OREGON STATE UNIVERSITY

college of earth

Study finds native Olympia oysters more resilient to ocean acidification

CORVALLIS, Ore. – Native Olympia oysters, which once thrived along the Pacific Northwest coast until over-harvesting and habitat loss all but wiped them out, have a built-in resistance to ocean acidification during a key shell-building phase after spawning, according to a newly published study.

Unlike the commercially raised Pacific oysters, Olympia oysters don’t begin making their shells until 2-3 days after fertilization and make them far more slowly, which helps protect them from corrosive water during this critical development phase, said Oregon State University’s George Waldbusser, principal investigator on the project.

Pacific oysters, on the other hand, only have a six-hour window to develop their calcium carbonate shell, and when exposed to acidified water, their energy stores become depleted. The larval oysters may get through the shell-building stage, Waldbusser said, but they often will not have enough energy to survive.

Results of the study are being published this week in the Journal of Limnology and Oceanography.

“This is a unique trait that allows native oysters to survive surprisingly high levels of acidification,” said Waldbusser, a marine ecologist in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “But they didn’t develop that trait in response to rising acidification. It has been there for some time. It does make you wonder if there may be traits in other organisms that we’re unaware of that may be beneficial.”

In their study, which was funded by the National Science Foundation, the OSU researchers measured the calcification rates of both Olympia and Pacific oysters for five days after spawning, taking measurements every three hours. Although other studies have looked at the effects of acidified water on adult oysters, this is the first time researchers have been able to pinpoint its effect on larval oysters in the shell-building stage.

What they found was a seven-fold difference in the calcification rate. Pacific oysters put all of their energy into rapidly developing a shell, but the price of that investment is huge.

Native Olympia oysters developed their shells much more slowly, but seemingly at a lower cost.

“Pacific oysters churn out tens of millions of eggs, and those eggs are much smaller than those of native oysters even though they eventually become much larger as adults,” Waldbusser said. “Pacific oysters have less energy invested in each offspring. Olympia oysters have more of an initial energy investment from Mom, and can spend more time developing their shells and dealing with acidified water.”

The OSU researchers found that relative energy stores of young Pacific oysters declined by 38.6 percent an hour, and only 0.9 percent in Olympia oysters.

The study noted other interesting differences between Pacific and Olympia oysters. Native Olympia oyster larvae develop in a brood chamber, where the embryos take longer to develop. However, these brood chambers don’t necessarily protect the young oysters from acidified water, since water is continually pumped through the chamber.

To test how the oysters would do when raised like Pacific oysters – outside the chamber – the researchers conducted an experiment raising the larval Olympia oysters outside their brood chamber and exposing them to acidified water.

“Brooding was thought to provide several advantages to developing young, but we found it does not provide any physiological advantage to the larvae,” said Matthew Gray, a former doctoral student in OSU’s Department of Fisheries and Wildlife and now a post-doctoral researcher at the University of Maine. “They did just as well outside the brood chamber as inside.

“Brooding does help guard the larvae from predators and some adverse environmental changes – such as low-salinity events.”

The research highlights this robust response to ocean acidification at this critical life-history stage of Olympia oyster larvae, a period which has not previously been studied. Past studies conducted by Annaliese Hettinger, a post-doctoral researcher in Waldbusser’s lab, found that the Olympia oyster larvae are sensitive to acidification in the later swimming stage, and those effects can carry over to adult stages.

The current research may, however, have implications for the future of the commercial oyster industry, given that many of the problems seem to originate at this very early developmental stage. Cultivation of native oysters could help guard against catastrophic Pacific oyster losses due to acidification, the researchers say, or it may be possible to breed some of the Olympia oysters’ beneficial traits into Pacific oysters – either slowing the calcification rate of early larvae or producing fewer and bigger eggs.

The Olympia oyster, which is smaller than the commercially grown Pacific oyster, is prized for its distinctive flavor. Originally, Olympia oysters grew from Baja California to Vancouver Island, and are found sparingly in three Oregon bays – Yaquina, Netarts and Coos Bay. During the height of these harvests in the 1890s, some 130,000 bushels of oysters were annually shipped from the Pacific Northwest to California and within 20 years, 90 percent of these native oysters had disappeared.

Researchers speculate that the remaining Olympia oyster populations may have succumbed to increased silt generated by 20th-century logging and mill operations, which either killed them outright or covered their beds and destroyed their habitat. They have not returned in discernible numbers to Oregon estuaries.

Story By: 
Source: 

George Waldbusser, 541-737-8964

waldbuss@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

Olympia oyster cluster

Olympia oysters



Olympia oysters
Olympia oysters
from Yaquina Bay

“Weather@Home” offers precise new insights into climate change in the West

CORVALLIS, Ore. – Tens of thousands of “citizen scientists” have volunteered some use of their personal computer time to help researchers create one of the most detailed, high resolution simulations of weather ever done in the Western United States.

The data, obtained through a project called Weather@Home, is an important step forward for scientifically sound, societally relevant climate science, researchers say in a an article published in the Bulletin of the American Meteorological Society. The analysis covered the years 1960-2009 and future projections of 2030-49.

“When you have 30,000 modern laptop computers at work, you can transcend even what a supercomputer can do,” said Philip Mote, professor and director of the Oregon Climate Change Research Institute at Oregon State University, and lead author on the study.

“With this analysis we have 140,000 one-year simulations that show all of the impacts that mountains, valleys, coasts and other aspects of terrain can have on local weather,” he said. “We can drill into local areas, ask more specific questions about management implications, and understand the physical and biological climate changes in the West in a way never before possible.”

The sheer number of simulations tends to improve accuracy and reduce the uncertainty associated with this type of computer analysis, experts say. The high resolution also makes it possible to better consider the multiple climate forces at work in the West – coastal breezes, fog, cold air in valleys, sunlight being reflected off snow – and vegetation that ranges from wet, coastal rain forests to ice-covered mountains and arid scrublands within a comparatively short distance.

Although more accurate than previous simulations, improvements are still necessary, researchers say. Weather@Home tends to be too cool in a few mountain ranges and too warm in some arid plains, such as the Snake River plain and Columbia plateau, especially in summer. While other models have similar errors, Weather@Home offers the unique capability to improve simulations by improving the physics in the model.

Ultimately, this approach will help improve future predictions of regional climate. The social awareness of these issues has “matured to the point that numerous public agencies, businesses and investors are asking detailed questions about the future impacts of climate change,” the researchers wrote in their report.

This has led to a skyrocketing demand for detailed answers to specific questions – what’s the risk of a flood in a particular area, what will be future wind speeds as wind farms are developed, how should roads and bridges be built to handle extremely intense rainfall?  There will be questions about heat stress on humans, the frequency of droughts, future sea levels and the height of local storm surges.

This type of analysis, and more like it, will help answer some of those questions, researchers say.

New participants in this ongoing research are always welcome, officials said. If interested in participating, anyone can go online to “climateprediction.net” and click on “join.” They should then follow the instructions to download and install BOINC, a program that manages the tasks; create an account; and select a project. Participation in climateprediction.net is available, as well as many others.

The work has been supported by Microsoft Corp., the U.S. Bureau of Land Management, the California Energy Commission, the U.S. Geological Survey and the USDA.

Collaborators on the report were from OSU, Oxford University in the United Kingdom, and the Met Office Hadley Centre in the United Kingdom.

Story By: 
Source: 

Phil Mote, 541-913-2274

pmote@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

Elevation map
Elevation map

PNAS Study: Eddies enhance survival of coral reef fish in sub-tropical waters

NEWPORT, Ore. – Swirling eddies in the ocean have long been thought to be beneficial to organisms such as larval fishes residing within them because of enhanced phytoplankton production. However, direct evidence for this hypothesis has been hard to come by.

A new study published this week in Proceedings of the National Academy of Sciences (PNAS), which sequentially sampled tropical fish from their larval stages to their settlement in reefs, confirms the critical role of these oceanographic features.

Researchers found that young fish reared in nutrient-rich eddies in the Straits of Florida grew faster and had a survival advantage compared to their counterparts outside eddies, and were more likely to populate nearby reefs because of their more robust upbringing.

“Eddies upwell nutrients and provide a high-productivity environment that gives larval fishes growing there a head start on survival,” said Su Sponaugle, a marine biologist and principal investigator on the study who is affiliated with both Oregon State University and the University of Miami. “In cooler springtime waters, when larval fish are growing more slowly, the difference between fish raised inside or outside of eddies is small.

“But by August, when warm waters elevate fish growth rates, food becomes scarce and larval fishes residing inside eddies are more likely to survive.”

The study is important because it provides resource managers and fish population modelers with valuable new data, said Robert Cowen, director of Oregon State University’s Hatfield Marine Science Center, and a co-author on the PNAS paper.

“If there are areas where eddies predictably occur, these could be considered pelagic nursery areas that would warrant higher levels of protection from human interference,” Cowen said. “Further, the role of theses eddies should be incorporated into modeling efforts, which inform decision-makers. The influence of eddies may become even more important with warming oceans.”

In their study, the researchers collected larval fishes both inside and outside of eddies, focusing on three species – bluehead wrasse (Thalassoma bifasciatum), bluelip parrotfish (Cryptotomus roseus) and bicolor damselfish (Stegastes partitus). They determined the daily growth rates of the fish through examination of their otoliths, or ear stones, and found that those raised within the eddies had substantially higher growth rates than fish captured outside the eddies.

A few weeks later, they sampled young juveniles that had settled to nearby reefs and again using otoliths to chart daily growth rates of the fish were able to determine that almost all of those that survived to the juvenile stage had growth patterns similar to larvae from eddies.

Fish raised inside of eddies have different growth signatures in their otoliths than those raised outside eddies, explained Kathryn Shulzitski, lead author and assistant scientist at the University of Miami. “This is the first time we have been able to sample fish throughout their larval upbringing offshore to their life as juveniles on the reef and see which fish had a survival advantage.

“It was overwhelmingly slanted toward eddy-raised fish.”

The researchers theorize that larval fish residing outside of eddies either starve to death or become sufficiently weak that they are more susceptible to predators.

“Although we were focusing on three species of smaller reef fish, it is likely that the importance of eddies for larger species – including those sought by people for food – are the same,” Cowen said. “Likewise, this probably is not unique to the Florida Straits. Eddies are ubiquitous in waters around the globe and their role in mixing and stirring up nutrients is critical.”

Other authors on the PNAS study include Martha Hauff and Kristen Walter of the University of Miami. Hauff also is affiliated with Stonehill College in Massachusetts.

Story By: 
Source: 

Su Sponaugle, 541-867-0314, su.sponaugle@oregonstate.edu;

Bob Cowen, 541-867-0211, robert.cowen@oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

 

 

 

 

(Left) Photo of a bluehead wrasse: https://flic.kr/p/HJ4t5G

Hydrothermal vents, methane seeps play enormous role in marine life, global climate

CORVALLIS, Ore. – The hydrothermal vents and methane seeps on the ocean floor that were once thought to be geologic and biological oddities are now emerging as a major force in ocean ecosystems, marine life and global climate.

However, even as researchers learn more about their role in sustaining a healthy Earth, these habitats are being threatened by a wide range of human activities, including deep-sea mining, bottom trawling and energy harvesting, scientists say in a report published in Frontiers in Marine Science.

Researchers from Oregon State University first discovered these strange, isolated worlds on the ocean bottom 40 years ago. These habitats surprised the scientific world with reports of hot oozing gases, sulfide chimneys, bizarre tube worms and giant crabs and mussels – life forms that were later found to eat methane and toxic sulfide.

“It was immediately apparent that these hydrothermal vents were incredibly cool,” said Andrew Thurber, an assistant professor in the OSU College of Earth, Ocean and Atmospheric Sciences, and co-author on the new report.

“Since then we’ve learned that these vents and seeps are much more than just some weird fauna, unique biology and strange little ecosystems. Rather than being an anomaly, they are prevalent around the world, both in the deep ocean and shallower areas. They provide an estimated 13 percent of the energy entering the deep sea, make a wide range of marine life possible, and are major players in global climate.”

As fountains of marine life, the vents pour out gases and minerals, including sulfide, methane, hydrogen and iron – one of the limiting nutrients in the growth of plankton in large areas of the ocean. In an even more important role, the life forms in these vents and seeps consume 90 percent of the released methane and keep it from entering the atmosphere, where as a greenhouse gas it’s 25 times more potent than carbon dioxide.

“We had no idea at first how important this ecological process was to global climate,” Thurber said. “Through methane consumption, these life forms are literally saving the planet. There is more methane on the ocean floor than there are other forms of fossil fuels left in the oceans, and if it were all released it would be a doomsday climatic event.”

In reviewing the status of these marine geological structures and the life that lives around them, a group of researchers from 14 international universities and organizations have outlined what’s been learned in the past four decades and what forces threaten these ecosystems today. The synthesis was supported by the J.M. Kaplan fund.

These vents and seeps, and the marine life that lives there, create rocks and habitat, which in some settings can last tens of thousands of years. They release heat and energy, and form biological hot spots of diversity. They host extensive mussel and clam beds, mounds of shrimp and crab, create some prime fishing habitat and literally fertilize the ocean as zooplankton biomass and abundance increases. While the fluid flows from only a small section of the seafloor, the impact on the ocean is global.

Some of the microorganisms found at these sites are being explored for their potential to help degrade oil spills, or act as a biocatalytic agent for industrial scrubbing of carbon dioxide.

These systems, however, have already been damaged by human exploitation, and others are being targeted, the scientists said. Efforts are beginning to mine them for copper, zinc, lead, gold and silver. Bottom trawling is a special concern, causing physical disturbance that could interfere with seeps, affect habitat and damage other biologic linkages.

Oil, gas or hydrate exploitation may damage seeps. Whaling and logging may interfere with organic matter falling to the ocean floor, which serves as habitat or stepping stones for species reliant on chemosynthetic energy sources. Waste disposal of munitions, sewage and debris may affect seeps.

The range of ecosystem services these vents and seeps provide is just barely beginning to be understood, researchers said in their report. As many of these habitats fall outside of territorial waters, vent and seep conservation will require international collaboration and cooperation if they are going to continue to provide ecosystem benefits.

Contributors to this report included researchers from the Scripps Institution of Oceanography, Florida State University, the National Institute of Water and Atmospheric Research in New Zealand, University of the Azores, Temple University, Universidade de Aveiro, the U.S. Geological Survey, University of the West Indies, Dalhousie University, University of Victoria, Duke University, Ghent University and the University of Hawaii at Manoa.

-30-

Editor’s note: Downloadable high resolution video; online “view only” video; live streamed video; and still photos are all available to illustrate this story. Please credit "Courtesy of D. Kelley, University of Washington, NSF/Ocean Observatories Initiative/Canadian Scientific Submersible Facility."

  • Video: Downloadable hydrothermal vents b-roll (Length 1:50)

https://drive.google.com/folderview?id=0B_nEpHVYyPtpM2F4bWxiY1dXeEU&usp=sharing

  • Video: Online view only hydrothermal vents b-roll (Length 1:50)

http://www.interactiveoceans.washington.edu/file/Inferno_Vent_at_Axial

  • Video: Live HD imagery streamed to shore 8 times/day. Every 3 hours, day and night, on this site you can watch live streaming video from about a mile below the oceans' surface, on the top of a submarine volcano known as Axial Seamount. Axial is located nearly 400 kilometers (~250 miles) due west of Astoria, Oregon on a mid-ocean ridge spreading center called the Juan de Fuca Ridge.  http://novae.ocean.washington.edu/story/Ashes_CAMHD_Live 
Story By: 
Source: 

Andrew Thurber, 541-737-4500

athurber@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

Tube worms
Tube worms

Study finds limit on evaporation to ice sheets, but that may change

CORVALLIS, Ore. – Although the coastal regions of the Greenland Ice Sheet are experiencing rapid melting, a significant portion of the interior of that ice sheet has remained stable – but a new study suggests that stability may not continue.

Researchers found that very little of the snow and ice on the vast interior of the ice sheet is lost to the atmosphere through evaporation because of a strong thermal “lid” that essentially traps the moisture and returns it to the surface where it refreezes.

However, there are signs that this lid is becoming leaky as global temperatures increase. The researchers say there may be a threshold at which warming becomes sufficient to turn on a switch that will destabilize the snow surface.

Results of the study, which was funded by the National Science Foundation, are being published in Science Advances. New measurements from a research tower atop the Greenland ice sheet helped uncovered the mystery of how much snow piles up on this ice sheet.

“Normally, the air temperature goes down as you climb, but near the surface in Greenland, it gets warmer,” said David Noone, an Oregon State University professor who is an atmospheric scientist and principal investigator on the study. “The surface is very cold, but it can be as much as 20 degrees warmer just 30 to 40 feet up in the air. It’s enough that you can feel the difference between your nose and your toes.”

“The temperature difference effectively forms a lid so that there is hardly any evaporation. Warm air likes to rise, but if it is already warmer up above the air is trapped nearer the ground. One consequence is that layers of fog form from water that had recently evaporated. Eventually the small fog water-drops drift back down to the very cold surface where it refreezes onto the ice sheet.”

“It’s a handy little trick of nature.”

Max Berkelhammer, a researcher at the University of Illinois and lead author on the study, said scientists have been aware of “accumulation zones” in high-altitude areas of the ice sheet, but they haven’t been comprehensively measured because of the difficulty in analyzing evaporation and condensation over time.

“Instruments capable of doing this are pretty new and while they have been used before on the ice sheet, they have never been able to run during an entire winter,” said Berkelhammer, who did his post-doctoral work with Noone when both were at the University of Colorado. “I think at this point we are still the only group who has been able to run this type of instrument for an entire year on top of an ice sheet.”

The research aims to better understand how ice cores capture information about past temperatures in Greenland. The snow and ice on Greenland’s interior originated from ocean water far to the south and is transported northward by weather systems and storms, and finally falls as snow on the pristine ice sheet.

The researchers are able to track the origins and fate of the water by the ratio of oxygen and hydrogen isotopes in the water.

Variations in the isotope ratios in layers of snow piled up on the ice sheet provide the team a history of Green climate that helps put recent warming into historical context, the researchers say.

To understand past climate, scientists must know how much precipitation fell and how much evaporated. Without the team’s analysis, what fraction of falling snow accumulates and what fraction evaporates was difficult to determine. When they began to explore evaporation rates, they discovered this unique thermal lid, which effectively “recycles” water back onto the Greenland Ice Sheet.

This finding will allow previous estimates of Greenland’s past water balance to be re-evaluated.

“When thinking about climate change, one often thinks about rising global temperatures,” Noone said. “However in Greenland, as like here in Oregon, climate change is also a story of the changing water cycle and how we lose water because evaporation rates are increasing.

“Climate models suggest that as temperatures increase, more precipitation may actually fall in Greenland because warmer air can hold more water. Taken by itself, that could indicate that parts of the ice sheet may grow. However, if the lid becomes increasingly leaky, the evaporation process has become more effective and moisture will escape to the atmosphere.

“The fate of the ice sheet is in the balance,” Noone said. “It becomes a question of which influence is stronger.”

Story By: 
Source: 

David Noone, 541-737-3629, dcn@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

 

This photo of fogbows can be downloaded at: https://flic.kr/p/FM1utW

 

 

 

IMG_3025

Summit Station in Greenland

 

David_Noone_Summit2012_IMG_1170

David Noone, OSU, in a snow pit.

 

IMG_2578

Max Berkelhammer measures ice crystals

OSU to issue RFI on ship project after design completion

CORVALLIS, Ore. – The design phase for a project to construct a new regional class research vessel to replenish the United States academic fleet is complete and Oregon State University will issue a request for information (RFI) on Monday, May 2, to shipyards that may be interested in the vessel construction phase.

In January 2013, the National Science Foundation selected Oregon State as the lead institution to finalize the design and coordinate the construction of the vessel – and possibly up to two more – a project considered crucial to maintaining the country’s marine science research capabilities.

The design phase has been completed by The Glosten Associates, a naval architecture firm based in Seattle, and the RFI is a chance to generate market interest and to get feedback from industry on the design and other project documents. OSU plans to issue a Request for Proposals (RFP) in two phases beginning this summer – a technical phase to establish a competitive pool of qualified shipyards and a cost phase to elicit vessel cost proposals.

“The Request for Information issued on May 2 is a chance for us to make final tweaks in the preliminary design and to open up a dialogue with industry about the project,” said Demian Bailey, Oregon State University’s former marine superintendent and a co-leader on the project. “Once we issue the RFP this summer, it will become more difficult to alter the design or other project documents.”

Although similar in size, the new ship will differ greatly from the R/V Oceanus, built in 1975 and operated by OSU, and its sister ships, Endeavor, operated by the University of Rhode Island, and Wecoma (retired), according to Clare Reimers, a professor in the College of Earth, Ocean, and Atmospheric Sciences and project co-leader.

“This class of ships will enable researchers to work much more efficiently at sea because of better handling and stability, more capacity for instrumentation and less noise,” Reimers said. “The design also has numerous ‘green’ features, including an optimized hull form, waste heat recovery, LED lighting, and variable speed power generation.”

These “regional class research vessels” are designed for studying coastal waters out to beyond the continental rise as part of the U.S. academic fleet that is available to all ocean scientists conducting federal and state-funded research and educational programs.

Among the design features:

  • Each regional class research vessel will be 193 feet, with a range of 7,064 nautical miles;
  • Cruising speed is 11 knots with a maximum speed of 13 knots;
  • There are 16 berths for scientists and 13 for crew members;
  • The ships can stay out at sea for 21 days before coming back to port.

The 2017 President’s budget calls for building two RCRVs, but until a final budget is passed by Congress the plan is to make ready a shipyard contract to build one RCRV with options for additional vessels.

After reviewing the proposals from industry, OSU will select a shipyard in early 2017. The NSF will assume ownership of the regional class research vessels, but Oregon State expects to operate the first vessel constructed, which will conduct science missions primarily in the eastern North Pacific Ocean basin.

Additional vessels would be operated in the Atlantic and Gulf regions of the U.S. by other institutions that the NSF would select in late 2017.

“These ships will also have the ability to operate near ice and are considered ‘ice classed,’ although they are not ice-breakers,” Bailey said. The first ship will likely be delivered in 2020.

More information about the project, including renderings, is available at: http://ceoas.oregonstate.edu/ships/rcrv/

Story By: 
Source: 

Demian Bailey, 541-737-0460, dbailey@coas.oregonstate.edu;

Clare Reimers, 541-737-2426, creimers@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

This image of the ship is available at: https://flic.kr/p/FGRCR8

West Coast scientists sound alarm for changing ocean chemistry

CORVALLIS, Ore. – The ocean chemistry along the West Coast of North America is changing rapidly because of global carbon dioxide emissions, and the governments of Oregon, California, Washington and British Columbia can take actions now to offset and mitigate the effects of these changes.

That is the conclusion of a 20-member panel of leading West Coast ocean scientists, who presented a comprehensive report on Monday outlining a series of recommendations to address the increase in ocean acidification and hypoxia, or extremely low oxygen levels.

“Ocean acidification is a global problem that is having a disproportionate impact on productive West Coast ecosystems,” said Francis Chan, an Oregon State University marine ecologist and co-chair of the West Coast Ocean Acidification and Hypoxia Science Panel. “There has been an attitude that there is not much we can do about this locally, but that just isn’t true. A lot of the solutions will come locally and through coordinated regional efforts.”

Ocean acidification and hypoxia are distinct phenomena that trigger a wide range of effects on marine ecosystems. They frequently occur together and represent two important facets of global ocean changes that have important implications for Oregon’s coastal oceans.

Among the panel’s recommendations:

  • Develop new benchmarks for near-shore water quality as existing criteria were not developed to protect marine organisms from acidification;
  • Improve methods of removing carbon dioxide from seawater through the use of kelp beds, eel grass and other plants;
  • Enhance coastal ecosystems’ ability to adapt to changing ocean chemistry through better resource management, including marine reserves, adaptive breeding techniques for shellfish, and other methods.

“Communities around the country are increasingly vulnerable to ocean acidification and long-term environmental changes," said Richard Spinrad, chief scientist for the National Oceanic and Atmospheric Administration, and former OSU vice president for research. “It is crucial that we comprehend how ocean chemistry is changing in different places, so we applaud the steps the West Coast Ocean Acidification and Hypoxia Science Panel has put forward in understanding and addressing this issue. We continue to look to the West Coast as a leader on understanding ocean acidification.”

Chan said regional awareness of the impact of changing ocean chemistry started in Oregon. Some of the first impacts were seen about 15 years ago when the state began experiencing seasonal hypoxia, or low-oxygen water, leading to some marine organism die-offs. Then the oyster industry was confronted with high mortality rates of juvenile oysters because of increasingly acidified water. It turns out that Oregon was on the leading edge of a much larger problem.

“It was a wakeup call for the region, which since has spread up and down the coast,” said Chan, an associate professor in the Department of Integrative Biology in OSU’s College of Science.

California responded to this call, and in partnership with Oregon, Washington and British Columbia, convened a panel of scientific experts to provide advice on the issue. The panel worked with federal and state agencies, local organizations and higher education institutions to identify concerns about ocean acidification and hypoxia, then developed a series of recommendations and actions that can be taken today.

“One of the things all of the scientists agree on is the need for better ocean monitoring or ‘listening posts,’ up and down the West Coast,” said Jack Barth, a professor and associate dean in OSU’s College of Earth, Ocean, and Atmospheric Sciences and a member of the panel. “It is a unifying issue that will require participation from state and federal agencies, as well as universities, ports, local governments and NGOs.”

Barth said one such “listening post” has been the Whiskey Creek Shellfish Hatchery in Netarts Bay, Oregon, which was able to solve the die-off of juvenile oysters with the help of OSU scientists George Waldbusser and Burke Hales, who both served on the 20-member panel. Together, they determined that the ocean chemistry changed throughout the day and by taking in seawater in the afternoon, when photosynthesis peaked and CO2 levels were lower, juvenile oysters could survive.

The West Coast is a hotspot for acidification because of coastal upwelling, which brings nutrient-rich, low-oxygen and high carbon dioxide water from deep in the water column to the surface near the coast. These nutrients fertilize the water column, trigger phytoplankton blooms that die and sink to the bottom, producing even more carbon dioxide and lowering oxygen further.

“We’re just starting to see the impacts now, and we need to accelerate what we know about how increasingly acidified water will impact our ecosystems,” said panel member Waldo Wakefield, a research fisheries biologist with NOAA Fisheries in Newport and courtesy associate professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

“There’s a lot at stake. West Coast fisheries are economic drivers of many coastal communities, and the seafood we enjoy depends on a food web that is likely to be affected by more corrosive water.”

Last year, OSU researchers completed the deployment of moorings, buoys and gliders as part of the Endurance Array – a component of the $386 million National Science Foundation-funded Ocean Observatories Initiative, created to address ocean issues including acidification.

These and other ocean-monitoring efforts will be important to inform policy-makers about where to best focus their adaptation and mitigation strategies.

“The panel’s findings provide a road map to help us prepare for the changes ahead,” said Gabriela Goldfarb, natural resource policy adviser to Oregon Gov. Kate Brown. “How Oregon and the West Coast address ocean acidification will inform those confronting this issue around the country and world.”

“With the best scientific recommendations in hand from the science panel, we now have the information on which to base our future management decisions,” added Caren Braby, marine resource manager at the Oregon Department of Fish and Wildlife. “These are practical recommendations natural resource managers and communities can use to ensure we continue to have the rich and productive ecosystem Oregonians depend on for healthy fisheries, our coastal culture and economy.”

Story By: 
Source: 

Francis Chan, 541-844-8415, chanft@science.oregonstate.edu;

Jack Barth, 541-737-1607, barth@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

oyster

An oyster at Whiskey Creek Shellfish Hatchery

PNAS Study: Carbon from land played a role during last deglaciation

CORVALLIS, Ore. – As the Earth emerged from its last ice age several thousand years ago, atmospheric carbon dioxide increased and further warmed the planet. Scientists have long speculated that the primary source of this CO2 was from the deep ocean around Antarctica, though it has been difficult to prove.

A new study being published this week in Proceedings of the National Academy of Sciences confirmed that the ocean played a significant role in the rise of atmospheric carbon dioxide, but also documents the signature of land-based carbon sources in Antarctic ice cores that contributed to abrupt increases in CO2.

“There wasn’t a steady rate of rising carbon dioxide during the last deglaciation,” said Edward Brook, an Oregon State University paleoclimatologist and co-author on the PNAS study. “It happened in fits and starts. With the new precise techniques we developed to fingerprint the sources, it is apparent that the early carbon largely came from the ocean, but we think the system got a jolt from an influx of land-based carbon a few times as the climate warmed.”

The study was funded by the National Science Foundation with support from the Marsden Fund Council in New Zealand.

The breakthrough came from the comparison of carbon isotope ratios in pristine samples of ice mined from the Taylor Glacier in Antarctica. Although such isotopic fingerprinting strategies have been attempted before, the key was detailed work both in the field and in the laboratory that improved the precision to read the record in fine detail.

The study found that during the initial rise in atmospheric CO2 – from 17,600 years ago to 15,500 years ago – the light isotope 12-C increased faster than the heavier isotopes, pointing to a release of carbon from the deep ocean. However, at about 16,300 years ago and 12,900 years ago, there were abrupt, century-scale perturbations in the carbon ratio that suggested rapid release of carbon from land sources such as plants and soils.

Although the region of the CO2 source is not clear, the scientists say, at least one of the two events may come from the tropics because methane from tropical swamps rose at the same time.

“One theory,” Brook said, “is that an influx of icebergs in the Northern Hemisphere at about 16,300 years ago – from retreating ice sheets – cooled the North Atlantic Ocean and pushed the tropical rain belt southward over Brazil, expanding the wetlands. Swamps in the Southern Hemisphere, in places like Brazil, may have become wetter and produced methane, while plants and soils in the Northern Hemisphere, in places like China, may have been hit by drought and produced CO2.”

During the next 4,000 years, the continued rise of atmospheric CO2 – by about 40 parts per million – was marked by small changes in the carbon-13 to carbon-12 ratio indicating additional sources of carbon from rising ocean temperatures. This CO2 source, analogous to the bubbles released from warming soda pop, may have added to the biological carbon sources.

The application of this carbon isotope technique became possible because of a unique site along the margin of the Antarctic ice sheet where old ice that flowed from the interior is exposed at the surface of a large glacier – Taylor Glacier – named for a geologist on an early expedition to the frozen continent. Ice that normally would be a mile or more below the surface is available to easily sample in large quantities.

These large samples, laboriously cut from the exposed ice layers, allowed the precise measurements, the  researchers report.

“The isotope ratio technique gives us a sort of ‘return address’ for carbon dioxide,” noted Thomas Bauska, a former Ph.D. student and post-doctoral researcher in OSU’s College of Earth, Ocean, and Atmospheric Sciences, who was lead author on the PNAS study.  “The technique is new, extremely precise and gives us one of the best windows into the Earth’s past climate.”

Bauska is now a post-doctoral researcher at the University of Cambridge in England.

That window into the past may provide hints at what may happen in the future under a new global warming regime, noted Alan Mix, an Oregon State oceanographer and co-author on the study. However, he cautioned, it isn’t always simple to predict the future based on past events.

“The rise of CO2 is a complicated beast, with different behaviors triggered at different times,” Mix said. “Although the natural changes at the end of the ice age are not a direct analogy for the future, the rapid changes do provide a cautionary tale. Manmade warming from CO2 pollution may trigger further release from ‘natural sources,’ and this could exacerbate greenhouse gases and warming.”

Other authors on the PNAS study include Daniel Baggenstos and Jeffrey Severinghaus, Scripps Institution of Oceanography; Shaun Marcott, University of Wisconsin-Madison; Vasillii Petrenko, University of Rochester; Hinrich Schaefer, National Institute of Water and Atmospheric Research in New Zealand; and James Lee, Oregon State University.

Story By: 
Source: 

Ed Brook, 541-737-8197, brook@geo.oregonstate.edu;

Thomas Bauska, +44 1223 764917, tkb28@cam.ac.uk;

Alan Mix, 541-737-5212, amix@coas.oregonstate.edu

Extreme events show signal of climate change

CORVALLIS, Ore. – The rapid warming of Earth may not have directly caused all of the extreme weather events that have taken place in the past two decades – from the European heat wave of 2003 to Hurricane Katrina – but climate change has in some way had an impact on them, a new report concludes.

A 10-person committee of the National Research Council issued a report on Friday that examined the influence of humans on recent extreme weather events. Though the committee stopped short of saying that climate change is causing more frequent and severe events – a link difficult to prove in a short time frame – the connection, it acknowledges, is unmistakable.

“Scientists used to say that we can’t attribute any one event to climate change,” said Philip Mote, an Oregon State University climatologist and co-author on the report. “But that is a copout. Every extreme weather event has the fingerprint of climate change. The question is not whether global warming caused Hurricane Sandy; but rather how much stronger it was because of global warming.

“There is little doubt that Hurricane Sandy would have had less impact without climate change.”

The committee issued its report today in the National Academies Press, published by the National Academies of Science, Engineering and Medicine.

Humans’ use of fossil fuel since the start of the Industrial Revolution has begun to modify the Earth’s climate in many ways, said David W. Titley, who chaired the Committee of Extreme Weather Events and Climate Change Attribution.

“The consequences of this change to the climate are seemingly everywhere: average temperatures are rising, precipitation patterns are changing, ice sheets are melting and sea levels are rising,” Titley noted in the report’s preface. “These changes are affecting the availability and quality of water supplies, how and where food is grown, and even the very fabric of ecosystems on land and in the sea.”

Despite progress on understanding these changes, scientists are still trying many different approaches to understanding the causes of extreme events.

Since 2012, the number of research groups issuing studies on the attribution of extreme weather events has exploded, shedding new light on the external “forcing” mechanisms of events and how they are similar or different from other events.

This is allowing scientists to get a better feel for the impact of climate change on extreme events, Mote pointed out.

“The clearest tie between climate change and weather is in heat-related events,” said Mote, who wrote the sections on heat and drought in the report. “Droughts are getting worse and some aspect of every major heat-related event is stronger today because of climate change. In fact, most types of extreme events are getting stronger or more frequent, except those related to cold events, which are weaker or less frequent.”

Mote said he understands public skepticism over the link between global warming and weather in places like the East Coast of the United States, which has suffered through strong blizzards in the past two to three winters – a brief return to a climate of decades past. A warming planet does not affect every region uniformly, he added, nor does it make every season warmer than average.

On the other side of the country the three Pacific coast states – California, Oregon and Washington – experienced major drought in 2014-15.

“I’m frequently asked if we can expect more of the same in the future for the West Coast,” said Mote, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “The answer is yes. The weather we had this past year, which was the warmest on record in Oregon, is the type of year we can expect to call ‘norm’ in the decade of the 2040s.”

Story By: 
Source: 

Phil Mote, 541-913-2274

Multimedia Downloads
Multimedia: 

5261
Phil Mote

Mariana Trench: Seven miles deep, the ocean is still a noisy place

NEWPORT, Ore. – For what may be the first time, scientists have eavesdropped on the deepest part of the world’s oceans and instead of finding a sea of silence, they discovered a cacophony of sounds both natural and caused by humans.

For three weeks, a titanium-encased hydrophone recorded ambient noise from the ocean floor at a depth of more than 36,000 feet in a trough known as Challenger Deep in the fabled Mariana Trench near Micronesia. The team of researchers from the National Oceanic and Atmospheric Administration, Oregon State University and the U.S. Coast Guard expected to hear little. They were surprised.

“You would think that the deepest part of the ocean would be one of the quietest places on Earth,” said Robert Dziak, a NOAA research oceanographer and chief scientist on the project. “Yet there really is almost constant noise from both natural and man-made sources. The ambient sound field at Challenger Deep is dominated by the sound of earthquakes, both near and far was well as the distinct moans of baleen whales and the overwhelming clamor of a category 4 typhoon that just happened to pass overhead.

“There was also a lot of noise from ship traffic, identifiable by the clear sound pattern the ship propellers make when they pass by,” added Dziak, who has a courtesy appointment in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences. “Guam is very close to Challenger Deep and is a regional hub for container shipping with China and The Philippines.”

The project, which was funded by the NOAA Office of Ocean Exploration and Research, was designed to establish a baseline for ambient noise in the deepest part of the Pacific Ocean. Anthropogenic, or human-caused noise has increased steadily over the past several decades and getting these first recordings will allow scientists in the future to determine if the noise levels are growing.

Getting those first sounds wasn’t easy.

The bottom of the Challenger Deep trough is roughly seven miles below the ocean’s surface. In fact, you could put the world’s tallest peak – Mount Everest – in the trench and its top would still be more than a mile from the surface.

The pressure at that depth is incredible, said Haru Matsumoto, an Oregon State ocean engineer who along with NOAA engineer Chris Meinig helped to develop a hydrophone capable of withstanding such pressure. In the average person’s home or office, the atmospheric pressure is about 14.7 pounds per square inch; at the bottom of the Mariana Trench, it is more than 16,000 PSI.

“We had never put a hydrophone deeper than a mile or so below the surface, so putting an instrument down some seven miles into the ocean was daunting,” Matsumoto said. “We had to drop the hydrophone mooring down through the water column at no more than about five meters per second. Structures don’t like rapid change and we were afraid we would crack the ceramic housing outside the hydrophone.”

Partnering with the U.S. Coast Guard, the researchers deployed the hydrophone from the Guam-based cutter Sequoia in July 2015. It took more than six hours for the instrument package to free-fall to the bottom of the Mariana Trench. Its recordings filled the flash drive in about 23 days, but the researchers had to wait until November to retrieve the hydrophone because of ships’ schedules and persistent typhoons.

Once back on site, they recovered the hydrophone mooring by sending an acoustic signal from the ship above, triggering its release from the seafloor. Attached floats allowed it to gradually ascend to the surface.

“It is akin to sending a deep-space probe to the outer solar system,” Dziak said. “We’re sending out a deep-ocean probe to the unknown reaches of inner space.”

For the past several months, Dziak and his colleagues have been analyzing the sounds and differentiating natural sounds from ships and other human activities.

“We recorded a loud magnitude 5.0 earthquake that took place at a depth of about 10 kilometers (or more than six miles) in the nearby ocean crust,” Dziak said. “Since our hydrophone was at 11 kilometers, it actually was below the earthquake, which is really an unusual experience. The sound of the typhoon was also dramatic, although the cacophony from big storms tends to be spread out and elevates the overall noise for a period of days.”

Matsumoto said the hydrophone also picked up a lot of noise from the surface of the ocean – some seven miles above – including waves and winds disturbing the surface.

“Sound doesn’t get as weak as you think it does even that far from the source,” he said.

Another OSU co-investigator on the project, Joe Haxel, will lead a planned return to Challenger Deep in 2017, where the researchers will deploy the hydrophone for a longer period of time and attach a deep-ocean camera.

Dziak, Matsumoto and Haxel are affiliated with the Acoustics Program in the NOAA/Pacific Marine Environmental Laboratory and work at OSU’s Hatfield Marine Science Center in Newport, Ore. The project in Challenger Deep is one of a number of projects in which the U.S. Coast Guard partners with NOAA to sponsor scientific research.

Story By: 
Source: 

Bob Dziak, 541-867-0175, Robert.P.Dziak@noaa.gov;

Haru Matsumoto, 541-867-0272; haru.matsumoto@oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

 

 

A link to sound files, images and a video can be found at: http://bit.ly/1QSb8Mv

 

 

Deep trench

 

ChallengerDeep

 

CD-hydrophone-close