OREGON STATE UNIVERSITY

marine science and the coast

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.”

Media Contact: 
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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

Study explains Pacific equatorial cold water region

CORVALLIS, Ore. – A new study published this week in the journal Nature reveals for the first time how the mixing of cold, deep waters from below can change sea surface temperatures on seasonal and longer timescales.

Because this occurs in a huge region of the ocean that takes up heat from the atmosphere, these changes can influence global climate patterns, particularly global warming.

Using a new measurement of mixing, Jim Moum and Jonathan Nash of the College of Earth, Ocean, and Atmospheric Sciences at Oregon State University have obtained the first multi-year records of mixing that permit assessment of seasonal changes. This is a significant advance beyond traditional shipboard measurements that are limited to the time that a ship can be away from port. Small instruments fueled by lithium batteries were built to be easily deployed on deep-sea equatorial moorings.

Moum employs a simple demonstration to show how mixing works.

He pours cold, white cream into a clear glass mug full of hot, black coffee, very carefully, using a straw to inject the heavier cream at the bottom of the mug, where it remains.

“Now we can wait until the cream diffuses into the coffee, and we’ll have a nice cuppa joe,” Moum says. “Unfortunately, the coffee will be cold by then. Or, we can introduce some external energy into the system, and mix it.”

A stirring spoon reveals motions in the mug outlined by the black/white contrasts of cream in coffee until the contrast completely disappears, and the color achieves that of café au lait.

“Mixing is obviously important in our normal lives, from the kitchen to the dispersal of pollutants in the atmosphere, reducing them to levels that are barely tolerable,” he said.

The new study shows how mixing, at the same small scales that appear in your morning coffee, is critical to the ocean. It outlines the processes that create the equatorial Pacific cold tongue, a broad expanse of ocean near the equator that is roughly the size of the continental United States, with sea surface temperatures substantially cooler than surrounding areas.

Because this is a huge expanse that takes up heat from the atmosphere, understanding how it does so is critical to seasonal weather patterns, El Nino, and to global climate change.

In temperate latitudes, the atmosphere heats the ocean in summer and cools it in winter. This causes a clear seasonal cycle in sea surface temperature, at least in the middle of the ocean. At low latitudes near the equator, the atmosphere heats the sea surface throughout the year. Yet a strong seasonal cycle in sea surface temperature is present here, as well. This has puzzled oceanographers for decades who have suspected mixing may be the cause but have not been able to prove this.

Moum, Nash and their colleagues began their effort in 2005 to document mixing at various depths on an annual basis, which previously had been a near-impossible task.

“This is a very important area scientifically, but it’s also quite remote,” Moum said. “From a ship it’s impossible to get the kinds of record lengths needed to resolve seasonal cycles, let alone processes with longer-term cycles like El Nino and La Nina. But for the first time in 2005, we were able to deploy instrumentation to measure mixing on a NOAA mooring and monitor the processes on a year-round basis.”

The researchers found clear evidence that mixing alone cools the sea surface in the cold tongue, and that the magnitude of mixing is influenced by equatorial currents that flow from east to west at the surface, and from west to east in deeper waters 100 meters beneath the surface.

“There is a hint – although it is too early to tell – that increased mixing may lead, or have a correlation to the development of La Niña,” Moum said. “Conversely, less mixing may be associated with El Niño. But we only have a six-year record – we’ll need 25 years or more to reach any conclusions on this question.”

Nash said the biggest uncertainty in climate change models is understanding some of the basic processes for the mixing of deep-ocean and surface waters and the impacts on sea surface temperatures. This work should make climate models more accurate in the future.

The research was funded by the National Science Foundation, and deployments have been supported by the National Oceanic and Atmospheric Administration. Continued research will add instruments at the same equatorial mooring and an additional three locations in the equatorial Pacific cold tongue to gather further data.

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Jim Moum, 541-737-2553

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Ocean buoy

Buoy at sea

New study finds “nighttime heat waves” increasing in Pacific Northwest

CORVALLIS, Ore. – A new study has found that heat waves are increasing in the western portions of the Pacific Northwest, but not the kind most people envision, with scorching hot days of temperatures reaching triple digits.

These heat waves occur at night.

Researchers documented 15 examples of “nighttime heat waves” from 1901 through 2009 and 10 of those have occurred since 1990. Five of them took place during a four-year period from 2006-09. And since the study was accepted for publication in the Journal of Applied Meteorology and Climatology, another nighttime heat wave took place at the end of this June, the authors point out.

“Most people are familiar with daytime heat waves, when the temperatures get into the 100s and stay there for a few days,” said Kathie Dello, deputy director of the Oregon Climate Service at Oregon State University and a co-author on the study. “A nighttime heat wave relates to how high the minimum temperature remains overnight.

“Daytime events are usually influenced by downslope warming over the Cascade Mountains, while nighttime heat waves seem to be triggered by humidity,” said Dello, who is in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “Elevated low-level moisture at night tends to trap the heat in.”

In their study, Dello and co-authors Karin Bumbaco and Nicholas Bond from the University of Washington defined heat waves as three consecutive days of temperatures at the warmest 1 percentile over the past century. Using that standard criterion, they documented 13 examples of daytime heat waves during the time period from 1901 to 2009. Only two of those occurred in the last 20 years.

In contrast, nighttime heat waves have been clustered over the past two decades, with what appears to be accelerating frequency. A warming climate suggests the problem may worsen, studies suggest.

“If you look at nighttime temperatures in Oregon and compared them to say the Midwest, people there would laugh at the concept of a Pacific Northwest heat wave,” Dello said. “However, people in the Midwest are acclimated to the heat while in the Northwest, they are not. People in other regions of the country may also be more likely to have air conditioning in their homes.

On occasion, daytime and nighttime heat waves coincide, Dello said, as happened in 2009 when temperatures in the Pacific Northwest set all-time records in Washington (including 103 degrees at SeaTac), and temperatures in Oregon surpassed 105 degrees in Portland, Eugene, Corvallis and Medford. It was the second most-intense daytime heat wave in the last century, but lasted only three days by the 1 percentile definition.

However, that same stretch of hot weather in 2009 results in a nighttime heat wave that extended eight days, by far the longest stretch since records were kept beginning in 1901.

The latest nighttime heat wave began in late June of this year, and continued into early July, Dello said.

“Like many nighttime heat waves, a large high-pressure ridge settled in over the Northwest, while at the same time, some monsoonal moisture was coming up from the Southwest,” she pointed out. “The high swept around and grabbed enough moisture to elevate the humidity and trap the warm air at night.”

Dello frequently provides weather facts and historical data via Twitter at: www.twitter.com/orclimatesvc.

The Oregon Climate Change Research Institute is supported by the state of Oregon, U.S. Department of the Interior, National Oceanic and Atmospheric Association, and other agencies.

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Kathie Dello, 541-737-8927

OSU student discovers floating tsunami dock on video one year later…

NEWPORT, Ore. – Oregon State University graduate student Cheryl Horton was meticulously scanning year-old video of a bird colony off Yaquina Head near Newport, Ore., last month when she noticed a strange object drifting by in the background.

Closer examination confirmed that the grainy, distant floating object captured on her research camera was the dock that washed ashore at Agate Beach in early June of 2012, some 15 months after a devastating earthquake and tsunami ripped it loose from its mooring in Misawa, Japan. In the weeks after it landed on the Oregon beach, the cement dock became a tourist attraction and drew attention from news media worldwide.

Her discovery came one year almost to the day that the dock landed on Agate Beach, bringing mystique – and potentially invasive species – to Oregon from Japan. It is the only known video of the dock during its trans-Pacific Ocean journey. It can be viewed at: http://bit.ly/112zAzb

“We’ve been behind analyzing our footage and had gone through video of common murre colonies at Cape Meares in the north and Coquille Point in the south,” said Horton, a master’s candidate in fisheries and wildlife at OSU. “But we got so busy that we didn’t get around to looking at the central coast data until this June. Then it was, ‘whoa – what is that?’”

“That” was the dock, which measured seven feet tall, was some 19 feet wide by 66 feet long, and weighed an estimated 188 tons. On camera, floating in the water, it looks much smaller – almost like a log. It takes about three minutes for the concrete dock to drift past the camera, slowly riding the current from north to south.

The discovery is more of a curiosity than anything, though OSU researchers have examined the video for clues that may tell them a bit more about the direction and speed the dock may have traveled – at least in the days before it beached.

Horton is sharing the video with others and is again focusing on her research on common murres, a species that increasingly is being preyed upon by bald eagles along the Oregon coast, as well as by “secondary” predators including gulls and pelicans.

“It was kind of fun to discover the dock video and share it with others,” she said. “Everyone has been pretty excited about it.”

A portion of the dock is on display at OSU’s Hatfield Marine Science Center in Newport, where Horton and major professor Rob Suryan are based. Horton also is mentored by Katie Dugger, another fisheries and wildlife faculty member on the OSU campus.

Horton is the second fisheries and wildlife student in recent years to make an accidental scientific discovery via camera.  In 2008, graduate student Katie Moriarty captured an image of a rare wolverine on camera in the Tahoe National Forest. It was the first sighting of a wolverine in California in nearly 75 years.

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Cheryl Horton, 845-548-2187; hortonc@onid.orst.edu

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Cheryl Horton

 

Link to Video:

http://bit.ly/112zAzb

Scientists outline long-term sea-level rise in response to warming of planet

CORVALLIS, Ore. – A new study estimates that global sea levels will rise about 2.3 meters, or more than seven feet, over the next several thousand years for every degree (Celsius) the planet warms.

This international study is one of the first to combine analyses of four major contributors to potential sea level rise into a collective estimate, and compare it with evidence of past sea-level responses to global temperature changes.

Results of the study, funded primarily by the National Science Foundation and the German Federal Ministry of Education and Research, are being published this week in the Proceedings of the National Academy of Sciences.

“The study did not seek to estimate how much the planet will warm, or how rapidly sea levels will rise,” noted Peter Clark, an Oregon State University paleoclimatologist and author on the PNAS article. “Instead, we were trying to pin down the ‘sea-level commitment’ of global warming on a multi-millennial time scale. In other words, how much would sea levels rise over long periods of time for each degree the planet warms and holds that warmth?”

“The simulations of future scenarios we ran from physical models were fairly consistent with evidence of sea-level rise from the past,” Clark added. “Some 120,000 years ago, for example, it was 1-2 degrees warmer than it is now and sea levels were about five to nine meters higher. This is consistent with what our models say may happen in the future.”

Scientists say the four major contributors to sea-level rise on a global scale will come from melting of glaciers, melting of the Greenland ice sheet, melting of the Antarctic ice sheet, and expansion of the ocean itself as it warms. Several past studies have examined each of these components, the authors say, but this is one of the first efforts at merging different analyses into a single projection.

The researchers ran hundreds of simulations through their models to calculate how the four areas would respond to warming, Clark said, and the response was mostly linear. The amount of melting and subsequent sea-level response was commensurate with the amount of warming. The exception, he said, was in Greenland, which seems to have a threshold at which the response can be amplified.

“As the ice sheet in Greenland melts over thousands of years and becomes lower, the temperature will increase because of the elevation loss,” Clark said. “For every 1,000 meters of elevation loss, it warms about six degrees (Celsius). That elevation loss would accelerate the melting of the Greenland ice sheet.”

In contrast, the Antarctic ice sheet is so cold that elevation loss won’t affect it the same way. The melting of the ice sheet there comes primarily from the calving of icebergs, which float away and melt in warmer ocean waters, or the contact between the edges of the ice sheet and seawater.

In their paper, the authors note that sea-level rise in the past century has been dominated by the expansion of the ocean and melting of glaciers. The biggest contributions in the future may come from melting of the Greenland ice sheet, which could disappear entirely, and the Antarctic ice sheet, which will likely reach some kind of equilibrium with atmospheric temperatures and shrink significantly, but not disappear.

“Keep in mind that the sea level rise projected by these models of 2.3 meters per degree of warming is over thousands of years,” emphasized Clark, who is a professor in Oregon State University’s College of Earth, Ocean, and Atmospheric Sciences. “If it warms a degree in the next two years, sea levels won’t necessarily rise immediately. The Earth has to warm and hold that increased temperature over time.

“However, carbon dioxide has a very long time scale and the amounts we’ve emitted into the atmosphere will stay up there for thousands of years,” he added. “Even if we were to reduce emissions, the sea-level commitment of global warming will be significant.”

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Peter Clark, cell phone: 541-740-5237 (clarkp@geo.oregonstate.edu)

Lionfish expedition: down deep is where the big, scary ones live

CORVALLIS, Ore. – Last month, the first expedition to use a deep-diving submersible to study the Atlantic Ocean lionfish invasion found something very disturbing – at 300 feet deep, there were still significant populations of these predatory fish, and they were big.

Big fish in many species can reproduce much more efficiently than their younger, smaller counterparts, and lionfish are known to travel considerable distances and move to various depths. This raises significant new concerns in the effort to control this invasive species that is devastating native fish populations on the Atlantic Coast and in the Caribbean Sea.

“We expected some populations of lionfish at that depth, but their numbers and size were a surprise,” said Stephanie Green, the David H. Smith Conservation Research Fellow in the College of Science at Oregon State University, who participated in the dives. OSU has been one of the early leaders in the study of the lionfish invasion.

“This was kind of an ‘Ah hah!’ moment,” she said. “It was immediately clear that this is a new frontier in the lionfish crisis, and that something is going to have to be done about it. Seeing it up-close really brought home the nature of the problem.”

OSU participated in this expedition with researchers from a number of other universities, in work supported by Nova Southeastern University, the Guy Harvey Foundation, NOAA, and other agencies. The five-person  submersible “Antipodes” was provided by OceanGate, Inc., and it dove about 300 feet deep off the coast of Ft. Lauderdale, Fla., near the “Bill Boyd” cargo ship that was intentionally sunk there in 1986 to create an artificial reef for marine life.

That ship has, in fact, attracted a great deal of marine life, and now, a great number of lionfish. And for that species, they are growing to an unusually large size – as much as 16 inches.

Lionfish are a predatory fish that’s native to the Pacific Ocean and were accidentally introduced to Atlantic Ocean waters in the early 1990s, and there became a voracious predator with no natural controls on its population. An OSU study in 2008 showed that lionfish in the Atlantic have been known to reduce native fish populations by up to 80 percent.

Eradication appears impossible, and they threaten everything from coral reef ecosystems to local economies that are based on fishing and tourism.

Whatever is keeping them in check in the Pacific – and researchers around the world are trying to find out what that is – is missing here. In the Caribbean, they are found at different depths, in various terrain, are largely ignored by other local predators and parasites, and are rapidly eating their way through entire ecosystems. They will attack many other species and appear to eat constantly.

And, unfortunately, the big fish just discovered at greater depths pose that much more of a predatory threat, not to mention appetite.

“A lionfish will eat almost any fish smaller than it is,” Green said. “Regarding the large fish we observed in the submersible dives, a real concern is that they could migrate to shallower depths as well and eat many of the fish there. And the control measures we’re using at shallower depths – catch them and let people eat them – are not as practical at great depth.”

Size does more than just increase predation.  In many fish species, a large, mature adult can produce far more offspring that small, younger fish. A large, mature female in some species can produce up to 10 times as many offspring as a fish that’s able to reproduce, but half the size.

Trapping is a possibility for removing fish at greater depth, Green said, and could be especially effective if a method were developed to selectively trap lionfish and not other species. Work on control technologies and cost effectiveness of various approaches will continue at OSU, she said.

When attacking another fish, a lionfish uses its large, fan-like fins to herd smaller fish into a corner and then swallow them in a rapid strike. Because of their natural defense mechanisms they are afraid of almost no other marine life, and will consume dozens of species of the tropical fish and invertebrates that typically congregate in coral reefs and other areas. The venom released by their sharp spines can cause extremely painful stings to humans.

Aside from the rapid and immediate mortality of marine life, the loss of herbivorous fish will also set the stage for seaweed to potentially overwhelm the coral reefs and disrupt the delicate ecological balance in which they exist.

This newest threat follows on the heels of overfishing, sediment deposition, nitrate pollution in some areas, coral bleaching caused by global warming, and increasing ocean acidity caused by carbon emissions. Lionfish may be the final straw that breaks the back of Western Atlantic and Caribbean coral reefs, some researchers believe.

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Stephanie Green, 541-737-5364

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The sounds of science – melting of iceberg creates surprising ocean din

CORVALLIS, Ore. – There is growing concern about how much noise humans generate in marine environments through shipping, oil exploration and other developments, but a new study has found that naturally occurring phenomena could potentially affect some ocean dwellers.

Nowhere is this concern greater than in the polar regions, where the effects of global warming often first manifest themselves. The breakup of ice sheets and the calving and grounding of icebergs can create enormous sound energy, scientists say. Now a new study has found that the mere drifting of an iceberg from near Antarctica to warmer ocean waters produces startling levels of noise.

Results of the study are being published this month in Oceanography.

A team led by Oregon State University researchers used an array of hydrophones to track the sound produced by an iceberg through its life cycle, from its origin in the Weddell Sea to its eventual demise in the open ocean. The goal of the project was to measure baseline levels of this kind of naturally occurring sound in the ocean, so it can be compared to anthropogenic noises.

“During one hour-long period, we documented that the sound energy released by the iceberg disintegrating was equivalent to the sound that would be created by a few hundred supertankers over the same period,” said Robert Dziak, a marine geologist at OSU’s Hatfield Marine Science Center in Newport, Ore., and lead author on the study.

“This wasn’t from the iceberg scraping the bottom,” he added. “It was from its rapid disintegration as the berg melted and broke apart. We call the sounds ‘icequakes’ because the process and ensuing sounds are much like those produced by earthquakes.”

Dziak is a scientist with the Cooperative Institute for Marine Resources Studies (CIMRS), a collaborative program between Oregon State University and NOAA based at OSU’s Hatfield center. He also is on the faculty of OSU’s College of Earth, Ocean, and Atmospheric Sciences.

When scientists first followed the iceberg, it encountered a 124-meter deep shoal, causing it to rotate and grind across the seafloor. It then began generating semi-continuous harmonic tremors for the next six days. The iceberg then entered Bransfield Strait and became fixed over a 265-meter deep shoal, where it began to pinwheel. The harmonic tremors became shorter and less pronounced.

It wasn’t until the iceberg broke loose and drifted into the warmer waters of the Scotia Sea that the real action began. Photos from the International Space Station showed visible melt ponds on the iceberg’s surface, indicating it had was in a period of rapid disintegration. Within two months, the iceberg had broken apart and scientists were no longer able to track it via satellite.

But the scientists’ hydrophone array recorded the acoustic signature of the breakup – short duration, broadband signals that were distinctly different from the harmonic tremors, and much louder.

“You wouldn’t think that a drifting iceberg would create such a large amount of sound energy without colliding into something or scraping the seafloor,” noted Dziak, who has monitored ocean sounds using hydrophones for nearly two decades.  “But think of what happens why you pour a warm drink into a glass filled with ice. The ice shatters and the cracking sounds can be really dramatic. Now extrapolate that to a giant iceberg and you can begin to understand the magnitude of the sound energy.”

“In fact, the sounds produced by ice breakup near Antarctica are often clearly recorded on hydrophones that we have near the equator,” Dziak added.

Scientists are just starting to study the impact of anthropogenic and naturally occurring sounds on marine life and are unsure about the possible impacts. Most at-risk are those animals that use sound to facilitate their life-sustaining activities, such as feeding, breeding and navigation.

“The breakup of ice and the melting of icebergs are natural events, so obviously animals have adapted to this noise over time,” Dziak said. “If the atmosphere continues to warm and the breakup of ice is magnified, this might increase the noise budget in the polar areas.

“We don’t know what impact this may have,” Dziak added, “but we are trying to establish what natural sound levels are in various parts of the world’s oceans to better understand the amount of anthropogenic noise that is being generated.”

The research is supported primarily by the NOAA Ocean Exploration and Research Program, the Department of Energy, and the Korea Polar Research Institute.

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Bob Dziak, 541-867-0175; robert.dziak@oregonstate.edu