OREGON STATE UNIVERSITY

marine science and the coast

Iron, steel in hatcheries may distort magnetic “map sense” of steelhead

CORVALLIS, Ore. – Exposure to iron pipes and steel rebar, such as the materials found in most hatcheries, affects the navigation ability of young steelhead trout by altering the important magnetic “map sense” they need for migration, according to new research from Oregon State University.

The exposure to iron and steel distorts the magnetic field around the fish, affecting their ability to navigate, said Nathan Putman, who led the study while working as a postdoctoral researcher in the Department of Fisheries and Wildlife, part of OSU’s College of Agricultural Sciences.

Just last year Putman and other researchers presented evidence of a correlation between the oceanic migration patterns of salmon and drift of the Earth’s magnetic field. Earlier this year they confirmed the ability of salmon to navigate using the magnetic field in experiments at the Oregon Hatchery Research Center. Scientists for decades have studied how salmon find their way across vast stretches of ocean.

“The better fish navigate, the higher their survival rate,” said Putman, who conducted the research at the Oregon Hatchery Research Center in the Alsea River basin last year. “When their magnetic field is altered, the fish get confused.”

Subtle differences in the magnetic environment within hatcheries could help explain why some hatchery fish do better than others when they are released into the wild, Putman said. Stabilizing the magnetic field by using alternative forms of hatchery construction may be one way to produce a better yield of fish, he said.

“It’s not a hopeless problem,” he said. “You can fix these kinds of things. Retrofitting hatcheries with non-magnetic materials might be worth doing if it leads to making better fish.”

Putman’s findings were published this week in the journal Biology Letters. The research was funded by Oregon Sea Grant and the Oregon Department of Fish and Wildlife, with support from Oregon State University. Co-authors of the study are OSU’s David Noakes, senior scientist at the Oregon Hatchery Research Center, and Amanda Meinke of the Oregon Hatchery Research Center.

The new findings follow earlier research by Putman and others that confirmed the connection between salmon and the Earth’s magnetic field. Researchers exposed hundreds of juvenile Chinook salmon to different magnetic fields that exist at the latitudinal extremes of their oceanic range.

Fish responded to these “simulated magnetic displacements” by swimming in the direction that would bring them toward the center of their marine feeding grounds. In essence, the research confirmed that fish possess a map sense, determining where they are and which way to swim based on the magnetic fields they encounter.

Putman repeated that experiment with the steelhead trout and achieved similar results. He then expanded the research to determine if changes to the magnetic field in which fish were reared would affect their map sense. One group of fish was maintained in a fiberglass tank, while the other group was raised in a similar tank but in the vicinity of iron pipes and a concrete floor with steel rebar, which produced a sharp gradient of magnetic field intensity within the tank. Iron pipes and steel reinforced concrete are common in fish hatcheries.

The scientists monitored and photographed the juvenile steelhead, called parr, and tracked the direction in which they were swimming during simulated magnetic displacement experiments. The steelhead reared in a natural magnetic field adjusted their map sense and tended to swim in the same direction. But fish that were exposed to the iron pipes and steel-reinforced concrete failed to show the appropriate orientation and swam in random directions.

More research is needed to determine exactly what that means for the fish. The loss of their map sense could be temporary and they could recalibrate their magnetic sense after a period of time, Putman said. Alternatively, if there is a critical window in which the steelhead’s map sense is imprinted, and it is exposed to an altered magnetic field then, the fish could remain confused forever, he said.

“There is evidence in other animals, especially in birds, that either is possible,” said Putman, who now works for the National Oceanic and Atmospheric Administration. “We don’t know enough about fish yet to know which is which. We should be able to figure that out with some simple experiments.”

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Nathan Putman, 205-218-5276 or Nathan.putman@gmail.com; or David Noakes, 541-737-1953, David.noakes@oregonstate.edu

Marine Science Day: An opportunity to explore behind-the-scenes

NEWPORT, Ore. – Oregon State University’s Hatfield Marine Science Center will host its popular Marine Science Day on Saturday, April 12, offering the public an opportunity to meet many of the scientists working at the research facility, as well as take tours and explore the exhibits.

The center also will commemorate the 25th anniversary of the Coastal Oregon Marine Experiment Station (COMES), which is the nation’s first Experiment Station dedicated to marine sciences.

The activities are free and open to the public, running from 10 a.m. to 4 p.m. at the Hatfield Center, located at 2030 S.E. Marine Science Drive in Newport, just south of the Highway 101 bridge over Yaquina Bay. An online schedule of events is available at: hmsc.oregonstate.edu/marinescienceday

The event will feature scientists and educators from OSU, federal and state agencies, Oregon Coast Aquarium, and the NOAA Marine Operations Center-Pacific. It is a chance for the public to explore one of the nation’s leading marine science and education centers.

Visitors can tour the research facilities of the Hatfield Marine Science Center, and see genetics laboratories, animal husbandry areas, and get a close-up view of ongoing research projects. Interactive research exhibits will feature larval fish ecology, bioacoustics of whales, volcanoes and deep ocean vents, and oceanographic tools such as a glider to study low-oxygen on the West Coast. Activities for children include a Bird Beak Buffet from the U.S. Fish and Wildlife Service, and the Mystery Fossil Dig by Oregon Sea Grant. Scheduled events include:

  • 10 a.m. – The open house begins, lasting until 4 p.m.
  • 11 a.m. – “Pumped up for Pinnipeds: Seals and Sea Lions of the Oregon Coast,” a presentation by Oregon Coast Aquarium staff, Hennings Auditorium (repeated at 2 p.m.);
  • 1:30 p.m. – Octopus feeding in the Visitor’s Center;
  • 3 p.m. – “A Food Chain of Fisheries Research: The Amazing Story of Oregon’s Marine Experiment Station,” a presentation by Gil Sylvia, director of COMES; Terry Thompson, a commercial fisherman, county commissioner and COMES board member; and Michael Morrissey, director of the Food Innovation Center in Portland. State Sen. Arnie Roblan will introduce the speakers.

The Coastal Oregon Marine Experiment Station is located in both Newport and Astoria. Researchers in Newport focus on fishery policy and management, marketing, fish stock assessment, aquaculture, ecology, genetics and marine mammal conservation. Astoria researchers at the OSU Seafood Laboratory work on seafood science, processing, safety and innovation.

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Maryann Bozza, 541-867-0234; maryann.bozza@oregonstate.edu

NOAA planning leader to direct Oregon Sea Grant program

CORVALLIS, Ore. – Shelby Walker, a marine scientist and administrative leader with the National Oceanic and Atmospheric Administration, has been named director of the Oregon Sea Grant College Program.

She will assume leadership of Oregon Sea Grant, the Oregon State University-based marine research, outreach, education and communication program, on July 7.

Walker has been the strategic planning team leader for the Office of Policy, Planning and Evaluation in NOAA’s Office of Oceanic and Atmospheric Research since August 2009. In that role, she has been responsible for the agency’s research and development planning efforts.

She also has been associate director for the NOAA RESTORE Act Science Program, an initiative funded through civil penalties resulting from the Deepwater Horizon oil spill that aims to increase scientific understanding of the Gulf of Mexico ecosystem and improve the region’s sustainability.

“Oregon Sea Grant deals with a range of marine issues that impacts the lives and livelihoods of Oregonians,” said Rick Spinrad, vice president for research at Oregon State. “Shelby Walker is an experienced leader and a superb collaborator who will be able to develop partnerships in research, education, communications and outreach to address these issues, which include natural hazards, climate change and managing our marine resources in a responsible and sustainable manner.”

Prior to joining NOAA, Walker was associate program director in the National Science Foundation’s Ocean Sciences Division, where she worked in the Ocean Technology and Interdisciplinary Coordination Program. She served as program officer for the Ocean Observatories Initiative, one of the largest oceanographic infrastructure investments in history. The OOI is a $386 million project to monitor the world’s oceans for environmental changes and their effects on biodiversity, coastal ecosystems and climate, led by several universities including OSU.

Walker also has been project manager for the Joint Subcommittee on Ocean Science and Technology, a group of 25 federal agencies with responsibilities for ocean research and technology development.

Her research has focused on organic contaminants in coastal systems, including highly industrialized urban estuaries. Walker received her Ph.D. in marine science from the College of William and Mary, and worked as a post-doctoral researcher at the Naval Research Laboratory.

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Rick Spinrad, 541-737-0664; rick.spinrad@oregonstate.edu

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Shelby Walker
Shelby Walker

OSU’s Hatfield Center to host regional STEM hub

NEWPORT, Ore. – One of six regional “STEM” hubs funded by the Oregon Department of Education and serving the Oregon coast from Astoria to Coos Bay will be headquartered at Oregon State University’s Hatfield Marine Science Center in Newport.

A series of meetings will begin next month along the coast to help launch the initiative.

The Science, Technology, Engineering, and Math, or STEM hubs are designed to boost the proficiency of K-14 students in these areas.

The Lincoln County School District was awarded a grant of $664,000 to coordinate the effort, partnering with OSU, Oregon Sea Grant, the Tillamook School District, and the Oregon Coast Aquarium. The new regional STEM hub will expand an existing program called the Oregon Coast Regional STEM Center, according to Tracy Crews, project manager for the newly formed coastal hub.

“Lincoln and Tillamook counties, along with 23 other partners, have been offering STEM support under a grant from the U.S. Department of Education,” Crews said. “What this new grant will do is allow us to expand the program up and down the coast, and enlist new partners and offer more resources for STEM-related instruction.”

In the first phase of the project, Crews and other hub coordinators will host a series of meetings along the coast to conduct a needs assessment and engage new partners. These meeting are scheduled as follows:

  • Newport: April 17, at Oregon Coast Community College;
  • Astoria: May 1 at Clatsop Community College;
  • Tillamook: May 7 at Tillamook Bay Community College;
  • Coos Bay: May 15, at Southwestern Oregon Community College.

Times and location will be set later, with information available by contact Tracy Crews at 541-867-0329, or tracy.crews@oregonstate.edu. A website is being be developed for the coast STEM hub.

“We hope to engage not only the K-12 schools and community colleges, but industry, local government, scientific agencies, community leaders and parents,” Crews said. “Once we determine some of the needs, we can begin connecting people with the appropriate resources.”

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 Tracy Crews, 541-867-0329; tracy.crews@oregonstate.edu

National survey reveals coastal concerns over climate change

CORVALLIS, Ore. – The American public may be divided over whether climate is changing, but coastal managers and elected officials in nine states say they see the change happening – and believe their communities will need to adapt.

That's one finding from a NOAA Sea Grant research project, led by Oregon Sea Grant at Oregon State University. The projected involved multiple other Sea Grant programs, which surveyed coastal leaders in selected parts of the nation's Atlantic, Pacific, Gulf and Great Lakes coasts, as well as Hawaii. 

Three-quarters of coastal professionals surveyed – and 70 percent of all participants – said they believe that the climate in their area is changing.

While national polls dating back more than a decade, including several by Gallup, have revealed some public skepticism and polarization about climate change, the Sea Grant findings are in line with a number of recent surveys – including several by the Yale Project on Climate Change and Communication – suggesting a growing majority of  Americans believes the earth's  climate is changing. However, many express uncertainty that anything can be done about it.

The Sea Grant survey was developed to understand what coastal and resource professionals and elected officials think about climate change, where their communities stand in planning for climate adaptation and what kinds of information they need, said project leader Joe Cone, assistant director of Oregon Sea Grant.

Sea Grant programs in Connecticut, Hawaii, Illinois-Indiana, Louisiana, Maryland, Minnesota, Oregon, and Washington – states that represent most of NOAA's coastal regions – took part, administering the survey between January 2012 and November 2013.

Among 30 questions, survey participants were asked how informed they felt about climate change in their area and whether they thought that the climate in their area is changing.  Participants identified where their agencies and communities stood in planning to adapt to climate change, and hurdles they have encountered and overcome. They also identified climate-related topics important to their work and how much information they had about those topics.

Overall, three-quarters of the 355 coastal/resource professionals who responded felt that the climate in their area is changing.  Most (68 percent) felt that they were moderately- to very well-informed about the local effects of climate change. A common hurdle respondents encountered was a lack of agreement over the importance of those effects. Shoreline change and flooding concerns were among the topics respondents considered important to their own work.

A newly published report by Oregon Sea Grant  presents the combined results for all survey respondents, as well as the responses from each participating state.  

Cone said this national survey, funded in part by Sea Grant's national focus team on hazard resilient coastal communities, represents an initial attempt to understand the opinions and information needs of coastal/resource professionals regarding climate change adaptation and planning.  Participating Sea Grant programs are already using the survey results to assist communities develop local adaptation strategies. In addition, Cone said he hoped that this survey may stimulate additional survey research by Sea Grant, NOAA, and other coastal interests on this vital topic.

The survey report is available as a free download from Oregon Sea Grant at: http://seagrant.oregonstate.edu/sgpubs/s14001-national-climate-survey-report

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Noted oceanographer to speak Nov. 12 at Hatfield

NEWPORT, Ore. – Don Walsh, a pioneering oceanographer famous for his 1960 dive to the deepest part of the ocean, will visit Newport on Tuesday, Nov. 12.

Walsh will give a free public lecture at Oregon State University’s Hatfield Marine Science Center. His presentation, “Lunch on Board the Titanic: Two Miles Deep in the Atlantic,” begins at 6:30 p.m. In his talk, Walsh will share his experience diving in a submersible down to the Titanic and other adventures from his career of more than 40 years.

A retired captain from the U.S. Navy, Walsh went on to enjoy a lengthy career as an oceanographer and ocean engineer who explored the deep oceans and polar regions. He has commanded submarines as a naval officer and deep-sea submersibles as a researcher.

In 1960, Walsh and Swiss oceanographer Jacques Piccard boarded the bathyscaphe Trieste and descended to the floor of the Mariana Trench in the northern Pacific Ocean – a depth of more than 35,000 feet, or nearly seven miles. It took five hours to reach the seafloor, and at 30,000 feet they heard a loud crack. Upon reaching the bottom, they discovered cracks in the window, and quickly began ascending.

The historic dive received worldwide attention. It also remained a world record dive for 52 years until James Cameron piloted his Deepsea Challenger to the same place in 2012.

Walsh, who has a courtesy appointment in OSU’s College of Earth, Ocean, and Atmospheric Sciences, will also visit schools in Newport during the week and give a seminar at the Hatfield Marine Science Center. That talk, intended for a research audience, is titled “Going the Last Seven Miles – Looking Backwards at the Future.” It begins at 3:30 p.m. on Nov. 12 in the Hennings Auditorium.

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Maryann Bozza, 541-867-0234; maryann.bozza@oregonstate.edu

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Don Walsh

Hatfield Marine Science Center finds creative solution to dwindling donations

NEWPORT, Ore. – The Visitor’s Center at Oregon State University’s Hatfield Marine Science Center was facing a serious problem. Donations were dropping, and staff members were trying to figure out why.

Then they hit on a realization. The donation box accepted cash, but very few people carry cash any more. The simple solution was to install a kiosk in the lobby that accepted donations via debit and credit cards.

But that’s when things got complicated. Because of security issues, as a governmental entity, the center wasn’t allowed to operate a wireless payment kiosk. The same issue prevented state workers such as Extension agents from using wireless card swipers when selling items at county fairs.

It all comes down to something called PCI (payment card industry) compliance. These national standards ensure the safety of debit and credit transactions, but to be in legal compliance as a state or governmental agency can be tricky. So Oregon Sea Grant’s Mark Farley, who works at the Hatfield Center, reached out to OSU’s Dee Wendler with the University Administration Business Center on campus, to find out how they could work with the State of Oregon to make compliance possible.

Wendler did some research, and was able to identify a company offering web-based PCI compliant payment services that was already under contract with the State of Oregon. However, recent changes to Oregon laws prevented OSU from utilizing the State’s contract, and prevented the Department of Justice from providing public universities advice or a review of the legal details surrounding the installation of an unmanned kiosk.

That’s when Wallace Rogers, State of Oregon manager of e-Government and Voice Services, stepped in. “It took some thinking outside the box,” Rogers said.

Rogers’ office contracts with an e-Government company, NIC-USA, to provide $1.8 billion in state e-commerce each year, and by contracting with them, Hatfield was able to be PCI compliant without taking on additional risk. Rogers’ office was able to contract with the Department of Justice to do a legal sufficiency review of the proposed Hatfield project.

Working with NIC not only allows Hatfield to install a cellular, wireless, unmanned kiosk (which should be installed by January) but may also open up the opportunity for OSU Extension agents and others who have items for sale to do so at a variety of locations outside of their offices.

“To have the ability to use a card swipe service will increase the efficiency of OSU employees, and increase their ability to do outreach,” Wendler said.

OSU’s Farley is grateful that so many entities came together to help solve what ended up being a rather complicated problem.

“Both the Justice Department and the Treasury Department went out of their way to help us negotiate the process,” Farley said.

Wendler believes if the kiosk is successful, it could be a model for other Oregon universities and state agencies.

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Mark Farley541-867-0276

Dee Wendler, 541-737-4128

Ocean sound: The Oregon Coast rules when it comes to ambient noise

NEWPORT, Ore. – For more than a year, scientists at Oregon State University’s Hatfield Marine Science Center deployed a hydrophone in 50 meters of water just off the coast of Newport, Ore., so they could listen to the natural and human-induced sounds emanating from the Pacific Ocean environment.

Their recently published analysis has a simple conclusion: It’s really noisy out there.

There are ships, including container shipping traffic, commercial fishers and recreationalists. There are environmental sounds, from waves pounding the beach, to sounds generating by heavy winds. And there are biological sounds, especially the vocalizations of blue whales and fin whales. And not only is Oregon’s ocean sound budget varied, it is quite robust.

“We recorded noise generated from local vessels during 66 percent of all hours during the course of a year,” said Joe Haxel, an OSU doctoral student who is affiliated with both the Cooperative Institute for Marine Resources Studies (CIMRS) and NOAA’s Pacific Marine Environmental Laboratory acoustics program at the Hatfield center. “In fact, there is an acoustic spike during the opening of the commercial crabbing season related to the high number of boats working the shallow coastal waters at the same time.

“But, at times, the biggest contributor to the low-frequency sound budget is from the surf breaking on the beach a few kilometers away,” he added. “That’s where Oregon trumps most other places. There haven’t been a lot of studies targeting surf-generated sound and its effect on ambient noise levels in the coastal ocean, but the few that are out there show a lot less noise than we have. Our waves are off the charts.”

The year-long study of noise, which was published in the Journal of the Acoustical Society of America, was supported by the Department of Energy, the Oregon Wave Energy Trust, NOAA and OSU.

The study is about more than scientific curiosity, researchers say. The research was carried out in support of OSU’s Northwest National Marine Renewable Energy Center and will play an important role in determining whether testing of wave energy devices off the Oregon coast may have environmental impacts.

Scientists must know what naturally occurring sounds exist, and at what levels, so when new sounds are introduced, there is some context for evaluating their intensity and impact.

Documenting marine noises for an entire year isn’t easy, the researchers pointed out. First, the equipment must withstand the rugged Pacific Ocean, so the OSU researchers deployed the hydrophone near the seafloor in about 50 meters of water so violent winter storms wouldn’t destroy the instrumentation. They focused on low-frequency sounds, where the majority of noise emitted by wave energy converters is expected to occur.

After combing through an entire year of data, they determined that Oregon’s low-frequency noise budget is often dominated by the constant sounds of breaking surf. These weren’t necessarily the loudest noises, though.

“The strongest signal we got during the course of the year came from a boat that drove right over our mooring,” said Haxel, who is pursuing his doctorate through OSU’s College of Earth, Ocean, and Atmospheric Sciences. “The second loudest sound came from the vocalizations of a blue whale, which can be incredibly loud. We were told by colleagues at the Marine Mammal Institute that blue whales have been sighted close to shore in recent years and it was probably within several kilometers of the hydrophone.”

Haxel said the OSU researchers also recorded numerous vocalizations of fin whales and humpback whales, but a startling omission was that of gray whales, one of the most common West Coast whales.

“We didn’t document a single gray whale sound during the entire year, which was really surprising,” Haxel said. “Even during times when gray whales were visually sighted from shore within close proximity of the hydrophone, we never recorded any vocalizations. One theory is that they are trying to keep as quiet as possible so they don’t give away their location to orcas, which target their calves.”

Another unusual source of noise was the wind. Even at 50 meters below the surface, the hydrophone picked up sound from the wind – but not in the way one might think. It wasn’t the howling of the wind that was noticeable, Haxel said, but the ensuing waves, known as “whitecaps” or “wind chop,” and the clouds of bubbles that were injected into the water column.

Haxel compared his data on Oregon sounds to a handful of studies in the literature associated with high-energy environmental conditions to see how the region fared. All of the other studies were limited: a Monterey Bay, Calif., survey focused only on surf noises. A study off the Florida coast examined wind-generated sounds. And a study of the Scotia Shelf in Canada looked at wind and surf.

Oregon noise levels were similar to other regions for frequencies above 100 Hz, Haxel said, but rose sharply for frequencies affected by surf-generated noise – generally below 100 Hz.

“The bottom line is that the Pacific Ocean in the Northwest can be a remarkably loud environment and our wave climate in particular is amazing,” Haxel said. “That’s why wave energy is being targeted for this region in the first place. The study will provide some valuable information as the wave energy industry goes forward.

“We will be able to measure noise levels from the testing, or even the loading and unloading of equipment from the vessels, and compare those measurements with the range of background ambient sound levels already occurring in the area,” he added.

“It is a balancing act as some noise from the testing sites may serve as a warning signal for whales and other animals to avoid the area, helping to reduce the risk for collision or entanglement,” Haxel said. “But adding too much noise can be harmful, disrupting their communication or navigation.”

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Joe Haxel, 541-867-0282; joe.haxel@oregonstate.edu

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Tail of the whale
Blue whale vocalizations
are second loudest


 Coastal waves
Breaking surf tops
the charts for noise

 

Sound file of breaking surf:

http://oregonstate.edu/dept/ncs/media/wave-breaking.wav

 

Sound file of boat motors:

http://oregonstate.edu/dept/ncs/media/boat-noise.wav

Bald eagles increasing impact on murre colony at Yaquina Head

NEWPORT, Ore. – The recovery of bald eagle populations in Oregon is an environmental success story that has resulted in a resurgence of this iconic symbol in the state, which is good news – unless you happen to be a common murre living at the coast.

Scientists at Oregon State University who are studying the seabird have documented how the increase of bald eagles – especially along the central Oregon coast – is having a significant impact on the murre’s reproductive success. It is developing into a fascinating ecological tale of which the ending has not yet played out.

What has happened, the researchers say, is that bald eagles have taken up a seasonal residence near Yaquina Head and forage on the murres, which have a major nesting colony there. The predation of an occasional adult murre isn’t the issue, the researchers point out – it is the encroachment of “secondary predators” that is having a negative impact on the murres’ reproductive success.

“An adult eagle that swoops down and grabs an adult murre may disrupt the colony for a minute or two, but things get back to normal rather quickly,” said Robert Suryan, an OSU seabird expert at the university’s Hatfield Marine Science Center. “The problem arises when the eagles – especially juveniles that are not yet accomplished hunters – land on the colony and send the adult murres scurrying.

“That opens the door for brown pelicans and gulls to come in and grab the eggs, or even the murre chicks, and the results are pretty devastating,” Suryan added. “They literally will destroy hundreds of eggs in just a few minutes.”

The OSU-led project is supported by the Bureau of Land Management, the Yaquina Head Outstanding Natural Area and the U.S. Fish and Wildlife Service.

Suryan and his colleagues conducted studies of the Yaquina Head colony in 2007-10 and documented reproductive success of 55 to 80 percent – even with some eagle disturbance. By 2011, however, when more eagles began hunting at this colony, that success dropped to 20 percent. And it has gotten worse since after brown pelicans arrived last year.

Cheryl Horton, an OSU graduate student working with Suryan on the project, said the eagles affect the colony in other ways as well.

“When juvenile pelicans or eagles land on the rocks, all of the birds scatter,” said Horton, a master’s candidate in fisheries and wildlife. “We documented some 300 murre chicks that washed up dead on the beach last summer after a single pelican disturbance. They no doubt panicked and slipped off the rock and weren’t yet able to swim.”

Horton said in past years, one or two bald eagles would perch in the trees above Yaquina Head and swoop down to prey on the murres. This year, the number has grown to as many as a dozen – many of them juveniles.

The eagles’ appearance is a reflection of protective measures adopted more than three decades ago, Horton said. In 1978, researchers documented 101 bald eagle breeding sites in Oregon; in 2007, that number had climbed to 662 sites.

Suryan said the eagles’ predation hasn’t had an apparent impact on the overall population of murres at the colony, but if the reproductive failures of the past couple of years continue, that will change.

“During the past 2-3 years, we are not only seeing more eagles, but the disturbances are lasting longer – into July – and more juveniles are hanging out at the colony,” Suryan said. “The implications really are quite interesting. Is the predation of the eagles on murres a learned behavior, or are they missing another food source?

“In Alaska, eagles feast on dead salmon on the streambanks, but when salmon numbers are low, they head over to the coast and decimate seabird colonies,” added Suryan, an associate professor of fisheries and wildlife at OSU. “What we’re seeing at Yaquina Head could just be a natural rebalancing of predators and prey as eagles recover, or it might be that the eagles are recovering into a system that is different than the one they previously occupied.”

As Yaquina Head is turning into an outdoor laboratory for this evolving ecological puzzle, the researchers are learning more than they ever imagined, Horton said.

“We captured video of a pelican grabbing a murre chick and shaking it until it regurgitated a fish that its parents had fed it,” Horton said. “Then the pelican dropped the chick and gobbled down the fish. Why were juvenile pelicans doing this? It seems like such a desperate way of finding food.”

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Bald eagle and murres

Bald eagle intrusion

Brown_pelican_disturb

"Secondary" predators

common murre chick carcasses

Young murres drown

Researchers use circulation models, genetics to track “lost years” of turtles

CORVALLIS, Ore. – When green turtles toddle out to the ocean after hatching from eggs at sandy beaches they more or less disappear from view and aren’t seen again for several years until they show up as juveniles at coastal foraging areas.

Researchers have long puzzled over what happens to the turtles during these “lost years,” as they were dubbed decades ago. Now a new study published in the Proceedings of the Royal Society outlines where they likely would be based on ocean currents.

It is the first quantitative estimate of juvenile turtle distribution across an entire ocean basin and experts say it is significant because it gives researchers in North America, South America, Europe and Africa an idea of where hatchlings that emerge on beaches will go next, and where the juveniles foraging along the coastlines most likely came from.

“Hatchling sea turtles are too small for transmitters and electronic tags, and their mortality rate is sufficiently high to make it cost-prohibitive anyway,” said Nathan F. Putman, a post-doctoral researcher at Oregon State University and lead author on the study. “Even if you could develop a perfect sensor, you would need tens of thousands of them because baby turtles get gobbled up at such a fast rate. So we decided to look at an indirect approach.”

Putman and his colleague, Eugenia Naro-Maciel of City University of New York, used sophisticated ocean circulation models to trace the likely route of baby green turtles from known nesting sites once they entered the water. They also identified known locations of foraging sites where the turtles reappeared as juveniles, and went backwards – tracing where they most likely arrived via currents.

“This is not a definitive survey of where turtles go – it is more a simplification of reality – but it is a starting point and a big and comprehensive starting point at that,” Putman pointed out. “Turtles have flippers and can swim, so they aren’t necessarily beholden to the currents. But what this study provides is an indication of the oceanic environment that young turtles encounter, and how this environment likely influences turtle distributions.

“When we compared the predictions of population connectivity from our ocean current model and estimates from a genetic model, we found that they correlate pretty well,” said Putman, a researcher in OSU’s Department of Fisheries and Wildlife. “Each approach, individually, has limitations but when you put them together the degree of uncertainty is substantially reduced.”

The researchers simulated the dispersal of turtles from each of 29 separate locations in the Atlantic and West Indian Ocean and identified “hot spots” throughout these basins where computer models suggest that virtual turtles would be densely aggregated. This includes portions of the southern Caribbean, the Sargasso Sea, and portions of the South Atlantic Ocean and the West Indian Ocean.

In contrast, they estimate that the fewest number of turtles would be located in the open ocean along the equator between South America and central Africa.

Based on the models, it appears that turtles from many populations would circumnavigate the Atlantic Ocean basin. “Backtracking” simulations revealed that numerous foraging grounds were predicted to have turtles arrive from the North Atlantic, South Atlantic and Southwest Indian oceans. Thus, a high degree of connectivity among populations appears likely based on circulation patterns at the ocean surface.

Putman said the next step in the research might be for turtle biologists throughout the Atlantic Ocean basin to “ground truth” the model by looking for young turtles in those hotspots. Knowing more about their early life history and migration routes could help in managing the population, he said.

“Perhaps the best part about this modeling is that it is a testable hypothesis,” Putman said. “People studying turtles throughout the Atlantic basin will have predictions of turtle distributions based on solid oceanographic data to help interpret what they are observing.

“Finding these little turtles is like looking for the proverbial needle in the haystack,” Putman added. “But at least we’ve helped researchers understand where that haystack most likely would be located.”

Putman also has a study coming out in Biology Letters using similar methodology to predict ocean distribution patterns for the Kemp’s ridley sea turtle.

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Nathan Putman, 205-218-5276; Nathan.putman@oregonstate.edu

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Green-Turtle_Projeto_Tamar_1
Hatchling green turtle

 

Florida_forwardtrack
Distribution of turtles
from Florida