OREGON STATE UNIVERSITY

environment and natural resources

Fish native to Japan found in Port Orford waters

NEWPORT, Ore. – A team of scientists from Oregon State University and the Oregon Department of Fish and Wildlife is studying an unusual fish captured alive in a crab pot near Port Orford this week called a striped knifejaw that is native to Japan, as well as China and Korea.

The appearance in Oregon waters of the fish (Oplegnathus fasciatus), which is sometimes called a barred knifejaw or striped beakfish, may or may not be related to the Japanese tsunami of 2011, the researchers say, and it is premature to conclude that this non-native species may be established in Oregon waters.

But its appearance and survival certainly raises questions, according to OSU’s John Chapman, an aquatic invasive species specialist at the university’s Hatfield Marine Science Center in Newport.

“Some association with Japanese tsunami debris is a strong possibility, but we cannot rule out other options, such as the fish being carried over in ballast water of a ship or an aquarium fish being released locally,” Chapman said. “But finding a second knifejaw nearly two years after the discovery of fish in a drifting Japanese boat certainly gets my attention.”

In March 2013, five striped knifejaws were found alive in a boat near Long Beach, Washington, that had drifted over from Japan. Four of the fish were euthanized, but one was taken to the Seaside Aquarium, where it is still alive and well.

OSU marine ecologist Jessica Miller examined the four euthanized knifejaws from Washington in 2013, analyzing their otoliths, or ear bones, for clues to their origin.

“The young fish of these species are known to associate with drift and may be attracted to floating marine debris,” Miller said. “Japanese tsunami marine debris continues to arrive on beaches in Oregon and Washington – and some debris from Japan washed up on the southern Oregon coast this month – so it is not inconceivable that the Port Orford fish was associated with Japanese marine debris.

“The species is also found in other parts of Asia and the northwest Hawaiian islands, so it is native to a broader range than just Japan,” she added. “At this time, there is no evidence that they are successfully reproducing in Oregon.”

Tom Calvanese, an Oregon State graduate student researcher working with Oregon Sea Grant on the start-up of a new OSU field station in Port Orford, worked with the fisherman to secure the exotic species. The fish is approximately 13 centimeters in length, and thus not a fully grown adult, and was captured in a crab pot between Port Orford and Cape Blanco  - just off the Elk River in southern Oregon.

“We are fortunate to have this occur in a fishing community that is ocean-aware,” Calvanese said. “The fisherman who caught the fish identified it as an exotic then transported it to shore alive, where the fish buyer was able to care for it. It was then brought to my attention, initiating a response from the scientific community that will result in an exciting learning opportunity for all.

“It appears to be in good shape and was swimming upright, though it had a small cut in its abdomen,” Calvanese said. “I talked to Keith Chandler at the Seaside Aquarium who suggested feeding it razor clams, which it took readily.”

Steven Rumrill, a biologist with the Oregon Department of Fish and Wildlife, is working with Calvanese and others to transport the fish to a quarantine facility at the Hatfield Marine Science Center, where it will be under the care of OSU aquatic veterinarian Tim Miller-Morgan of Oregon Sea Grant.

“It is important that the fish be held in quarantine until the wound is healed and for sufficient time to ensure that it is free from any pathogens or parasites that could pose a threat to our native fishes,” Rumrill said.

Sam Chan, an OSU invasive species expert affiliated with Oregon Sea Grant and vice-chair of the Oregon Invasive Species Council, has seen striped knifejaws in Japan and estimates this fish may be 1-2 years old.

“Therefore, it is unlikely to have left Japan in the 2011 tsunami,” Chan said, “but a boat could have been milling around Asian waters for the past 2-3 years and then picked up the fish and ridden the currents over. The big question is – are there more of these?”

Chan said Oregon Sea Grant – an OSU-based marine research, education and outreach program – would work with Oregon fishermen, crabbers and others to keep a lookout for additional striped knifejaws and other exotic species.

Calvanese posted a brief video of the fish on you-tube: http://youtu.be/XzA4NPXTYqg

Oregonians who believe they have spotted an invasive species are encouraged to report it at http://oregoninvasiveshotline.org, or call 1-866-INVADER.

Media Contact: 
Source: 

John Chapman, 541-961-3258, john.chapman@oregonstate.edu;

Jessica Miller, 541-867-0381, Jessica.miller@oregonstate.edu;

Tom Calvanese, 415-309-6568, tom.calvanese@oregonstate.edu;

Sam Chan, 503-679-4828, sam.chan@oregonstate.edu;

Steven Rumrill, 541-867-0300, ext. 245; Steven.S.Rumrill@state.or.us

OSU to outfit undersea gliders to “think like a fish”

CORVALLIS, Ore. – Oregon State University researchers have received a $1 million grant from the W.M. Keck Foundation that will allow them to outfit a pair of undersea gliders with acoustical sensors to identify biological “hot spots” in the coastal ocean.

They also hope to develop an onboard computing system that will program the gliders to perform different functions depending on what they encounter.

In other words, the scientists say, they want to outfit a robotic undersea glider to “think like a fish.”

“We spend all of this time on ships, deploying instrumentation that basically is designed to see how ocean biology aggregates around physical features – like hake at the edge of the continental shelf or salmon at upwelling fronts,” said Jack Barth, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences and a principal investigator on the project. “But that just gives us a two-week window into a particular area.

“We already have a basic understanding of the ecosystem,” Barth added. “Now we want to get a better handle of what kind of marine animals are out there, how many there are, where they are distributed, and how they respond to phytoplankton blooms, schools of baitfish or oceanic features. It will benefit a variety of stakeholders, from the fishing industry and resource managers to the scientific community.”

Barth is a physical oceanographer who knows the physical processes of the coastal ocean. He’ll work with Kelly Benoit-Bird, a marine ecologist, who specializes in the relationships among marine organisms from tiny plankton to large whales. Her work utilizes acoustics to identify and track animals below the ocean surface – and it is these sensors that will open up a new world of research aboard the gliders.

“Our first goals are to understand the dynamics of the Pacific Northwest upwelling system, find the biological hotspots, and then see how long they last,” Benoit-Bird said. “Then we’d like to learn what we can about the distribution of prey and predators – and the relationship of both to oceanic conditions.”

Using robot-mounted acoustic sensors, the OSU researchers will be able to identify different kinds of marine animals using their unique acoustical signatures. Diving seabirds, for example, leave a trail of bubbles through the water like the contrail left by a jet. Zooplankton show up as a diffuse cloud. Schooling fish create a glowing, amoeba-shaped image.

“We’ve done this kind of work from ships, but you’re more or less anchored in one spot, which is limiting,” Benoit-Bird said. “By putting sensors on gliders, we hope to follow fish, or circle around a plankton bloom, or see how seabirds dive. We want to learn more about what is going on out there.”

Programming a glider to spend weeks out in the ocean and then “think” when it encounters certain cues, is a challenge that falls upon the third member of the research team, Geoff Hollinger, from OSU’s robotics program in the College of Engineering. Undersea gliders operated by Oregon State already can be programmed to patrol offshore for weeks at a time, following a transect, moving up and down in the water column, and even rising to the surface to beam data back to onshore labs via satellite.

But the instruments aboard the gliders that measure temperature, salinity and dissolved oxygen are comparatively simple and require limited power. Using sophisticated bioacoustics sensors that record huge amounts of data, and then programming the gliders to respond to environmental cues, is a significant technological advance.

“All of the technology is there,” Hollinger said, “but combining it into a package to perform on a glider is a huge robotics and systems engineering challenge. You need lots of computing power, longer battery life, and advanced control algorithms.”

Making a glider “think,” or respond to environmental cues, is all about predictive algorithms, he said.

“It is a little like looking at economic indicators in the stock market,” Hollinger pointed out. “Just one indicator is unlikely to tell you how a stock will perform. We need to develop an algorithm that essentially turns the glider into an autonomous vehicle that can run on autopilot.”

The three-year research project should benefit fisheries management, protection of endangered species, analyzing the impacts of new ocean uses such as wave energy, and documenting impacts of climate change, the researchers say.

Oregon State has become a national leader in the use of undersea gliders in research to study the coastal ocean and now owns and operates more than 20 of the instruments through three separate research initiatives. Barth said the vision is to establish a center for underwater vehicles and acoustics research – which would be a key component of its recently announced Marine Studies Initiative.

The university also has a growing program in robotics, of which Hollinger is a key faculty member. This collaborative project funded by Keck exemplifies the collaborative nature of research at Oregon State, the researchers say, where ecologists, oceanographers and roboticists work together.

“This project and the innovative technology could revolutionize how marine scientists study the world’s oceans,” Barth said.

Media Contact: 
Source: 

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

Kelly Benoit-Bird, 541-737-2063, kbenoit@coas.oregonstate.edu;

Geoff Hollinger, 541-737-5906, Geoff.hollinger@oregonstate.edu

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Study outlines threat of ocean acidification to coastal communities in U.S.

CORVALLIS, Ore. – Coastal communities in 15 states that depend on the $1 billion shelled mollusk industry (primarily oysters and clams) are at long-term economic risk from the increasing threat of ocean acidification, a new report concludes.

This first nationwide vulnerability analysis, which was funded through the National Science Foundation’s National Socio-Environmental Synthesis Center, was published today in the journal Nature Climate Change.

The Pacific Northwest has been the most frequently cited region with vulnerable shellfish populations, the authors say, but the report notes that newly identified areas of risk from acidification range from Maine to the Chesapeake Bay, to the bayous of Louisiana.

“Ocean acidification has already cost the oyster industry in the Pacific Northwest nearly $110 million and jeopardized about 3,200 jobs,” said Julie Ekstrom, who was lead author on the study while with the Natural Resources Defense Council. She is now at the University of California at Davis.

George Waldbusser, an Oregon State University marine ecologist and biogeochemist, said the spreading impact of ocean acidification is due primarily to increases in greenhouse gases.

“This clearly illustrates the vulnerability of communities dependent on shellfish to ocean acidification,” said Waldbusser, a researcher in OSU’s College of Earth, Ocean, and Atmospheric Sciences and co-author on the paper. “We are still finding ways to increase the adaptive capacity of these communities and industries to cope, and refining our understanding of various species’ specific responses to acidification.

“Ultimately, however, without curbing carbon emissions, we will eventually run out of tools to address the short-term and we will be stuck with a much larger long-term problem,” Waldbusser added.

The analysis identified several “hot zones” facing a number of risk factors. These include:

  • The Pacific Northwest: Oregon and Washington coasts and estuaries have a “potent combination” of risk factors, including cold waters, upwelling currents that bring corrosive waters closer to the surface, corrosive rivers, and nutrient pollution from land runoff;
  • New England: The product ports of Maine and southern New Hampshire feature poorly buffered rivers running into cold New England waters, which are especially enriched with acidifying carbon dioxide;
  • Mid-Atlantic: East coast estuaries including Narragansett Bay, Chesapeake Bay, and Long Island Sound have an abundance of nitrogen pollution, which exacerbates ocean acidification in waters that are shellfish-rich;
  • Gulf of Mexico: Terrebonne and Plaquemines Parishes of Louisiana, and other communities in the region, have shellfish economies based almost solely on oysters, giving this region fewer options for alternative – and possibly more resilient – mollusk fisheries.

The project team has also developed an interactive map to explore the vulnerability factors regionally.

One concern, the authors say, is that many of the most economically dependent regions – including Massachusetts, New Jersey, Virginia and Louisiana – are least prepared to respond, with minimal research and monitoring assets for ocean acidification.

The Pacific Northwest, on the other hand, has a robust research effort led by Oregon State University researchers, who already have helped oyster hatcheries rebound from near-disastrous larval die-offs over the past decade. The university recently announced plans to launch a Marine Studies Initiative that would help address complex, multidisciplinary problems such as ocean acidification.

"The power of this project is the collaboration of natural and social scientists focused on a problem that has and will continue to impact industries dependent on the sea,” Waldbusser said.

Waldbusser recently led a study that documented how larval oysters are sensitive to a change in the “saturation state” of ocean water – which ultimately is triggered by an increase in carbon dioxide. The inability of ecosystems to provide enough alkalinity to buffer the increase in CO2 is what kills young oysters in the environment.

Media Contact: 
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George Waldbusser, 541-737-8964; waldbuss@coas.oregonstate.edu

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Northwest hatchery operation

 

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Oysters threatened by acidification

 

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A young oyster

Study finds lamprey decline continues with loss of habitat in Oregon

CORVALLIS, Ore. – A new study aimed at understanding habitat needs for Pacific lamprey in western Oregon found this once-abundant fish that is both ecologically and culturally significant prefers side channels and other lower water velocity habitats in streams.

However, because of the legacy of historic land uses in the Northwest – including human settlement and activities – these habitats are much less common than they were in the past. And that may explain why populations of lamprey have declined over the past several decades – not only in western Oregon, but throughout the Pacific Northwest.

Results of the study were just published in the Ecology of Freshwater Fish.

“The lamprey decline has probably been going on for the past half century, but it wasn’t until the last 15-20 years that it has been recognized by many in the scientific community,” said Luke Schultz, a research assistant in Oregon State University’s Department of Fisheries and Wildlife and lead author on the study. “Today lamprey populations are at about 5 to 10 percent of the 1960s totals at Bonneville Dam, and the story is much the same elsewhere.

“The Willamette River basin is one of the few places that still appears to have decent numbers of lamprey because of its system of sloughs and side channels,” he added. “But they are facing new threats, such as introduced fish species that prey on them – especially bass – so we’ll likely be hearing more about this emerging threat in the next few years.”

Schultz is project leader Oregon Cooperative Fish Research Unit’s Pacific lamprey project – a joint effort between OSU and the U.S. Geological Survey that is seeking to learn more about the fish and restore its habitat. Although this latest article focuses on the Willamette Basin, Schultz and his colleagues at OSU, the USGS, Oregon Department of Fish and Wildlife and the U.S. Fish and Wildlife Service have looked at lamprey populations and habitat from the Columbia River in northeastern Oregon to southern Oregon’s Umpqua River.

The causes of Pacific lamprey decline are myriad, the researchers say. Restoring their numbers will require mitigation in the form of restoring habitat to include complex channels and deep pools, and the removal of barriers that block access to spawning grounds for adult lampreys, the authors note.

“Removal or mitigation will allow lampreys to recolonize those areas,” Schultz said.

Some factors affecting the lamprey decline may be out of the researchers’ control, Schultz said, specifically ocean conditions. They require an abundance of food; ocean conditions that are favorable to salmon are usually beneficial for lampreys, as well. Rather than swimming freely, they may attach themselves to large fishes, or even whales, sea lions or other marine animals – and the abundant ocean prey lets them grow large.

“Pacific lamprey may spend one or two years in the ocean,” Schultz noted. “They will weigh less than an ounce when they go out there as juveniles, and they may grow to 30 inches in length and up to two pounds before they return.”

Although Pacific lampreys are anadromous, another species, the brook lamprey, only grows to a length of 6-7 inches and stays in fresh water for its entire lifespan of 4-8 years.

It is the Pacific lamprey that researchers are focusing on because of their one-time abundance, larger size, and more prominent ecological role.

“These are really interesting animals that have historic importance in the Pacific Northwest,” Schultz noted. “They can live up to about 10 years or so – about three times longer than the coho salmon life cycle – and they are roughly six times as energy-dense as salmon, making them important prey.

“Because of that, I like to call them swimming sticks of butter.”

When lampreys are abundant, they reduce predation by a variety of species – especially sea lions, but also sturgeon, birds, bass and walleye – on juvenile salmon and steelhead. It may not be an accident that salmonid numbers have declined at the same time lamprey populations have diminished.

The research in the study has led to some habitat restoration work supported by the Columbia River Inter-Tribal Fish Commission. Helping lamprey populations recover has important social significance as well as ecological importance, Schultz said.

“Lampreys were an incredibly important resource for many Northwest tribes because they provided a source of protein in the summer months when salmon weren’t as readily available,” he noted. “Now the only place where there is even a limited tribal harvest is at Willamette Falls.”

More information on lampreys is available in this feature article in OSU’s Terra Magazine: http://bit.ly/1fhu8k4

Media Contact: 
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Luke Schultz, 541-737-1961; luke.schultz@oregonstate.edu

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Sampling at Willamette Falls

 

 

 

 

 



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Juvenile lamprey



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Measuring in the field

Oregon experienced second warmest year on record in 2014

CORVALLIS, Ore. – The year 2014 was the hottest on Earth in 134 years of record-keeping, the National Oceanic and Atmospheric Administration (NOAA) reported on Friday, continuing a pattern of global warming that is attributed primarily to rising levels of greenhouse gases.

Oregon was not exempt from the warming and logged the second hottest year since records were kept beginning in 1895, according to researchers with the Oregon Climate Change Research Institute at Oregon State University.

“We had a warm summer, and now a warm winter and that’s where we got our warm year,” said Kathie Dello, deputy director of the center. “We are looking at our future right now – warm winters and low snowpacks.”

The average statewide temperature in Oregon in 2014 was 49.5 degrees, which is 3.0 degrees above the average for the 20th century. The only hotter year on record was 1934 – when the United States suffered through the Dust Bowl. The average temperature in Oregon that year was 49.9.

Low snowpacks are of particular concern later in the year when less water is available, Dello pointed out.

“Drought continues to be a concern in southern and eastern Oregon, as well as in California,” she said. “The temperature outlook for the next three months is pointing toward continued warm temperatures for the western United States.”

According to NOAA, the average 2014 temperature across both land and ocean surfaces globally was 1.24 degrees above the 20th-century average. This was the highest among all years on record dating back to 1880, the agency noted.

Regions that were considered the warmest last year, according to NOAA, included eastern Russia, the western United States, portions of Australia, much of the northeastern Pacific Ocean, segments of the equatorial Pacific, large swaths of the Atlantic Ocean, most of the Norwegian Sea, and parts of the central to southern Indian Ocean.

Philip Mote, director of the Oregon Climate Change Research Institute, said the subtlety of rising temperatures on a global scale can be hard to comprehend, since people tend to view climate based on their personal experiences.

“Most of us relate to climate through what we remember and the week-long spell of near-record cold, snow and ice last February may seem more pertinent or convincing than global mean temperature,” Mote said. “But from a physics perspective, global mean temperature represents lots of interesting processes – rising greenhouse gases among them.

“Setting a record like this means those processes lined up this year,” Mote added. “On average, greenhouse gas increases make each year roughly .04 degrees warmer than the last – which may not sound like much, but really adds up over time.”

At that rate, the temperature would increase one degree every 25 years, and four degrees each century – an alarming rate of increase, scientists say. “And unless emissions of greenhouse gases are curbed,” Mote said, “the warming is likely to be faster than that in the future.”

Although globally the planet experienced its hottest year, it was only the 34th warmest year on record for the United States overall, Dello said. The western U.S. as a whole had its hottest year on record, as did the states of California, Nevada and Arizona, but the eastern part of the country experienced a severe winter.

Dello and Mote are both in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

Media Contact: 
Source: 

Phil Mote, 541-913-2274,  pmote@coas.oregonstate.edu;

Kathie Dello, 585-307-6492, kdello@coas.oregonstate.edu

 

 

 

 

 

Wallowa Lake in northeastern Oregon

Study finds tropical fish moving into temperate waters

CORVALLIS, Ore. – Tropical herbivorous fish are beginning to expand their range into temperate waters – likely as a result of climate change – and a new international study documents the dramatic impact of the intrusion in the Mediterranean Sea.

Temperate waters are typically dominated by algal “forests” and have naturally low levels and limited diversity of herbivores, the researchers say. But as tropical fish move into these waters, they are consuming much of the plant life and changing the habitat as well as the manner in which different species interact.

Results of the study, which was funded primarily by the Pew Foundation, have just been published in the Journal of Ecology. It builds on a previous study documenting the move of tropical fish species into temperate waters that recently was published in Proceedings of the Royal Society B.

“The introduction of tropical fish into more temperate regions is troubling and this new study gives a vivid example of what can happen when non-native species occupy a new ecosystem,” said Fiona Tomas Nash, a courtesy professor of fisheries and wildlife at Oregon State University and a co-author on both studies.

“We now know that the arrival of tropical fish into temperate areas is occurring on an increasing basis around the world,” she added. “This is the first attempt to characterize what impacts these fish are having – and the mechanisms driving these impacts.”

In this latest study, an international research team surveyed roughly 1,000 kilometers of coastline in the eastern Mediterranean to study two species of tropical fish called rabbitfish. They were introduced to the region through the Suez Canal and now have become a dominant component of the total fish biomass in the southernmost part of the eastern Mediterranean.

This part of the Mediterranean has two distinct areas – one with warmer regions that attract abundant numbers of rabbitfish, and colder regions where they are very rare or completely absent. Where abundant, their damage has been striking: a 65 percent reduction in canopy algae, a 60 percent reduction in overall benthic biomass (algae and invertebrates) and a 40 percent decrease in the total number of plant and animal species.

“The fear is that if the colder regions warm just a bit through climate change or some other mechanism, rabbitfish will begin moving into those areas as well,” Tomas Nash said.

To learn more about how the rabbitfish changed the ecosystem, the researchers videotaped fish feeding in the Mediterranean off Turkey in two areas – one dominated by tropical rabbitfish and the other dominated by native temperate fish. They were surprised by what they found. Native temperate herbivorous fish actually had higher consumption rates than the tropical rabbitfish. “We did not expect to see that,” Tomas Nash said.

But while native fish targeted only adult macroalgae, the two species of rabbitfish fed complementarily – one targeted the mature kelps while the other fed almost exclusively on emerging algal “recruits,” or juvenile plants.

“The result is that one species denudes the forest and the other prevents it from recovering,” said Tomas Nash, who also has a faculty appointment with the Mediterranean Institute for Advanced Studies in Spain.

A study off Japan by collaborators found that the introduction of tropical species there, including rabbitfish and parrotfish, resulted in the loss of kelp forests and the emergence of non-native corals in as little as 20 years.

In the first paper, the researchers outlined how tropical herbivorous fish primarily along west boundary currents are moving into temperate zones, including South Africa, Brazil, the Gulf of Mexico, Australia and Japan, as well as the Mediterranean. Other areas, including the Pacific Northwest of the United States, have not seen sustained spread of tropical species likely due to prevailing currents and because surface waters are too cold due to seasonal upwelling.

The researchers found algal forests in the waters off Greece had not been severely affected because only the rabbitfish that feeds on adult algae is present and in relatively low densities. They have just begun studies of rabbitfish and chub arrivals in Australia.

“The greatest damage that we documented was off Turkey, which may be serving as the proverbial canary in the coal mine,” Tomas Nash said. “The barrenness of the underwater habitat is unique and quite striking – it is spread over hundreds of kilometers.”

Media Contact: 
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Fiona Tomas Nash, 541-737-4531; fiona.tomasnash@oregonstate.edu

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Healthy ecosystem

 

 

denuded landscape

Effects of non-native fish

New study finds “saturation state” directly harmful to bivalve larvae

CORVALLIS, Ore. – The mortality of larval Pacific oysters in Northwest hatcheries has been linked to ocean acidification, yet the rate of increase in anthropogenic carbon dioxide in the atmosphere and the decrease of pH in near-shore waters have been questioned as being severe enough to cause the die-offs.

However, a new study of Pacific oyster and Mediterranean mussel larvae found that the earliest larval stages are directly sensitive to saturation state, not carbon dioxide (CO2) or pH. Saturation state is a measure of how corrosive seawater is to the calcium carbonate shells made by bivalve larvae, and how easy it is for larvae to produce their shells.

It is important to note that increasing CO2 lowers saturation state, the researchers say, and saturation state is very sensitive to CO2; the challenge interpreting previous studies is that saturation state and pH typically vary together with increasing CO2. The scientists utilized unique chemical manipulations of seawater to identify the direct sensitivity of larval bivalves to saturation state.

Results of the study, which was funded by the National Science Foundation, are being reported this week in the journal Nature Climate Change.

“Bivalves have been around for a long time and have survived different geologic periods of high carbon dioxide levels in marine environments,” said George Waldbusser, an Oregon State University marine ecologist and biogeochemist and lead author on the study, “The difference is that in the past, alkalinity levels buffered increases in CO2, which kept the saturation state higher relative to pH.”

“The difference in the present ocean is that the processes that contribute buffering to the ocean cannot keep pace with the rate of anthropogenic CO2 increase,” added Waldbusser, who is in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences. “As long as the saturation state is high, the oysters and mussels we tested could tolerate CO2 concentrations almost 10 times what they are today.”

The idea that early bivalve development and growth is not as physiologically linked to CO2 or pH levels as previously thought initially seems positive. However, the reverse is actually true, Waldbusser noted. Larval oysters and mussels are so sensitive to the saturation state (which is lowered by increasing CO2) that the threshold for danger will be crossed “decades to centuries” ahead of when CO increases (and pH decreases) alone would pose a threat to these bivalve larvae.

“At the current rate of change, there is not much more room for the waters off the Oregon coast to absorb more CO2 without crossing the threshold we have identified with respect to saturation state,” he said. Results of the study help explain commercial hatchery failures and why improving water chemistry in those hatcheries has been successful.

What kept the system more balanced in the geologic past likely included a combination of factors, the researchers say. One factor in past increases of carbon dioxide was high levels of volcanic activity. However, greater volcanic activity also coincides with more tectonic plate activity and uplift, increasing the weathering of rock surfaces – and thus alkalinity in rivers, where it eventually flowed into the ocean to offset the CO2.

Computer models suggest that carbon dioxide is increasing through human activity some 100 to 1,000 times faster than the weathering processes that produce alkalinity can keep up, Waldbusser noted.

The Nature Climate Change study builds on previous research by Waldbusser and colleagues that outlined the mechanisms by which young bivalves create their shells after fertilization. In that study, the researchers found that young oysters and mussels had to build their shells within 48 hours to successfully begin feeding at a rate fast enough to survive, and that rate of shell-building would require a lot of energy. Thus in the presence of acidic water, they had to divert too much energy to shell-building and lacked the energy to swim and get food.

“The hatcheries call it the ‘lazy larvae syndrome’ because these tiny oysters just sink in the water and stop swimming,” Waldbusser said. “These organisms have really sensitive windows to ocean acidification – even more sensitive then we previously thought.”

In this latest study, the researchers used high-resolution images to analyze the development of oyster and mussel shells. They found that the organisms – which are about 1-100th the diameter of a human hair – actually build a complete calcium carbonate shell within six hours, about 12 hours after fertilization.

Throw off the ocean chemistry just a bit however, the researchers say, and a greater proportion of the shells do not develop normally. The ones that do are smaller, leading to potentially weaker organisms that will take longer to get to a size where they can settle into adult life.

“When the water is more saturated and has greater alkalinity it helps offset higher levels of carbon dioxide, ensuring that shell formation can proceed – and also making the shells bigger,” Waldbusser said. “This can have a significant impact on their survivability into the future.”

Shellfish hatcheries are altering their water chemistry based on the OSU research to create more favorable saturation state conditions for young bivalves; however this only helps organisms that can be cultured easily and increasing alkalinity in natural environments is a formidable challenge because of the amount required.

Other Oregon State researchers on the Nature Climate Change study included Burke Hales, Chris Langdon, Brian Haley, Paul Schrader, Elizabeth Brunner, Matthew Gray, Cale Miller and Iria Gimenez.

Media Contact: 
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George Waldbusser, 541-737-8964; waldbuss@coas.oregonstate.edu

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“Big Data” challenge seeks techie solution to science problem

NEWPORT, Ore. – Hatfield Marine Science Center researchers studying the marine food web have literally tens of millions of photographic images of small marine organisms called “plankton” to identify – a task that would take two lifetimes to finish manually.

Their hope is that the data science community can develop a computer algorithm that can do it automatically.

This week, Booz Allen Hamilton, a management and technology consultant firm, and Kaggle, the leading online data science competition community, announced the launch of the inaugural National Data Science Bowl to seek a solution to this “big data” challenge.

They are offering prize money totaling $175,000 to the creators of the top three algorithms – the largest such purse designated for a Kaggle competition benefitting social good. More information on the National Data Science Bowl is available at: http://www.datasciencebowl.com/

The 90-day competition will not only provide the data science community a chance to flex its creativity and brain power, it hopefully will solve a challenge facing marine science researchers who need to process massive amounts of data in hours, not decades. The winning algorithms will be donated to Oregon State University’s Hatfield Marine Science Center in Newport, Ore., for use by the scientific community.

“The National Data Science Bowl was born from the realization that, in order for the data science community to grow and thrive, it must be given opportunities to use its talents to benefit both business and society,” said Josh Sullivan, vice president of Booz Allen Hamilton’s Strategic Innovation Group. “We are extremely honored to partner with leaders such as Kaggle and the Hatfield Marine Science Center for this initiative.”

Robert Cowen, director of OSU’s Hatfield Marine Science Center, admits the task is daunting. In the summer of 2014, center researchers embarked on an 18-day expedition funded by the National Science Foundation to study interactions between larval fishes, their planktonic prey, and their predators in the Straits of Florida. With their specially designed imaging system, the In Situ Ichthyoplankton Imaging System (ISIIS), they collected 32 terabytes of images of plankton, fish and jellyfish.

That is an amount of data equivalent to 9 million MP3 songs, or enough music to listen to nonstop for 52 years.

Plankton are the fundamental biological building blocks of ocean ecosystems, yet scientists don’t know as much about them as they would like, including their diversity, interactions with other marine organisms, what triggers their blooms, and how they respond to climate change.

Advancing scientific knowledge about these tiny organisms begins with identifying and cataloguing them, Cowen pointed out.

“Many economically important animals – including fishes, crabs and other shellfish – are part of the plankton in their early life stages,” he said. “Much of what we study relates to understanding the relationship between larval fishes and their planktonic prey and predators.”

Ultimately, what scientists are interested in “is what drives variation in year-to-year population abundances of key fish species,” said Su Sponaugle, co-principle investigator on the project and a professor in the Department of Integrative Biology at OSU.

Jessica Luo, a doctoral student from the University of Miami’s Rosenstiel School of Marine and Atmospheric Sciences working with Cowen and Sponaugle at the Hatfield Center, said what the researchers need from the data science community is akin to “facial recognition” software for planktonic species.

“At a minimum, we’re aiming for an automatic classification system that can identify organisms to the class or order level, in general groups like fish or shrimps,” she said. “But with distinctly shaped or transparent organisms, we think it might be possible to get down to the genus or even species level. It will be difficult, because plankton are of all different sizes, shapes and orientations, and are moving in all different directions.”

Kelly Robinson, a post-doctoral researcher at the Hatfield Marine Science Center, said scientists would benefit greatly from an automated system that could provide near real-time data of plankton abundance and diversity while aboard ships.

“From a resource management perspective, it is less effective to analyze plankton abundance and diversity from four years earlier if the resource that depends on plankton responds rapidly to environmental change,” she said. “The current process of manually identifying organisms is time-consuming and laborious.  The ocean is changing rapidly and there is an urgency to learn as much as we can about plankton interrelationships to help ensure the health of our marine environments.”

For the competition, participants will be given access to nearly 100,000 underwater images and tasked with developing an algorithm that will identify and monitor them at a scale never before attempted. If successful, it will open up new doors to researchers and vastly improve the ability of resource managers to apply science to decision-making.

“The algorithms resulting from this competition will be applied to millions of images taken in a variety of marine environments, allowing cross-comparison and analysis at an unprecedented scale,” Cowen said.

Media Contact: 
Source: 

Bob Cowen, 541-867-0211; Robert.Cowen@oregonstate.edu;

Jessica Luo, 650-387-5700; Jessica.luo@rsmas@miami.edu;

Kelly Robinson, 253-232-3899, Kelly.robinson@oregonstate.edu

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No laughing matter: Nitrous oxide rose at end of last ice age

CORVALLIS, Ore. – Nitrous oxide (N2O) is an important greenhouse gas that doesn’t receive as much notoriety as carbon dioxide or methane, but a new study confirms that atmospheric levels of N2O rose significantly as the Earth came out of the last ice age and addresses the cause.

An international team of scientists analyzed air extracted from bubbles enclosed in ancient polar ice from Taylor Glacier in Antarctica, allowing for the reconstruction of the past atmospheric composition. The analysis documented a 30 percent increase in atmospheric nitrous oxide concentrations from 16,000 years ago to 10,000 years ago. This rise in N2O was caused by changes in environmental conditions in the ocean and on land, scientists say, and contributed to the warming at the end of the ice age and the melting of large ice sheets that then existed.

The findings add an important new element to studies of how Earth may respond to a warming climate in the future. Results of the study, which was funded by the U.S. National Science Foundation and the Swiss National Science Foundation, are being published this week in the journal Nature.

“We found that marine and terrestrial sources contributed about equally to the overall increase of nitrous oxide concentrations and generally evolved in parallel at the end of the last ice age,” said lead author Adrian Schilt, who did much of the work as a post-doctoral researcher at Oregon State University. Schilt then continued to work on the study at the Oeschger Centre for Climate Change Research at the University of Bern in Switzerland.

“The end of the last ice age represents a partial analog to modern warming and allows us to study the response of natural nitrous oxide emissions to changing environmental conditions,” Schilt added. “This will allow us to better understand what might happen in the future.”

Nitrous oxide is perhaps best known as laughing gas, but it is also produced by microbes on land and in the ocean in processes that occur naturally, but can be enhanced by human activity. Marine nitrous oxide production is linked closely to low oxygen conditions in the upper ocean and global warming is predicted to intensify the low-oxygen zones in many of the world’s ocean basins. N2O also destroys ozone in the stratosphere.

“Warming makes terrestrial microbes produce more nitrous oxide,” noted co-author Edward Brook, an Oregon State paleoclimatologist whose research team included Schilt. “Greenhouse gases go up and down over time, and we’d like to know more about why that happens and how it affects climate.”

Nitrous oxide is among the most difficult greenhouse gases to study in attempting to reconstruct the Earth’s climate history through ice core analysis. The specific technique that the Oregon State research team used requires large samples of pristine ice that date back to the desired time of study – in this case, between about 16,000 and 10,000 years ago.

The unusual way in which Taylor Glacier is configured allowed the scientists to extract ice samples from the surface of the glacier instead of drilling deep in the polar ice cap because older ice is transported upward near the glacier margins, said Brook, a professor in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences.

The scientists were able to discern the contributions of marine and terrestrial nitrous oxide through analysis of isotopic ratios, which fingerprint the different sources of N2O in the atmosphere.

“The scientific community knew roughly what the N2O  concentration trends were prior to this study,” Brook said, “but these findings confirm that and provide more exact details about changes in sources. As nitrous oxide in the atmosphere continues to increase – along with carbon dioxide and methane – we now will be able to more accurately assess where those contributions are coming from and the rate of the increase.”

Atmospheric N2O was roughly 200 parts per billion at the peak of the ice age about 20,000 years ago then rose to 260 ppb by 10,000 years ago. As of 2014, atmospheric N2Owas measured at about 327 ppb, an increase attributed primarily to agricultural influences.

Although the N2O increase at the end of the last ice age was almost equally attributable to marine and terrestrial sources, the scientists say, there were some differences.

“Our data showed that terrestrial emissions changed faster than marine emissions, which was highlighted by a fast increase of emissions on land that preceded the increase in marine emissions,” Schilt pointed out. “It appears to be a direct response to a rapid temperature change between 15,000 and 14,000 years ago.”

That finding underscores the complexity of analyzing how Earth responds to changing conditions that have to account for marine and terrestrial influences; natural variability; the influence of different greenhouse gases; and a host of other factors, Brook said.

“Natural sources of N2O are predicted to increase in the future and this study will help up test predictions on how the Earth will respond,” Brook said.

Media Contact: 
Source: 

Adrian Schilt, schilta@science.oregonstate.edu;

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

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Photo at left: Taylor Glacier in Antarctica

Science study links greenhouse gases to African rainfall

CORVALLIS, Ore. – Scientists may have solved a long-standing enigma known as the African Humid Period – an intense increase in cumulative rainfall in parts of Africa that began after a long dry spell following the end of the last ice age and lasting nearly 10,000 years.

In a new study published this week in Science, an international research team linked the increase in rainfall in two regions of Africa thousands of years ago to an increase in greenhouse gas concentrations. The study was funded by the National Science Foundation and the U.S. Department of Energy.

The findings are critical, researchers say, because they provide new evidence that increases in carbon dioxide and other greenhouse gases could have a significant impact on the future climate of Africa.

“This study is important not only because it explains a long-standing puzzle, but it helps to validate model predictions of how rising greenhouse gas concentrations might change rainfall patterns in a highly populated and vulnerable part of the world,” said Peter Clark, an Oregon State University paleoclimatologist and co-author on the study.

The study was led by the National Center for Atmospheric Research (NCAR). It used computer simulations and analysis of geologic records of past climate.

The researchers focused on the era following the last ice age. When ice sheets covering North America and northern Europe began retreating after the last glacial maximum some 21,000 years ago, there was a long dry spell in central Africa that lasted until about 14,700 years ago, when rainfall increased abruptly. Scientists have long been puzzled by the regime shift, which turned deserts into grasslands and earned the African Humid Period moniker.

Rainfall actually increased in two separate regions of Africa – one north of the equator, the other south. Some previous studies had suggested that the shift may have been triggered by changes in the Earth’s orbit, but lead author Bette Otto-Bliesner said orbital patterns alone could not explain increased rainfall of that extent in both regions.

As the Earth emerged from the ice age, atmospheric levels of carbon dioxide and methane increased significantly – almost to pre-industrial levels – by 11,000 years ago. As the planet continued warming, ice sheets melted and the influx of fresh water from North America and northern Europe began weakening the Atlantic Meridional Overturning Circulation, which brings warm water up from the tropics and keeps Europe temperate.

This weakening of the Atlantic ocean current simultaneously moved precipitation southward toward the southernmost part of Africa, and suppressed rainfall in east Africa and northern equatorial Africa during the long dry spell, the researchers say.

When the ice sheets stopped melting, the circulation strengthened and brought precipitation back to the north. This change, coupled with the orbital shift and warming of both the atmosphere and oceans by greenhouse gases, triggered the African Humid Period.

“This study provides yet another demonstration of the sensitivity of the Earth’s climate to small changes in atmospheric greenhouse gases,” said Clark, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

The science team recreated records of past moisture conditions by examining fossils, former lake levels and other geologic data, and simulated past climate with a power climate model developed by NCAR.

”The future impact of greenhouse gases on rainfall in Africa is a critical socioeconomic issue,” Otto-Bliesner said. “Africa’s climate seems destined to change, with far-reaching implications for water resources and agriculture in ways that may generate new conflicts.”

The study focused on the Sahel region of Africa to the north, including Niger, Chad and northern Nigeria; and the southeastern equatorial region of Africa, including the Democratic Republic of Congo, Rwanda, Burundi, Tanzania and Kenya.

Media Contact: 
Source: 

Peter Clark, 541-737-1247; clarkp@geo.oregonstate.edu