marine science and the coast

Scientists seeking to save threatened Nassau grouper

CORVALLIS, Ore. – Scientists studying the Nassau grouper, an iconic Caribbean reef fish decimated by over-fishing, say it is showing tentative signs of recovery off the Cayman Islands since the government there imposed protective restrictions eight years ago.

However, their research also shows that the groupers’ behavior during spawning – and subsequent dispersal of their larvae – may threaten the long-term viability of the species without further protection.

“Nassau groupers form large aggregations to spawn,” said Scott Heppell, a fisheries ecologist at Oregon State University. “They are very predictable. The same trait that promotes their reproductive success, however, also makes them extremely vulnerable to fishing. And once their populations diminish, it is hard to rebuild them.”

Heppell and his colleagues are working with the Reef Environmental Education Foundation (REEF) and the Cayman Islands Department of Environment on a project to learn more about the Nassau grouper. They are particularly interested in how far the larvae disperse with the currents after spawning – a key factor in Caribbean nations’ efforts to rebuild depleted stocks.

As part of REEF’s “Grouper Moon Project,” the researchers deployed short-term and long-term drifter buoys to see where the currents potentially could carry the larvae. They also tagged several adult fish and set up telemetry sites to track the adults en route to their spawning aggregation – work supported by the Lenfest Ocean Program.

What they’ve found is that the groupers aggregate during the first full moon after the winter solstice. As many as 4,000 fish will gather at a site west of Little Cayman Island, then spawn some three to eight days later. The timing of their spawning appears driven by currents, said Heppell, an assistant professor in OSU’s Department of Fisheries and Wildlife.

“We wondered why the fish waited to spawn after aggregating,” Heppell said, “and the buoys appear to have provided the answer. As soon as the currents died down and eddies formed, spawning began. This has the effect of limiting short-term dispersal of larvae and keeps resident fish close to home.”

The long-term buoys that were released eventually drifted south, suggesting that some larvae would be carried far from the Cayman Islands. However, halfway through their 45-day journey, the buoys rode currents back to within 100 kilometers of the Cayman Islands.

“The combination of spawning when eddies arrive, and the circular nature of long-term currents has the effect of keeping fish close to home,” Heppell said. “The Cayman Islands used to have five spawning sites for Nassau groupers; now there is one. Despite protections, the other sites haven’t yet regenerated – and the limited distribution of larvae may be the reason.”

Project leaders have started a Baby Grouper Adrift website to track the location of drifter buoys over the next month in an effort funded by the Disney Worldwide Conservation Fund. The public is invited to follow the progress of the researchers at: http://www.reef.org/programs/grouper_moon/adrift/

Nassau grouper are fish that often grace tropical postcards and photographs, and they attract tourists who like to see them while scuba diving. In addition to that cultural benefit, the fish have an ecological role; they are a keystone species that influences the structure of reef communities and promotes coral health.

Scientists estimate that 60 to 80 percent of historic Nassau grouper aggregations have been wiped out from over-fishing. Those populations are slow to rebuild. Groupers don’t reach maturity until four to eight years of age, and juveniles are subject to predation by invasive lionfish and other species.

That’s what makes the protection of remaining aggregation sites important, Heppell said.

“Since protections were established in the Cayman Islands, we’ve seen evidence of increasing numbers of fish from diver survey, mark-and-recapture data, and video laser observations that document more juveniles,” Heppell said. “Sustaining that aggregation site is critical.”

“Ultimately, it is a cultural decision on managing the population,” Heppell added. “Is a fish worth more one time on a dinner plate, or being seen a hundred different times by diving tourists?”

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Scott Heppell, 541-737-1086

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Nassau grouper
Nassau grouper

Cayman Islands study
Brice Semmens of NOAA (left) and Scott Heppell, OSU

Oregon teens to compete in annual Salmon Bowl competition

CORVALLIS, Ore. – Fourteen teams from Northwest high schools will test their knowledge of marine sciences this Saturday, Feb. 26, during the annual Salmon Bowl competition at Oregon State University.

In this event, high school teens compete to see who knows the most about ocean-dwelling organisms, undersea earthquakes and volcanoes, tsunamis, marine biology, hypoxia and other oceanography-related topics.

The four- and five-student teams will compete for a chance to represent the region at the 14th annual National Ocean Sciences Bowl this spring in Texas. The national competition is a program developed by the Consortium for Ocean Leadership to raise student interest in ocean sciences as a potential field of study and a career choice.

About 100 volunteers, including faculty, staff and students in the OSU College of Oceanic and Atmospheric Sciences, will help host the event.

“The Salmon Bowl is a fun way to encourage student interest in the marine sciences, and to get students to think about what may happen in the future,” said Jenna Halsey, a COAS graduate student who helps coordinate the event.

The public is invited to watch the round-robin, single-elimination event, which will be held on the OSU campus from 9 a.m. to 4 p.m. in Burt Hall, Wilkinson Hall and Gilfillan Auditorium. All three facilities are located roughly at 26th Street and Monroe in Corvallis. Admission is free.

Neah-Kah-Nie High School, which has won the Salmon Bowl a record nine times, will return to defend its title. The school’s “A” team went on to finish sixth at nationals last year.

Competing teams include:

  • Astoria High School (three teams)
  • Benson Polytechnic, Portland (three teams)
  • Crater Renaissance Academy
  • Crater Academy of Natural Sciences
  • McMinnville High School (two teams)
  • Neah-Kah-Nie High School, Rockaway Beach (two teams)
  • Oregon Coast Aquarium (a team from Newport-area high schools)
  • Salmon Creek
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OSU expanding fleet of offshore gliders as part of ocean observatory

CORVALLIS, Ore. – Oregon State University oceanographers deployed their first undersea glider in 2005 and in the past five years, their small fleet of data-gathering autonomous vehicles has logged more than 43,000 kilometers – a distance that would more than circumnavigate the globe.

That fleet is set to expand, opening the door for a new wave of oceanic research that will greatly enhance scientific understanding of issues ranging from climate change to hypoxia and “dead zones.”

The university’s College of Oceanic and Atmospheric Sciences has been operating as many as nine gliders during the past year, a number that will grow to 21 by 2012 through funding from the national Ocean Observatories Initiative.

Three years ago, OSU was selected as one of the lead institutions for the OOI, a $387 million National Science Foundation-funded project to study the world’s oceans and their relationship to climate variability. One component of that project is to create a coastal observatory off the Northwest coast that will use moorings, buoys and gliders to better observe and monitor the ocean.

The gliders have revolutionized the study of the ocean off the Pacific Northwest, scientists say.

“In more than half a century of work, OSU scientists have recorded about 4,000 profiles of the near-shore from ships,” said Jack Barth, an Oregon State professor of oceanography and one of the lead scientists for the Ocean Observatories Initiative. “During the past five years, our gliders have logged more than 156,000 profiles – nearly 40 times what six decades of shipboard studies have provided.

“That’s pretty amazing, when you think about it,” Barth added. “Each year alone, we log more profiles than have ever been recorded via ship off Newport. And the beauty of gliders is that the data is continual. They record 24 hours a day, regardless of the weather or how rough the sea is.”

The glider project led by Barth and fellow oceanographer Kipp Shearman is featured in a special marine science issue of Terra, OSU’s research magazine. It is online at: http://oregonstate.edu/terra/ and offers stories on marine reserves, ocean acidification and the Gulf of Mexico. A two-page info-graphic presents 10 examples of ocean observing systems used by West Coast scientists.

OSU’s glider fleet represents a significant investment. Each of the undersea gliders costs between $100,000 and $200,000. The machines can be programmed to run for 3-5 weeks, from near-shore to the continental slope, and every six hours they rise to the surface and transmit data to OSU computers via satellite.

The data they collect informs scientists on conditions including El Niño and La Niña, hypoxia and resulting “dead zones,” harmful algal blooms and others.

In addition to recording ocean temperatures, salinity and dissolved oxygen levels, the newest gliders will use acoustics to measure water velocity. “For the first time,” Barth said, “we will be able to nearly simultaneously map ocean currents – from the surface to the bottom of the ocean – and detect just where these underwater ‘rivers’ run.”

OSU scientists are excited about sharing their data – in near real-time – with researchers, fishermen and the public.

“The fishermen we’ve talked to are intensely interested in the data we will generate,” Barth pointed out “Crabbers don’t want to put their pots into areas that have strong bottom currents, nor do trawlers want to contend with strong drifts. The findings will also be important for ecologists studying larval dispersal of marine animals.”

Technology is advancing so rapidly, Barth says, that the gliders will carry new instruments as early as the next year or two.

“We’re putting hydrophones onto the moorings, for example, and there’s no reason why we can’t put them onto the gliders and listen for marine mammals or fish that have been tagged with transmitters,” he said.

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Jack Barth, 541-737-1607

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Glider on Elakha
Glider launch from the R/V Elakha


Glider launch
OSU glider technician Justin Brodersen

Fossil Fest set for Feb. 12 at OSU’s Hatfield Marine Science Center

NEWPORT, Ore. – Have you found an interesting fossil on an Oregon beach and wondered about its origin? Are you curious about what other treasures can be found on our shoreline?

Oregon State University’s Hatfield Marine Science Center will hold a special event on Saturday, Feb. 12, called “Fossil Fest.” It will feature William Orr, known as Oregon’s pre-eminent paleontologist, and co-author of the book, “Oregon Fossils,” with his wife, Elizabeth. Published by the OSU Press, it is considered the definitive book on the state’s paleontology.

The Hatfield center is located on the south side of Yaquina Bay, just below the Hwy. 101 bridge. Visitors are encouraged to bring their fossils, or other beach finds, to the center on Feb. 12, and Orr will attempt to identify them.

He also will give a presentation at 1:30 p.m. at the center called “Digging up the King’s Valley Groundsloth.”

Other activities for Fossil Fest include a fossil swap and special displays staffed by the North American Research Group.

The HMSC visitor center, operated by Oregon Sea Grant, is open from 10 a.m. until 4 p.m. Admission is by a suggested donation.

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Bill Hanshumaker, 541-867-0167

Forum paper: Scientists urge new research policies in wake of Gulf disaster

CORVALLIS, Ore. – Scientists are having a difficult time gauging the recovery of marine species from the Deepwater Horizon oil spill in the Gulf of Mexico because they lack sufficient data about historical population size and the distribution, growth rates and reproduction rates of many species.

In a forum paper published this week in the journal Science, they call for a new research agenda that prioritizes systematic acquisition of baseline data for marine species.

“It is impossible to diagnose whether a species is recovering or floundering if you don’t have good data on their status and trends,” said Selina Heppell, an Oregon State University fisheries biologist and one of the authors of the article. “Too much of the funding in this country goes toward putting fires out instead of gaining basic biological information, which is what resource managers need to identify and diagnose changes at the population level.

“This is not just about the Gulf of Mexico,” Heppell added. “It is a problem for protected species everywhere.”

Heppell, lead author Karen Bjorndal from the University of Florida, and eight other authors point to the 1989 Exxon Valdez oil spill in Alaska, where scientists encountered difficulty evaluating the effects on wildlife because of limited data on abundance and demography – the rates of survival, growth and reproduction that are primary indicators of population change.

“Sadly,” they wrote, “the situation in the (Gulf of Mexico) is similar more than 20 years later.”

Heppell, who is a professor in the Department of Fisheries and Wildlife at Oregon State University, said doing an ecological and biological assessment of all marine species would be difficult and expensive. Therefore, she says, the emphasis should be on those species that are the most endangered, or those that have an economic impact, such as those creatures that interact with important fisheries.

“We spend millions of dollars assessing fish stocks,” she said. “If we want to monitor endangered species in the same way, we need to focus resources on the aspects of biology that provide the best information about population recovery. That involves research on demography, not just efforts to count individuals.”

In their Science article, the authors describe the assessment of sea turtle populations as a microcosm of the larger issue. Sea turtle populations are monitored almost exclusively by counting nests on beaches, but when those populations increase or decrease, scientists often don’t know why because nesting females are such a tiny fraction of the total population. In Florida, the number of loggerhead turtles, for example, increased from 1989-98, then plummeted.

Several factors could have contributed, but a lack of knowledge about age distribution, reproduction rates, mortality rates and other data have made it difficult to determine what triggered the changes – and impossible to create  management strategies to deal with them, noted Heppell, who has worked with the National Marine Fisheries Service on turtle conservation issues since 1995.

In contrast, Australian researchers have logged 30 years of demographic data on loggerhead turtles and when a steep decline in their population on the Great Barrier Reef took place in the 1980s and 1990s, they were able to attribute it to predation by foxes on nests and incidental capture in trawl fisheries.

“Both hazards have now been mitigated by government agencies,” the authors wrote,” resulting in an apparently recovering stock.”

The authors list seven elements that should be considered in crafting new research priorities for protected marine species, including sea birds and mammals, as well as turtles:

  • Integrate demography with abundance trends for the species at all life stages and determine environmental effects on those parameters;
  • Emphasize analyses of cumulative effects instead of focusing on individual threats such as pollution, bycatch or habitat loss;
  • Elucidate links among and within populations since oceans have greater movement, genetic exchange and dispersal than terrestrial systems;
  • Revise permitting processes to allow more rapid and flexible response to environmental concerns;
  • Encourage data sharing and increase access to data as a prerequisite for funding;
  • Improve assessment tools for evaluating anthropogenic impacts on populations;
  • Prioritize investments to focus on long-term population management needs.


“We know that hundreds, possibly thousands, of endangered Kemp’s Ridley sea turtles were killed or injured by the Gulf spill,” Heppell said. “That species had been recovering rapidly – a great conservation success story. What we don’t know, and can’t determine with available data, is how detrimental the spill effects will be on that recovery.

“We can use money from the resulting fines to develop a new strategy for monitoring and assessment that can identify the specific causes of population decline and make management more efficient,” she added.

Shifting the priorities of federal agencies to focus on research that emphasizes how and why populations change over time is a key, the authors say.

Conclude the authors: “In the wake of the BP oil spill, the need for this policy shift is as clear as it is compelling. If the largest offshore oil spill in U.S. history is not enough to effect this policy shift, what would it take?”

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Hydrophones in North Atlantic document endangered right whales

NEWPORT, Ore. – Scientists using undersea hydrophones have documented the appearance of endangered right whales in a region east of Greenland, where they historically had been hunted but were thought to be extinct.

The scientists recorded more than 2,000 whale vocalizations from 2007-08, and since have identified them as right whales and mapped the geographic origin of those recordings. This mapping shows that the whales are using an area where ships commonly pass while in transit between the United States and Europe. And more shipping may take place as northern regions become increasingly ice-free.

Results of the research were published this week in the journal Biology Letters.

Lead author David Mellinger of Oregon State University said the use of hydrophones enables scientists to “listen” for whales in remote areas where visual observations are difficult to conduct. Right whales have unique vocalization patterns that allow scientists to differentiate their calls from those of other whales.

“In the last 50 years, there have only been two confirmed sightings of right whales in the Cape Farewell Ground, which is about 500 kilometers east of the southern tip of Greenland,” said Mellinger, an associate professor at OSU’s Hatfield Marine Science Center in Newport, Ore. “The weather there makes it almost impossible to conduct regular surveys.

“But it was an important area historically for the whales, and we needed to determine if they were still using it,” he added. “The hydrophones showed that not only are they using the Cape Farewell Ground, but that they’ve broadened the range of where we’ve known them to be in the past.”

The North Atlantic right whale is among the rarest cetaceans in the world. Despite more than 75 years of international protection, scientists estimate that fewer than 450 individuals remain. Most of those are a “western stock” that can be seen off the East Coast of North America from Florida to the Gulf of Saint Lawrence. It is unknown whether most of the whales heard off Greenland and Iceland are from this stock.

Nor are scientists certain of the size of the population.

“We can’t tell how many individuals might have been in the area, because they aren’t individually distinctive in their vocalizations,” Mellinger said. “But we know there were multiple whales because we recorded vocalizations at roughly the same time from different locations.”

Right whales were nearly decimated by whaling in the 1800s and early 1900s, and despite a moratorium on hunting them, their recovery has been slow. The cause of many recent deaths has been anthropogenic, scientists say, especially collisions with ships and entanglement with fishing gear.

Also contributing to the journal article were other scientists from OSU, the National Oceanic and Atmospheric Administration, and the University of Iceland. Funding for the study was provided by NOAA.

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David Mellinger, 541-867-0372

New study: Loss of reflectivity in the Arctic double estimate of climate models

CORVALLIS, Ore. – A new analysis of the Northern Hemisphere’s “albedo feedback” over a 30-year period concludes that the region’s loss of reflectivity due to snow and sea ice decline is more than double what state-of-the-art climate models estimate.

The findings are important, researchers say, because they suggest that Arctic warming amplified by the loss of reflectivity could be even more significant than previously thought.

The study was published online this week in Nature Geoscience. It was funded primarily by the National Science Foundation, with data also culled from projects funded by NASA, the Department of Energy and others.

“The cryosphere isn’t cooling the Earth as much as it did 30 years ago, and climate model simulations do not reproduce this recent effect,” said Karen Shell, an Oregon State University atmospheric scientist and one of the authors of the study. “Though we don’t necessarily attribute this to global warming, it is interesting to note that none of the climate models used for the 2007 International Panel on Climate Change report showed a decrease of this magnitude.”

The cryosphere is the collective portion of the Earth’s surface where water is in solid form and includes sea ice, snow, lake and river ice, glaciers, ice sheets and frozen ground. Most of these frozen areas are highly reflective, and “bounce” sunlight back into the atmosphere, keeping the Earth cooler than it would be without the cryosphere.

But as temperatures warm, ice and snow melts and reflectivity decreases, noted Shell, an assistant professor in OSU’s College of Oceanic and Atmospheric Sciences.

“Instead of being reflected back into the atmosphere, the energy of the sun is absorbed by the Earth, which amplifies the warming,” Shell said. “Scientists have known for some time that there is this amplification effect, but almost all of the climate models we examined underestimated the impact – and they contained a pretty broad range of scenarios.”

As part of the study, Shell, lead author Mark Flanner of the University of Michigan, and their colleagues compared Northern Hemisphere cryosphere changes between 1979 and 2008 in 18 different climate models to changes in actual snow, ice and reflectivity measurements of the same period. They determined that mean radiative forcing – or the amount of energy reflected into the atmosphere – ranged from 4.6 to 2.2 watts per meter squared.

During the 30-year study period, cryosphere cooling declined by 0.45 watts per meter squared. The authors attribute that decline equally to loss of snow and sea ice.

“Some of the decline may be natural climate variability,” Shell said. “Thirty years isn’t a long enough time period to attribute this entirely to ‘forcing,’ or anthropogenic influence. But the loss of cooling is significant. The rate of energy being absorbed by the Earth through cryosphere decline – instead of being reflected back to the atmosphere – is almost 30 percent of the rate of extra energy absorption due to carbon dioxide increase between pre-industrial values and today.”

The “albedo” or reflectivity process is simple, scientists say, but difficult to measure on a broad scale. The reflectivity of ice and snow is obviously much greater than that of darker, unfrozen ground, or open sea water. But researchers also have discovered that variations in the snow and ice result in different albedo impacts.

For example, pools of melted water on top of sea ice can have significantly less reflectivity, which in essence may speed up the warming and possibly melting of that sea ice.

“While the current group of models underestimates these Northern Hemisphere cryosphere changes, new models will be released this year that will have better representations of snow and ice,” Shell said. “This study will help climate modelers improve the new generation of models to better predict the rate of cryosphere and albedo decline in the future.”

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Karen Shell, 541-737-0980

OSU’s Abbott president-elect of The Oceanography Society Council

CORVALLIS, Ore. – Mark Abbott, dean of the College of Oceanic and Atmospheric Sciences at Oregon State University, has been elected president-elect The Oceanography Society Council.

The council is the governing body for The Oceanography Society, which was founded in 1988 to disseminate knowledge of oceanography, enhance research and education, promote communication among oceanographers and bring together different disciplines. Its membership includes oceanographers, engineers and other scientists active in ocean-related fields, as well as persons who have advanced oceanography through leadership and public service.

This non-profit organization, headquartered in Washington, D.C., also publishes the magazine, Oceanography.

“With the release last year of a new national ocean policy, this is an important time for the oceanographic community in regards  to research, education and public service,” Abbott said. “The Oceanography Society will engage its members in the implementation of this policy.”

Abbott joined the OSU faculty in 1988 and has been dean of the College of Oceanic and Atmospheric Sciences since 2001. He is a member of the National Science Board, and serves as vice-chair of the Oregon Global Warming Commission.

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Mark Abbott, 541-737-5195

Scientists in Newport may hold key to future of Alaska king crab

NEWPORT, Ore. – Both the red and blue varieties of Alaska king crab have declined significantly and as resource managers struggle to determine why, a small team of scientists in a most unlikely location is working on an insurance policy – trying to raise crabs from the larval stage to juveniles in a hatchery setting.

The idea isn’t to immediately begin seeding the Bering Sea or Gulf of Alaska with hatchery-raised youngsters, the scientists say. It is to see if it’s even feasible – in case it’s needed in the future.

And this all is taking place in Newport, Ore., where the only places to find king crab are in stores and restaurants. In Oregon, the Dungeness reigns supreme among crabs; but Newport is also the site of Oregon State University’s Hatfield Marine Science Center, a place that more than a dozen scientists and technicians from NOAA’s Alaska Fisheries Science Center call home.

The reason for locating at HMSC is simple, according to Allan Stoner, who directs the Alaska Fisheries group in Newport. “The OSU lab provides seawater facilities rivaling any in the country for research with cold-water species, and our biologists have more than 25 years experience working with the systems here,” he said.

In the OSU laboratories, where clean seawater is pumped daily from Yaquina Bay, the scientists will try to perfect culture of king crab through the juvenile stages – and explore whether or not the young crabs can be conditioned or “trained” to select good habitat and avoid predators. Hatchery-reared animals are “often deficient in these tasks,” Stoner pointed out.

“Pacific halibut are death on crabs,” Stoner said. “We’re going to see if experience with young halibut about 25 centimeters long helps the juvenile crabs to learn avoidance behavior. Pacific cod can also be a problem, though they aren’t as aggressive as halibut. If these controlled experiments work, we’ll test similarly trained crabs in the field in Alaska.”

The Alaska King Crab Research, Rehabilitation and Biology program – known as AKCRRAB –  received $303,000 from the NOAA SeaGrant Aquaculture Research Program, and an additional $157,000 in matching funds from Alutiiq Pride Shellfish Hatchery, Alaska Department of Fish and Game, University of Alaska, and Alaska SeaGrant for the project, some of which will support the Newport research.

AKCRRAB scientists from the University of Alaska-Fairbanks, the Alaska Fisheries Science Center and the Alutiiq Pride Shellfish Hatchery have made great strides in producing king crab larva that can survive in hatcheries. Their early experiments, in 2007, generated just a 2 percent survival rate and a few thousand juveniles. That rose to 31 percent in 2008, and 50 percent in 2009 and 2010, when scientists successfully raised more than 100,000 red king crabs to their first juvenile stage.

But the key now is helping them get bigger – and smarter – so they eventually could be released back into the wild and have a chance at survival, Stoner said.

“It should be an interesting experiment,” Stoner said. “Ben Daly (a Ph.D. student at the University of Alaska) will take crabs into the Gulf of Alaska on tethers during 2011 to see how they respond to their environment and potential predators. The action will be observed using underwater cameras with live-feed to the nearby shore.”

The project is ambitious, but so are the stakes. Red king crab has been Alaska’s top shellfish fishery and since 1959, U.S. fishers have harvested nearly 2 billion pounds of the delicacy from Alaska waters, worth about $1.6 billion. But the fishery has crashed as fewer crabs are reaching adulthood and the fishery for red king crab is now closed entirely in the Gulf of Alaska.

“Overfishing, climate change, predation by fish, and ocean acidification are all possible explanations,” Stoner said, “though it’s likely a host of factors.”

George Boehlert, director of OSU’s Hatfield Marine Science Center, said the location of so many scientists from state and federal agencies on site is equally important to the center’s seawater system.

“We have scientists from many different disciplines, as well as agencies, who can provide different experiences and perspectives that make the Hatfield Marine Science Center unlike any research facility in the country,” Boehlert said.

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Allan Stoner, 541-867-0165

Oceanic “garbage patch” not nearly as big as portrayed in media

CORVALLIS, Ore. – There is a lot of plastic trash floating in the Pacific Ocean, but claims that the “Great Garbage Patch” between California and Japan is twice the size of Texas are grossly exaggerated, according to an analysis by an Oregon State University scientist.

Further claims that the oceans are filled with more plastic than plankton, and that the patch has been growing tenfold each decade since the 1950s are equally misleading, pointed out Angelicque “Angel” White, an assistant professor of oceanography at Oregon State.

“There is no doubt that the amount of plastic in the world’s oceans is troubling, but this kind of exaggeration undermines the credibility of scientists,” White said. “We have data that allow us to make reasonable estimates; we don’t need the hyperbole. Given the observed concentration of plastic in the North Pacific, it is simply inaccurate to state that plastic outweighs plankton, or that we have observed an exponential increase in plastic.”

White has pored over published literature and participated in one of the few expeditions solely aimed at understanding the abundance of plastic debris and the associated impact of plastic on microbial communities. That expedition was part of research funded by the National Science Foundation through C-MORE, the Center for Microbial Oceanography: Research and Education.

The studies have shown is that if you look at the actual area of the plastic itself, rather than the entire North Pacific subtropical gyre, the hypothetically “cohesive” plastic patch is actually less than 1 percent of the geographic size of Texas.

“The amount of plastic out there isn’t trivial,” White said. “But using the highest concentrations ever reported by scientists produces a patch that is a small fraction of the state of Texas, not twice the size.”

Another way to look at it, White said, is to compare the amount of plastic found to the amount of water in which it was found. “If we were to filter the surface area of the ocean equivalent to a football field in waters having the highest concentration (of plastic) ever recorded,” she said, “the amount of plastic recovered would not even extend to the 1-inch line.”

Recent research by scientists at the Woods Hole Oceanographic Institution found that the amount of plastic, at least in the Atlantic Ocean, hasn’t increased since the mid-1980s – despite greater production and consumption of materials made from plastic, she pointed out.

“Are we doing a better job of preventing plastics from getting into the ocean?” White said. “Is more plastic sinking out of the surface waters? Or is it being more efficiently broken down? We just don’t know. But the data on hand simply do not suggest that ‘plastic patches’ have increased in size. This is certainly an unexpected conclusion, but it may in part reflect the high spatial and temporal variability of plastic concentrations in the ocean and the limited number of samples that have been collected.”

The hyperbole about plastic patches saturating the media rankles White, who says such exaggeration can drive a wedge between the public and the scientific community. One recent claim that the garbage patch is as deep as the Golden Gate Bridge is tall is completely unfounded, she said.

“Most plastics either sink or float,” White pointed out. “Plastic isn’t likely to be evenly distributed through the top 100 feet of the water column.”

White says there is growing interest in removing plastic from the ocean, but such efforts will be costly, inefficient, and may have unforeseen consequences. It would be difficult, for example, to “corral” and remove plastic particles from ocean waters without inadvertently removing phytoplankton, zooplankton, and small surface-dwelling aquatic creatures.

“These small organisms are the heartbeat of the ocean,” she said. “They are the foundation of healthy ocean food chains and immensely more abundant than plastic debris.”

The relationship between microbes and plastic is what drew White and her C-MORE colleagues to their analysis in the first place. During a recent expedition, they discovered that photosynthetic microbes were thriving on many plastic particles, in essence confirming that plastic is prime real estate for certain microbes.

White also noted that while plastic may be beneficial to some organisms, it can also be toxic. Specifically, it is well-known that plastic debris can adsorb toxins such as PCB.

“On one hand, these plastics may help remove toxins from the water,” she said. “On the other hand, these same toxin-laden particles may be ingested by fish and seabirds. Plastic clearly does not belong in the ocean.”

Among other findings, which White believes should be part of the public dialogue on ocean trash:

  • Calculations show that the amount of energy it would take to remove plastics from the ocean is roughly 250 times the mass of the plastic itself;
  • Plastic also covers the ocean floor, particularly offshore of large population centers. A recent survey from the state of California found that 3 percent of the southern California Bight’s ocean floor was covered with plastic – roughly half the amount of ocean floor covered by lost fishing gear in the same location. But little, overall, is known about how much plastic has accumulated at the bottom of the ocean, and how far offshore this debris field extends;
  • It is a common misperception that you can see or quantify plastic from space. There are no tropical plastic islands out there and, in fact, most of the plastic isn’t even visible from the deck of a boat;
  • There are areas of the ocean largely unpolluted by plastic. A recent trawl White conducted in a remote section of water between Easter Island and Chile pulled in no plastic at all.

There are other issues with plastic, White said, including the possibility that floating debris may act as a vector for introducing invasive species into sensitive habitats.

“If there is a takeaway message, it’s that we should consider it good news that the ‘garbage patch’ doesn’t seem to be as bad as advertised,” White said, “but since it would be prohibitively costly to remove the plastic, we need to focus our efforts on preventing more trash from fouling our oceans in the first place.”

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Angel White, 541-737-6397

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Larger plastic from trawls

A sample of plastic found in the ocean