean, and Atmospheric Sciences at Oregon State University, Benoit-Bird has received young investigator or early career awards from the Office of Naval Research, the White House and the American Geophysical Union. She also has received honors from the Acoustical Society of America, which has used her as a model scientist in publications aimed at middle school students.

Her work has taken her around the world, including Hawaii where she has used acoustics to study the sophisticated feeding behavior of spinner dolphins. Those studies, she says, helped lead to new revelations about the importance of patchiness.

Ocean physics in the region results in long, thin layers of phytoplankton that may stretch for miles, but are only a few inches thick and a few meters below the surface. Benoit-Bird and her colleagues discovered a layer of zooplankton – tiny animals that feed on the plankton – treading water a meter below to be near the food source. Next up in the food chain were micronekton, larger pelagic fish and crustaceans that would spend the day 600 to 1,000 meters beneath the surface, then come up to the continental shelf at night to target the zooplankton. And the spinner dolphins would emerge at night, where they could reach the depth of the micronekton.

“The phytoplankton were responding to ocean physics,” Benoit-Bird said, “but all of the others in the food chain were targeting their prey by focusing on the densest patches. We got to the point where we could predict with 70 percent accuracy where the dolphins would show up based just on the phytoplankton density – without even considering the zooplankton and micronekton distribution.”

Ocean “patchiness” is not a new concept, Benoit-Bird reiterated, but may have been under-appreciated in importance.

“If you’re a murre that is diving a hundred meters below the surface to find food, you want to maximize the payoff for all of the energy you’re expending,” Benoit-Bird said. “Now we need more research to determine how different species are able to determine where the best patches are.”

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Kelly Benoit-Bird, 541-737-2063

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Dolphins circling prey
Prey density is key

OSU unveils new seafloor mapping of Oregon’s nearshore ocean

CORVALLIS, Ore. – After more than two years of intense field work and digital cartography, researchers have unveiled new maps of the seafloor off Oregon that cover more than half of the state’s territorial waters – a collaborative project that will provide new data for scientists, marine spatial planners, and the fishing industry.

The most immediate benefit will be improved tsunami inundation modeling for the Oregon coast, according to Chris Goldfinger, director of the Active Tectonics and Seafloor Mapping Laboratory at Oregon State University, who led much of the field work.

“Understanding the nature of Oregon’s Territorial Sea is critical to sustaining sport and commercial fisheries, coastal tourism, the future of wave energy, and a range of other ocean-derived ecosystem services valued by Oregonians,” Goldfinger said. “The most immediate focus, though, is the threat posed by a major tsunami.

“Knowing what lies beneath the surface of coastal waters will allow much more accurate predictions of how a tsunami will propagate as it comes ashore,” he added. “We’ve also found and mapped a number of unknown reefs and other new features we’re just starting to investigate, now that the processing work is done.”

The mapping project was a collaborative effort of the National Oceanic and Atmospheric Administration, OSU’s College of Earth, Ocean, and Atmospheric Sciences, David Evans and Associations, and Fugro. It was funded by NOAA and the Oregon Department of State Lands.

Goldfinger said the applications for the data are numerous. Scientists will be better able to match near-shore biological studies with undersea terrain; planners will be able to make better decisions on siting marine reserves and wave energy test beds; and commercial and recreational fishermen will be able to locate reefs, rockpiles and sandy-bottomed areas with greater efficiency.

“Prior to this, most people used nautical charts,” Goldfinger said. “They would provide the depth of the water, the distance off shore, and in some cases, a bit about the ocean floor – whether it might be mud, rock or sand. Through this project, we’ve been able to map more than half of Oregon’s state waters in a much more comprehensive way.”

Oregon’s Territorial Sea extends three nautical miles from the coast and comprises about 950 square nautical miles. The researchers have created numerous different habitat maps covering 55 percent of those waters, which show distinction between fine, medium and coarse sands; display rocky outcrops; and have contour lines, not unlike a terrestrial topographic map.

Some of the mapping was done aboard the Pacific Storm, an OSU ship operated by the university’s Marine Mammal Institute. The project also utilized commercial fishing boats during their off-season.

More information about the project, as well as the maps and data, are available at: http://activetectonics.coas.oregonstate.edu/state_waters.htm

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Chris Goldfinger, 541-737-5214

Hatchery, OSU scientists link ocean acidification to larval oyster failure

CORVALLIS, Ore. – Researchers at Oregon State University have definitively linked an increase in ocean acidification to the collapse of oyster seed production at a commercial oyster hatchery in Oregon, where larval growth had declined to a level considered by the owners to be “non-economically viable.”

A study by the researchers found that elevated seawater carbon dioxide (CO2) levels, resulting in more corrosive ocean water, inhibited the larval oysters from developing their shells and growing at a pace that would make commercial production cost-effective. As atmospheric CO2 levels continue to rise, this may serve as the proverbial canary in the coal mine for other ocean acidification impacts on shellfish, the scientists say.

Results of the research have just been published in the journal, Limnology and Oceanography.

“This is one of the first times that we have been able to show how ocean acidification affects oyster larval development at a critical life stage,” said Burke Hales, an OSU chemical oceanographer and co-author on the study. “The predicted rise of atmospheric CO2 in the next two to three decades may push oyster larval growth past the break-even point in terms of production.”

The owners of Whiskey Creek Shellfish Hatchery at Oregon’s Netarts Bay began experiencing a decline in oyster seed production several years ago, and looked at potential causes including low oxygen and pathogenic bacteria. Alan Barton, who works at the hatchery and is an author on the journal article, was able to eliminate those potential causes and shifted his focus to acidification.

Barton sent samples to OSU and the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory for analysis. Their ensuing study clearly linked the production failures to the CO2 levels in the water in which the larval oysters are spawned and spend the first 24 hours of their lives, the critical time when they develop from fertilized eggs to swimming larvae, and build their initial shells.

“The early growth stage for oysters is particularly sensitive to the carbonate chemistry of the water,” said George Waldbusser, a benthic ecologist in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “As the water becomes more acidified, it affects the formation of calcium carbonate, the mineral of which the shell material consists. As the CO2 goes up, the mineral stability goes down, ultimately leading to reduced growth or mortality.”

Commercial oyster production on the West Coast of North America generates more than $100 million in gross sales annually, generating economic activity of some $273 million. The industry has depended since the 1970s on oyster hatcheries for a steady supply of the seed used by growers. From 2007 to 2010, major hatcheries supplying the seed for West Coast oyster growers suffered persistent production failures.

The wild stocks of non-hatchery oysters simultaneously showed low recruitment, putting additional strain on limited seed supply.

Hales said Netarts Bay, where the Whiskey Creek hatchery is located, experiences a wide range of chemistry fluctuations. The OSU researchers say hatchery operators may be able to adapt their operations to take advantage of periods when water quality is at its highest.

“In addition to the impact of seasonal upwelling, the water chemistry changes with the tidal cycle, and with the time of day,” Hales said. “Afternoon sunlight, for example, promotes photosynthesis in the bay and that production can absorb some of the carbon dioxide and lower the corrosiveness of the water.”

A previous study co-authored by Hales found the water that is being upwelled in the Pacific Ocean off the Oregon coast has been kept at depth away from the surface for about 50 years – meaning it was last exposed to the atmosphere a half-century ago, when carbon dioxide levels were much lower. “Since atmospheric CO2 levels have risen significantly in the past half-century, it means that the water that will be upwelled in the future will become increasingly be more corrosive,” Hales said.

The OSU researchers also found that larval oysters showed delayed response to the water chemistry, which may cast new light on other experiments looking at the impacts of acidification on shellfish. In their study, they found that larval oysters raised in water that was acidic, but non-lethal, had significantly less growth in later stages of their life.

“The takeaway message here is that the response to poor water quality isn’t always immediate,” said Waldbusser. “In some cases, it took until three weeks after fertilization for the impact from the acidic water to become apparent. Short-term experiments of just a few days may not detect the damage.”

The research has been funded by a grant from the National Science Foundation, and supported by NOAA and the Pacific Coast Shellfish Growers Association. Other authors on the journal article include Chris Langdon, of OSU’s Hatfield Marine Science Center, and Richard Feely, of NOAA’s Pacific Marine Environmental Laboratories.

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Burke Hales, 541-737-8121

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Whiskey Creek Hatchery Oyster larvae oyster spat

Coastal workshops to address tsunami debris risks

CORVALLIS, Ore. – Organizations on the Oregon coast are partnering with the National Oceanic and Atmospheric Administration, Oregon State University Extension, Oregon Sea Grant, state and local agencies, and conservation groups on a series of community meetings to share information and science about the marine debris left by the 2011 Japanese tsunami.

The meetings will take place between April 11 and 20 in coastal communities from Port Orford to Seaside, and inland in Portland and Eugene.

Debris pulled out to sea by the Japanese tsunami last March is gradually riding the Pacific currents toward the West Coast, raising public questions about everything from derelict "ghost" ships to what to expect while beachcombing.  Oceanographers predict that the bulk of the debris could arrive on U.S. shores next year, but no one can yet predict exactly when – or how much. 

“Right now, as a result of the tragic tsunami disaster, Brookings, Ore., is rebuilding, Japan is reeling and the West Coast states are preparing to clean up an unprecedented amount of debris being carried to our coast on the ocean currents,” said Cylvia Hayes, Oregon’s First Lady. “Our oceans connect us and are essential to a healthy environment and economy.

“These workshops are important to helping us effectively deal with the tsunami debris and better protect the health of oceans and coastal communities,” Hayes added.

Oregon non-profit organizations that specialize in caring for the state’s shoreline and coping with litter report an overwhelming volume of requests and questions from their volunteers and the public about the possible arrival of tsunami-related debris.  SOLV, Surfrider Foundation, the CoastWatch program of the Oregon Shores Conservation Coalition, and the Washed Ashore Project are partnering with Oregon Sea Grant Extension to sponsor information sessions featuring staff from NOAA’s Marine Debris Program. 

Key speaker will be Nir Barnea, West Coast regional coordinator for NOAA’s marine debris program.  He will describe what is known about the contents and trajectory of the debris and what is being done across the Pacific to prepare for it.

Barnea will be joined by representatives from the U.S. Coast Guard, Oregon Parks and Recreation Department, Oregon Health Authority Public Health Division, County Emergency Managers, and Oregon Department of Environmental Quality. Local waste managers and coastal haulers have also been invited as their experience with marine debris disposal could prove invaluable.

All events are free and open to the public.  After presentations, audience members will have a chance to ask questions about everything from public health to returning any personal valuables that may be found amid the debris.

Here is the tentative list of times and locations for the Japanese tsunami marine debris presentations. 

  • April 11th, Seaside 2-3:30 pm, Seaside Community Center, 1225 Ave A , Seaside
  • April 11, Bay City: 6-7:30 p.m., Bay City Arts Center, 5680 A St.
  • April 12, Pacific City: 10-11:30 a.m., Kiwanda Community Center, 34600 Cape Kiwanda Dr.
  • April 12, Newport: 6-7:30 p.m., Newport City Hall, 169 SW Coast Hwy.
  • April 13, Florence: 10-11:30 a.m., Florence Fire Station,  2625 Hwy 101.
  • April 13, North Bend: 2-3:30 p.m., North Bend Public Library, 1800 Sherman Ave.
  • April 13, Bandon: 6-7:30 p.m., City Council Chamber/City Hall, 555 Highway 101.
  • April 14, Port Orford: 10-11 a.m., American Legion Hall, 421 11th St.
  • April 14, Eugene: 3-4:30 p.m., EWEB Training Center, 500 East 4th Ave N Bldg.
  • April 15, Portland 3:30-5 p.m., Ecotrust Natural Capital Center, 721 NW 9th Ave.
  • April 20, Cannon Beach, time and location TBD

Updated information will be available from www.solv.org.

The groups expect to conduct organizing and education efforts later this year to strengthen their citizen response networks before the expected arrival of the bulk of the debris.

Source: 

Rachael Pecore, SOLV, 503-844-9571, ext. 317

 

Rising CO2 levels linked to global warming during last deglaciation

CORVALLIS, Ore. – Many scientists have long suspected that rising levels of carbon dioxide and the global warming that ended the last Ice Age were somehow linked, but establishing a clear cause-and-effect relationship between CO2  and global warming from the geologic record has remained difficult.

A new study, funded by the National Science Foundation and published in the journal Nature, identifies this relationship and provides compelling evidence that rising CO2 caused much of the global warming.

Lead author Jeremy Shakun, who conducted much of the research as a doctoral student at Oregon State University, said the key to understanding the role of CO2 is to reconstruct globally averaged temperature changes during the end of the last Ice Age, which contrasts with previous efforts that only compared local temperatures in Antarctica to carbon dioxide levels.

“Carbon dioxide has been suspected as an important factor in ending the last Ice Age, but its exact role has always been unclear because rising temperatures reflected in Antarctic ice cores came before rising levels of CO2,” said Shakun, who is a National Oceanic and Atmospheric Administration (NOAA) Post-doctoral Fellow at Harvard University and Columbia University.

“But if you reconstruct temperatures on a global scale – and not just examine Antarctic temperatures – it becomes apparent that the CO2 change slightly preceded much of the global warming, and this means the global greenhouse effect had an important role in driving up global temperatures and bringing the planet out of the last Ice Age,” Shakun added.

Here is what the researchers think happened.

Small changes in the Earth’s orbit around the sun affected the amount of sunlight striking the northern hemisphere, melting ice sheets that covered Canada and Europe. That fresh water flowed off of the continent into the Atlantic Ocean, where it formed a lid over the sinking end of the Atlantic Meridional Overturning Circulation – a part of a global network of currents that brings warm water up from the tropics and today keeps Europe temperate despite its high latitudes.

The ocean circulation warms the northern hemisphere at the expense of the south, the researchers say, but when the fresh water draining off the continent at the end of the last Ice Age entered the North Atlantic, it essentially put the brakes on the current and disrupted the delivery of heat to the northern latitudes.

“When the heat transport stops, it cools the north and heat builds up in the Southern Hemisphere,” Shakun said. “The Antarctic would have warmed rapidly, much faster than the time it takes to get CO2 out of the deep sea, where it was likely stored.

“The warming of the Southern Ocean may have shifted the winds as well as melted sea ice, and eventually drawn the CO2 out of the deep water, and released it into the atmosphere,” Shakun said. “That, in turn, would have amplified warming on a global scale.”

The researchers constructed a record of global surface temperature from 80 temperature reconstructions spanning the end of the Ice Age and found that average temperature around the Earth correlated with – and generally lagged behind – rising levels of CO2.

Peter Clark, an Oregon State University scientist and co-author on the paper, said changes in solar radiation were the likely trigger for the series of effects that followed. His 2009 study, published in Science, confirmed an earlier theory that wobble in the Earth’s axis, which changes the amount of sunlight captured by Earth, first caused melting of the large northern ice sheets.

“It has long been known that Earth’s slow wobble is caused primarily by the gravitational influences of the larger planets, such as Jupiter and Saturn, which pull and tug on the Earth in slightly different ways over periods of thousands of years,” said Clark, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

Shakun said there is “an enormous amount” of carbon sequestered in the deep ocean.

“The Southern Ocean is connected to all the deep ocean basins,” he pointed out, “so the most likely mechanisms to draw it out of the ocean were certainly there.”

The question now, the researchers say, is how human-generated carbon dioxide will affect the planet when there isn’t an ice age.

“CO2 was a big part of bringing the world out of the last Ice Age,” Shakun said, “and it took about 10,000 years to do it. Now CO2 levels are rising again, but this time an equivalent increase in CO2 has occurred in only about 200 years, and there are clear signs that the planet is already beginning to respond.”

“While many of the details of future climate change remain to be figured out, our study bolsters the consensus view that rising CO2 will lead to more global warming,” Shakun added.

Other authors on the study include Feng He, University of Wisconsin-Madison; Shaun Marcott, Alan Mix, and Andreas Schmittner, Oregon State University; Zhengyu Liu, University of Wisconsin-Madison and Peking University; Bette Otto-Bliesner, National Center for Atmospheric Research; and Edouard Bard, CNRS-Universite Aix-Marseille.

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Peter Clark, 617-740-5237

Public invited behind doors of HMSC April 14 for Marine Science Day

NEWPORT, Ore. – Oregon State University’s Hatfield Marine Science Center will open its doors a bit wider on Saturday, April 14, when the Newport facility hosts its first Marine Science Day.

The free public event, which runs from 10 a.m. to 4 p.m., will feature scientists and educators from OSU, federal and state agencies, the Oregon Coast Aquarium, and the new NOAA Marine Operations Center-Pacific. It is a rare opportunity for the public to go behind the scenes of one of the nation’s leading marine science and education facilities.

Oregon First Lady Cylvia Hayes will speak briefly at 3 p.m. in the auditorium, along with OSU Vice President for Research Richard Spinrad. Bruce Mate, director of OSU’s Marine Mammal Institute, will follow with a presentation showcasing the center’s pioneering role in tracking whales by satellite.

“Marine Science Day will be fun and engaging for people of all ages,” said Maryann Bozza, program manager for the Hatfield Marine Science Center. “Visitors will wind through the campus, getting a true behind-the-scenes experience with an unparalleled opportunity to learn directly from marine scientists.”

“The diverse science conducted at the facility reaches from local coastlines and estuaries to the depths of the world’s oceans,” she added, “and in scale from microbes on the seafloor to undersea volcanoes and the whales that swim over them.”

Visitors can meet Pearl, the Visitor Center’s new octopus; observe a sea turtle necropsy; and meet fisheries scientists and geologists whose research is described in center exhibits. The public also can participate in self-guided tours through the facility’s marine research labs, library and classrooms, where scientists will have interactive exhibits explaining their research.

Among the highlights:

  • Hear volcanoes erupt and whales ‘sing’ in an audio display by NOAA and OSU researchers using undersea hydrophones;
  • Learn how researchers are supporting sustainable fisheries through innovative, collaborative research;
  • Collect biological data from fish, plankton and even a shrimp parasite through hands-on experimentation;
  • Explore novel oceangoing and ocean floor instrument platforms and meet the scientists who designed them.

Visitors may also take guided tours of HMSC’s seawater facilities and ornamental fish laboratory. More information, including program and special events, is available at hmsc.oregonstate.edu

The event will showcase OSU’s unique partnership with state and federal agencies, which makes the Hatfield Marine Science Center a national leader for marine research and education, according to director George Boehlert.

“OSU’s Newport campus is known for a diversity of research and the expertise of its scientists, which offer unique opportunities in education and outreach,” Boehlert said. “Visitors to Marine Science Day will get a sense of the innovation and synergy that makes the Hatfield Marine Science Center unique.”

Collaborative research partners that share the campus with OSU labs include six federal and state agencies: National Oceanic and Atmospheric Administration (NOAA) Fisheries and NOAA Research, Oregon Department of Fish and Wildlife, U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, U.S. Geological Survey, and U.S. Department of Agriculture.

Most Marine Science Day exhibits and activities will be indoors, although visitors are advised to dress for the weather as portions of tours, paths between buildings and some exhibits will be outdoors.

The OSU Hatfield Marine Science Center is located at 2030 S.E. Marine Science Drive in Newport, just south of the Highway 101 bridge over Yaquina Bay. For more information, see hmsc.oregonstate.edu. Accommodation requests related to a disability should be made to the HMSC Director's Office, 541-867-0234 or by email to maryann.bozza@oregonstate.edu.

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Maryann Bozza, 541-867-0234

 

Task force recommends reducing global harvest of “forage fish”

CORVALLIS, Ore. – A task force that conducted one of the most comprehensive analyses of global “forage fish” populations issued its report this week, which strongly recommends implementing more conservative catch limits for these crucial prey species.

The Lenfest Forage Fish Task Force calls for the harvest reduction of sardines, anchovies and other forage fish so that they can continue to serve as critical prey for larger species, including salmon, cod and tuna, as well as for dolphins, whales, penguins and seabirds.

The report concludes that the fish are “twice as valuable in the water as in a net.”

“Forage fish are essential components of marine ecosystems,” said Selina Heppell, an Oregon State University fisheries ecologist and one of the authors on the report. “The status and importance of each species can be difficult to evaluate because many of them migrate long distances and they can fluctuate dramatically in abundance.

“There also are regional differences in how the fisheries are managed and the relative health of the population,” added Heppell, who is an associate professor in OSU’s Department of Fisheries and Wildlife. “The West Coast sardine fishery, for example, is carefully monitored. They have a ‘harvest control rule’ that sets the harvest at about 10 percent of the overall stock, and when the population gets below a certain level, they stop fishing.

“Those are the kinds of regulations that may need to be adopted in other parts of the world.”

Funded by the Lenfest Ocean Program, the task force is comprised of 13 scientists from the United States, Canada, Australia, United Kingdom, and France. They include researchers who have studied forage fish, as well as their predators, including larger fish, seabirds and marine mammals.

The task force reviewed forage fisheries worldwide and conducted analyses of 82 marine ecosystem models. It concluded that these small schooling fish are a crucial link in marine food webs because they consume phytoplankton and in turn are preyed upon by a variety of animals that may switch from one forage fish species to another, depending on relative abundance.

In computer model simulations, reduced harvest of forage fish led to persistence of top predators, and more fish for fisheries.

The harvest of these forage fish has increased with demand, as they are used not only for food – from canned sardines to anchovies on pizza – but primarily for fish meal and fish oil to feed farmed fish, pigs and chickens. They also are used as nutritional supplements for people.

“Traditionally, we have been managing fisheries for forage species in a manner that cannot sustain the food webs, or some of the industries they support,” said Ellen K. Pikitch of Stony Brook University in New York, who led the task force. “As three-fourths of marine ecosystems in our study have predators highly dependent on forage fish, it is economically and biologically imperative that we develop smarter management for these small but significant species.”

The report estimates that forage fish worldwide generate $5.6 billion as direct catch, but contribute more than double that - $11.3 billion – by serving as food for other commercially important fish.

Oregon State’s Heppell said conservative management is particularly important because these forage fish are subject to major fluctuations. Sardines almost completely disappeared from the northern California Current System for about 30 years then reappeared during the 1980s. By the 1990s, sardines were again harvested and their numbers peaked around 2000, but have begun dropping again.

Likewise, eulachon smelt once filled many Northwest rivers and have largely disappeared, she noted.

"There has been a growing concern by commercial and recreational fishing groups about the status of forage fish, because they are so important to their livelihood,” said Heppell, who is on the science team of the Pacific Fishery Management Council, which manages West Coast fisheries.

“This report underscores the need for ecosystem-based management because the success of forage fish is important for dozens of other species that we care about,” she added.

The report is called “Little Fish, Big Impact: Managing a Crucial Link in Ocean Food Webs.” More information on the Lenfest Forage Fish Task Force is available at: http://www.oceanconservationscience.org/foragefish/

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Selina Heppell, 541-737-9039

Scientists still following far-ranging Varvara as Russian whale returns

NEWPORT, Ore. – After visiting three different lagoons in the Pacific Ocean side of Baja Mexico, a rare western gray whale named “Varvara” is migrating up the West Coast – presumably en route to her home range near Russia’s Sakhalin Island.

The Mexican lagoons are known calving and breeding grounds for eastern gray whales and Varvara may have gone there in search of a partner, scientists say.

“She did not calve for sure, or she would have stayed in one place for four to eight weeks because the calves need to gain strength, coordination and blubber – for fuel and insulation,” said Bruce Mate, director of the Marine Mammal Institute at Oregon State University. “More likely, she would have been breeding this year and spent time around three areas where that activity is commonly seen.”

By Friday, the 9-year-old female was near the Washington/Canadian border, traveling northward at a rate of up to 100 miles a day.

There is “great interest” in Varvara’s journey in Tofino, the whale watching hub on the west coast of Vancouver Island, according to Jim Darling of the Pacific Wildlife Foundation, who has studied whale populations for years.

“Many have been following each update on Varvara since she passed on her southward trek last January,” Darling said. “Among the many things Varvara and Flex have taught us is the potential for intermingling between the western and eastern gray whales – not only on breeding grounds, but during migrations and spring feeding aggregations along the way.”

The public can follow the travels of Varvara online at: http://mmi.oregonstate.edu/Sakhalin2011

The long-distance journey of Varvara – which means Barbara in Russian – is critical because this is the first time scientists have documented that critically endangered western gray whales travel to Baja Mexico, where eastern gray whales frequent. Western gray whales are thought to be genetically distinct from their more populous cousins that are common up and down the West Coast, but Varvara clearly was mingling with eastern gray whales.

Mate said there are only about 130 western gray whales in the world and the behavior of Varvara has significant ecological and management implications.

“Clearly the experience of Varvara, and Flex before her, demonstrates that western gray whales can and do come over to the eastern Pacific,” Mate said. “Whether this suggests that they are not a distinct population or that we underestimated their range isn’t yet clear.”

Last year, American and Russian scientists teamed up to follow “Flex,” a 13-year-old western gray whale that journeyed across the Bering Sea and North Pacific Ocean to Vancouver Island and down to Oregon before the tag finally quit working. The scientists returned to Sakhalin Island last fall to tag a half-dozen western gray whales and this time one of the tags, on Varvara, lasted all the way through her journey to the Sea of Cortez and is still transmitting – some 8,000 miles later.

“The average tag survives 123 days,” said Mate, who works out of OSU's Hatfield Marine Science Center, “and this one is still working. Hopefully it will last so we can see if Varvara takes the same route back to Russia, or travels through different waters.”

In the 1970s, western gray whales were thought to have gone extinct, but a small aggregation was discovered by Russian scientists off Sakhalin Island and has been monitored by Russian and U.S. scientists since the 1990s. Eastern gray whales likewise were decimated by whaling and listed as endangered, but conservation efforts led to a recovery and, at 18,000 strong, they have been delisted.

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Bruce Mate, 541-867-0202

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Varvara
Varvara returns north

Scientists document first consumption of abundant life form, Archaea

CORVALLIS, Ore. – A team of scientists has documented for the first time that animals can and do consume Archaea – a type of single-celled microorganism thought to be among the most abundant life forms on Earth.

Archaea that consume the greenhouse gas methane were in turn eaten by worms living at deep-sea cold seeps off Costa Rica and the West Coast of the United States. Archaea perform many key ecosystem services including being involved with nitrogen cycling, and they are known to be the main mechanism by which marine methane is kept out of the atmosphere.

The finding of this new study adds a wrinkle to scientific understand of greenhouse gas cycles. Results of the study, which was funded by the National Science Foundation, have been published online in the International Society for Microbial Ecology Journal, a subsidiary of the journal Nature.

“This opens up a new avenue of research,” said Andrew Thurber, a post-doctoral researcher at Oregon State University and lead author on the study. “Archaea weren’t even discovered until 1977, and were thought to be rare and unimportant, but we are beginning to realize that they not only are abundant, but they have roles that have not fully been appreciated.”

Archaea are considered one of the three “domains of life” on Earth, along with bacteria and eukaryota (plants and animals). Despite their abundance, no member of the Archaea domain has been known to be part of a food web.

One of the basic questions scientists have asked is whether this life form could act as a food source for animals. To answer this, the researchers performed a laboratory study during which they fed two types of Archaea to the worms, as well as meals of bacteria, spinach or rice, and the worms thrived on all of the food sources, growing at the same rate.

“That showed us that Archaea can be a viable food source for at least some animals,” Thurber pointed out. 

Thurber and his colleagues initially were looking at biological life forms at a cold seep in the deep ocean off Costa Rica, when they opened up a rock and found worms living within the crevices. They found that the worms had been feeding on Archaea, which had, in turn, been consuming methane. They were able to trace the isotopic signature of the methane from the Archaea to the worms.

From what they learned from the Costa Rican study, the scientists also discovered that worms of the same family as those found in the rocks consume methane-munching Archaea at cold seeps off northern California and at Hydrate Ridge off the central Oregon coast, west of Newport. The researchers think the family of worms, the Dorvilleids, uses its teeth to scrape the Archaea off rocks.

The consumption of Archaea by grazers, a process coined “archivory” by Thurber in the article, is particularly interesting because the only way it could be documented was by tracing the isotopic biomarkers from the methane. When the researchers attempted to trace consumption of Archaea through lipid types and other mechanisms, they failed because the chemicals and proteins broke down within the worms.

“It could be that many other animals are consuming Archaea but we haven’t been able to detect it,” pointed out Thurber, who did much of the research as a doctoral candidate at the Scripps Institution of Oceanography.  “We still haven’t found the right technique to identify animals that eat Archaea that don’t rely on methane, but now we know to look.

“Hopefully, this will open up a lot of new research,” Thurber added, “and provide a greater understanding of how the world works.”

The deep ocean sequesters vast amounts of methane and researchers believe that Archaea consume a majority of it before it reaches the water column. The role of Archaea consumers now will have to be taken into effect, Thurber said.

“We’re not yet sure of the implications,” said Thurber, who is affiliated with OSU’s College of Earth, Ocean, and Atmospheric Sciences. “But Archaea are found in many different places, from estuaries to the deep sea, so it is possible that they fit into food webs beyond the cold seeps where we documented the process.”

Other authors on the paper include Lisa Levin of Scripps, and Victoria Orphan and Jeffrey Marlow of the California Institute of Technology.

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Study: Endangered Antarctic blue whales show surprising genetic diversity

NEWPORT, Ore. – More than 99 percent of Antarctic blue whales were killed by commercial whalers during the 20th century, but the first circumpolar genetic study of these critically endangered whales has found a surprisingly high level of diversity among the surviving population of some 2,200 individuals.

That, says lead author Angela Sremba of Oregon State University, may bode well for their future recovery.

Results of the study have just been published in the open-access journal, PLoS ONE. As part of the study, the researchers examined 218 biopsy samples collected from living Antarctic blue whales throughout the Southern Ocean from 1990 to 2009, through a project coordinated by the International Whaling Commission.

The genetic survey revealed a “surprisingly high” level of diversity that may help the population slowly rebound from its catastrophic decimation by whalers.

“Fewer than 400 Antarctic blue whales were thought to have survived when this population was protected from commercial hunting in 1966,” noted Sremba, who conducted the research as part of her master’s degree with the Marine Mammal Institute at OSU’s Hatfield Marine Science Center.  “But the exploitation period, though intense, was brief in terms of years, so the whales’ long lifespans and overlapping generations may have helped retain the diversity.”

“In fact,” she added, “some of the Antarctic blue whales that survived the genetic bottleneck may still be alive today.”

Prior to whaling Antarctic blue whales were thought to number about 250,000 individuals – a total that dwindled to fewer than 400 animals by 1972 when blue whales were last killed by illegal Soviet whaling. Blue whales are thought to be the largest animals ever to have lived on Earth, said OSU’s Scott Baker, associate director of the Marine Mammal Institute and an author on the study – and the Antarctic blue whales were even larger than their cousins in other oceans.

“These animals are very long-lived – maybe 70 to 100 years – and they can grow to a length of more than 100 feet and weigh more than 330,000 pounds,” he said. “There is a jawbone in a museum in South Africa that takes up most of the lobby. This is one reason they were so intensively exploited; they were the most valuable whales to hunt.”

Despite their history of exploitation, little is known about modern-day movements of Antarctic blue whales, which are considered a separate subspecies – differing in size and habitat use – from the smaller “pygmy” blue whales, which live in more temperate regions of the Southern Hemisphere.

Through “microsatellite genotyping,” or DNA fingerprinting, the PLoS ONE study was able to track some of the movements of individual Antarctic blue whales.

“We documented one female that traveled from one side of Antarctica to the other – a minimum distance of more than 6,650 kilometers over a period of four years,” said Sremba, who is now continuing her studies as a Ph.D. student in the Department of Fisheries and Wildlife at OSU. “It is the first documentation of individual movements by Antarctic blue whales since the end of the commercial whaling era.”

Baker said the long distance movement of a few individuals was “somewhat surprising” in comparison to the evidence for genetic differences between areas of the Southern Ocean. On one hand, it is apparent that individual Antarctic blue whales are capable of traveling enormous distances in search of food.

“On the other hand,” Baker said, “there seems to be some fidelity to the same feeding grounds as a result of a calf’s early experience with its mother. This ‘maternally directed’ fidelity to migratory destinations seems to be widespread among great whales.”

There is much, however, which scientists still don’t know about Antarctic blue whales, Baker pointed out.

“This is a poorly understood species of whales, despite its history of exploitation,” Baker said. “Only now are we developing the technology to study such a small number of whales spread across such a vast habitat.”

The biopsy samples were collected during more than two decades of research cruises supervised by the International Whaling Commission, and with international scientists joining research vessels from the Japanese Ministry of Fisheries.

Now that their population is slowly recovering, future studies may focus on Antarctic blue whales’ migration patterns, and the locations of their breeding and calving grounds.

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