Study findings show how warming complicates fisheries management.
Cod fishing in the Gulf of Maine. Credit: Gulf of Maine Research Institute.
For centuries, cod were the backbone of New England's fisheries and a key species in the Gulf of Maine ecosystem. Today, cod stocks are on the verge of collapse, hovering at 3-4% of sustainable levels. Even cuts to the fishery have failed to slow this rapid decline, surprising both fishermen and fisheries managers. For the first time, a new report in Science explains why. It shows that the cod collapse is in large part due to rapid warming of the ocean in the Gulf of Maine - 99 percent faster than anywhere else on the planet.
The rapid warming is linked to changes in the position of the Gulf Stream and to climate oscillations in the Atlantic and the Pacific. These factors add to the steady pace of warming caused by global climate change. In the face of already depleted cod stocks, fisheries managers in 2010 had placed a series of restrictions on harvesting this key Gulf of Maine species, but even strict quota limits on fishermen failed to help cod rebound.
"Managers kept reducing quotas, but the cod population kept declining," said Andrew Pershing, Chief Scientific Officer of the Gulf of Maine Research Institute (GMRI) and lead author of the study. "It turns out that warming waters were making the Gulf of Maine less hospitable for cod, and the management response was too slow to keep up with the changes."
Pershing and colleagues from GMRI, the University of Maine, Stony Brook University, the Bigelow Laboratory for Ocean Sciences, and NOAA's Earth System Research Laboratory, including the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder, found that increasing water temperatures reduce the number of new cod produced by spawning females. Their study also suggests that warming waters led to fewer young fish surviving to adulthood.
The models used by managers over the last decade to set the quotas for cod did not account for the impact of rising temperatures, leading to quotas that were too high. Fishermen stayed within their quotas, but still took more fish than the population could sustain.
"This creates a frustrating situation that contributes to mistrust between fishermen, scientists, and managers," says Pershing. "The first step toward adapting fisheries to a changing climate is recognizing that warming impacts fish populations."
According to the report, recovery of Gulf of Maine cod depends on sound fishery management and on future temperatures. Cod are a coldwater species, and the Gulf of Maine is at the edge of their geographic range. As the ocean warms, the capacity of the Gulf of Maine to support cod will decline, leading to a smaller population and a smaller fishery.
The study shows the risk of not including temperature in fisheries models, especially for stocks like Gulf of Maine cod that are at the edge of their range. The warmer our climate gets, the less fisheries managers can rely on historical data.
Timely vehicle recall by German automaker would avoid some 130 early deaths, researchers say.
Volkswagen's use of software to evade emissions standards in more than 482,000 diesel vehicles sold in the U.S. will directly contribute to 60 premature deaths across the country, a new MIT-led study finds.
In September, the Environmental Protection Agency discovered that the German automaker had developed and installed "defeat devices" (actually software) in light-duty diesel vehicles sold between 2008 and 2015. This software was designed to sense when a car was undergoing an emissions test, and only then engage the vehicle's full emissions-control system, which would otherwise be disabled under normal driving conditions -- a cheat that allows the vehicles to emit 40 times more emissions than permitted by the Clean Air Act.
That amount of excess pollution, multiplied by the number of affected vehicles sold in the U.S. and extrapolated over population distributions and health risk factors across the country, will have significant effects on public health, the study finds.
Assessing health outcomes
According to the study, conducted by researchers at MIT and Harvard University and published in the journal Environmental Research Letters, excess emissions from Volkswagen's defeat devices will cause around 60 people in the U.S. to die 10 to 20 years prematurely. If the automaker recalls every affected vehicle by the end of 2016, more than 130 additional early deaths may be avoided. If, however, Volkswagen does not order a recall in the U.S., the excess emissions, compounding in the future, will cause 140 people to die early.
In addition to the increase in premature deaths, the researchers estimate that Volkswagen's excess emissions will contribute directly to 31 cases of chronic bronchitis and 34 hospital admissions involving respiratory and cardiac conditions. They calculate that individuals will experience about 120,000 minor restricted activity days, including work absences, and about 210,000 lower-respiratory symptom days.
In total, Volkswagen's excess emissions will generate $450 million in health expenses and other social costs, the study projects. But a total vehicle recall by the end of 2016 may save up to $840 million in further health and social costs.
Steven Barrett, the lead author of the paper and an associate professor of aeronautics and astronautics at MIT, says the new data may help regulatory officials better estimate the effects of Volkswagen's actions.
"It seemed to be an important issue in which we could bring to bear impartial information to help quantify the human implications of the Volkswagen emissions issue," Barrett says. "The main motivation is to inform the public and inform the developing regulatory situation."
Cheating (and) death
To estimate the health effects of Volkswagen's excess emissions, Barrett and his colleagues at MIT and Harvard based their calculations on measurements by researchers at West Virginia University, who found that the vehicles produced up to 40 times the emissions allowed by law. They then calculated the average amount that each vehicle would be driven over its lifetime, and combined these results with sales data between 2008 and 2015 to estimate of the total excess emissions during this period.
The group then calculated the resulting emissions under three scenarios: the current scenario, in which 482,000 vehicles have already emitted excess emissions into the atmosphere; a scenario in which Volkswagen recalls every affected vehicle by the end of 2016; and a future in which there is no recall, and every affected vehicle remains on the road, continuing to emit excess pollution over the course of its lifetime.
The group then estimated the health effects under each emissions scenario, using a method they developed to map emissions estimates to public exposure to fine particulate matter and ozone. Diesel vehicles emit nitrogen oxides, which react in the atmosphere to form fine particulate matter and ozone. Barrett's approach essentially maps emissions estimates to population health risk, accounting for atmospheric transport and chemistry of the pollutants.
"We all have risk factors in our lives, and [excess emissions] is another small risk factor," Barrett explains. "If you take into account the additional risk due to the excess Volkswagen emissions, then roughly 60 people have died or will die early, and on average, a decade or more early."
Barrett says that, per kilometer driven, this number is about 20 percent of the number of deaths caused by road transport accidents.
"So it's about the same order of magnitude, just from these excess emissions," Barrett says. "If nothing's done, these excess emissions will cause around another 140 deaths. However, two-thirds of the total deaths could be avoided if the recalls could be done quickly, in the course of the next year."
A climate change research project in the Blue Mountains of Jamaica, involving local partners, the company Oubu Coffee and co-author of the study Bo Dalsgaard, is an example of recommended research collaborations across geographical, climatic and political-economic boundaries. Credit: Oubu Coffee.
Collaborations on climate change research are divided into separate regions of the world with little knowledge exchange between them shows a new Danish-Brazilian study led by the University of Copenhagen. The most vulnerable countries of the world are largely disconnected from the production and flow of scientific knowledge on climate change, leaving their climate policymaking with little contextually relevant advice. The study calls for initiatives across private, governmental and non-governmental organisations, and from researchers themselves to diminish the knowledge gap.
When new research on climate change is published it most often concerns and is produced by the developed countries and the BRICS countries Brazil, India, China and South Africa rather than countries most vulnerable, but less contributing, to climate change.
The little research that does concern developing countries often lacks a locally based author. For instance, only about one fifth of the publications concerning climate change in Africa have a locally based first author - for the developed regions, it is two thirds of the publications. For some countries, such as the Republic of Congo and North Korea with up to 72 relevant publications, there are no locally based authors, not even co-authors.
"Without locally generated knowledge, it is more challenging to provide and integrate contextually relevant advice, and this leaves a critical gap in the climate policy debates. This is particularly worrying as we are dealing with countries likely to experience severe climatic changes and that are most sensitive to its detrimental impacts" says lead-author and postdoc Maya Pasgaard from the Department of Geosciences and Natural Resource Management at the University of Copenhagen.
In total, the study analysed author affiliations of more than 15.000 climate change publications published between 1999 and 2010. Authors focusing on the same countries for climate change research typically share geographical proximity, common climate, politics and economic characteristics.
"The regional divides limit critical flows of experiences and competencies across geographical and political-economic boundaries; a flow which is also needed to tackle the many threats and challenges of comparable character across regions, such as changes in crops, pest management and adaptation to climate hazards," says co-author and Professor Niels Strange from the Center for Macroecology, Evolution and Climate at the University of Copenhagen.
A large group of countries has few or no locally based authors in climate change research publications. The darker color indicates higher percentages of locally based authors. Credit: Pasgaard et al (2015).
With the exception of some South American and African countries who share research interests, knowledge exchange on climate change suffers from large regional divides, in particular among vulnerable, developing regions.
The study recommends initiatives that focus on strengthening collaborations across geographical distances and across national differences in climate, export, democracy and national economy, as well as strengthening the local production and integration of knowledge.
Co-author and Assistant Professor Bo Dalsgaard from the Center for Macroecology, Evolution and Climate says:
"There is an array of partners responsible for increasing collaborations, ranging from big international organisations, such as the UN, to individual governments and higher education leaders. We also urge individual researchers and private companies alike to take responsibility for increasing cross-national collaborations and thus increase knowledge exchange between regions".
He is personally involved in a collaborative project across geographical, climatic and political-economic boundaries with UNICAMP in Brazil, the University of the West Indies in Jamaica, local coffee growers from, amongst other players, the Jamaican Coffee Growers' Association, and the London-based gourmet coffee brand Oubu Coffee. Together they study the effects of climate on the pollination of coffee in the Blue Mountains of Jamaica, West Indies.
"This project was initiated through a personal network between me, Oubu Coffee and their relations within Jamaica. As researchers we have to be willing to drive the transition forward through such opportunities and networks. Waiting for international institutions or governments to create new initiatives is not the only way forward" says Bo Dalsgaard.
Maya Pasgaard also has experience with research collaboration across regions, working together with a local researcher from Cambodia on community-based forest protection to mitigate climate change.
"Cross-border collaborations are not just highly relevant scientifically, but also rewarding on a personal level, as cultural knowledge exchange becomes an integrated part of the collaboration" she says.
A massive field effort on the Belizean Barrier Reef has revealed for the first time that the offspring of at least one coral reef fish, a neon goby, do not disperse far from their parents. The results indicate that if marine protected areas aim to conserve such fishes, and biodiversity more broadly, then they must be spaced closely enough to allow larvae to disperse successfully between them.
A growing body of scientific research has demonstrated that marine protected areas, particularly no-take marine reserves that exclude extractive activities like fishing, can increase biodiversity and sustain fisheries within the reserves, often with spillover benefits in surrounding areas. But despite the decline of coral reefs and fisheries worldwide, only 3.5 percent of the ocean is protected and only 1.6 percent of it is fully protected. Moreover, for reserves to conserve marine biodiversity most effectively, they must be embedded in networks that are connected such that marine life from one reserve can repopulate other reserves.
"Before our study, we didn't have a deep, quantitative understanding of how far fish larvae do and do not disperse from their parents," says study co-author Peter Buston of Boston University. "If we're going to design effective networks of marine reserves, we need to know how far baby fish can and cannot travel. Our study suggests that for fishes like the neon gobies, protected areas may need to be close together."
Last week, the Pacific Island nation of Palau was the most recent nation to announce the designation of a large-scale marine reserve in its waters. Other nations announcing large marine reserves in the past year include New Zealand and Chile. In the U.S., in September 2014, President Obama expanded the impressive Pacific Remote Islands National Marine Monument to more than 490,000 square miles.
Such large reserves can provide habitat for a wide variety of species. But most marine reserves remain much smaller, and lead author Cassidy D'Aloia, now at the University of Toronto, notes that marine life still needs to travel among reserves. "If reserves are connected, then if a catastrophe occurs in one reserve, then that population can potentially be rescued by larvae from another reserve."
For their study, D'Aloia and her co-authors collected thousands of tissue samples from neon goby parents and offspring along a 41 km (about 25 miles) length of the Belizean Barrier Reef to determine how far those offspring traveled. They found that larvae typically dispersed no more than 1.7 kilometers (about one mile) from their parents and in no cases dispersed more than 16.4 km (about 10 miles). Although the study looked at only one species, gobies are the most diverse family of ocean fishes.
"Our research shows that some larval fish are not traveling very long distances, and that pattern is likely stable over long-periods of time. This result suggests that large marine reserves will need stepping stone reserves to help some fishes disperse between them," says Buston.
Study shows declines in whales, fish, seabirds and large animals damages Earth's nutrient cycle.
This diagram shows an interlinked system of animals that carry nutrients from ocean depths to deep inland -- through their poop, urine, and, upon death, decomposing bodies. A new study in the Proceedings of the National Academy of Sciences reports that -- in the past--this chain of whales, seabirds, migratory fish and large land mammals transported far greater amounts of nutrients than they do today. Here, the red arrows show the estimated amounts of phosphorus and other nutrients that were moved or diffused historically -- and how much these flows have been reduced today. Grey animals represent extinct or reduced densities of animal populations. Diagram from PNAS; designed by Renate Helmiss.
Giants once roamed the earth. Oceans teemed with ninety-foot-long whales. Huge land animals--like truck-sized sloths and ten-ton mammoths--ate vast quantities of food, and, yes, deposited vast quantities of poop.
A new study shows that these whales and outsized land mammals--as well as seabirds and migrating fish--played a vital role in keeping the planet fertile by transporting nutrients from ocean depths and spreading them across seas, up rivers, and deep inland, even to mountaintops.
However, massive declines and extinctions of many of these animals has deeply damaged this planetary nutrient recycling system, a team of scientists reported October 26 in the Proceedings of the National Academy of Sciences.
"This broken global cycle may weaken ecosystem health, fisheries, and agriculture," says Joe Roman, a biologist at the University of Vermont and co-author on the new study.
On land, the capacity of animals to carry nutrients away from concentrated "hotspots," the team writes, has plummeted to eight percent of what it was in the past--before the extinction of some 150 species of mammal "megafauna" at the end of the last ice age.
And, largely because of human hunting over the last few centuries, the capacity of whales, and other marine mammals, to move one vital nutrient--phosphorous--from deep ocean waters to the surface has been reduced by more than seventy-five percent, the new study shows.
IGNORING ANIMALS
"Previously, animals were not thought to play an important role in nutrient movement," said lead author Christopher Doughty, an ecologist at the University of Oxford.
But the new study shows that animals are a crucial "distribution pump," the scientists write, transporting masses of fecal matter to fertilize many places that would otherwise be less productive, including ocean surface waters and the interior of continents.
These fertilized ecosystems, in turn, maintain natural functions vital to people. For example, the new study notes that restoring whale populations could help increase the ocean's capacity to absorb climate-warming carbon dioxide.
Traditionally, scientists studying nutrient cycling have focused on weathering of rocks and nitrogen collection by bacteria--largely ignoring animals. This view assumed that the role of animals was minor, and mostly that of a passive consumer of nutrients. "However, this notion may be a peculiar world view that comes from living in an age where the number and size of animals have been drastically reduced from their former bounty," the team of nine scientists write.
"This study challenges the bottom-up bias that some scientists have--that microbes are running the show, and phytoplankton and plants are all that matter," says Joe Roman, a whale expert in UVM's Rubenstein School of Environment and Natural Resources and the Gund Institute for Ecological Economics.
"This once was a world that had ten times more whales; twenty times more anadromous fish, like salmon; double the number of seabirds; and ten times more large herbivores--giant sloths and mastodons and mammoths," says Roman.
On land, before the rise of modern humans, there were elephant-like gomphotheres the size of a backhoe, deer with twelve-foot wide antlers, and bison herds to the horizon. These were just a few of the huge animals that could eat huge amounts of plant matter, accelerating the release of nutrients through digestion and carrying these nutrients away from feeding areas to higher ground through their deposit of feces, urine and, upon death, decomposing bodies.
Overall, the scientists calculate that this animal-powered, planetary pump may have dropped to just six percent of its former capacity to spread nutrients away from concentrated sources on both land and sea.
WHALE WORK
A series of recent studies show that large animals appear to disproportionately drive nutrient movements. To make their new study, the team--including scientists from University of Oxford, University of Vermont, Harvard University, Aarhus University in Denmark, Princeton University, Netherlands Institute of Ecology, and Purdue University--used these findings and other existing data about historic and current animal populations. Then they applied a set of mathematical models to estimate the movement of nutrients vertically in the oceans and across the land--and how this movement changed with extinctions and declining animal populations.
For example, whale densities are estimated to have declined by between 66% and 90% over the last three centuries due to commercial hunting, the study notes. Most grievously, 350,000 blue whales, many over one hundred tons, used to inhabit oceans around the globe. Only a few thousand now remain. These and other great whales feed in the depths--and then defecate at the sun-lit surface "in a flocculent, liquidy cloud," says Roman.
LIMITED PHOSPHOROUS
In particular, the new study examined phosphorous, a nutrient critical for plant growth. Prior to the era of commercial hunting, the scientists estimate that whales and other marine mammals annually moved around 750 million pounds of phosphorus from the depths to the surface. Now that figure is about 165 million pounds--some 23% of former capacity.
The team also gathered data on seabird and fish populations that feed in the sea and then come onto land--like ocean-going salmon that move up rivers to defecate, spawn, and die. Movements by these birds and fish once carried more than 300 million pounds of phosphorus onto land each year, but that number has declined to less than four percent of past values as a result of destroyed seabird colonies, habitat loss, and overfishing.
"Phosphorus is a key element in fertilizers and easily accessible phosphate supplies may run out in as little as fifty years," says Oxford's Chris Doughty. "Restoring populations of animals to their former bounty could help to recycle phosphorus from the sea to land, increasing global stocks of available phosphorus in the future."
RECOVERY
The world of giants came to an end on land after the megafauna extinctions that began some 12,000 years ago--driven by a complex array of forces including climate change and Neolithic hunters. And it ended in the oceans in the wake of whale and other mammal hunting in the industrial era of humans.
"But recovery is possible and important," says UVM's Roman. He points to bison as an example. "That's achievable. It might be a challenge policy-wise, but it's certainly within our power to bring back herds of bison to North America. That's one way we could restore an essential nutrient pathway."
And many whale and marine mammal populations are also recovering, Roman notes. "We can imagine a world with relatively abundant whale populations again," he says.
But have domestic animals, like cows, taken over the nutrient distribution role of now-extinct large land animals? No, the new study shows. Though there are many cows, fences constrain the movement of domestic animals and their nutrients. "Future pastures could be set up with fewer fences and with a wider range of species," the team writes.
"The typical flow of nutrients is down mountains to the oceans," says Joe Roman. "We are looking at ways that nutrients can go in the other direction--and that's largely through foraging animals. They're bringing nutrients from the deep sea that could eventually reach a mountain in British Columbia."
Researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science developed a new method to estimate fish movements using ocean heat content images, a dataset commonly used in hurricane intensity forecasting. With Atlantic tarpon as the messenger, this is the first study to quantitatively show that large migratory fishes, such as yellowfin and bluefin tunas, blue and white marlin, and sailfish have affinities for ocean fronts and eddies.
"Ocean heat content data revealed detailed movements of fishes that were not readily apparent using surface temperature data," said Jerald S. Ault, UM Rosenstiel School professor of marine biology and ecology. "This offers a powerful new approach to study how fish interact with dynamic water features relatively common in the ocean."
Ocean heat content (OHC) relative to the 26°C isotherm, a measure of heat stored in the upper surface layers of the ocean, has been used for more than four decades by scientists to help predict hurricane intensity. Over the past two decades, OHC has been monitored daily using satellite fields and in-situ data that provide basin-scale variability for both weather and climate studies. In addition to providing the OHC for forecasting, these previous studies showed OHC images reveal dynamic ocean features, such as fronts and eddies, in the ocean better than just using standard techniques (e.g., sea surface temperature), especially during the summer months.
The researchers compared data on fish movements obtained from pop-up satellite tags affixed to the highly migratory fish alongside maps of the heat stored in the upper ocean. "Using an advanced optimization algorithm and OHC maps, we developed a method to greatly improve geolocation accuracy and refine fish movement tracks derived from satellite tags," said Jiangang Luo, lead author and UM scientist at the Tarpon and Bonefish Research Center. The analysis revealed that fish commonly swim along the boundaries of water features in the ocean, such as fronts, like the Florida and Loop Current and their complex eddy fields.
This image shows front and eddy utilization in the Gulf of Mexico by pelagic fishes revealed by ocean heat content: (a) a yellowfin tuna (Thunnus albacares); and, (b) an Atlantic sailfish. OHC maps are based on calculating thermal energy from the depths of the 20°C isotherm. Credit: Jiangang Luo, UM Rosenstiel School of Marine and Atmospheric Science.
"Using the OHC approach in a new way offers an unprecedented view of how these animals move with currents and eddies in the ocean," said Nick Shay, UM Rosenstiel School professor of ocean sciences. "Our study provides a more detailed picture of the ocean ecosystem as an entity."
In one 109-day analysis, the researchers documented a yellowfin tuna move along a weak front off the Mississippi River before reaching an eddy centered in the Gulf of Mexico. In separate analysis, a yellowfin tuna swam around the periphery of the same eddy many times over a 20-day period, rarely passing over it.
Eddies are swirling masses of water that have been shed from strong ocean current fronts, and pump nutrient-rich water to the surface. Fronts are a type of current created at a boundary between two distinct water masses with differing physical properties, such as different temperatures, salinities. In the Gulf of Mexico, warm eddies are often shed from the Loop Current in the summer months causing a rapid intensification of hurricanes (e.g., Katrina) as they pass over it.
"Our new method shows that hurricanes and highly migratory fish share at least one common oceanographic interest - warm swirling ocean eddies," said Ault.
Countries are loosely interpreting the legal meaning of "rational use" of natural resources to escalate fishing efforts in Antarctic waters and hinder efforts to establish marine protected areas in the Southern Ocean, scientists and legal scholars say.
Also on the meeting agenda are plans for extensive marine protected areas (MPAs), including the Ross Sea, Antarctica, a region scientists have deemed Earth's "Last Ocean" because it is perhaps the healthiest large intact marine ecosystem left on the planet.
"Largely protected by an icy shield and sheer remoteness, the southernmost waters around Antarctica are the least affected by people. They also contain some of our last pockets of untapped fish stocks," said co-author Cassandra Brooks, a PhD candidate in the Emmett Interdisciplinary Program in Environment and Resources (E-IPER) at Stanford University's School of Earth, Energy & Environmental Sciences.
CCAMLR is tasked with managing the waters around Antarctica and is considered a global leader in fisheries management that prioritizes conservation. As part of that leadership, it has been moving toward adopting an extensive network of MPAs to conserve the ecosystem and protect biodiversity in the Southern Ocean. Yet, in recent years, their progress has stalled, in part due to willful misinterpretation by member countries of the law that governs its icy waters.
As its name states, the goal of the commission is conservation, but under its legal Convention - the international treaty that governs the Southern Ocean - conservation includes "rational use," which allows for fishing in the Antarctic waters, but under strict and precautionary conditions. For example, it requires that fishing does not cause irreversible damage to the greater marine ecosystem. While defined in the text of the legal Convention, the term is increasingly being interpreted to mean an unfettered right to fish. Even more surprising, countries such as China and Ukraine have recently invoked rational use to protest the adoption of marine protected areas in the Southern Ocean.
"Our research into the treaty negotiation record shows that 'rational use' on its own did not have a clear, consistent, or objective meaning," said lead author Jennifer Jacquet, an assistant professor in New York University's Environmental Studies Program.
"In recent years, some countries have argued that MPAs interfere with their right to rational use," Brooks said. "Yet adopting MPAs in CCAMLR waters is in complete accordance with stipulations of rational use, which require conservation of the fished species and the greater ecosystem in the Southern Ocean."
Currently, the main species harvested in the Antarctic are Antarctic krill and Patagonian and Antarctic toothfish, also known on the market as the lucrative "Chilean sea bass."
"The Southern Ocean is a global commons. As such, marine protected areas would allow CCAMLR member states to continue fishing while also ensuring a legacy for future generations," Brooks said. "What could be more rational than that?"
An international team of biologists has made the first-ever field observations of one of the least known species of whales in the world--Omura's whales--off the coast of Madagascar.
In a paper published October 14, 2015, in the Royal Society Open Science journal, the researchers describe the whales' foraging and vocal behaviors, and habitat preferences in the shallow waters of coastal Madagascar.
For many years, these marine mammals were misidentified as Bryde's whales due to their similar appearance--both are small tropical baleen whales with comparable dorsal fins, though Omura's are slightly smaller in size and have unique markings with a lower jaw that is white on the right side and dark on the left.
In 2003, using genetic data from samples obtained from old whaling expeditions and a few strandings in the western tropical Pacific, scientists determined Omura's whales were actually a distinct species. But there had been no confirmed records of sightings in the wild and little else has been known about the elusive species until now.
"Over the years, there have been a small handful of possible sightings of Omura's whales, but nothing that was confirmed," says lead author Salvatore Cerchio, who led the research while at the Wildlife Conservation Society. He is now at the New England Aquarium (NEAQ) and a guest investigator at the Woods Hole Oceanographic Institution (WHOI). "They appear to occur in remote regions and are difficult to find at sea because they are small--they range in length from approximately 33 to 38 feet--and do not put up a prominent blow."
So little is known about Omura's whales that scientists are unsure how many exist or how rare the species is.
"What little we knew about these whales previously came primarily from eight specimens of Omura's whales taken in Japanese scientific whaling off the Solomon and Keeling Islands and a couple strandings of dead animals in Japan," Cerchio adds. "This is the first definitive evidence and detailed descriptions of Omura's whales in the wild and part of what makes this work particularly exciting."
When Cerchio and his colleagues, who have been conducting field research on marine mammals off the northwest coast of Madagascar since 2007, first spotted an Omura's whale in the area in 2011, they too believed it was a Bryde's whale.
"From the little information on their habitat and range, Omura's whales were not supposed to be in that part of the Indian Ocean," Cerchio says.
After moving study areas in 2013, the sightings became more frequent and the team noticed the distinct markings-- unique asymmetrical pigmentation on the head-- that led them to believe the whales might be Omura's whales.
Over a two-year period, the researchers observed 44 groups and were able to collect skin biopsies from 18 adult whales. The samples were then sent to coauthor Alec Lindsay at Northern Michigan University who performed the DNA analysis that confirmed the whales' species.
The research team also observed four mothers with young calves. Using hydrophones, they recorded song-like vocalizations that may indicate reproductive behavior.
Cerchio will return to the field in November to do further study on the whales' vocalizations, behavior and population characteristics. He also hopes to expand the research area in future studies of Omura's whales, working with colleagues at WHOI to deploy Digital Acoustic Recording Tags (DTAGS) and to study the species in other parts of its range.
Cerchio hopes to produce the first estimate of abundance for any population of Omura's whales with the work off Madagascar. So far, the team has catalogued approximately 25 individuals through photographic identifications.
A type of bacteria plucked from the bottom of the ocean could be put to work neutralizing large amounts of industrial carbon dioxide in the Earth's atmosphere, a group of University of Florida researchers has found.
Carbon dioxide, a major contributor to the buildup of atmospheric greenhouse gases, can be captured and neutralized in a process known as sequestration. Most atmospheric carbon dioxide is produced from fossil fuel combustion, a waste known as flue gas. But converting the carbon dioxide into a harmless compound requires a durable, heat-tolerant enzyme. That's where the bacterium studied by UF Health researchers comes into play. The bacterium -- Thiomicrospira crunogena -- produces carbonic anhydrase, an enzyme that helps remove carbon dioxide in organisms.
So what makes the deep-sea bacterium so attractive? It lives near hydrothermal vents, so the enzyme it produces is accustomed to high temperatures. That's exactly what's needed for the enzyme to work during the process of reducing industrial carbon dioxide, said Robert McKenna, Ph.D., a professor of biochemistry and molecular biology in the UF College of Medicine, a part of UF Health.
"This little critter has evolved to deal with those extreme temperature and pressure problems. It has already adapted to some of the conditions it would face in an industrial setting," he said.
The findings by the McKenna group, which included graduate research assistants Brian Mahon and Avni Bhatt, were published recently in the journals Acta Crystallographica D: Biological Crystallographyand Chemical Engineering Science.
The chemistry of sequestering works this way: The enzyme, carbonic anhydrase, catalyzes a chemical reaction between carbon dioxide and water. The carbon dioxide interacts with the enzyme, converting the greenhouse gas into bicarbonate. The bicarbonate can then be further processed into products such as baking soda and chalk.
In an industrial setting, the UF researchers believe the carbonic anhydrase could be captured this way: The carbonic anhydrase would be immobilized with solvent inside a reactor vessel that serves as a large purification column. Flue gas would be passed through the solvent, with the carbonic anhydrase converting the carbon dioxide into bicarbonate.
Neutralizing industrial quantities of carbon dioxide can require a significant amount of carbonic anhydrase, so McKenna's group found a way to produce the enzyme without repeatedly harvesting it from the sea floor. The enzyme can be produced in a laboratory using a genetically engineered version of the common E. coli bacteria. So far, the UF Health researchers have produced several milligrams of the carbonic anhydrase, though Bhatt said much larger quantities would be needed to neutralize carbon dioxide on an industrial scale.
That's just one of the challenges researchers face before the enzyme could be put to use against carbon dioxide in real-world settings. While it has good heat tolerance, the enzyme studied by McKenna's team isn't particularly efficient.
"You want it to do the reaction faster and more efficiently," Bhatt said. "The fact that it has such a high thermal stability makes it a good candidate for further study."
Ideally, Bhatt said, more research will produce a variant of the enzyme that is both heat-tolerant and fast-acting enough that it can be used in industrial settings. Next, they want to study ways to increase the enzyme's stability and longevity, which are important issues to be addressed before the enzyme could be put into widespread industrial use.
While carbonic anhydrase's ability to neutralize carbon dioxide has been widely studied by McKenna and other scientists around the world for some time, finding the best enzyme and putting it to work in an efficient and affordable carbon sequestration system has been challenging. Still, McKenna said he is encouraged by the prospect of discoveries that could ultimately benefit the planet.
"It shows that it's physically possible to take known enzymes such as carbonic anhydrase and utilize them to pull carbon dioxide out of flue gas," he said.
