Research Highlights
News & Insights
WHOI geochemist Chris German pairs an autonomous surface vehicle (ASV) called a Wave Glider with other vehicles to expand research here and on other Ocean Worlds
Researchers investigate dust from the ocean’s farthest point from land to reconstruct the climactic history of the Southern Hemisphere, and understand how micronutrients have influenced biological productivity in this oceanic desert.
WHOI-MIT joint program student outfits her basement to do vital work on a marine carbon sensor
Infographics strive to give us a sense of how long plastic goods will last in the environment. But is this information reliable? The findings of a new study from WHOI may surprise you.
Marine life has been naturally producing toxic chemicals well before chemical companies were manufacturing PCBs. But are these naturally-produced compounds as harmful as man-made environmental pollutants, and do those pose a human health threat?
A marine chemist spends his time at home tinkering on a high-tech buoy in the basement, proving that being homebound doesn’t mean you can’t think big.
Ken Buesseler joins the hosts of Future Hindsight Podcast to talk about the safety of the Pacific Ocean, the natural occurrence of radioactivity in our environment, and a citizen scientist project for oceanic testing.
A decade of research since the Deepwater Horizon disaster has revealed how sunlight—its importance long understated in oil spill science—substantially alters petroleum floating at the sea surface.
The test being used to diagnose the novel coronavirus—and other pandemics like AIDS and SARS—was developed with the help of an enzyme isolated from a microbe found in marine hydrothermal vents as well as freshwater hot springs.
News Releases
Low-to-mid latitude land surfaces at low elevation cooled on average by 5.8 ± 0.6⁰C during the Last Glacial Maximum (LGM), based on an analysis of noble gases dissolved in groundwater, according to a new study published in Nature.
Temperature estimates in the study are substantially lower than indicated by some notable marine and low-elevation terrestrial studies that have relied on various proxies to reconstruct past temperatures during the LGM, a period about 20,000 years ago that represents the most recent extended period of globally stable climate that was substantially cooler than present.
“The real significance of our paper is that prior work has badly underestimated the cooling in the last glacial period, which has low-balled estimates of the Earth’s climate sensitivity to greenhouse gases,” said paper co-author Jeffrey Severinghaus, a professor of geosciences at Scripps Institution of Oceanography, University of California San Diego. “The main reason that prior work was flawed was that it relied heavily on species abundances in the past. But just like humans, species tend to migrate to where the climate suits them. Think, for instance, of snowbirds moving from Canada to Arizona in winter. So, species aren’t very good thermometers.”
The paper does broadly support a recent marine proxy study by Tierney et al. published last year that found substantially greater low-latitude cooling than previous efforts and, in turn, suggested greater climate sensitivity than prior studies. That earlier paper suggested the equilibrium response of Earth’s global-mean surface temperature is 3.4⁰C per doubling of atmospheric carbon dioxide, in line with the consensus range of estimates from state-of-the-art climate models, but somewhat higher than the usual best estimate of 3.0 °C.
“The rather high climate sensitivity that our results suggest is not good news regarding future global warming, which may be stronger than expected using previous best estimates. In particular, our global review reinforces the finding of several single noble gas case studies that the tropics were substantially cooler during the last glacial maximum than at present. The unpleasant implication for the future is that the warmest regions of the world are not immune to further heating,” commented co-author Werner Aeschbach, a professor at the Institute of Environmental Physics, Heidelberg University, Heidelberg, Germany.
The paper made use of a technique in which measurements of noble gases dissolved in ancient groundwater enable direct and quantitative determination of past surface temperature. Noble gases in the atmosphere are chemically and biologically inactive and have no appreciable sinks or sources over the 40,000-year timescales relevant to this study. They dissolve into groundwater, and their equilibrium concentrations depend strongly on temperature. The authors compiled four decades worth of groundwater noble gas data from every continent except Antarctica, along with previously unpublished measurements from some key tropical locations to produce a global record of noble gas-derived temperatures (NGTs) of the LGM.
“Noble gas paleo temperature records are so powerful because they are based on a physical principle and are not much influenced by life-which always complicates everything- and short term extreme events.” said journal article co-author Martin Stute, a professor in the Environmental Science Department at Barnard College and an adjunct senior research scientist at the Lamont-Doherty Earth Observatory. “They provide a temperature average over hundreds to thousands of years. It is remarkable, and rewarding for me, how consistent noble gas paleo temperature reconstructions are in low latitudes from the early studies that I led in the 1990s to the most recent ones.”
The study bolsters the method of analyzing noble gases to reconstruct paleo temperatures and provides more confidence in climate models, according to the authors.
“Another key goal of our study was to evaluate the overall accuracy of the so-called ‘noble gas paleo-thermometer’ for reconstructing temperatures on land during the last glacial period. Naturally, our ability to confidently use this tool to understand the past is related to how well it works in the present. By comparing modern temperature observations to independent estimates using noble gases in relatively young groundwater, we found that the noble gas thermometer is remarkably accurate over a wide temperature range from around 2 to 33 ⁰C (36 to 91 ⁰F). This adds a good deal of confidence to our estimates of cooling during the LGM,” said the paper’s lead author, Alan Seltzer, an assistant scientist in the Marine Chemistry and Geochemistry Department at the Woods Hole Oceanographic Institution.
Seltzer added that the new analysis is important because climate models “provide an important tool that policy makers can use to decide on how to prepare for future environmental changes. This study alleviates the concern that, based on LGM proxy data, models might over-predict the global mean temperature response to carbon dioxide. In fact, based on both our study and the recent marine-proxy compilation, it is becoming clear that paleoclimate proxies and models are in agreement.”
Violent continental collisions and volcanic eruptions are not things normally associated with comfortable conditions for life. However, a new study, coauthored by Peter Barry, assistant scientist at the Woods Hole Oceanographic Institution, along with University of Tennessee, Knoxville, Associate Professor of Microbiology Karen Lloyd, unveils a large microbial ecosystem living deep within the earth that is fueled by chemicals produced during these tectonic cataclysms.
When oceanic and continental plates collide, one plate is pushed down, or subducted, into the mantle and the other plate is pushed up and studded with volcanoes. This is the main process by which chemical elements are moved between Earth’s surface and interior and eventually recycled back to the surface.
“Subduction zones are fascinating environments-they produce volcanic mountains and serve as portals for carbon moving between the interior and exterior of Earth,” said Maarten de Moor, associate professor at the National University of Costa Rica and another coauthor of the study.
Normally this process is thought to occur outside the reach of life because of the extremely high pressures and temperatures involved. Although life almost certainly does not exist at the extreme conditions where Earth’s mantle mixes with the crust to form lava, in recent decades scientists have learned that microbes extend far deeper into Earth’s crust than previously thought.
This opens the possibility for discovering previously unknown types of biological interactions occurring with deep plate tectonic processes.
An interdisciplinary and international team of scientists has shown that a vast microbial ecosystem primarily eats the carbon, sulfur, and iron chemicals produced during the subduction of the oceanic plate beneath Costa Rica. The team obtained these results by sampling the deep subsurface microbial communities that are brought to the surface in natural hot springs, in work funded by the Deep Carbon Observatory and the Alfred P. Sloan Foundation.
The team found that this microbial ecosystem sequesters a large amount of carbon produced during subduction that would otherwise escape to the atmosphere. The process results in an estimated decrease of up to 22 percent in the amount of carbon being transported to the mantle.
“This work shows that carbon may be siphoned off to feed a large ecosystem that exists largely without input from the sun’s energy. This means that biology might affect carbon fluxes in and out of the earth’s mantle, which forces scientists to change how they think about the deep carbon cycle over geologic time scales,” said WHOI’s Barry.
The team found that these microbes-called chemolithoautotrophs-sequester so much carbon because of their unique diet, which allows them to make energy without sunlight.
“Chemolithoautotrophs are microbes that use chemical energy to build their bodies. So, they’re like trees, but instead of using sunlight they use chemicals,” said Lloyd, a co-corresponding author of the study. “These microbes use chemicals from the subduction zone to form the base of an ecosystem that is large and filled with diverse primary and secondary producers. It’s like a vast forest, but underground.”
This new study suggests that the known qualitative relationship between geology and biology may have significant quantitative implications for our understanding of how carbon has changed through deep time. “We already know of many ways in which biology has influenced the habitability of our planet, leading to the rise in atmospheric oxygen, for example,” said Donato Giovannelli, a professor at the University of Naples Federico II and co-corresponding author of the study. “Now our ongoing work is revealing another exciting way in which life and our planet coevolved.”
Image caption: Scientists, including WHOI’s Peter Barry (front left) set up gas sampling apparatus. Credit: Tom Owens
Northern Star Coral Study Could Help Protect Tropical Corals
Rhode Island Considers Naming the Local Coral as a State Emblem
Close-up of a Northern Star Coral (Astrangia poculata) colony taken from a microscope in the laboratory at Roger Williams University, Rhode Island. Credit: Alicia Schickle
As the Rhode Island legislature considers designating the Northern Star Coral an official state emblem, researchers are finding that studying this local creature’s recovery from a laboratory-induced stressor could help better understand how to protect endangered tropical corals.
A new study published today in mSystems, a journal of the American Society for Microbiology, investigates antibiotic-induced disturbance of the coral (Astrangia poculata) and shows that antibiotic exposure significantly altered the composition of the coral’s mucus bacterial microbiome, but that all the treated corals recovered in two weeks in ambient seawater.
The stony Northern Star Coral naturally occurs off the coast of Rhode Island and other New England states in brown colonies with high (symbiotic) densities and in white colonies with low (aposymbiotic) densities of a symbiotic dinoflagellate alga. The study found that those corals with algal symbionts – organisms that are embedded within the coral’s tissue and are required by tropical corals to survive – recovered their mucus microbiomes more consistently and more quickly.
The study also identified six bacterial taxa that played a prominent role in reassembling the coral back to its healthy microbiome. This is the first microbiome manipulation study on this coral.
“The work is important because it suggests that this coral may be able to recover its mucus microbiome following disturbance, it identifies specific microbes that may be important to assembly, and it demonstrates that algal symbionts may play a previously undocumented role in the microbial recovery and resilience to environmental change,” the paper states.
With thermal bleaching and disease posing major threats to tropical corals, this research, along with other work on tropical corals, “provides a major step toward identifying the microbiome’s roles in maintaining coral resilience,” the paper notes.
“We think that the algae are helping the coral select the microbes that live with it, and this suggestion of symbiont-microbe coordination following disturbance is a new concept for corals,” said paper co-author Amy Apprill, associate scientist at the Woods Hole Oceanographic Institution.
“Worldwide, coral reefs are in crisis. Any time we see corals recover, that’s always good news. It shows that they can combat a stressor and figure out how to become healthy again,” said Apprill. “What we found here is translatable to tropical corals which are faced with different stressors, such as warming water, disease, and pollution. This paper suggests that the symbiotic algae play a major role in providing consistency and resilience to the coral microbiome.”
“When we think about corals, it’s usually assumed that we’re thinking about the tropics and the bright blue water and where it’s warm, sunny, and sandy. However, the Northern Star Coral lives in murkier and much colder waters, yet it can still teach us a lot about expanding our understanding of corals,” said lead author Shavonna Bent, a student in the MIT-WHOI Joint Program in Oceanography/Applied Ocean Science and Engineering.
The Northern Star Coral is an ideal emblem for Rhode Island, said co-author Koty Sharp. The coral is small like the state; it’s New England-tough in dealing with large temperature fluctuations; and it’s a local, offering plenty of insight that can help address global problems, said paper co-author Koty Sharp, an associate professor at Roger Williams University who is leading the effort for official designation of the coral.
Committees from both the Rhode Island House and Senate have held hearings on the proposed legislation. The Senate has approved the bill, and the House could vote on it in the coming month. Assuming the House also approves the bill, it will be sent to Rhode Island Gov. Daniel McKee for signing into law.
Sharp said the designation effort has a big educational component. “If designating this as a state emblem allows us to teach more people about the power of basic research to support conservation, or if this allows us to teach a generation of school children about the local animals that live around them, then this state coral will have a great deal of value,” she said.
1Woods Hole Oceanographic Institution, Woods Hole, MA, USA
2 Johnson State College, Johnson, VT, USA
3Roger Williams University, Bristol, RI, USA
The vast reservoir of carbon that is stored in soils probably is more sensitive to destabilization from climate change than has previously been assumed, according to a new study by researchers at WHOI and other institutions.
The study found that the biospheric carbon turnover within river basins is vulnerable to future temperature and precipitation perturbations from a changing climate.
Although many earlier, and fairly localized, studies have hinted at soil organic carbon sensitivity to climate change, the new research sampled 36 rivers from around the globe and provides evidence of sensitivity at a global scale.
“The study results indicate that at the large ecosystem scale of river basins, soil carbon is sensitive to climate variability,” said WHOI researcher Timothy Eglinton, co-lead author of the paper in the Proceedings of the National Academy of Sciences of the United States of America. “This means that changing climate, and particularly increasing temperature and an invigorated hydrological cycle, may have a positive feedback in terms of returning carbon to the atmosphere from previously stabilized pools of carbon in soils.”
The public is generally aware that climate change can potentially destabilize and release permafrost carbon into the atmosphere and exacerbate global warming. But the study shows that this is true for the entire soil carbon reservoir, said WHOI researcher Valier Galy, the other co-lead author of the study.
The soil carbon reservoir is a key component in keeping the atmosphere in check in terms of how much carbon dioxide is in the air. The amount of carbon stored in terrestrial vegetation and soils is three times more than how much the atmosphere holds, and it consumes more than a third of the anthropogenic carbon that is emitted to the atmosphere.
To determine the sensitivity of terrestrial carbon to destabilization from climate change, researchers measured the radiocarbon age of some specific organic compounds from the mouths of a diverse set of rivers. Those rivers—including the Amazon, Ganges, Yangtze, Congo, Danube, and Mississippi—account for a large fraction of the global discharge of water, sediments and carbon from rivers to the oceans.
Terrestrial carbon, however, is not so simple to isolate and measure. That’s because carbon in rivers comes from a variety of sources, including rocks, organic contaminants such as domestic sewage or petroleum that differ widely in their age, and vegetation. To determine what’s happening within the rivers’ watersheds, and to measure radiocarbon from the terrestrial biosphere, researchers focused on two groups of compounds: the waxes of plant leaves that serve a protective function for the plants’ leaf surface and lignin, which is the woody “scaffolding” of land plants.
Taking these measurements showed a relationship between the age of the terrestrial carbon in the rivers and the latitude where the rivers reside, researchers found. That latitudinal relationship prompted researchers to infer that climate must be a key control in the age of the carbon that is exported from the terrestrial biosphere to these rivers, and that temperature and precipitation are primary controls on the age of that carbon.
“Why this study is powerful is because this large number of rivers, the wide coverage, and the wide range of catchment properties give a very clear picture of what’s happening at the global scale,” said Galy. “You could imagine that by going after lots of rivers, we would have ended up with a very complicated story. However, as we kept adding new river systems to the study, the story was fairly consistent.”
“In many respects, Earth scientists see rivers as being a source signal that is sent to sedimentary records that we can interpret,” said Eglinton. “By going to sedimentary records, we have the opportunity to look at how the terrestrial biosphere has responded to climate variability in the past. In addition, by monitoring rivers in the present day, we can also use them as sentinels in order to assess how these watersheds may be changing.”
The ocean twilight zone, a dimly lit region roughly 200–1000 meters (650–3200 feet) below the surface, contains the largest amount of fish biomass on Earth—yet it remains largely unexplored by scientists. A new observation network under development by the Woods Hole Oceanographic Institution (WHOI) seeks to change that. Encompassing 250,000 square kilometers (roughly 155,300 square miles) of the northwest Atlantic Ocean, the network will collect around-the-clock data about the twilight zone over months or even years, offering unprecedented insight into this little-known, yet vitally important region of the sea.
“It will cover a really huge piece of the ocean,” says WHOI ocean ecologist Simon Thorrold, a Principal Investigator for the network. “We’re used to going out for several weeks on a research vessel to study just a small area, and returning there maybe once or twice a year if we’re lucky,” Thorrold says. “Now, we’ll be able to get continuous measurements from a large chunk of the ocean twilight zone over significant periods of time. It’s very exciting.”
The network will give scientists a comprehensive view of the twilight zone, or mesopelagic, using several different technologies including moored buoys equipped with acoustic survey systems; a swarm of optical and geochemical sensors; and new fish-tracking tags that will continuously record the position of major predators such as sharks and tuna. All of these components will connect to the network’s buoys using acoustic signals underwater and an Iridium satellite link at the surface.
The information provided by the network will improve estimates of the density and distribution of fish and invertebrates in the twilight zone, reveal new insights about their interactions and daily migrations to and from the surface—and help fuel new strategies for conservation and policy making. The network will also help researchers better understand how the twilight zone affects carbon cycling and global climate, says WHOI marine radiochemist Ken Buesseler.
“Plankton—tiny plant-like organisms—at the surface remove carbon dioxide from the atmosphere as they grow,” Buesseler says. “When animals from the twilight zone migrate up to feed on those plankton and then return back to deeper waters, they take that carbon with them. The question is, how much does that natural cycle of life and death affect the amount of carbon that is sequestered in the deep ocean? And if humans start removing large numbers of fish from the twilight zone, how could that change?”
Buesseler compares the new observation network to a “field of dreams.”
“You build something like it, and all kinds of researchers will come and use it, because they’ve just never had the opportunity or infrastructure in place for them to be able to do these sorts of observations,” Buesseler says.
Also collaborating on the project are WHOI scientists Andone Lavery and Dana Yoerger, and Melissa Omond from the University of Rhode Island.
Former WHOI President and Director Mark Abbott says it would be challenging to fund this kind of multidisciplinary, large-scale, long-term marine infrastructure through federal sources. Abbott was instrumental in planning the observation network during his tenure. Instead of going through traditional funding channels, he turned to German philanthropist Otto Happel, whose interest in WHOI’s work in the ocean twilight zone led to a generous gift from the Happel Foundation.
“I think what’s really exciting about Otto is his deep appreciation and understanding and curiosity about the science, the engineering, and how this informs ocean policy,” Abbott says. “He’s concerned about all the changes we’re seeing in the marine environment, and he wants to fund work that enables people to make better decisions about the ocean.”
The Happel Foundation’s support will enable WHOI’s ocean twilight zone research team to turn their plans for an observation network into a reality. Work is already underway on sensors and other network components.
“The ocean always has been my passion, in many respects,” Happel says. “I’m thrilled that with a relatively small amount of funding, we can start to answer questions about it that may be vital to changing how we operate and how we live in this world.”
The Woods Hole Oceanographic Institution (WHOI) is a private, non-profit organization on Cape Cod, Massachusetts, dedicated to marine research, engineering, and higher education. Established in 1930, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate an understanding of the ocean’s role in the changing global environment. WHOI’s pioneering discoveries stem from an ideal combination of science and engineering—one that has made it one of the most trusted and technically advanced leaders in basic and applied ocean research and exploration anywhere. WHOI is known for its multidisciplinary approach, superior ship operations, and unparalleled deep-sea robotics capabilities. We play a leading role in ocean observation, and operate the most extensive suite of data-gathering platforms in the world. Top scientists, engineers, and students collaborate on more than 800 concurrent projects worldwide—both above and below the waves—pushing the boundaries of knowledge and possibility. For more information, please visit www.whoi.edu
Paper finds ocean pollution is a complex mix of chemicals and materials, primarily land-based in origin, with far-reaching consequences for environmental and human health, but there are options available for world leaders
For centuries, the ocean has been viewed as an inexhaustible receptacle for the byproducts of human activity. Today, marine pollution is widespread and getting worse and, in most countries, poorly controlled with the vast majority of contaminants coming from land-based sources. That’s the conclusion of a new study by an international coalition of scientists taking a hard look at the sources, spread, and impacts of ocean pollution worldwide.
The study is the first comprehensive examination of the impacts of ocean pollution on human health. It was published December 3 in the online edition of the Annals of Global Health and released the same day at the Monaco International Symposium on Human Health & the Ocean in a Changing World, convened in Monaco and online by the Prince Albert II de Monaco Foundation, the Centre Scientifique de Monaco and Boston College.
“This paper is part of a global effort to address questions related to oceans and human health,” said Woods Hole Oceanographic Institution (WHOI) toxicologist and senior scientist John Stegeman who is second author on the paper. “Concern is beginning to bubble up in a way that resembles a pot on the stove. It’s reaching the boiling point where action will follow where it’s so clearly needed.”
Despite the ocean’s size—more than two-thirds of the planet is covered by water—and fundamental importance supporting life on Earth, it is under threat, primarily and paradoxically from human activity. The paper, which draws on 584 peer-reviewed scientific studies and independent reports, examines six major contaminants: plastic waste, oil spills, mercury, manufactured chemicals, pesticides, and nutrients, as well as biological threats including harmful algal blooms and human pathogens.
It finds that ocean chemical pollution is a complex mix of substances, more than 80% of which arises from land-based sources. These contaminants reach the oceans through rivers, surface runoff, atmospheric deposition, and direct discharges and are often heaviest near the coasts and most highly concentrated along the coasts of low- and middle-income countries. Waters most seriously impacted by ocean pollution include the Mediterranean Sea, the Baltic Sea, and Asian rivers. For the many ocean-based ecosystems on which humans rely, these impacts are exacerbated by global climate change. According to the researchers, all of this has led to a worldwide human health impacts that fall disproportionately on vulnerable populations in the Global South, making it a planetary environmental justice problem, as well.
In addition to Stegeman, who is also director of the NSF- and NIH-funded Woods Hole Center for Oceans and Human Health, WHOIbiologists Donald Anderson and Mark Hahn, and chemist Chris Reddy also contributed to the report. Stegeman and the rest of the WHOI team worked on the analysis with researchers from Boston College’s Global Observatory on Pollution and Health, directed by the study’s lead author and Professor of Biology Philip J. Landrigan, MD. Anderson led the report’s section on harmful algal blooms, Hahn contributed to a section on persistent organic pollutants (POPs) with Stegeman, and Reddy led the section on oil spills. The Observatory, which tracks efforts to control pollution and prevent pollution-related diseases that account for 9 million deaths worldwide each year, is a program of the new Schiller Institute for Integrated Science and Society, part of a $300-million investment in the sciences at BC. Altogether, over 40 researchers from institutions across the United States, Europe and Africa were involved in the report.
In an introduction printed in Annals of Global Health, Prince Albert of Monaco points out that their analysis, in addition to providing a global wake-up, serves as a call to mobilize global resolve to curb ocean pollution and to mount even greater scientific efforts to better understand its causes, impacts, and cures.
“The link between ocean pollution and human health has, for a long time, given rise to very few studies,” he says. “Taking into account the effects of ocean pollution—due to plastic, water and industrial waste, chemicals, hydrocarbons, to name a few—on human health should mean that this threat must be permanently included in the international scientific activity.”
The report concludes with a series of urgent recommendations. It calls for eliminating coal combustion, banning all uses of mercury, banning single-use plastics, controlling coastal discharges, and reducing applications of chemical pesticides and fertilizers. It argues that national, regional and international marine pollution control programs must extend to all countries and where necessary supported by the international community. It calls for robust monitoring of all forms of ocean pollution, including satellite monitoring and autonomous drones. It also appeals for the formation of large, new marine protected areas that safeguard critical ecosystems, protect vulnerable fish stocks, and ultimately enhance human health and well-being.
Most urgently, the report calls upon world leaders to recognize the near-existential threats posed by ocean pollution, acknowledge its growing dangers to human and planetary health, and take bold, evidence-based action to stop ocean pollution at its source.
“The key thing to realize about ocean pollution is that, like all forms of pollution, it can be prevented using laws, policies, technology, and enforcement actions that target the most important pollution sources,” said Professor Philip Landrigan, MD, lead author and Director of the Global Observatory on Pollution on Health and of the Global Public Health and the Common Good Program at Boston College. “Many countries have used these tools and have successfully cleaned fouled harbors, rejuvenated estuaries, and restored coral reefs. The results have been increased tourism, restored fisheries, improved human health, and economic growth. These benefits will last for centuries.”
The report is being released in tandem with the Declaration of Monaco: Advancing Human Health & Well-Being by Preventing Ocean Pollution, which was read at the symposium’s closing session. Endorsed by the scientists, physicians and global stakeholders who participated in the symposium in-person and virtually, the declaration summarizes the key findings and conclusions of the Monaco Commission on Human Health and Ocean Pollution. Based on the recognition that all life on Earth depends on the health of the seas, the authors call on leaders and citizens of all nations to “safeguard human health and preserve our Common Home by acting now to end pollution of the ocean.”
“This paper is a clarion call for all of us to pay renewed attention to the ocean that supports life on Earth and to follow the directions laid out by strong science and a committed group of scientists,” said Rick Murray, WHOI Deputy Director and Vice President for research and a member of the conference steering committee. “The ocean has sustained humanity throughout the course of our evolution—it’s time to return the favor and do what is necessary to prevent further, needless damage to our life planetary support system.”
Funding for this work was provided in part by the U.S. Oceans and Human Health Program (NIH grant P01ES028938 and National Science Foundation grant OCE-1840381), the Centre Scientifique de Monaco, the Prince Albert II of Monaco Foundation, the Government of the Principality of Monaco, and Boston College.
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The Woods Hole Oceanographic Institution (WHOI) is a private, non-profit organization on Cape Cod, Massachusetts, dedicated to marine research, engineering, and higher education. Established in 1930, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate an understanding of the ocean’s role in the changing global environment. WHOI’s pioneering discoveries stem from an ideal combination of science and engineering—one that has made it one of the most trusted and technically advanced leaders in basic and applied ocean research and exploration anywhere. WHOI is known for its multidisciplinary approach, superior ship operations, and unparalleled deep-sea robotics capabilities. We play a leading role in ocean observation, and operate the most extensive suite of data-gathering platforms in the world. Top scientists, engineers, and students collaborate on more than 800 concurrent projects worldwide—both above and below the waves—pushing the boundaries of knowledge and possibility. For more information, please visit www.whoi.edu
When the Japanese bulk carrier MV Wakashio struck a coral reef off the coast of Mauritius on July 25, 2020, and began leaking fuel oil two weeks later, local residents and the international community sprang into action to protect the pristine habitats that fringe the Indian Ocean nation. But they did so without insight from careful chemical analysis, which is customary after spills to help guide short and long-term response plans and protects the health of people facing such a spill.
Now the first ultra-high-resolution analysis of an oil sample from Mauritius shows that the material is a complex and unusual mix of hydrocarbons—and even though some of the components in it may have already degraded or evaporated, what remains still gives it the ability to persist in the environment. That is the conclusion of marine oil spill experts Chris Reddy and Bob Nelson at the Woods Hole Oceanographic Institution (WHOI), who are collaborating with Professor Kliti Grice, Director of the Western Australian Organic Isotope Geochemistry Centre (WA-OIGC) and Associate Professor Monique Gagnon and Alan Scarlett at Curtin University in Perth, Australia. Both teams analyzed a sample of floating residue collected August 16. They subjected it to many of the same analytical techniques used to “fingerprint” samples from other large spills around the world.
The two teams use comprehensive two-dimensional gas chromatography (GC×GC), complemented by compound-specific isotope analyses to identify compounds specific to spilled oils. The analyses performed by the two laboratories provide some of the most highly advanced analytical services and scientific support to oil spill responders. They found their results were consistent with what they would expect from a sample of fuel oil, which is a non-standardized mix of petroleum products that ships often use to run their engines. In recent years, calls to improve air quality around ports has driven the industry to adopt new low-sulfur formulations that reduce emissions. At the same time, however, the potential is rising for spills of this type, but the scientific community has yet to see what happens to these new low-sulfur fuels when they enter the environment.
Key Takeaways
- Marine oil spill experts from Woods Hole Oceanographic Institution recently provided one of the first detailed oil sample analysis from the July 25 Mauritius oil spill.
- WHOI worked with experts from the Western Australian Organic Isotope Geochemistry Centre (WA-OIGC) and Curtin University in Perth, Australia.
- Their analysis shows that the material is a complex and unusual mix of hydrocarbons.
- This type of analysis is the gold standard in oil spills—it’s not only used to fingerprint the oil, but also to positively identify the constituent parts of an oil to figure out how to best fight a spill and guide short and long-term response plans while protecting the health of people facing such a spill.
A comprehensive two-dimensional gas chromatography (GCxGC) of the fuel oil collected in Mauritius after the wreck of the ship Wakashio reveals (A) a relatively low ratio of aromatic hydrocarbons relative to saturated hydrocarbons, likely a result of the de-sulfurization process the fuel underwent; and (B) a high concentration of secohopanes compared to hopanes, which can be used to help “fingerprint” the sample and potentially identify the source of future samples. (Image by Bob Nelson, ©Woods Hole Oceanographic Institution)
“Fuel oils, are arguably the most challenging petroleum products to analyze and investigate following marine-based spills,” said Reddy. “There is no single recipe or set of ingredients, and it gets even more complicated with these new low-sulfur fuel oils that require more steps in their manufacture. We don’t know if this was a low-sulfur material, but it’s unlike anything we’ve seen spilled before—that alone demands a closer look.”
Analysis by WA-OIGC at Curtin and also confirmed by WHOI’s Organic Geochemistry Analysis Lab showed that the sample contained relatively low levels of polycyclic aromatic hydrocarbons (PAHs), which are known carcinogens in humans and animals. Although low, the levels of PAHs might accumulate in certain parts of the marine environment. In addition, Reddy found a relatively high concentration and variety of secohopanes and surprisingly low levels of hopanes, both of which are “biomarkers” that will help connect future samples of oil to the Wakashio ship. These substances were present in minute amounts, but still detectable thanks to the technology available in the collaborating laboratories. Only comparison to a “fresh” sample taken from the ship would allow researchers to determine what has already been lost from the oil as a result of evaporation, dilution, photodegradation, and other effects.
“This was just a first step,” said Grice. “Our limited view of what spilled only reinforces the need for long-term monitoring, access to samples from the ship, and a more in-depth analysis that officials can incorporate into detailed plans to help Mauritius and its environment recover from this.”
The sample was acquired by Associate Professor Monique Gagnon at Curtin University. If members of the public have photos of oil and oiled material or other information, including photos of unoiled beaches and reefs, that might help Reddy and Grice and their research teams better understand the nature of the spill, they are welcome to email oilsamples@whoi.edu.
The Woods Hole Oceanographic Institution (WHOI) is a private, non-profit organization on Cape Cod, Massachusetts, dedicated to marine research, engineering, and higher education. Established in 1930, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate an understanding of the ocean’s role in the changing global environment. WHOI’s pioneering discoveries stem from an ideal combination of science and engineering—one that has made it one of the most trusted and technically advanced leaders in basic and applied ocean research and exploration anywhere. WHOI is known for its multidisciplinary approach, superior ship operations, and unparalleled deep-sea robotics capabilities. We play a leading role in ocean observation, and operate the most extensive suite of data-gathering platforms in the world. Top scientists, engineers, and students collaborate on more than 800 concurrent projects worldwide—both above and below the waves—pushing the boundaries of knowledge and possibility. For more information, please visit www.whoi.edu
On October 29, 2020, the National Science Foundation approved a $53 million grant to a consortium of the country’s top ocean-research institutions to build a global network of chemical and biological sensors that will monitor ocean health. Scientists at the Monterey Bay Aquarium Research Institute (MBARI), Woods Hole Oceanographic Institution (WHOI), University of Washington, Scripps Institution of Oceanography, and Princeton University will use this grant to build and deploy 500 robotic ocean-monitoring floats around the globe.
This new network of floats, called the Global Ocean Biogeochemistry Array (GO-BGC Array), will collect observations of ocean chemistry and biology between the surface and a depth of 2,000 meters (6,562 feet). Data streaming from the float array will be made freely available within a day of being collected, and will be used by scores of researchers, educators, and policy makers around the world.
These data will allow scientists to pursue fundamental questions about ocean ecosystems, observe ecosystem health and productivity, and monitor the elemental cycles of carbon, oxygen, and nitrogen in the ocean through all seasons of the year. Such essential data are needed to improve computer models of ocean fisheries and climate, and to monitor and forecast the effects of ocean warming and ocean acidification on sea life.
Although scientists can use Earth-orbiting platforms and research vessels to monitor the ocean, satellites can only monitor near-surface waters, and the small global fleet of open-ocean research ships can only remain at sea for relatively short periods of time. As a result, ocean-health observations only cover a tiny fraction of the ocean at any given time, leaving huge ocean regions unvisited for decades or longer.
A single robotic float costs the same as two days at sea on a research ship. But floats can collect data autonomously for over five years, in all seasons, including during winter storms, when shipboard work is limited.
Funding for the GO-BGC Array is provided through the NSF’s Mid-scale Research Infrastructure-2 Program (MSRI-2). The GO-BGC Array is the National Science Foundation’s contribution to the Biogeochemical-Argo (BGC-Argo) project. It extends biological and chemical observing globally, and builds on two ongoing efforts to monitor the ocean using robotic floats, both of which have been highly successful.
The first of these programs, the Argo array, consists of 3,900 robotic floats that drift through the deep ocean basins, providing information on temperature and salinity in the water column. Since its inception in 1999, Argo data have been used in 4,100 scientific papers. As the first global, subsurface ocean observing system, the Argo array has done an incredible job of measuring the physical properties of our ocean, but Argo floats do not provide information about the ocean’s vital chemical and biological activity.
Starting in 2014, the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) program deployed a large array of robotic “biogeochemical” floats, based on the Argo design, but carrying sensors to monitor the chemical and biological properties of the ocean. SOCCOM floats have operated for nearly six years in the remote, stormy, and often ice-covered Southern Ocean—arguably one of the harshest marine environments on Earth. These floats have already provided critical new information about how the Southern Ocean interacts with the Earth’s atmosphere and winter sea ice.
Similar to the SOCCOM floats, the new GO-BGC floats will carry a number of sensors in addition to the core Argo sensors for temperature, depth, and salinity. These include instruments to measure oxygen concentration, pH (ocean acidity), nitrate (an essential nutrient for microscopic algae), sunlight (required for algal growth), chlorophyll (an indicator of algal populations), and particles in the water (including microscopic algae). Over the last few years, researchers have been testing, refining, and calibrating these sensitive instruments as part of the SOCCOM program and other international efforts.
The instruments on these floats will allow researchers to monitor the health of the ocean, including the growth and respiration of phytoplankton (drifting algae and microbes that use sunlight as a source of energy) and the nutrients and light that control these processes. In addition to supporting most of life in the ocean, including commercial fisheries, phytoplankton supply oxygen to and remove carbon dioxide from the ocean and the atmosphere. These microscopic plankton have huge impacts on our climate through their control on carbon dioxide. The new floats will also provide first-hand data on long-term changes in the ocean, including ocean acidification and the expansion of low-oxygen zones.
This five-year effort involves five research institutions. MBARI will coordinate the project, refine the sensors, take the lead in processing data from the floats, and perform outreach for the program. WHOI, the University of Washington, and the Scripps Institution of Oceanography, will build and deploy floats in collaboration with commercial partners. Researchers at Princeton University will contribute to the array design and project management, and ensure that the data are linked to global computer models of the Earth’s ocean and climate. This program will also have a significant impact on the ocean technology industry, including a number of commercial suppliers of ocean sensors and profiling floats.
A broad public-outreach program, including workshops, web-based curricula, and hands-on activities, will help scientists, teachers, students, and others use these data. In an expansion of the existing SOCCOM Adopt-A-Float program, the floats will be adopted by elementary- to college-level classes. Student activities will be developed through a partnership with the national Marine Advanced Technology Education program. In addition, courses based on GO-BGC technology will be offered through the The Sandbox, a makerspace at the Scripps Institution of Oceanography.
The researchers hope that GO-BGC will inspire other countries to contribute similarly instrumented floats, as part of the new global biogeochemical ARGO effort. Ideally, this expanded network would grow to a sustained array of 1,000 biogeochemical floats uniformly distributed around the world ocean, and spaced about 1,000 kilometers (620 miles) apart.
“Vast swaths of the Atlantic remain unmonitored with respect to ocean health, except for sporadic, infrequent research ship visits and widely spaced moored instruments,” added Susan Wijffels, WHOI senior scientist and co-principal investigator of GO-BCG. “Based on what we know about the Atlantic’s critical role in Earth’s climate and other key planetary systems, we need to fill in those gaps.”
“The GO-BGC Array will provide the scientific community with the unprecedented ability to take the pulse of ocean ecosystems and monitor the health of underlying chemical cycles on a global scale,” said David “Roo” Nicholson, WHOI associate scientist and co-lead of GO-BCG at WHOI. “Such observations are critical to understanding how the ocean will respond to multiple, broad-scale stressors such as warming, acidification, and deoxygenation.”
The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment. For more information, please visit www.whoi.edu.
Key Takeaways
- A five-year, $53 million grant from the National Science Foundation to a consortium of ocean-research institutions will build a global network of 500 robotic biochemical sensors.
- The GO-BGC (Global Ocean Biogeochemistry) Array will be led by the Monterey Bay Aquarium Research Institute and include WHOI, the University of Washington, Scripps Institution of Oceanography, and Princeton University.
- The array will measure critical indicators of ocean health, including temperature, salinity, oxygen concentration, pH, nitrate concentration, chlorophyll, and light levels from the surface to 2,000 meters depth.
- WHOI’s role will focus on the construction and deployment of floats in the Atlantic Ocean with academic and commercial partners.
The GO-BGC array will be based on floats used in the SOCCOM (Southern Ocean Carbon and Climate Observations and Modeling) project like the one here being deployed in 2016. (Image courtesy of SOCCOM. SOCCOM is supported by the National Science Foundation under NSF Award PLR-1425989 and OPP-1936222)
WHOI engineer Bill Dullea with one of the autonomous profiling floats that WHOI will help deploy in the Atlantic Ocean as part of the GO-BGC Array. (Photo by Ken Kostel, ©Woods Hole Oceanographic Institution)
Illustration showing the operation of a typical Argo profiling float. (Image by Kim Fulton-Bennett, © 2020 MBARI)
Configuration of a GO-BGC autonomous profiling float. (Illustration by Kelly Lance, ©2020 MBARI)
Additional Information
Scientists have long suspected that ocean acidification is affecting corals’ ability to build their skeletons, but it has been challenging to isolate its effect from that of simultaneous warming ocean temperatures, which also influence coral growth. New research from the Woods Hole Oceanographic Institution (WHOI) reveals the distinct impact that ocean acidification is having on coral growth on some of the world’s iconic reefs.
In a paper published Aug. 27, 2020, in the journal Geophysical Research Letters, researchers show a significant reduction in the density of coral skeleton along much of the Great Barrier Reef—the world’s largest coral reef system—and also on two reefs in the South China Sea, which they attribute largely to the increasing acidity of the waters surrounding these reefs since 1950.
“This is the first unambiguous detection and attribution of ocean acidification’s impact on coral growth,” says lead author and WHOI scientist Weifu Guo. “Our study presents strong evidence that 20th century ocean acidification, exacerbated by reef biogeochemical processes, had measurable effects on the growth of a keystone reef-building coral species across the Great Barrier Reef and in the South China Sea. These effects will likely accelerate as ocean acidification progresses over the next several decades.”
Roughly a third of global carbon dioxide emissions are absorbed by the ocean, causing an average 0.1 unit decline in seawater pH since the pre-industrial era. This phenomenon, known as ocean acidification, has led to a 20 percent decrease in the concentration of carbonate ions in seawater. Animals that rely on calcium carbonate to create their skeletons, such as corals, are at risk as ocean pH continues to decline. Ocean acidification targets the density of the skeleton, silently whittling away at the coral’s strength, much like osteoporosis weakens bones in humans.
“The corals aren’t able to tell us what they’re feeling, but we can see it in their skeletons,” said Anne Cohen, a WHOI scientist and co-author of the study. “The problem is that corals really need the strength they get from their density, because that’s what keeps reefs from breaking apart. The compounding effects of temperature, local stressors, and now ocean acidification will be devastating for many reefs.”
Key Takeaways
- An innovative numerical model developed by researchers at the Woods Hole Oceanographic Institution demonstrates the distinct impact of ocean acidification—separate from ocean warming—on coral growth.
- The model shows that ocean acidification has caused a 13 percent decline in the skeletal density of Porites corals in the Great Barrier Reef, and a 7 percent decline in the South China Sea since 1950.
- Pollution and land runoff can exacerbate the effects of ocean acidification, causing corals in local reefs to weaken more quickly than those located farther away from human settlements.
- A global-scale investigation of coral CT scans could help to target protections for vulnerable reefs.
MIT-WHOI Joint Program student Nathaniel Mollica (left) and WHOI scientist Weifu Guo examine a core extracted from a coral skeleton. Photo by Anne Cohen Lab, ©Woods Hole Oceanographic Institution
In their investigation, Guo and his co-authors examined published data collected from the skeletons of Porites corals—a long-living, dome-shaped species found across the Indo-Pacific— combined with new three-dimensional CT scan images of Porites from reefs in the central Pacific Ocean. Using these skeletal archives, which date back to 1871, 1901, and 1978, respectively, the researchers established the corals’ annual growth and density. They plugged this information, as well as historical temperature and seawater chemistry data from each reef, into a model to predict the corals’ response to constant and changing environmental conditions.
The authors found that ocean acidification caused a significant decline in Porites skeletal density in the Great Barrier Reef (13 percent) and the South China Sea (7 percent), starting around 1950. Conversely, they found no impact of ocean acidification on the same types of corals in the Phoenix Islands and central Pacific, where the protected reefs are not as impacted by pollution, overfishing, runoff from land.
While carbon dioxide emissions are the largest driver of ocean acidification on a global scale, the authors point out that sewage and runoff from land can exacerbate the effect, causing even further reductions of seawater pH on nearby reefs. The authors attribute the declining skeletal density of corals on the Great Barrier Reef and South China Sea to the combined effects of ocean acidification and runoff. Conversely, reefs in marine protected areas of the central Pacific have so far been shielded from these impacts.
“This method really opens a new way to determine the impact of ocean acidification on reefs around the world,” said Guo. “Then we can focus on the reef systems where we can potentially mitigate the local impacts and protect the reef.”
Co-authors of the paper include Rohit Bokade (Northeastern University), Nathaniel Mollica (MIT-WHOI joint program), and Muriel Leung (University of Pennsylvania), as well as Russell Brainard of King Abdullah University of Science and Technology and formerly at the Coral Reef Ecosystem Division of the Pacific Islands Fisheries Science Center.
Funding for this research was provided by the National Science Foundation, the Robertson Foundation, The Tiffany & Co. Foundation, the Atlantic Donor Advised Fund, and WHOI’s Investment in Science Fund.
The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment. For more information, please visit www.whoi.edu.
Nearly 10 years after the Tohoku-oki earthquake and tsunami devastated Japan’s Fukushima Dai-ichi Nuclear Power Plant and triggered an unprecedented release radioactivity into the ocean, radiation levels have fallen to safe levels in all but the waters closest to the shuttered power plant. Today, fish and other seafood caught in waters beyond all but a limited region have been found to be well within Japan’s strict limits for radioactive contamination, but a new hazard exists and is growing every day in the number of storage tanks on land surrounding the power plant that hold contaminated wastewater. An article published August 7 in the journal Science takes a look at some of the many radioactive elements contained in the tanks and suggests that more needs to be done to understand the potential risks of releasing wastewater from the tanks into the ocean.
“We’ve watched over the past nine-plus years as the levels of radioactive cesium have declined in seawater and in marine life in the Pacific,” said Ken Buesseler, a marine chemist at the Woods Hole Oceanographic Institution and author of the new paper. “But there are quite a few radioactive contaminants still in those tanks that we need to think about, some of which that were not seen in large amounts in 2011, but most importantly, they don’t all act the same in the ocean.”
Since 2011, Buesseler has been studying the spread of radiation from Fukushima into and across the Pacific. In June of that year, he mobilized a team of scientists to conduct the first international research cruise to study the early pathways that cesium-134 and -137, two radioactive isotopes of cesium produced in reactors, were taking as they entered the powerful Kuroshio Current off the coast of Japan. He has also built a network of citizen scientists in the U.S. and Canada who have helped monitor the arrival and movement of radioactive material on the Pacific coast of North America.
Now, he is more concerned about the more than 1,000 tanks on the grounds of the power plant filling with ground water and cooling water that have become contaminated through contact with the reactors and their containment buildings. Sophisticated cleaning processes have been able to remove many radioactive isotopes and efforts to divert groundwater flows around the reactors have greatly reduced the amount of contaminated water being collected to less than 200 metric tons per day, but some estimates see the tanks being filled in the near future, leading some Japanese officials to suggest treated water should be released into the ocean to free up space for more wastewater.
One of the radioactive isotopes that remains at the highest levels in the treated water and would be released is tritium, an isotope of hydrogen is almost impossible to remove, as it becomes part of the water molecule itself. However, tritium has a relatively short half-life, which measures the rate of decay of an isotope; is not absorbed as easily by marine life or seafloor sediments, and produces beta particles, which is not as damaging to living tissue as other forms of radiation. Isotopes that remain in the treated wastewater include carbon-14, cobalt-60, and strontium-90. These and the other isotopes that remain, which were only revealed in 2018, all take much longer to decay and have much greater affinities for seafloor sediments and marine organisms like fish, which means they could be potentially hazardous to humans and the environment for much longer and in more complex ways than tritium.
“The current focus on tritium in the wastewater holding tanks ignores the presence other radioactive isotopes in the wastewater,” said Buesseler. “It’s a hard problem, but it’s solvable. The first step is to clean up those additional radioactive contaminants that remain in the tanks, and then make plans based on what remains. Any option that involves ocean releases would need independent groups keeping track of all of the potential contaminants in seawater, the seafloor, and marine life. The health of the ocean—and the livelihoods of countless people—rely on this being done right.”
The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment. For more information, please visit www.whoi.edu.
Key Takeaways
- Concentrations of radioactive material released into the Pacific from the Fukushima Dai-ichi nuclear power plant and found in the Pacific Ocean or in fish have largely declined to safe levels.
- A larger problem exists in the form of more than 1,000 tanks full of contaminated, but treated, wastewater stored on the grounds of the power plant and that have been suggested need to be emptied into the ocean to free up space for more untreated water.
- Current focus on tritium levels overlooks the much larger problem presented by other radioactive isotopes in the treated water, not all of which have been made public.
- Many of these other isotopes emit more dangerous forms of radiation, and act in more complex ways in the environment, accumulating in seafloor sediments and in marine life, more readily than tritium.
Ocean Topic
Oceanus Magazine
Science RoCS Initiative to increase ocean monitoring
By Randy Showstack | June 10, 2021
A boxed Argo float ready for deployment aboard the merchant vessel Tijuca. (Photo courtesy of Capt. Erwin A.
Augusto, Master of M/V Tijuca)
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A commercial ship’s mid-May deployment of two tube-shaped Argo robotic instruments to measure the temperature, salinity, and other properties of the North Atlantic opens a new chapter in ocean monitoring. The deployment of the free-drifting instruments by a merchant vessel is the first collaboration under a new effort-the Science Research on Commercial Ships (Science RoCS) initiative-between research institutions and industry to monitor the vast and open ocean. The initiative could help to meet a long-standing need for more scientific observations and monitoring of the ocean.
Science RoCS aims to pair scientists and industry to use commercial vessels to regularly monitor the oceans, and particularly some hard-to-reach areas that may be far from normal shipping routes, according to Kerry Strom, marine operations coordinator for the Woods Hole Oceanographic Institution (WHOI), which is spearheading the effort.
Additionally, the initiative includes an innovative “RoCS box” that connects multiple scientific sensors to make installation more practical for ship owners and to make their data streams more accessible to scientists and other stakeholders onshore.
With more than 80% of the ocean unmapped, unobserved, and unexplored, according to the National Oceanic and Atmospheric Administration, Science RoCs aims to fill in some gaps in ocean monitoring.
“The ocean is vastly under-sampled. If we want to solve problems that matter to people on shore-like identifying and mitigating harmful algal blooms, or predicting how air/sea interactions will cause hurricanes to intensify, or tracking nutrient inputs that can lead to deoxygenation in regions important for fisheries-we need in situ observations of the ocean,” said Magdalena Andres, the principle investigator on some Science RoCS proposals.
Andres, an associate scientist in WHOI’s Department of Physical Oceanography, said that numerical modeling of the oceans can accomplish a lot, but unless you have actual observations from the ocean you don’t know if the models are telling the truth. Science RoCS “can keep us honest about how the ocean is really working,” she said.
She added that the observations should also complement information from satellites, whose measurements are “skin deep,” and from Argo floats, which cannot sample the continental shelves and slopes, and which typically under-sample strong currents like the Gulf Stream.
“This is exactly where Science RoCS can help,” she said. “By complementing existing observing programs, Science RoCS will fill in those holes so scientists and stakeholder can address societally relevant problems using integrated observing platforms hosted on commercial vessels.”
The initiative “envisions a future where scientific data collection on commercial ships is the new industry standard,” according to a document by WHOI and others. That data would come from regular and repeated measurements across the world’s oceans, including in remote areas that are difficult for the scientific community to access.
Science RoCS, which also includes many other collaborators, builds on some other efforts and earlier plans by scientists to engage commercial “ships of opportunity” to collect ocean data. The initiative also aims to accomplish this in a more structured way than has been done previously, which would result in increased opportunities for ocean observations. In doing so, the initiative helps to cut through some red tape to more readily connect scientists with the commercial shipping industry.
“Our dream is to have commercial ships built with a suite of scientific sensors appropriate for their trade routes,” said Strom.
She noted that upcoming Science RoCS projects planned for this summer include deploying from commercial vessels more Argo floats, installing a plankton recorder on a vessel that has a round-the-world voyage route, and also installing on a ship an instrument that measures the partial pressure of carbon dioxide (pCO2).
With ocean-going research vessels worldwide estimated at less than 100 and with more than 50,000 commercial ships on the ocean at any given time, “it will be a game changer” to have sensors on more vessels, Strom said. “Imagine what we could accomplish in terms of science advancement with even just a one percent increase in ocean monitoring.”
A crew member deploys an Argo float from the side of the ship. Once it enters the water, the biodegradable cardboard box quickly decomposes. (Photo courtesy of Capt. Erwin A.
Augusto, Master of m/v Tijuca)
“Helping to turn commercial vessels into integrated observing platforms is a lot of work, but the payback in terms of science advancement is huge,” said Andres. “Interactions with commercial vessels are one way in which we can drive science forward.”
Strom, whose background includes working in commercial shipping, said that the collaboration between scientists and industry has to be beneficial to both parties to succeed.
“It can’t be a one-way street. Whatever Science RoCS does with industry has to benefit company sustainability directives as well,” she said. “With more sensors out there on the oceans, we can more accurately model weather and currents, which can help with ship safety and save on fuel, carbon emissions, time, and money.”
That perspective was one of the reasons why the shipping company Wallenius Wilhelmsen was eager to collaborate on Science RoCS’ initial effort by deploying two Argo floats, on May 20 and 21, from the company’s merchant vessel Tijuca. Strom said that the initiative wanted to start with something simple to get its feet wet, before getting involved with ship retrofits or other complex efforts. The Argo floats, which just need to be deployed into the ocean within a general area, fit the bill, she said.
“It makes sense for us to facilitate research into ocean currents, because that enables us to make our operations safer and more efficient,” said Roger Strevens, vice president of sustainability for the company, which operates 125 vessels in 15 trade routes to six continents, and is the leader in the shipping industry’s vehicle carrier segment.
Strevens said that WHOI’s understanding of industry needs also was helpful. WHOI “understands what it’s like to operate vessels,” he said, adding that it made the collaboration work on a practical basis.
The initiative, Strom said, is part of the solution to observing and monitoring more of the world’s oceans.
Strom anticipates that Science RoCS collaborations “will be the new norm” and that other companies will jump on board. “Why wouldn’t they get involved?” she said. “They’re already at sea. If we’re paying for the instrumentation and we’re not interrupting their trade, why not? They’ll look like a rock star, or in this case, a ‘RoCS star’.”
Argo Floats Marine Facilities & Operations Instruments
A new ocean soundscape
MIT-WHOI Joint Program student turns ocean data into tunes
By Evan Lubofsky | May 20, 2021
During a quick break from his work, Noah Germolus plays some soulful runs on his tenor saxophone in WHOI’s Molecular Environmental Science Lab. (Daniel Hentz, © Woods Hole Oceanographic Institution)
A new ocean soundscape
MIT-WHOI Joint Program student turns ocean data into tunes
By Evan Lubofsky | May 19, 2021
A new ocean soundscape
MIT-WHOI Joint Program student turns ocean data into tunes
By Evan Lubofsky | May 20, 2021
When you think of the sounds of the ocean, you might think of waves pounding on the shore or the call of a humpback whale. But can the ocean create music?
In a sense, it can. Noah Germolus, a third-year MIT-WHOI Joint Program chemical oceanography student, converts chemical data he’s gathered in the ocean into musical notes he plays on his tenor sax. His original compositions are not only interesting to the ear, but offer a unique window into the chemical makeup of different areas of the ocean.
The idea grew out of Synergy II, a volunteer-based program aimed at conveying ocean science through artistic expression. For the program, Germolus paired up with a former museum director and contemporary artist, Heather Stivison. They are working together on a four-painting exhibit that Germolus describes as “expressively representative” of ocean chemistry.
“Working with Heather got me looking at art a bit differently,” he says. “But I’m not a visual artist, so I wanted to stimulate a different sense and turn the same data that was used to inspire the paintings into music.”
Germolus is passionate about music and has played in rock bands as a saxophone player and singer since his undergrad days. He’s also had a long-time fascination with chemistry, something that stems from his own realization that chemicals are essential to the life of every living cell.
“Music and chemistry complement each other, and this project is probably the only time I’ve tried to so explicitly connect the two things,” he says. “I’ve tried writing lyrics about chemistry before, but believe me: they were either hopelessly obtuse or tiringly pedantic.”
To convert ocean data into tunes-a process formally known as data sonification-Germolus ran seawater samples taken from Cape Cod and Bermuda through a liquid chromatography system and mass spectrometer. The instruments quantify chemical compounds in the samples, sometimes hundreds or thousands of them, and represents them in graphs known as chromatograms. Larger peaks in the graph represent more abundant chemicals, while smaller peaks are rarer chemicals.
Germolus (middle) as front man in one of the bands he played in during college. (Photo courtesy of Noah Germolus)
Germolus focused on five biomolecules in particular: tryptophan, glutamic acid, pantothenic acid, thymidine, and 5′-(methylthio)adenosine (MTA). “I’m interested in these compounds because of their behavior outside cells,” he says, “and how those behaviors may contribute to what microbes have to compete with to survive in the ocean.”
Once the data was processed, they were output into specialized software that converts the measurement values into sheet music. The pitch of each musical note corresponds to the abundance of chemicals in the various water samples: More concentrated chemicals translate to higher-pitch notes and vice-versa. “I got six times more peaks from the coastal samples than anything in the middle of the ocean,” Germolus says. This is due to two factors: the complexity of runoff from land and the rich coastal biology.
Fortunately for the listener, variations in the ocean’s chemical makeup allows for variation in the songs, and prevents them from becoming endless sequences of sax screech. “The hard part is figuring out how to make it all sound musical, or at least somewhat pleasurable to listen to,” he says.
This, he says, requires taking some creative liberties. He alters the length of individual notes, for example, and organizes them into measures for more of an arranged sound.
During our Zoom meeting, he held up a printout of one of his compositions, and then reached over to grab his saxophone. He rested the mouthpiece on his lower lip and a second later, out came a frenetic, scale-like chorus of biomolecules. It sounded a lot like jazz.
The jury’s still out as to how catchy these chemical tunes are. But if you know little to nothing about the chemical makeup of the ocean and how it varies in different areas, these lively tracks will open your ears to ocean nuances that are otherwise impossible to hear.
福島第一と海:
災害対応の10年間を語る
English Version
On the high seas
Observers join Orpheus cruise thanks to the Neil Armstrong Fund
By Hannah Piecuch
２０１１年３月１１日、日本の都市仙台の東約１２９キロメートルで起きた震度９の地震によって発生した津波は、水柱となって沿岸部に激突し、福島第一原子力発電所を大破した。一万六千人近い人々が犠牲となり、現在も発電所から放射能汚染水が流出している。（撮影：ケン・コステル、©ウッズホール海洋研究所）
２０１１年３月１１日、日本の都市仙台の東約１２９キロメートルで、海底が激しく隆起した。日本を支える構造プレートの下部にゆっくりと沈み込んでいる太平洋プレートによって蓄積された歪みが、突如スライドし跳ね上げられたのである。ほんの一瞬にして、サッカー場の半分もの大きさの海底の一部が水平方向に押しやられ、９メートル以上上昇した。
日本では毎年数百もの地震を経験するのだが、しかし、東北地方太平洋沖地震はこの国が記録した中でも未曾有の大規模なものであった。マグニチュード９の揺れが長くとも６分も続き、本州を２メートル半も東へシフトさせた。
海底が上部大きく突き上げられ発生した津波は、半時間もしないうちに近隣の日本沿岸地域を襲った。街全体が三階立ての建物に匹敵する水壁によって破壊され、一万六千人近い人々が犠牲となった。
福島第一原子力発電所もこの時被災を免れなかった。地震翌日には爆発が起き、拡散される放射性降下物を避けるため、15万人以上の近隣住民が強制的に避難することを余儀なくされた。さらなる放射性物質が海洋に直接流出し、大気中に拡散したものも最終的には海洋表面に降下した。
「このような天災によって海に流出する放射性物質の量としては、福島第一原発事故は、前例のない出来事だったのです。」と、ウッズホール海洋研究所シニアサイエンティストであるケン・ベッセラー博士は話す。「起きたことを振り返り、現状を把握することは非常に重要です。」
三重の災害から１０年目となる今年、ベッセラー博士は世界中の研究者たちと福島での出来事において過去１０年間学んできたこと、さらにどのように状況が引き続き変化するのか、遠隔で議論してきた。
福島第一原子力発電所は、適切に地震に対応するシステムを備えていた。激震によって送電線が破損し、プラントと六基の原子炉が送配電網から遮断され、三基の稼働中の原子炉が自動的に停止した。しかし、原子炉を停止させることは電気を消すように容易なことではない。
「核分裂反応が止まったとしても、放射性物質は熱を発し続けます。」福島県沿岸における研究調査隊を幾度も率いてきた東京海洋大学の神田穣太教授は云う。「かなり長期にわたり水で冷し続けなくてはなりません。」
燃料棒を冷却する水を汲み上げ続けるために、施設は予備発電機に切り替えた。そして、津波が襲った。
原発は海面から9メートル上に掘削された丘陵に建設されていた。その区域で予測されていた津波の高さは最大６メートルであったと、神田教授は云う。しかし、その日襲った津波は11〜１５メートルの間と記録された。それは施設を浸水させ、予備発電を破壊した。
冷却システムが故障したのち、原子炉の炉心の温度が上昇し始めた。原子炉内の燃料棒が過熱し溶解し始め、ウラニウム燃料が露出して格納容器が破損した。同時に原子炉の水が蒸気になり金属製燃料棒に反応して、揮発性の水素ガスが発生した。
炉心内に蓄積した圧力を軽減するため、発電所の作業員たちは数日間にわたり何度かガスを放出した。このガスは放射性同位体、あるいは放射性物質を大気中へ流出したが、それだけでは済まなかった。続く数日の間に原発での三度の水素爆発が今まで以上の放射性物質を空中に放出し、その多くは最終的に海洋上に落下したのである。
緊急隊員たちが過熱した原子炉へ必死に高圧放水砲と消火ホースで噴水し、そして自衛隊のヘリが上空から何百トンもの水を投下させた。こうした水は放射性物質を取り込み、海洋へ溢れ出すか、地面に浸透していき、最終的には海へと運ばれていくこととなった。
地震により福島第一原子力発電所は停電し、津波により予備の発電機が浸水したことで、6基の原子炉のうち3基が過熱溶解し、水素ガスが発生したのち爆発した。放射性物質を含んだ地下水や冷却水は海に流出し、海岸の砂や海底の堆積物に、あるいは魚類やその他の生物に蓄積され、大部分は海流に乗って太平洋を横断した。(福島中央テレビ)
2011年6月に行われた最初の国際調査航海では、福島第一原発付近沿岸から４８２キロメートル以上沖合までの放射性核種の拡散を追跡した。過去10年以上にわたり、科学者、技術者、一般市民が、発電所近海からカナダ及びアメリカ合衆国の西海岸の広範囲において、海水、堆積物、海洋生物のサンプルを採取してきた。（撮影：ケン・コステル、©ウッズホール海洋研究所）
今回の災害で最も著しく放出された放射性同位体は、ヨウ素１３１、セシウム１３４及びセシウム１３７である。これら全ては有害物質の可能性はあるが、それぞれ異なった速度で減衰する。ほとんどのヨウ素１３１は数週間で消失する。２年間の半減期を持つセシウム１３４は10年後わずか３％しか残留しない。しかし急速に減少することを物語ってはいても、福島の海洋への打撃として拭いきれない跡を残した。セシウム１３７、これは３０年の半減期を持つため、減少には何十年もかかる。実際、１９５０〜６０年代に行われた核兵器の大気圏内実験によって放出されたセシウム１３７が、現在もなお世界中の海洋に少量ではあるが計測可能な量存在するのである。
「原子力発電が多くの国で利用され始め、海洋中には常にある程度のセシウムが存在してきましたが、問題は、今回の事故でどのくらい増加したかということです。」２０１１年６月に福島県近海で放射性物質計測のための調査航海を率いたベッセラー博士は語る。「我々は、福島第一原発に近い海洋で、1立方メートルにつき5千万ベクレル以上という極めて高いレベルの放射性セシウム濃度を検知しました。」
１ベクレルは、1秒につき一個の原子核が崩壊するのに等しく、非常に微量の放射能である。世界保健機構（WHO）のガイドラインでは、飲料水に含有されるセシウム１３７の量は１立方メートルにつき1万ベクレル以上でないことを推奨している。災害に見舞われる以前、福島周辺の水質は、１立方メートルにつき約２ベクレルであった。それが、事故直後には５千万を超えるまでに上昇し、その後原発からの放射性物質の流出を食い止めるための対策が功を奏し、数ヶ月で急速に数値は下がった。ある程度の放射性物質は海底の堆積物に累積したが、多くは強い黒潮によって太平洋へと移流拡散され、セシウムが海流にのって北米にまで運ばれてしまうのではないかという恐怖心に火をつけた。
太平洋を横断する福島からの放射性物質の動向を調査するため、ベッセラー博士は西海岸でのセシウムがどのくらいの数値であるかを調査する地域密着型の活動を結成した。彼の研究室は、付近を運行中の船舶から、サーファーたちから、さらには海水浴客から、沿岸域の海水サンプルを入手した。彼らは一部の放射性物質が太平洋を渡って福島から北米まで運ばれてきたことを示す証拠を発見したものの、その数値は１立方メートルにつき１０ベクレル以下という極めて低いものだった。
「非常に小さな数字でした。」ベッセラー博士は云った。「もし仮に１立方メートルにつき約１０ベクレルという水中で一年間毎日海水浴をしたとして、線量、追加被曝は、歯科のレントゲン一回の千分の一程度でしょう。危険性はゼロではありませんが、非常に少量で、西海岸で水泳をしたり、サーフィンやボートで漕ぎだしたりしても、心配することはありません。」
しかしながら、福島における放射性物質の流出は完全に消散したわけではない。震災後の数年間に比べればはるかに少量ではあるが、原子炉からの漏出、河川の放射性堆積物、汚染された地下水が、海洋に流出し続けている。福島近海における放射性物質濃度は、２０１６年以来１立方メートルあたり100ベクレル前後というレベルで停滞している。
突然の海洋への放射性物質放出は即座に地元の海洋生物への懸念となり、消費者たちが長期にわたって心配することとなった。日本政府は直ちに漁業を停止させ、領域のどの海産物が安全で、それらを食べても心配はないのかを判断するための徹底した検査とテストプログラムを開始した。
放射性物質は水中で溶解されるかもしくは微粒子状となって存在し海洋に放出されます。」フランス放射線防御・原子力安全研究所上級専門員のサビーン・シャーマソン氏は説明した。「どちらの形態でも海洋生物が取り込む可能性があります。」
汚染された環境に生息する魚類は、外皮を通して、もしくは餌や海水を摂取することで放射性物質を吸収するかもしれない。しかし、どのくらいの期間体内に残留するかは、元素固有である。セシウムは例えば元素周期表上で同じ列に属する、カリウムと似た働きをするため、筋肉や臓器に取り込まれ、海洋生物の体内に何週間も何ヶ月も残留する可能性がある。トリチウム、これは水素の放射性物質であり、主に水のように振る舞い、生物の体内機能からほんの数日で排出されてしまう。ストロンチウムはカルシウムに類似していると、シャーマソン氏は話した。そして、それは生物の骨内に何年も残存する可能性があるとも云う。
また、海洋生物にも固有である。タコはウニとは異なる放射性物質を吸収する。活発な代謝機能を持つ魚類は、汚染をより急速に除去できるかもしれない。
研究者たちは、福島周辺の海底近くに生息する生物に、海水の汚染濃度が下降し始めていたにもかかわらず、より高濃度の放射性物質を検知した。
「これは、これら魚類が汚染された堆積物上や内部の餌を摂取していたからです。」シャーマソン氏は説明する。
しかしながら、数年後には、日本の福島の漁場を含む東北沿岸で水揚げされた圧倒的多数の海産物は、１キログラムあたり１００ベクレル（アメリカ合衆国の制限値は１キログラムあたり１２００ベクレル）という日本の厳しい放射線量制限値を下回った。２０１５年以来、何千匹もの魚類が検査された中で、その制限値を超えたのはたった二匹のみであった。
福島第一原発の事故後、誤った情報が拡散し、科学者や政府関係者の情報へ対する世間の不信感が高まった。一般的に誤って伝わったもののひとつの例として、福島第一原発でメルトダウンした直後の放射性物質の広がりを示した地図と思われたものは、実際には地震後に太平洋を横断する津波モデルの分布図であった。 （米国海洋大気庁太平洋海洋環境研究所より転載）
安全が実証されたにもかかわらず、福島県地方から流通する海産物には汚染という汚名が今もつきまとう。２０１３年から２０１７年まで駐日アメリカ合衆国大使を務めたキャロライン・ケネディ前大使は、地域を訪問し地元産のものを食べることが安全であると人々に示すため、繰り返し現地を訪れたことを思いおこした。
「漁業に携わる人々や大勢の生産者に会いましたが、当然のことながら多くの場合、皆が彼らの食品や魚を購入することを恐れています。」ケネディ前大使は語った。「これら全てのエピソードはバラバラのようにみえますが、災害対応のための様々な分野に対して、個人そして集団としての責任、さらには科学のために、多くの教訓を与えてくれます。」
放射性物質は土地や海洋上でどのように分布しているのか？避難が必要なのは誰か？どの食べ物が安全なのか？人々がこうした当たり前の疑問であるはずのものに答えを希求してやまない時、福島についての信頼性を欠いた情報が災害後何日も何週間もかけて広まっていった。
しかし、日本政府から発信された情報は乱雑で、遅延し、不透明であったのみならず、不完全なものだったと、福島原発事故を受け組織された環境監視団体であるセーフキャストの主任研究員アズビー・ブラウン氏は話した。東京周辺地域の放射線汚染を示す最初の公式マップは、災害から７ヶ月も経過した２０１１年１０月になるまで発表されなかった。風評と誤報が混乱とともに、どのような公式発表よりも急速により遠方へ広がっていった。
「信頼は、再生可能なものではありません。」ブラウン氏は云う。「一度失ったら、二度と取り戻せないかもしれません。」
福島原発事故以前、日本における魚類の放射性物質濃度の制限値は１キログラムあたり５００ベクレルと、すでに国際的基準よりも厳しいものであった。２０１２年４月、福島産海産物の安全性への国民の信頼を高めるために、制限値は１キログラムあたり１００ベクレルに引き下げられた。しかし、この改正を取り巻く明確な情報の欠如が、多くの人々にさらなる混乱と不安をもたらした。以前は安全ではない海産物を食べてきたのか？と。
「誰のための情報なのか、その情報に対しどう反応するのか、いかにしてその情報を得るのか、もしそうしたことを想定しなければ、その情報は的外れになる可能性があります。」ブラウン氏は話す。「我々は情報発信の際、想定される混乱と、とどのように物事は誤解され得るのかを、予測しなければなりません。」
震災後の早い時期にすでに多くの国民が公式の情報源への信用を失い、続く不手際や同様に幾つかの情報の不正確さが問題をさらに深刻化させ、福島原発事故を取り巻く全てに信頼の危機が生まれた。
2011年3月11日に始まった終わりない惨劇の遺物、それは福島第一原子力発電所の敷地内に設置された千基以上の汚染された処理水を保存する貯蔵タンクである。日本政府はこれらのタンク内の汚染水を徐々に海洋に放出する予定である。厳密にはその処理水の中にどの放射性同位体がどの程度含まれているのか、明確にされていない。（撮影：ケン・ベッセラー、©ウッズホール海洋研究所）
東北の景観を変えただけでなく、震災は日本人の意識を根本的に変えた。震災の余波で、日本にはボランティア活動とフィランソロピーの感覚が戻った（新しく芽生えたと一部の人は云うだろう）。フィッシュ・ファミリー財団理事で、日本女性リーダー育成支援事業の共同創設者でもあるフィッシュ東光厚子氏は、地震と津波発生からわずか３週間後に手助けと彼女が在住するボストンで自ら募った基金を配布するため東北を訪れた。日本社会は伝統的に国外からの援助やもしくは別居する家族からであっても、外部の助けに抵抗する気風がある。そのためフィッシュ氏は人々が彼女を信頼することでしか援助を受けいれてもらえないと理解していた。彼女の動機が心から援助したいと望んでのことであると証明するためであれば、何ヶ月もかけて、時には被災地まで運送トラックに便乗させてもらうなど、根気強くボストンと東北を行き来した。
フィッシュ氏とそしてその他多くの人々の努力は、「信頼に基づくフィランソロフィー」とによって実ったと彼女は言う。特に信頼関係を築くことに重点をおいた支援の提供を担う女性たちの役割には、日本における女性たちの権利に、新たな推進力をもたらす強い影響を与えたと、彼女は指摘する。
「これら女性たちは、東北の将来を担うでしょう。」フィッシュ氏は語る。「同時に、彼女たちは日本にとって重要な将来のリーダーになる存在です。」そして、まだ成し遂げなければならないことがあり、彼女たちのリーダーシップが必要とされるはずである、と。
現在、福島第一原発敷地内には、千基以上の貯蔵タンクがそびえ立ちひしめきあっている。それらには汚染地下水と原子炉心や炉心内の瓦礫に接触した汚染冷却水が溜められている。目下のところ、1日１００トン以上の割合で排出、蓄積され続けている。当初は一時的なものと考えられていたが、１０年前に始まったことは長期化する可能性のある事象の遺物として、一つのより目立つ存在となってきた。原発を所有する東京電力ホールディング株式会社（TEPCO)によれば、２０２２年までに貯蔵タンクのためのスペースが、確保できなくなるとみられている。貯水したものは除染を経たうえで、現状のプランでは徐々に海洋に放出する計画である。
しかし、除染処理は完全ではなく、東京電力と日本政府の不透明性は計画への大衆の反発を招いた、とブラウン氏は語った。東京電力は何年もトリチウムのみがタンクに残存していると主張し、水素の放射性物質は取り除くのが困難ではあるが、他の放射性同位体に比べ健康へのリスクは低いという立場を取っている。２０１８年１０月にようやく、同社は貯蔵タンクには他の放射性同位体が含まれていると認めた。
それら他の放射性同位体というものが、人間の健康により危険であると、ベッセラー博士は云う。そして海底に残存して海洋生物に蓄積する可能性が高いとも。「少しでも透明性があれば我々の理解を得るのに長い時間はかからなかったでしょう。そしてトリチウムだけでなく他の同位体も含めた解決策を構築させたでしょう。」
最初のステップはタンクの中身を完全に把握することである。そして、ベッセラー博士は続ける。東京電力はトリチウム以外の放射性同位体を除去できることを証明しなければならない。東京電力は全タンクの70％以上にその除染処理が必要であると認めている。最後に、再処理後に各放射性同位体が許可された許容可能な数値内に抑えられているかを徹底的に調査する独立した監視が必要となる。ベッセラー博士は、短命な汚染物質の一部が減衰するのを受け入れるため、原発の周囲１９キロメートル弱の立ち入り禁止区域を設け、さらにタンクを設置する可能性も示唆している。しかし、再度巨大な地震に見舞われれば、タンクを破損し、制御不可能な漏出を起こす可能性が懸念される。
どのような解決策であれ、完全な廃炉と汚染除去は何十年もの長期事業になるだろう。そして、海洋生態系の回復と地域社会の復興が続く中、「安全なのか？」という疑問は多分これからも決して消え失せることはないと、ベッセラー博士は認知している。
「数値が下がったとしても、世間はなおそうした疑問を持つでしょう。」ベッセラー博士は云う。「そして次の１０年後も、我々がその疑問の答えを見つけようとしていることを願っています。」
＝（ローラ・カスタニヨン) biology Coastal Ecosystems Ocean Life
Fukushima Dai-ichi and the Ocean:
A decade of disaster response
By Laura Castañon
On the high seas
Observers join Orpheus cruise thanks to the Neil Armstrong Fund
By Hannah Piecuch
On March 11, 2011, a magnitude 9 earthquake 80 miles east of the Japanese city of Sendai generated a towering tsunami that slammed into the coastline and critically damaged the Fukushima Dai-ichi nuclear power plant. Nearly 16,000 people died and the releases of radioactive water from the plant continue today. (Photo by Ken Kostel, © Woods Hole Oceanographic Institution)
On March 11, 2011, 80 miles east of the Japanese city of Sendai, the seafloor heaved. The tectonic plate that holds Japan, which had been slowly compressed by the Pacific plate diving underneath it, suddenly slipped and sprang back. In a matter of moments, parts of the ocean floor were shoved as much as half a football field horizontally and 30 feet upwards.
Japan experiences hundreds of earthquakes every year, but the Great Tohoku Earthquake was the most powerful the country had ever recorded. The 9.0-magnitude quake lasted as long as six minutes and shifted the main island eight feet to the east.
Tsunami waves, generated as the seafloor thrust upwards, hit the closest parts of the Japanese coastline less than half an hour later. Entire towns were destroyed by the three-story wall of water and nearly 16,000 people were killed.
The Fukushima Dai-ichi nuclear power plant had also been damaged. In the following days, explosions rocked the facility and more than 150,000 people were forced to evacuate the surrounding area to avoid potential radioactive fallout. Even more radioactivity was washed into the ocean or deposited there from the atmosphere.
“Fukushima Dai-ichi was an unprecedented event for the ocean, in terms of the amount of radioactivity going in to the ocean from a disaster of this nature,” said Ken Buesseler, a senior scientist at the Woods Hole Oceanographic Institution. “It seems very important to look back and take stock of where we’re at.”
A decade after Japan’s triple disaster, Buesseler joined researchers around the world for a remote discussion of the events at Fukushima, what they’ve learned over the past decade, and how the situation continues to evolve.
Inside the power plant
The Fukushima Dai-ichi nuclear plant had systems in place to cope with an earthquake. When the violent shaking damaged utility lines and cut off the plant and its six reactors from the power grid, the three active reactors shut down automatically. But shutting off a nuclear reactor isn’t as simple as turning off the lights.
“Even if the fission reaction stops, the radioactive material continues to generate heat,” said Jota Kanda, a professor at Tokyo University of Marine Science and Technology who has led several research expeditions off the coast of Fukushima. “You have to keep cooling by water for quite a long period.”
The facility switched over to its backup generators to continue pumping the water needed to cool the fuel rods. Then the tsunami hit.
The nuclear plant was constructed on a cliff which had been excavated down to 30 feet above the ocean. The maximum expected height of a tsunami in that area was around 20 feet, Kanda said. But the tsunami waves that hit that day measured between 37 and 50 feet high. They flooded the facility and destroyed the backup generators.
When the cooling systems failed, the temperatures in the reactor cores began to rise. The fuel rods inside the reactors started to overheat and melt, exposing the uranium fuel and damaging their containment vessels. At the same time, water in the reactors turned to steam and began reacting with the metal fuel rods, generating volatile hydrogen gas.
To relieve the pressure building up in the reactor cores, plant workers vented the gas several times over the next few days. This gas carried radioactive isotopes, also known as radionuclides, into the atmosphere, but this was not enough. Over following days, three hydrogen explosions at the plant sent even more radioactivity skyward, much of it eventually settling in the ocean.
Emergency crews desperately sprayed the overheating reactors with water cannons and firehoses, and military helicopters dropped hundreds of gallons of water from above. This water also picked up radionuclides and overflowed into the ocean or seeped into the ground, carrying those isotopes to the ocean.
The earthquake knocked out power at Fukushima Dai-ichi and the tsunami flooded back-up generators, causing three of the six reactors to overheat and generating hydrogen gas that later exploded. Irradiated groundwater and cooling water flowed into the ocean, some collecting in beach sands and seafloor sediment, some building up in fish and other organisms, and the rest spreading with currents across the Pacific. (Fukushima Central Television)
The first international research expedition in June 2011 traced the spread of radionuclides from the coast near Fukushima Dai-ichi to more than 300 miles offshore. Over the past decade, scientists, technicians, and members of the public have collected samples of water, sediment, and marine life from the ocean near the power plant to the West Coast of Canada and the U.S. (Photo by Ken Kostel, © Woods Hole Oceanographic Institution)
A radioactive ocean
Some of the most abundant radionuclides released in the disaster were iodine-131, cesium-134 and cesium-137. All are potentially hazardous, but they decay at different rates. Most of the iodine-131 was gone in a matter of weeks. With a two-year half-life, only 3% of the cesium-134 remains after 10 years, making it a telltale, but rapidly diminishing, fingerprint of Fukushima’s impact on the ocean. The cesium-137, which has a half-life of 30 years, will linger for decades. In fact, there is still a small but measurable amount of cesium-137 in oceans around the world from atmospheric nuclear weapons testing in the 1950s and ’60s.
“Since the dawn of the nuclear era, we’ve always have some cesium; the question is how much more did this accident add,” said Buesseler, who led a research trip to measure radiation near Fukushima in June 2011. “We saw extremely high levels-more than 50 million Becquerels per cubic meter-of this radioactive form of cesium in the ocean close to Fukushima Dai-ichi.”
One Becquerel is a very small amount of radioactivity-it equates to one atomic nucleus decaying per second. The World Health Organization guidelines suggest that drinking water shouldn’t contain more than 10,000 Becquerels per cubic meter of cesium-137. Prior to the disaster, the waters around Fukushima had about 2 Becquerels per cubic meter. That shot up to over 50,000,000 immediately after the accident, then quickly dropped in the months following as measures to stanch the flow of radionuclides from the plant were put into the effect. Some of the radioactivity accumulated in the seafloor sediments, but much of it was dispersed into the Pacific by the strong Kuroshio Current, sparking fears that ocean currents would carry cesium to North America.
To investigate the movement of Fukushima radionuclides across the Pacific, Buesseler organized a community-based effort to determine what the levels of cesium were on the West Coast. His lab received seawater samples from ships operating in the area, and from surfers and beachgoers up and down the coast. While they did find evidence that some of the radioactivity from Fukushima had been carried across the Pacific to North America, the levels were extremely low-less than 10 Becquerels per cubic meter.
“That’s a very small number,” Buesseler said. “If you swam in the ocean every day for a year in waters that were about 10 Becquerels per cubic meter, the dose, the additional exposure, would be about a thousand times less than a single dental X-ray. The risk isn’t zero, but it’s so small that I wouldn’t be concerned about swimming, surfing or boating off the West Coast.”
The radioactivity at Fukushima has not entirely dispersed, however. Leaks from the reactors, radioactive sediment in rivers, and contaminated groundwater continue to flow into the ocean, albeit in much smaller amounts than in the first few years after the disaster. Levels in the coastal waters near Fukushima have stayed around 100 Becquerels per cubic meter since 2016.
What about the fish?
The abrupt flood of radioactivity into the ocean was an immediate concern for local marine life, and a long-term concern for the people who consume it. The Japanese government immediately shut down fisheries and began an extensive monitoring and testing program to determine what seafood from the region, if any, would be safe to eat.
“Radionuclides that have been released into the ocean can be in either dissolved or particulate form,” said Sabine Charmasson, senior expert at the Institute for Radiological Protection and Nuclear Safety in France. “Both can be taken up by marine organisms.”
A fish living in a contaminated environment might absorb radionuclides through its skin or ingest them with its food or water, but how long they remain depends on the specific element. Cesium, for example, acts like its cousin on the periodic table, potassium, and is taken up by muscles and organs, where it can remain in the animal for weeks or months. Tritium, a radioactive form of hydrogen, behaves primarily like water and can be flushed out of an animal’s system in a matter of days. Strontium is more akin to calcium, Charmasson said, and can linger in a creature’s bones for years.
The particular animal species in question matters as well. An octopus will take up certain radionuclides differently than a sea urchin. A fish with a speedy metabolism might clear contamination more quickly.
Researchers found that animals living near the seafloor around Fukushima had higher levels of radioactivity, even as the contamination levels in the water began to fall.
“This is because these fish feed on prey living on or inside contaminated sediment,” Charmasson said.
After a few years, however, the vast majority of seafood caught off the Northeast Coast of Japan, including the fisheries off Fukushima, was below Japan’s strict radiation limit of 100 Becquerels per kilogram. (The U.S. limit is 1200 becquerels per kilogram.) Since 2015, out of thousands of fish that were tested, only two have exceeded that level.
In the wake of the accidents at Fukushima Dai-ichi the spread of misinformation inflamed public distrust of information from scientists and government officials. One commonly shared fallacy was a map, supposedly showing the spread of radiation immediately after the meltdowns at Fukushima Dai-ichi, but that was actually a model of tsunami waves crossing the Pacific after the earthquake. (Image courtesy of NOAA Pacific Marine Environmental Lab)
A crisis of trust
Despite being demonstrably safe, the seafood from the Fukushima region still carries a stigma of contamination. Caroline Kennedy, who served as the U.S. ambassador to Japan from 2013 to 2017, recalled traveling to the region repeatedly to show that it was safe to visit and eat the local foods.
“You meet these people who are fishing and trying to grow food but everybody is scared to buy their food or their fish, understandably so in many cases,” Kennedy said. “This whole episode is something that, as we piece apart, has many lessons for different areas of disaster response, as well as personal and collective responsibility and science.”
Mistrust of information about Fukushima built in the days and weeks after the disaster, when people were desperate for answers to what seemed like simple questions: Where was the radioactivity traveling on land and in the ocean? Who needed to evacuate? What food was safe?
But communication from the government was messy, delayed, unclear, and incomplete said Azby Brown, lead researcher for Safecast, an environmental monitoring group formed in response to Fukushima. The first official map showing radiation contamination in the Tokyo area wasn’t released until October 2011, seven months after the disaster. Rumors and disinformation spread faster and farther than any official communication, adding to the confusion.
“Trust is not a renewable resource,” Brown said. “Once you lose it, you may never get it back.”
Before the Fukushima disaster, the Japanese limit for radioactivity in fish was 500 Becquerels per kilogram, already stricter than the international standard. In April 2012, in an in an attempt to build public confidence in the safety of Fukushima seafood, the limit was lowered to 100 Becquerels per kilogram. But the lack of clear communication around this change created more confusion and anxiety for many people. Had they previously been eating seafood that was unsafe?
“If you don’t think about who it’s for, how they’re likely to react, how they’re going to find this information, then the information may miss the target,” Brown said. “We have to anticipate the potential failure points and how things can be misunderstood.”
Many people lost faith in official sources of information early on in the disaster and continued missteps, as well as misrepresentation of some information, have compounded the problem, creating a crisis of trust around Fukushima.
One of the enduring legacies of events that began on March 11, 2011, is the more than 1,000 storage tanks on the grounds of the Fukushima Dai-ichi nuclear power plant holding contaminated wastewater that the Japanese government wants to empty into the ocean. Exactly what that water is contaminated with remains unclear. (Photo by Ken Buesseler, © Woods Hole Oceanographic Institution)
Fukushima’s ongoing legacy
In addition to changing the landscape of Tohoku, the disaster fundamentally changed the attitudes of of the Japanese people. In the aftermath, there was a renewed (some would say a new) sense of volunteerism and philanthropy in Japan. Atsuko Toko Fish, trustee of the Fish Family Foundation and co-founder of the Japanese Women’s Leadership Initiative, went to Tohoku just three weeks after the earthquake and tsunami to lend a hand and to distribute funds that she’d helped raise from her home in Boston. Japanese society has traditionally been resistant to outside help, whether it came from outside the country or even outside one’s family, so she knew that her help would only be accepted if the people trusted her. She spent months traveling back and forth between Boston and Tohoku, sometimes hitching rides on cargo trucks to get to the disaster-struck region-anything to prove that her motivations came from a sincere desire to help.
Her efforts, and those of many others, form the basis of something Fish calls “trust-based philanthropy.” In particular, she points to the role women have played in providing aid by focusing on building trust, which has had the added impact of giving new momentum to women’s rights in Japan.
“These women will shoulder the future of Tohoku,” said Fish. “They will be important future leaders of Japan, as well.” And their leadership will be needed, as there is still work to be done.
Today, the Fukushima Dai-ichi site is crowded with more than 1,000 towering storage tanks. They are filled with contaminated groundwater and cooling water that came into contact with the radioactive cores and debris. Currently, the wastewater is accumulating at a rate of more than 100 tons each day. The tanks were originally intended to be temporary, but they have become one of the more visible, and potentially long-lasting legacies of events that began ten years ago. The site will run out of space to store water by 2022, according to the Tokyo Electric Power Company (TEPCO), which owns the plant. The stored water has undergone a decontamination process, and the current plan is to slowly release it into the ocean.
But the decontamination process is not perfect, and a lack of transparency from TEPCO and the government has caused a public backlash against the plan, Brown said. TEPCO insisted for years that there was only tritium left in the tanks, a radioactive form of hydrogen that is difficult to remove but poses a lower health risk than other radionuclides. Only in October 2018 did the company finally admit that the water still contained additional contaminants.
These other radionuclides are more dangerous to human health, Buesseler said, and are more likely to remain on the seafloor and accumulate in marine life. “A little transparency would have gone a long way to make us accept and build a solution around not just tritium, but the other isotopes.”
The first step is to get a full accounting of what is in the tanks. Then, says Buesseler, TEPCO needs to demonstrate that they can remove the additional radionuclides, which they admit is needed for more than 70 percent of the tanks. Finally, independent monitoring of the ocean is needed to ensure that they only release what is permitted and at allowable rates. Buesseler also raised the possibility of building more tanks in the surrounding area-there is a 12-mile exclusion zone around the plant-to allow some of the shorter-lived contaminants to decay. But there are concerns that another large earthquake could fracture the tanks and cause uncontrolled leaks.
Whatever the solution, fully decommissioning and decontaminating the site will be a decades-long project. And as the marine ecosystem rebounds and communities in the area continue to rebuild, Buesseler knows the question of “is it safe?” will probably never go away.
“Even as levels get lower, the public will still have these questions,” Buesseler said. “And what I hope in ten years is that we’re still trying to give them answers.”
Finding answers in the ocean
In times of uncertainty, the deep sea provides potential solutions
By Elise Hugus | November 9, 2020
Deep-sea hydrothermal vents harbor diverse microbes whose enzymes can be used in diagnostic tests, like the ones to detect the novel coronavirus and other pandemics like AIDS and SARS. (Video acquired from the submersible Alvin at the East Pacific Rise near 9° 50’N at 2510 meters depth. © WHOI-NDSF, Alvin Group, National Science Foundation)
Deep-sea hydrothermal vents harbor diverse microbes whose enzymes can be used in diagnostic tests, like the ones to detect the novel coronavirus and other pandemics like AIDS and SARS. (Video courtesy of Chris German, WHOI/NSF/ROV Jason/2012/© Woods Hole Oceanographic Institution)
The test being used to diagnose the novel coronavirus—and other pandemics like AIDS and SARS—was developed with the help of an enzyme isolated from a microbe found in marine hydrothermal vents as well as freshwater hot springs.
Biomedical breakthroughs sometimes happen in the most unlikely places. Take the deep ocean, for example, where mineral-laden fluid superheated by magma gushes from hydrothermal vents. Under extreme pressure and acidity, at times with no oxygen to speak of, microbes not only survive there, they thrive. This incredible adaptation offers insight into how life evolved billions of years ago—and how modern humans may be able to fight infections and disease.
“We’ve found marine microorganisms that produce antimicrobials—basically chemical weapons that help them fight off other organisms, and molecular mechanisms that help them resist viruses,” says Virginia (Ginny) Edgcomb, a WHOI microbiologist who investigates fungi and bacteria living in the deep sea and deep subsurface biosphere. These microbes feed on tough compounds like hydrocarbons and produce antimicrobial compounds. “Almost every antibiotic we have was produced by microorganisms. Who knows—maybe we’ll find new antimicrobials when we start to look in deep ocean habitats.”
The deep ocean has already given us compounds to treat cancer, inflammation, and nerve damage. But breakthroughs have also come from the ocean depths in the form of diagnostic tools. Case in point: the test being used to diagnose the novel coronavirus—and other pandemics like AIDS and SARS—was developed with the help of an enzyme isolated from a microbe found in marine hydrothermal vents as well as freshwater hot springs.
The pathway to developing this test started back in 1969 when scientists discovered a bacterium, Thermus aquaticus, living in the extreme temperatures of a hot spring in Yellowstone National Park. Two decades later, WHOI biologist Carl Wirsen and colleagues discovered new strains of bacteria on a hydrothermal vent off of Italy that could withstand even greater extremes (including heat, pressure, and lack of oxygen). More heat-loving microbes have since been found in hydrothermal vent communities across the globe to depths as great as 5000 meters beneath the sea surface.
By the mid-1980s, the unassuming microbes had enabled a major advance in the emerging field of genetics. Scientists found that their enzymes remained stable, even at the temperatures required to perform a revolutionary procedure known as polymerase chain reaction (PCR). With enzymes recovered from the microbes, it became possible to make millions of copies of a single DNA sequence in just a few hours, essentially upgrading geneticists’ tools from carbon-copy paper to state-of-the-art Xerox machinery. A technique using these enzymes, termed DNA polymerases, as well as enzymes isolated from viruses, now make it possible to quickly test for viruses, including coronaviruses like SARS (avian flu) and COVID-19.
Identifying microbial processes in the deep ocean is an essential first step for discerning human applications, says WHOI microbiologist Julie Huber.
“A lot of people think of the deep sea as a desert,” she says. “To our naked eye, it looks like there’s nothing there. But hydrothermal vents have a remarkable diversity of microbes, including genetic diversity. There’s huge potential there. What I can do as a basic science researcher is describe them and make their genome available. And folks in applied science can take that data and turn it into something useful.”
Edgcomb says the coronavirus outbreak underscores the importance of funding basic exploratory research, which may help lead to a cure or diagnostic tool in the future.
“You need to have people exploring different habitats in order to continue feeding the pipeline of medically-relevant enzymes (proteins),” she says. “This is a tough lesson to learn, with this pandemic, but I do hope people realize that the more we can learn more about microbes, the better off we are.”
biology Hydrothermal Vents Ocean Chemistry
WHOI establishes new fund to accelerate microplastics innovation
By Hannah Piecuch | October 26, 2020
Confetti-sized bits of microplastic get swept through the ocean by fast-moving currents and shifting circulation patterns. (Photo by Shutterstock)
Despite regular media coverage and international concern over microplastics in the ocean, funding to study this emerging ocean pollutant has been surprisingly scarce. Early microplastics research by WHOI scientists was mostly funded through small grants that allowed them to explore very limited facets of the issue.
In 2017 and 2018, WHOI awarded Catalyst Funds—an incubator program funded by private donations—to form the Marine Microplastics Initiative. Leveraging WHOI’s interdisciplinary scientific staff, the initiative’s first priorities were taking stock of the existing research and coordinating a workshop to bring international experts together to chart a course forward. Now, the group has turned its attention to some of the most pressing—and foundational—questions about microplastics: How long do they last in the environment? Where do plastics discharged from wastewater systems end up? And what kinds of health risks do these plastics pose to animals and humans? They are also developing tools to sense and measure microplastics in the water and working on ambitious new projects related to the recovery and processing of plastic waste in the ocean. With the backing of a handful of family foundations, WHOI is launching a Marine Microplastics Innovation Accelerator to help drive innovation and support projects that will have the most impact.Hannes Frey, a director at March Limited, says the company chose to fund WHOI’s microplastics research in order to help close knowledge gaps that stand in the way of a healthier ocean and to inspire others to make similar philanthropic investments. “As we talked to scientists, we realized that the breakdown into microplastics and their entry into the food chain is one of the most challenging issues to understand. It’s not as visible as animals trapped in fishnets or a seashore covered with plastic bags, but I think that on a scientific basis, it is crucial.” The Seaver Institute is another organization that is helping fund microplastics research at WHOI. “We give seed money for research and support projects that other people aren’t willing to fund until they become understandable,” says the foundation’s president, Victoria Dean. “We are interested in the discovery of scientific fundamentals and getting the information out there—WHOI does a great job of sharing their work.” Funding from private foundations has been an indispensable part of moving this research forward, says Mark Hahn, principal investigator of the Microplastics Initiative. “Currently, there are many more questions than answers about the fate and impacts of microplastics in the ocean,” he says. “The growing support from private foundations is critical in enabling the interdisciplinary, cutting-edge research that is needed to understand and solve this global problem.”
Putting the ‘nuclear coffin’ in perspective
Marine chemist weighs in on leaking radioactive dome in the Pacific
By Evan Lubofsky | August 13, 2019
WHOI geochemist Ken Buesseler discusses marine radioactivity monitoring in the Marshall Islands atop Runit Dome—a 350-foot-wide concrete lid built to contain contaminated material from nuclear weapons tests. (Photo courtesy of Ken Buesseler, Woods Hole Oceanographic Institution)
There has been a flurry of headlines this summer about a “nuclear coffin” leaking radioactive waste into the Pacific Ocean. The coffin—a bomb crater filled with radioactive soil on a tiny island in the Marshall Islands—sits under a 350-foot-wide concrete lid known as Runit Dome. It’s arguably the region’s most visible scar from a series of U.S. nuclear weapons tests that took place off Bikini and Enewetak Atolls between 1946 and 1958.
The concerns aren’t unfounded—the area has been a hotspot for lingering radioactivity for more than half a century. But according to Ken Buesseler, a world-renowned expert in marine radioactivity at Woods Hole Oceanographic Institution (WHOI), the concerns are nothing new.
“We’ve known for years that the dome is leaking,” he said. “When we were there doing fieldwork in 2015, we sampled groundwater and could see there was an exchange between the lagoon water and material under the dome. But it was clear that only a small amount of radioactivity was actually leaking into the lagoon.”
To put “a small amount of radioactivity” into perspective, Buesseler says the amount of plutonium under the dome is just one percent of the total amount buried in the surrounding lagoon sediments, which is less than 0.1% of the plutonium released during the weapons testing more than 60 years ago. These amounts fall below contamination levels for U.S. and international water-quality standards. More generally, radiation levels for the islands of Enewetak Atoll, according to a 2016 study from researchers at Columbia University, are even lower than those in New York City’s Central Park due to the high background radioactivity of granite rocks in the park.
“The dome is a significant visible scar on the landscape, but it’s a relatively small source of radioactivity,” said Buesseler, who had no hesitancy swimming in the azure waters off Runit Island during the 2015 field study.
However, he says the area is generally still of great concern and needs to be closely monitored. A more recent study from Columbia suggests that radiation levels vary significantly between islands, and higher levels have been measured on nearby Bikini and Rongelap atolls. Rongelap, in particular, had received considerable fallout from the 1954 Bravo test, resulting in subsequent decades of local contamination and radiation poisoning throughout the atoll.
Runit Dome sits roughly 25 feet above sea level on low-lying Runit Island, making it vulnerable to inundation from rising seas. People on top of the thick concrete cap, which measures nearly 400 feet in diameter, look like ants in this aerial view. (Photo from Wikimedia Commons)
Runit Dome, which is located on Runit Island—one of 40 islands that make up Enewetak Atoll—was built in 1977 as a temporary measure to contain some of the radioactive material left behind from the bomb explosions, some of which were one thousand times more powerful than those that destroyed Hiroshima and Nagasaki. The U.S. Army bulldozed more than 100,000 cubic yards of contaminated soil and debris into a bomb crater and capped it with hundreds of 18-inch-thick concrete slabs. From a Google Earth perspective, the massive dome looks like something out of science fiction, and completely out of place against the expanse of paradise around it.
While the dome has helped contain the waste and residual contamination levels on Enewetak, there’s no telling what the future holds.
“As long as the plutonium stays put under the dome, it won’t be a large new source of radiation to the Pacific Ocean,” he said. “But a lot depends on future sea-level rise and how things like storms and seasonal high tides affect the flow of water in and out of the dome. It’s a small source right now, but we need to monitor it more regularly to understand what’s happening, and get the data directly to the affected communities in the region.”
Runit Dome, which is located on Runit Island—one of 40 islands that make up Enewetak Atoll—was built in 1977. It was an attempt to contain some of the radioactive material left behind from nuclear testing during which more than 30 megatons of TNT was detonated. The U.S. Army troops bulldozed more than 100,000 cubic yards of contaminated soil and debris into a bomb crater and capped it with hundreds of 18-inch-thick concrete slabs. From a Google Earth perspective, the massive dome looks like something out of science fiction—and completely out of place against the expanse of paradise around it.
The military never returned to the islands to remove the waste—and it’s hard to say where they would have put it if they had. But it turns out, the dome may end up being a temporary container for the contamination after all: rising sea levels have caught up with it.
“The dome is only about 25 feet above sea level to begin with,” Buesseler said. “And sea levels are now at the point where seawater has been washing up on the dome and eroding its concrete edges.”
He says there has been some patching of the concrete, but it’s not a long-term solution. Increased seawater inundation over time will hasten the deterioration.
“They hadn’t considered sea level rise in the 1970s when they built this,” Buesseler said. “And at the current rate, the whole dome will be at least partially submerged by the end of this century.”
That begs the obvious question of what higher seas will mean for additional radiation flow into the Pacific. Buesseler says it’s impossible to predict, but ongoing monitoring of the situation will be critical.
“As long as the plutonium stays put under the dome, it won’t be a large new source of radiation to the Pacific Ocean,” he said. “But a lot depends on future sea-level rise and how things like storms and seasonal high tides affect the flow of water in and out of the dome. It’s a small source right now, but we need to monitor it more regularly to understand what’s happening, and get the data directly to the affected communities in the region so the people there have more confidence in what their levels of exposure are.”
MC&G Department Radiation Health Risks Café Thorium
How do you measure a chemical in the ocean that exists for less than a minute?
This was the conundrum facing Colleen Hansel, a scientist at the Woods Hole Oceanographic Institution (WHOI). She studies superoxide, a molecule so unstable that it reacts almost instantly with other molecules around it, vanishing in about 30 seconds.
Bringing water back to the lab simply didn’t work. Any superoxide in it would be gone long before the water could be tested. For years, scientists had measured superoxide in experiments using pumps and a benchtop instrument in the lab designed for the task. However, that device was not built to be used in the field. Superoxide had never been directly measured in the ocean.
Superoxide molecules are an accidental byproduct of breathing. They are ubiquitous and highly toxic. Any living organism that breathes oxygen creates them, and then needs to dispose of them quickly.
To create energy, cells extract electrons from fats and carbohydrates and transfer them to oxygen. When an oxygen molecule grabs four electrons, it then combines with hydrogen to form water.
But this process can be sloppy, particularly when organisms are stressed. Sometimes, oxygen only takes one electron. This makes superoxide. The extra, unpaired electron makes superoxide highly reactive. It either wants to lose or gain another electron to become more stable. To do that, superoxide gives or takes electrons from other cells, setting off destructive chain reactions.
Superoxide has been linked to harmful impacts ranging from cancer to premature aging in humans. Ocean scientists also suspect that superoxide might be involved in coral bleaching—the phenomenon that occurs when the symbiotic algae that live inside corals (giving them food and their vibrant colors) suddenly depart, leaving corals pale and vulnerable to starvation, disease, and ultimately death.
But a link between superoxide and coral bleaching has only been indirectly inferred from studies in the lab.
“It’s difficult to directly measure superoxide in the ocean,” Hansel said. “We were discouraged by the fact that we couldn’t make any measurements in the field.”
Expensive equipment in a very small boat
If Hansel couldn’t bring the samples to the lab, then she had to bring her lab to the samples.
“We said, ‘Let’s just take this lab benchtop instrument out onto a small zodiac on a local pond to see if we can make measurements and hope that we don’t tip the boat over,’” Hansel said.
In 2012, she and a postdoctoral scientist in her lab at WHOI brought their lab instrument out onto Oyster Pond, a large, brackish pond on Cape Cod. They knew bacteria in the water produced superoxide, but could they pump the water fast enough into the instrument on the boat to capture it before it reacted away? If the water pumped into the instrument too quickly, the sensor wouldn’t have enough time to make a measurement. If the water moved too slowly, the superoxide would be gone.
It was a complicated operation. They lowered a weighted tube into the water connected to a pump to draw samples up to the boat. As those waters fed into the sensor, a second pump pulled in a chemical from a separate bottle that specifically binds with superoxide. Once it was analyzed, the waste water was collected through a third tube, while the data was sent to a laptop via Bluetooth, where Hansel could see it in real time. The whole system was connected to portable lithium batteries—also balanced precariously in the zodiac.
And it worked. The setup was unwieldy, and if the tube went too deep, the superoxide would be gone before it made it to the instrument on the surface. But it worked: Hansel had proved it was possible to measure superoxide in situ outside the lab.
This presented an opportunity that Hansel and her WHOI colleague, Amy Apprill, had been waiting for. They now had a tool to measure superoxide around corals in the wild to explore its role in coral stress and bleaching. They finally got their chance in 2014 when widespread bleaching occurred in shallow corals in Hawaii.
Into the wild
The fall of 2014 was a bad time for coral in Hawaii. The weather was unusually warm and prevailing winds, which usually pushed cooling open-ocean water toward shore and over coral reefs, died down. Coastal water temperatures in Kaneohe Bay, on the western side of Oahu, rose into the high 80s. More than three quarters of the dominant corals on the Kaneohe reef had bleached.
The theory behind coral bleaching is that superoxide builds up inside corals in response to heat stress and causes them to eject the algae they rely on. But as Hansel and Apprill loaded their setup into a small rented boat, they weren’t planning to measure the superoxide inside the corals. They wanted to know whether the corals were producing superoxide outside their cells in the surrounding waters.
They had seen this behavior in corals growing in aquaria in the lab. But were they doing it in the wild as well?
“I had concerns that the approach wasn’t going to work,” Hansel said. “Were the corals making enough superoxide for us to measure it using the set-up on the boat?”
But when the first measurements started coming in, from a resilient coral species known as Porites compressa, they showed that the corals had high levels of superoxide surrounding their colonies. Hansel couldn’t contain her excitement.
Several more days of sampling began to reveal a pattern: Hardier coral species, the ones more likely to recover from coral bleaching or avoid infections, had more superoxide around their colonies. More fragile species had less, or none at all.
Clearly, there was more to the superoxide story. Perhaps superoxide could be beneficial to corals as well.
To see if these results were part of a larger pattern, Hansel would need to test other, deeper reefs. The reefs in Hawaii were shallow, allowing Hansel and her team to pump water to the instrument set-up in their boat before the superoxide vanished. She needed a better tool.
“After Hawaii, I knew that I wanted to make an in-situ instrument,” Hansel said.
DISCO designs
Back in Woods Hole, Hansel started brainstorming ideas with WHOI biogeochemist Scott Wankel. Wankel had experience building deep-sea sensing instruments for exploring hydrothermal vents on the seafloor. The two scientists have been married for 11 years.
“We sit around talking a lot, obviously,” said Wankel. “I remember sitting in the kitchen, taking a napkin, and drawing it. ‘What do you need? And how does it work? I have a pump that could do that …’ and putting this idea together.”
Together, over a year’s worth of Saturday morning coffees, they began to design what would become the DISCO: a portable, underwater, superoxide detector.
DISCO is short for DIver-operated Submersible Chemiluminescent sensOr (“We cheated on the acronym a little bit,” Wankel said.) It’s a device the size of a small suitcase, controlled by a handheld screen with five buttons and real-time read out display. It is a hefty 60 pounds in air, but neutrally buoyant in water and can operate to depths of 100 feet (30 meters).
The basic mechanics of the DISCO are similar to the lab instrument. Water is pulled inside through a long, thin wand and mixes with a chemical that reacts with superoxide in a mixing cell to produce light that is detected by a photomultiplier tube. The amount of light detected is translated through a small computer to show how much superoxide is in the water.
But this relatively straightforward reaction is made exponentially more complicated by superoxide’s tendency to react with any material it meets. “Superoxide is non-selective,” Hansel said. “It reacts with carbon, metals, other organisms. It reacts with nearly everything.”
The DISCO had to be built out of inert materials such as certain plastics, ceramics, or glass that superoxide can’t react with—nothing metal. These parts can be found, but they’re highly specialized and typically not made for underwater use.
Wankel reached out to WHOI engineer Jason Kapit, who he had worked with on several other projects. “Jason is a master of perusing the literature to find parts and pieces we can use,” Wankel said.
“You’re trying not to re-invent the wheel,” Kapit said. “Sometimes it takes cannibalizing a part that already exists and adapting it to what you want.”
Eventually he found parts from inert benchtop chemistry pumps to pull in seawater and intravenous bags from the medical industry to hold the necessary chemicals. These, along with a small computer, a lightproof chamber, and various other components were packed into a waterproof, pressure-bearing case.
Hansel had been invited to bring the DISCO on a joint U.S.-Cuban expedition to the Gardens of the Queen reefs in Cuba in October 2017. The expedition, led by Apprill, was aboard the research vessel Alucia. The group had hoped to finish the DISCO in time to test it locally, but design and construction took them longer than expected—into the fall of 2017.
“Right before we had to leave, we got it dunk-tested to confirm that it turned on underwater and didn’t leak,” Hansel said. “Cuba was the first field test.”
The trip to Cuba was an opportunity to see if coral species in a healthy Caribbean reef were producing superoxide like their stressed Hawaiian counterparts. That information could lead to a better understanding of the role of superoxide. But getting the data was entirely dependent on the unproven DISCO actually working.
A two-faced chemical?
Scott Wankel knew there were a lot of things that could go wrong.
“This was Colleen’s first project developing an instrument,” he said. “I kept warning her that the alpha prototype may never even make it to the water, let alone make a measurement, let alone make a measurement that is actually meaningful.”
Hansel wasn’t even going to be the one to first test the DISCO in the ocean. Her graduate student, Kalina Grabb, was joining the boat in Cuba two weeks before Hansel.
“It was nerve-wracking. We didn’t know what would happen,” Hansel said. “This was a lot of pressure for a first-year student, so I told her before she went, if you don’t feel comfortable, don’t do it. But she jumped in with it, and she got data on the first dive.”
It wasn’t entirely smooth sailing. The pumps ran too hot and caused the readout screen to overheat.
“After about 10 minutes of use under water, the screen would freeze,” Hansel said. “It took us a while to realize that DISCO was actually still collecting data, we just couldn’t see it.”
Flying blind, they collected data from a variety of coral species. When they were able to view it on the computers, it matched up with what they had previously seen in Hawaii and in the lab experiments.
“What we got from the DISCO is exactly what we got from the benchtop instrument that we schlepped onto the boat in Hawaii and the same that we got with the aquaria-based corals,” Hansel said. “Porites, a coral known for its resistance to stress, has extremely high concentrations of superoxide around itself, sometimes a hundred times higher than seawater.”
If the most resilient corals are producing the most superoxide, maybe superoxide isn’t all bad for corals. Perhaps the layer of superoxide on the outside of corals provides some kind of protection for stressed corals, like fending off viruses or bacteria that might otherwise infect them or helping with tissue repair. This would be similar to what scientists have observed in other forms of life, such as plants and fungi, and even mammalian cells.
“It’s exciting to think about,” Hansel said. “Is superoxide providing a physiological benefit to the coral?”
To answer this question, the team began working on a smaller, lighter version of the DISCO. Kapit took the lead on incorporating smaller, more efficient pumps to avoid overheating, a sleek touchscreen screen for the diver, and other improvements. He also eliminated machinery humming that emanated from the original DISCO, which attracted curious wildlife. Grabb field-tested the new DISCO in the Caribbean over six weeks in the summer of 2018.
The team is also working on a project called the SOLARIS (Submersible Oceanic Luminescent Analyzer of Reactive Intermediate Species), a superoxide detector that can be used at deeper depths and could be incorporated into a deep-sea sampling platform such as WHOI’s submersible, Alvin.
SOLARIS will allow the team to better understand superoxide’s role throughout the ocean. In addition to coral bleaching, superoxide has been implicated in harmful algal blooms and fish kills associated with red tides. But based on lab experiments, Hansel and colleagues have an emerging theory that superoxide is important, perhaps essential, for cell growth in bacteria and phytoplankton.
“Because superoxide is so reactive, it’s going to play a central role in nearly all biogeochemical cycles,” said Hansel. “Being able to finally measure superoxide directly within various marine ecosystems will transform our understanding of its role in ocean chemistry and health.”
This research was funded by Schmidt Marine Technology Partners and the National Science Foundation’s Division of Ocean Science.
An estimated eight million tons of plastics enter our oceans each year, yet only one percent can be seen floating at the surface. This is the first in a three-part article series about how researchers at Woods Hole Oceanographic Institution are trying to understand the fate of “hidden” microplastics and their impacts on marine life and human health.
When we think of plastic in the ocean, we often think of easily seen things such as water bottles and plastic bags. In reality, the vast majority of plastics in the ocean are smaller than a millimeter and can’t be seen with an unaided eye; some particles resemble bird seed, others look like dust.
These small fragments are known as microplastics. Some are “micro” by design: Microbeads, for example, are tiny plastic spheres manufacturers add to body washes, toothpastes and other products to give them extra scrubbing power. Lentil-sized pellets known as nurdles are ubiquitous fodder used in the manufacture of many common plastic products, are also intentionally small.
Other microplastics become “micro” over time when larger pieces of plastic debris, such as water bottles, straws, cups, and car fenders, are exposed to forces of nature that cause them to degrade. Sunlight, for example, oxidizes plastic and causes it to weather and degrade. Freeze-thaw cycles can weaken the structure of plastics over time. And ocean waves could also be taking a toll, making plastics more brittle by constantly washing over them and grinding them into sand.
Scientists have a decent sense for the types of physical and chemical weathering processes that can cause plastics to break down. However, little is known about how quickly degradation happens, and whether most of it is happening on land, in rivers, or in the ocean. It’s unclear, for example, what happens to a plastic water bottle between the time someone takes his or her last swig and when the empty bottle ends up in the ocean, said WHOI senior scientist Chris Reddy.
“There’s a perception that most of the fragmentation of plastics is happening in the ocean, but it could be that a lot of the activity is actually happening on land,” he said. “For example, if you take a red ‘Solo’ cup and leave it on the ground outside for a week, you can see that the red color starts to fade to pink and that the cup is more brittle. So, pre-aging on land could be playing a major, currently unaccounted for role in the fate of plastics in the ocean.”
Another big unknown is the impact marine microbes have on the breakdown of plastics in the ocean. Studies have demonstrated that microbes cling to even tiny plastic fragments, and nibble at them as well. But whether they are causing any significant breakdown of the material is something that scientists at WHOI are just starting to investigate.
The uncertainty surrounding where and how quickly plastics break down has become a critical knowledge gap not only for scientists, but also for chemical companies and plastic manufacturers that want to design plastics that decompose faster into materials that are non-harmful and have minimal effects on the environment.
One way to gauge the speed of degradation is by placing plastics—including “raw” plastics containing no additives, as well as consumer products such as Styrofoam cups—in specialized weathering chambers. Scientists can conduct experiments in these chambers that test how factors such as sunlight, temperature, and humidity contribute to physical breakdown processes.
“These chambers provide a realistic picture of what happens on land and in the ocean,” Reddy said.
Collin Ward, a marine chemist at WHOI, says one of the main advantages of the weathering chamber is speed: It can accelerate the weathering process to answer environmentally relevant questions faster. When testing the effects of sunlight, for example, the chamber’s light source can be cranked up to flood plastics with ultraviolet light that is ten times more intense than natural sunlight.
“Some of the longest experiments I’ve ever run have been on plastics, and the reaction times are very slow since plastics are designed to not break down easily,” he said. “With these chambers, we can easily get the equivalent of a month’s worth of sunlight in one week, so it really accelerates the weathering.”
Weathering chambers will help, but Ward says that gaining a true sense for how plastics breakdown will be far more complex than simply blasting them with sunlight in a box. This is due to the fact that there are so many different types of plastics, and each type may break down at different rates in the environment due to the base polymers used and the types of additives and pigments applied to the materials during the manufacturing process.
“Cellulose acetate is completely different from polystyrene and polyethylene,” he said, “so these products will weather at different rates and by different processes. And then you have plastics that come in various colors, each with their own pigments and additives that can initiate the fragmentation process at different rates. When you consider all the variables that can impact the breakdown process, it becomes an incredibly complex science question.”
For more information about WHOI’s Marine Microplastics Initiative, visit microplastics.whoi.edu.
