Constantine Alexander's Journal

Plan to delist gray wolf endangers other threatened species

Scientists say proposal to end wolf protection across US disregards science, history, threats

Written by Emily Caldwell

The federal government's proposal to discontinue protection for the gray wolf across the United States could have the unintended consequence of endangering other species, researchers say.

As written, scientists assert, the proposed rule would set a precedent allowing the U.S. Fish and Wildlife Service (FWS) to declare habitat unsuitable for an endangered animal because a threat exists on the land – the exact opposite of the service's mandate to impose regulations that reduce threats against imperiled species.

The FWS has "conflated threats with habitat suitability" by stating that U.S. land currently unoccupied by wolves – most of the country that historically served as wolf habitat – is now unsuitable because humans living in those regions won't tolerate the animals, the lead scientist said. This claim runs counter to existing research, which the service did not cite in its explanation of the rule.

"The Fish and Wildlife Service is supposed to detail what the threats are and if they're substantial enough, they're supposed to list a species and put in place policies to mitigate the threats," said Jeremy Bruskotter, associate professor in The Ohio State University's School of Environment and Natural Resources and lead author of the paper.

"Here, they're saying that they recognize the threat of human intolerance and instead of mitigating the threat, they're just going to say the land is unsuitable."

Were this rule to stand, he said, "Anytime the U.S. Fish and Wildlife Service finds that something is in the way of a species' recovery, they can just say the habitat is unsuitable for the species and disregard the threat altogether."

FWS proposed removing the gray wolf (Canis lupus) from the list of threatened and endangered species in June. The rule covers most of the continental United States where wolves historically existed, before being exterminated by people in the late 19th and early 20th centuries. Public comments closed Dec. 17, and will be analyzed and considered before the service issues a final rule.

The critique is published online in the journal Conservation Letters.

Congress passed the Endangered Species Act in 1973. The act expanded on previous legislation by providing for the protection of any species in danger of or threatened with extinction throughout all or a significant portion of its range.

The act's language is critical to what follows: In determining whether a species has recovered, the law requires FWS to declare it is no longer endangered in all or a "significant portion of its range." The gray wolf has recovered in the northern Rockies and upper Great Lakes.

The proposed rule, however, discounts the other 85 percent of the wolf's historic range, which stretches across northern states from the west coast through New England and as far east as mid-Texas in the southern half of the country.

"So what the service is saying is that wolves are going to be called recovered in most of the United States despite the fact that very few wolves live outside these two recovered areas," Bruskotter said. "Wherever they are now, that's their range – which means taking the historic and geographic component out of the listing process."

He and colleagues suggest that this practice not only disregards the law, but "specifically creates incentive to destroy habitat in advance of a listing and do things that aren't good for endangered species."

The law also requires the service to consider the "best available science" in assessing whether threats have eased and a species is recovered. Instead of citing the dozens of studies that suggest human support for wolf restoration is high, the service simply ignored this research and claimed that these areas are unsuitable because of human intolerance. When federal protection is lifted, species management falls to the states.

"That process is not the best available science," Bruskotter said.

Bruskotter acknowledged that FWS is under enormous pressure from the opposing sides of a highly contentious fight about wolves: hunters and livestock producers on one side and wildlife advocates on the other. But that pressure doesn't relieve the service of its duty to act on behalf of endangered species as the law requires, he said.

"The law is supposed to help the protected species, not just describe the threats to that species. But to construct this delisting rule, they've had to interpret policy and science in every case in a way that either disregards threats to wolves, or treats them as insurmountable," he said. "They're doing the opposite of what the act requires."

Co-authors of the critique include John Vucetich of Michigan Technological University, Sherry Enzler of the University of Minnesota, Adrian Treves of the University of Wisconsin and Michael P. Nelson of Oregon State University.

Contact: Jeremy Bruskotter
614-247-2118
Ohio State University

 

Major reductions in seafloor marine life from climate change by 2100

Large animals (megafauna), such as this hydroid Corymorpha glacialis, are projected to suffer major declines under the latest climate change predictions. Credit: National Oceanography Centre

A new study quantifies for the first time future losses in deep-sea marine life, using advanced climate models. Results show that even the most remote deep-sea ecosystems are not safe from the impacts of climate change.

An international team of scientists predict seafloor dwelling marine life will decline by up to 38 per cent in the North Atlantic and over five per cent globally over the next century. These changes will be driven by a reduction in the plants and animals that live at the surface of the oceans that feed deep-sea communities. As a result, ecosystem services such as fishing will be threatened.

In the study, led by the National Oceanography Centre, the team used the latest suite of climate models to predict changes in food supply throughout the world oceans. They then applied a relationship between food supply and biomass calculated from a huge global database of marine life.

The results of the study are published this week in the scientific journal Global Change Biology.

These changes in seafloor communities are expected despite living on average four kilometres under the surface of the ocean. This is because their food source, the remains of surface ocean marine life that sink to the seafloor, will dwindle because of a decline in nutrient availability. Nutrient supplies will suffer because of climate impacts such as a slowing of the global ocean circulation, as well as increased separation between water masses – known as 'stratification' – as a result of warmer and rainier weather.

Lead author Dr Daniel Jones says: "There has been some speculation about climate change impacts on the seafloor, but we wanted to try and make numerical projections for these changes and estimate specifically where they would occur.

"We were expecting some negative changes around the world, but the extent of changes, particularly in the North Atlantic, were staggering. Globally we are talking about losses of marine life weighing more than every person on the planet put together."

The projected changes in marine life are not consistent across the world, but most areas will experience negative change. Over 80 per cent of all identified key habitats – such as cold-water coral reefs, seamounts and canyons – will suffer losses in total biomass. The analysis also predicts that animals will get smaller. Smaller animals tend to use energy less efficiently, thereby impacting seabed fisheries and exacerbating the effects of the overall declines in available food.

Citation: Jones, D.O.B., Yool, A., Wei, C-L., Henson, S.A., Ruhl, H.A., Watson, R.A., Gehlen, M. (2013) Global reductions in seafloor biomass in response to climate change, Global Change Biology, doi: 10.1111/gcb.12480

The study was funded by the Natural Environment Research Council (NERC) as part of the Marine Environmental Mapping Programme (MAREMAP), and involved researchers from the National Oceanography Centre, the Memorial University of Newfoundland, Canada, the University of Tasmania, and the Laboratoire des Sciences du Climat et de l'Environnement, France.

Contact: Catherine Beswick
National Oceanography Centre, Southampton (UK)

Some plants may not adapt quickly to future climate change

Amborella female flower. Photograph by Sangtae Kim.

By Stephenie Livingston

Using the largest dated evolutionary tree of flowering plants ever assembled, a new study suggests how plants developed traits to withstand low temperatures, with implications that human-induced climate change may pose a bigger threat than initially thought to plants and global agriculture.

The study appearing Sunday (Dec. 22) in the journal Nature and co-authored by University of Florida scientists shows many angiosperms, or flowering plants, evolved mechanisms to cope with freezing temperatures as they radiated into nearly every climate during pre-historic times. Researchers found the plants likely acquired many of these adaptive traits prior to their movement into colder regions. The study also suggests some modern angiosperms, including most flowering plants, trees and agricultural crops, may not have the traits needed to rapidly respond to human-induced climate change, said study co-author Pam Soltis, a distinguished professor and curator of molecular systematics and evolutionary genetics at the Florida Museum on the UF campus.

"Only some plants were able to make the adjustments to survive in cold climates," said Soltis, who also is a member of the UF Genetics Institute. "In fact, some had traits used for other purposes that they co-opted for cold tolerance. The results have implications for plant response to climate change -- some plant lineages, including many crops, will not have the underlying genetic attributes that will allow for rapid responses to climate change."

Early flowering plants are thought to have been woody -- meaning they maintain a prominent stem above ground across years and changing weather conditions, such as a maple tree -- and restricted to warm, wet, tropical environments. But they have since put down roots in colder climates, dominating large swaths of the globe where freezing occurs. How they managed this expansion has long vexed researchers searching for plants' equivalent to the winter parka.

"Until now, we haven't had a compelling narrative about how leaf and stem traits have evolved to tolerate cold temperatures," said lead author Amy Zanne, assistant professor of biology in George Washington University's Columbian College of Arts and Sciences who earned her doctorate at UF. "Our research gives us this insight, showing us the 'whens,' 'hows' and 'whys' behind plant species' trait evolution and movements around the globe."

Zanne continued: "Freezing is a challenge for plants. Their living tissues can be damaged. It's like a plant's equivalent to frostbite. Their water-conducting pipes can also be blocked by air bubbles as water freezes and thaws. So over time, if plants moved into colder climates, they've had to figure out how to get around these problems."

Amborella male flowers. Photograph by  Joel McNeal.

Identifying evolutionary adaptations to these problems and likely paths to them required the team to build two sets of data. Researchers first created a database of 49,064 species, recording whether each maintains a stem aboveground over time, loses or keeps its leaves, has been exposed to freezing, and the width of its water-carrying pathways. Researchers combined the information with a dated evolutionary tree of 32,223 plant species and modeled the evolution of species' traits and climate over time, which identified the order of evolutionary events.

"We can determine the relative order of events without a dated tree, but the dated tree allows us to say exactly when something happened, so that we can correlate the events with geological events, like big changes in Earth's temperature," Soltis said.

Using this "timetree," researchers identified three repeated evolutionary shifts they believe flowering plants made to fight the cold. Plants either dropped their leaves seasonally, shutting down the pathways that would normally carry water between roots and leaves; developed thinner water-conducting pathways, allowing them to keep their leaves while reducing the risk of air bubbles developing during freezing and thawing; or avoided the cold seasons altogether as herbs, losing aboveground stems and leaves and retreating as seeds, or storing organs underground, such as tulips or potatoes.

"Angiosperms were not successful until they got the adaptation to drop their leaves," said study co-author Doug Soltis, a Florida Museum distinguished professor with appointments in UF's biology department and the UF Genetics Institute. "Sometimes the trait evolves for some other purpose, and then the organism is able to adapt and use it for something new."

Researchers found that woody plants most often became herbs or developed thinner pathways before moving into freezing climates, while plants that dropped their leaves usually did so after moving into freezing climates. But the changes did not occur rapidly, Pam Soltis said.

"Some of these changes were probably not as simple as we once thought," she said. "Adjusting to big shifts in their environments is probably not easy for plants to do."

The researchers plan to use the findings to explore other aspects of plants' evolutionary history, including examining how they respond to environmental changes other than freezing temperatures.

"The onset of freezing temperatures did not affect the entire world, but only certain habitats became colder," Pam Soltis said. "Certain lineages could not move into the cold, but were able to persist unaffected by the cold in warmer areas. With climate change that is human-induced, all habitats will be affected over a short period of time, and plants and other organisms will have to adapt quickly if they are to survive."

Contact: Doug Soltis
352-273-1963
University of Florida

Not just the Koch brothers: New Drexel study reveals funders behind the climate change denial effort

A new study conducted by Drexel University's environmental sociologist Robert J. Brulle, PhD, exposes the organizational underpinnings and funding behind the powerful climate change countermovement. This study marks the first peer-reviewed, comprehensive analysis ever conducted of the sources of funding that maintain the denial effort.

Through an analysis of the financial structure of the organizations that constitute the core of the countermovement and their sources of monetary support, Brulle found that, while the largest and most consistent funders behind the countermovement are a number of well-known conservative foundations, the majority of donations are "dark money," or concealed funding.

The data also indicates that Koch Industries and ExxonMobil, two of the largest supporters of climate science denial, have recently pulled back from publicly funding countermovement organizations. Coinciding with the decline in traceable funding, the amount of funding given to countermovement organizations through third party pass-through foundations like Donors Trust and Donors Capital, whose funders cannot be traced, has risen dramatically.

Dr. Robert J. Brulle is a professor of sociology and environmental science at Drexel University in Philadelphia. Credit: CASBS

Brulle, a professor of sociology and environmental science in Drexel's College of Arts and Sciences, conducted the study during a year-long fellowship at Stanford University's Center for Advanced Study in the Behavioral Sciences. The study was published today in Climatic Change, one of the top 10 climate science journals in the world.

The climate change countermovement is a well-funded and organized effort to undermine public faith in climate science and block action by the U.S. government to regulate emissions. This countermovement involves a large number of organizations, including conservative think tanks, advocacy groups, trade associations and conservative foundations, with strong links to sympathetic media outlets and conservative politicians.

"The climate change countermovement has had a real political and ecological impact on the failure of the world to act on the issue of global warming," said Brulle. "Like a play on Broadway, the countermovement has stars in the spotlight – often prominent contrarian scientists or conservative politicians – but behind the stars is an organizational structure of directors, script writers and producers, in the form of conservative foundations. If you want to understand what's driving this movement, you have to look at what's going on behind the scenes."

To uncover how the countermovement was built and maintained, Brulle developed a listing of 118 important climate denial organizations in the U.S. He then coded data on philanthropic funding for each organization, combining information from the Foundation Center with financial data submitted by organizations to the Internal Revenue Service. The final sample for analysis consisted of 140 foundations making 5,299 grants totaling $558 million to 91 organizations from 2003 to 2010.

Key findings include:

• Conservative foundations have bank-rolled denial. The largest and most consistent funders of organizations orchestrating climate change denial are a number of well-known conservative foundations, such as the Searle Freedom Trust, the John William Pope Foundation, the Howard Charitable Foundation and the Sarah Scaife Foundation. These foundations promote ultra-free-market ideas in many realms.
• Koch and ExxonMobil have recently pulled back from publicly visible funding. From 2003 to 2007, the Koch Affiliated Foundations and the ExxonMobil Foundation were heavily involved in funding climate-change denial organizations. But since 2008, they are no longer making publicly traceable contributions.
• Funding has shifted to pass through untraceable sources. Coinciding with the decline in traceable funding, the amount of funding given to denial organizations by the Donors Trust has risen dramatically. Donors Trust is a donor-directed foundation whose funders cannot be traced. This one foundation now provides about 25% of all traceable foundation funding used by organizations engaged in promoting systematic denial of climate change.
• Most funding for denial efforts is untraceable. Despite extensive data compilation and analyses, only a fraction of the hundreds of millions in contributions to climate change denying organizations can be specifically accounted for from public records. Approximately 75% of the income of these organizations comes from unidentifiable sources.

"The real issue here is one of democracy. Without a free flow of accurate information, democratic politics and government accountability become impossible," said Brulle. "Money amplifies certain voices above others and, in effect, gives them a megaphone in the public square. Powerful funders are supporting the campaign to deny scientific findings about global warming and raise public doubts about the roots and remedies of this massive global threat. At the very least, American voters deserve to know who is behind these efforts."

This study is part one of a three-part project by Brulle to examine the climate movement in the U.S. at the national level. The next step in the project is to examine the environmental movement or the climate change movement. Brulle will then compare the whole funding flow to the entire range of organizations on both sides of the debate.

• Download the Institutionalizing Delay - Foundation funding and the creation of US climate change counter movement organizations study

Brulle has authored numerous articles and book chapters on environmental science, and is a frequent media commentator on climate change. He co-edited Power, Justice and the Environment: A Critical Appraisal of the Environmental Justice Movement (2005) with David Pellow, and is the author of Agency, Democracy, and Nature: U.S. Environmental Movements from a Critical Theory Perspective (2000). Brulle previously served as a commissioned officer in the United States Coast Guard for two decades. He received a doctorate in sociology from George Washington University, a master of science degree in natural resources from the University of Michigan, a master of arts degree in sociology from the New School for Social Research and a bachelor of science degree in marine engineering from the United States Coast Guard Academy.

Contact: Alex McKechnie
215-895-2705
Drexel University

Efforts to curb climate change require greater emphasis on livestock

Credit: Rick Harrison (CC)

While climate change negotiators struggle to agree on ways to reduce carbon dioxide (CO2) emissions, they have paid inadequate attention to other greenhouse gases associated with livestock, according to an analysis by an international research team.

A reduction in non-CO2 greenhouse gases will be required to abate climate change, the researchers said. Cutting releases of methane and nitrous oxide, two gases that pound-for-pound trap more heat than does CO2, should be considered alongside the challenge of reducing fossil fuel use.

The researchers' analysis, "Ruminants, Climate Change, and Climate Policy," is being published today as an opinion commentary in Nature Climate Change, a professional journal.

William Ripple, a professor in the College of Forestry at Oregon State University, and co-authors from Scotland, Austria, Australia and the United States, reached their conclusions on the basis of a synthesis of scientific knowledge on greenhouse gases, climate change and food and environmental issues. They drew from a variety of sources including the Food and Agricultural Organization, the United Nations Framework Convention on Climate Change (UNFCCC) and recent peer-reviewed publications.

"Because the Earth's climate may be near a tipping point to major climate change, multiple approaches are needed for mitigation," said Ripple. "We clearly need to reduce the burning of fossil fuels to cut CO2 emissions. But that addresses only part of the problem. We also need to reduce non-CO2 greenhouse gases to lessen the likelihood of us crossing this climatic threshold."

Methane is the second most abundant greenhouse gas, and a recent report estimated that in the United States methane releases from all sources could be much higher than previously thought. Among the largest human-related sources of methane are ruminant animals (cattle, sheep, goats, and buffalo) and fossil fuel extraction and combustion.

One of the most effective ways to cut methane, the researchers wrote, is to reduce global populations of ruminant livestock, especially cattle. Ruminants are estimated to comprise the largest single human-related source of methane. By reflecting the latest estimates of greenhouse gas emissions on the basis of a life-cycle or a "farm to fork" analysis, the researchers observed that greenhouse gas emissions from cattle and sheep production are 19 to 48 times higher (on the basis of pounds of food produced) than they are from producing protein-rich plant foods such as beans, grains, or soy products.

Unlike non-ruminant animals such as pigs and poultry, ruminants produce copious amounts of methane in their digestive systems. Although CO2 is the most abundant greenhouse gas, the international community could achieve a more rapid reduction in the causes of global warming by lowering methane emissions through a reduction in the number of ruminants, the authors said, than by cutting CO2 alone.

The authors also observed that, on a global basis, ruminant livestock production is having a growing impact on the environment: 

• Globally, the number of ruminant livestock has increased by 50 percent in the last 50 years, and there are now about 3.6 billion ruminant livestock on the planet.
• About a quarter of the Earth's land area is dedicated to grazing, mostly for cattle, sheep and goats.
• A third of all arable land is used to grow feed crops for livestock.

In addition to reducing direct methane emissions from ruminants, cutting ruminant numbers would deliver a significant reduction in the greenhouse gas emissions associated with the production of feed crops for livestock, they added.

"Reducing demand for ruminant products could help to achieve substantial greenhouse gas reductions in the near-term," said co-author Helmut Haberl of the Institute of Social Ecology in Austria, "but implementation of demand changes represent a considerable political challenge."

Among agricultural approaches to climate change, reducing demand for meat from ruminants offers greater greenhouse gas reduction potential than do other steps such as increasing livestock feeding efficiency or crop yields per acre. Nevertheless, they wrote, policies to achieve both types of reductions "have the best chance of providing rapid and lasting climate benefits."

Such steps could have other benefits as well, said co-author Pete Smith of the University of Aberdeen in Scotland. "Cutting the number of ruminant livestock could have additional benefits for food security, human health and environmental conservation involving water quality, wildlife habitat and biodiversity," he explained.

Agricultural researchers are also studying methane reduction through improved animal genetics and methods to inhibit production of the gas during digestion.

International climate negotiations such as the UNFCCC have not given "adequate attention" to greenhouse gas reductions from ruminants, they added. The Kyoto Protocol, for example, does not target ruminant emissions from developing countries, which are among the fastest-growing ruminant producers.

In addition to Smith and Haberl, co-authors include Stephen A. Montzka of the U.S. National Oceanic and Atmospheric Administration, Clive McAlpine of the University of Queensland in Australia and Douglas Boucher of the Union of Concerned Scientists in Washington D.C.

Contact: Bill Ripple
541-737-3056
Oregon State University

Greek economic crisis leads to air pollution crisis

Levels of dangerous air particulates jump 30 percent as people turn to burning cheaper fuel sources

Thessaloniki.

In the midst of a winter cold snap, a study from researchers in the United States and Greece reveals an overlooked side effect of economic crisis – dangerous air quality caused by burning cheaper fuel for warmth.

The researchers, led by Constantinos Sioutas of the USC Viterbi School of Engineering, show that the concentration of fine air particles in one of Greece's economically hardest hit areas has risen 30 percent since the financial crisis began, leading to potential long-term health effects.

These fine particles – measuring less than 2.5 microns in diameter (approximately 1/30th the diameter of a human hair) – are especially dangerous because they can lodge deep into the tissue of lungs, according to the EPA.

"People need to stay warm, but face decreasing employment and rising fuel costs," explained Sioutas, senior author of the study in the journal Environmental Science & Technology and Fred Champion Professor in Civil and Environmental Engineering at the USC Viterbi School. "The problem is economic hardship has compelled residents to burn low quality fuel, such as wood and waste materials, that pollutes the air."

Unemployment in Greece climbed above 27 percent in 2013. Meanwhile, heating oil prices have nearly tripled in Greece during the Greek financial crisis of the last few years – driven in part by a fuel tax hike. Cold Greeks, it would appear (according to the air quality), have turned to wood as a major fuel source.

In their study, the researchers collected air samples that supported anecdotal evidence of Greek residents burning of wood and trash for heating. Taken over two-month stretches in Winter 2012 and again in Winter 2013, the samples reveal a dramatic increase in airborne fine particles since the beginning of the economic crisis.

The concentration of these particles, which has been linked to increased risk for heart disease and respiratory problems, rose from 26 to 36 micrograms per square meter over the study period, the researchers found. The EPA standard in the United States is an average of 20 micrograms per square meter over a 24-hour period. Worse yet, the concentrations of carcinogenic organic compounds such as polycyclic aromatic hydrocarbons (PAH) increased five-fold during the study period, the researchers found.

The concentration of the particulates was highest in the evening, presumably when more people were burning fuel for warmth, the study found. An analysis of the air samples also showed a two-to-five-fold increase in the airborne concentrations of organic compounds such as levoglucosan, mannosan and galactosan, which indicate the burning of biomass. The presence of these compounds has been strongly correlated in past research to oxidative stress in human cells, which is linked to inflammation, aging and the development of age-related diseases.

"Wood's cheap, but it's having a major negative impact on air quality," Sioutas said. The authors recommend active involvement of public authorities and local agencies to implement effective air pollution control strategies. They suggest increasing natural gas distribution in residential areas as a practical long-term solution. Catalytic domestic wood burners and increasing the energy efficiency of existing buildings might be additional possible solutions, according to the report.

Sioutas collaborated with researchers from USC, Aristotle University of Thessaloniki and the University of Wisconsin-Madison on the study. Arian Saffari, a Provost PhD fellow at the USC Viterbi School, is lead author of the study. The research was funded by the USC Provost, the USC Viterbi School of Engineering and the City of Thessaloniki Mayor's office.

Contact: Robert Perkins
213-740-9226
University of Southern California

Mediterranean seagrass meadows threatened by increasing sulphide stress

By Science for Environment Policy

Warmer sea temperatures are increasing the toxic effect of sulphides on seagrass meadows in the Mediterranean Sea, new research reveals. Higher sea temperatures in the region, as projected using climate modelling, will therefore further threaten these habitats which are already declining from the damage caused by other human activities.

Meadows of seagrass (Posidonia oceanica) are important and widespread ecosystems in the Mediterranean Sea, but are under threat from human influences such as dredging and trawling as well as eutrophication caused by excess nutrients from agricultural runoff, sewage wastewater and aquaculture. These impacts have caused the meadows to shrink in area by 5-20% since the early 20^th century and there is concern that they will be further threatened by the effects of climate change, as the grass is sensitive to warmer temperatures.

Seagrass is particularly vulnerable to the toxic effects of sulphides. Sulphides occur naturally, and can accumulate in sediment when there are high concentrations of organic matter (which typically occurs in nutrient-enriched waters) and under anaerobic (i.e. without oxygen) conditions. In these situations, sulphides enter and damage the plants, leading to seagrass loss.

This study, partly funded by the EU WISER project, investigated the impact of warmer sea temperatures on the sulphide stress of seagrass based on records which monitored meadows around Spain's Balearic Islands in the northwestern Mediterranean over eight years. The researchers used chemical tracing techniques to estimate the percentage of sulphur entering seagrass leaf tissue from sedimentary sulphides, as well as the total sulphur content.

Higher concentrations of sulphur in leaf tissue had reduced the growth and development of the studied meadows and the percentage of sulphur in the plants that came from sediment sulphides increased between 2002 and 2008. Two heat waves occurred in the summers of 2003 and 2006 which pushed the maximum sea surface temperatures to 28.5 °C and 29.5 °C, respectively.

These results indicate that sulphide intrusion into the seagrass was enhanced by the warmer temperatures and that even warmer sea temperatures projected under climate changemodelling will exacerbate this process.

Shallower meadows also appeared to be more prone to sulphide intrusion than deeper ones, implying that deeper meadows would be better protected from sulphide intrusion under the temperatures observed in this study. However, if sea temperatures in the western Mediterranean reach 30.5 °C, as predicted, then even meadows as deep as 40 m below the surface of the sea would be exposed to a risk of sulphide intrusion.

Given that seagrass meadows are already declining and climate change is likely to lead to even greater losses, the researchers call for rapid action to reduce the impacts of human activities such as eutrophication and physical damage to the seabed. They also call for a reduction in greenhouse gas emissions, mitigating the long term impacts of climate change.

Source: García, R., Holmer, M, Duarte, C.M. et al. (2013). Global warming enhances sulphide stress in a key seagrass species (NW Mediterranean). Global Change Biology. DOI: 10.1111/gcb.12377.

Contact: R. Garcia

What threat do sunken nuclear submarines pose to fisheries?

The sunken USS Scorpion containing two nuclear torpedoes on the sea floor

By Science for Environment Policy

Leakage of radioactive material from the wreck of the nuclear submarine K-159 in the Barents Sea could increase levels of radioactivity in local populations of cod by a hundred times, new research suggests. However, this level remains well below 'safe' standards set by the Norwegian government.

Global fallout from nuclear weapons, dumping of radioactive waste and sunken nuclear submarines all cause radioactive contamination in the Arctic marine environment. In this study, researchers investigated the potential effects of leakages from two sunken submarines, which contain large amounts of caesium-137. This radioactive isotope decays very slowly, with a half life of 30 years, and may accumulate in the body tissues of marine organisms.

The researchers used computer models of ocean currents in the Barents Sea, which lies north of Norway in the Arctic Ocean, to simulate and track a leak of caesium-137 from K-159 from the day it sank in 2003 and continuing for five years afterwards. The researchers combined maps of the estimated caesium-137 concentration in the Barents Sea with the geographical distribution of two commercially important fish species, Northeast Arctic cod and capelin, obtained from surveys carried out between 2004-2008.

Knowing the rate that these species absorb caesium-137, the researchers then estimated whether levels in the fish would have exceeded the 'safe' standards for radioactivity set by the Norwegian authorities.

The researchers carried out a similar exercise for Komsomolets, a more well-studied submarine that sank in the Norwegian Sea in 1989. For each submarine, the scientists investigated the effects of two possible scenarios of leakage that may have occurred: (i) a continuous release of caesium-137 for five years, and (ii) a single initial release equivalent to 100% of the total amount contained in the submarine.

The results suggest that neither continuous leakage nor pulses of caesium-137 from K-159 orKomsomolets would raise radioactivity in cod or capelin to levels considered dangerous. However, a single release of 100% of the caesium-137 from K-159 would raise concentrations in cod to a hundred times their current level for two years after the leakage.

While the radioactivity of cod and capelin was not predicted by this study to reach dangerous levels, the researchers caution that further research is needed to assess the effects on the whole ecosystem.

In conclusion, this approach could be used to evaluate the risk of contamination of marine resources after a spill of radioactive material, say the researchers, or even to track a contaminant from where it is observed back to its source.

Source: Heldal, H.E., Vikebø, F. & Johansen, G.O. (2013). Dispersal of the radionuclide caesium -137 (¹³⁷Cs) from point sources in the Barents and Norwegian Seas and its potential contamination of the Arctic marine food chain: Coupling numerical ocean models with geographical fish distribution data. Environmental Pollution. 180: 190-198. DOI: 10.1016/j.envpol.2013.04.032.

Contact: Hilde Elise Heldal

Scientists Report Some Gulf Dolphins Are Gravely Ill

Following the Deepwater Horizon oil spill, numerous dolphins were documented encountering oil, such as those in this photo from July 2010. Credit: NOAA

Bottlenose dolphins in Louisiana’s Barataria Bay have lung damage and adrenal hormone abnormalities not previously seen in other dolphin populations, according to a new peer-reviewed study published Dec. 18, 2013 in the journal Environmental Science & Technology.

The Deepwater Horizon spill heavily oiled Barataria Bay. The study was conducted in August 2011 as part of the Natural Resource Damage Assessment (NRDA) by a team of government, academic and non-governmental researchers. In the NRDA process, federal and state trustee agencies working cooperatively with BP identify potential injuries to natural resources and lost public uses resulting from the spill, along with restoration projects to ensure that the public is fully compensated for its loss.

The publication details the first evidence that dolphins in heavily oiled areas are exhibiting injuries consistent with toxic effects observed in laboratory studies of mammals exposed to petroleum hydrocarbons. The dolphin health study concludes that the health effects seen in the Barataria Bay dolphins are significant and likely will lead to reduced survival and ability to reproduce.

Twenty-nine of the total 32 dolphins sampled in Barataria Bay received comprehensive physical examinations, including ultrasound examinations to assess lung condition. The researchers assigned almost half (48 percent) of the dolphins a guarded or worse prognosis. In fact, they classified 17 percent as being in  poor or grave condition, meaning the dolphins were not expected to survive.

These findings are in contrast to dolphins sampled in Sarasota Bay, Florida, an area not oiled by the Deepwater Horizon spill. For Dr. Lori Schwacke, the study’s lead author and veteran of a number of similar dolphin health studies across the southeast, the findings are troubling: “I’ve never seen such a high prevalence of very sick animals — and with unusual conditions such as the adrenal hormone abnormalities.”

The NRDA researchers found that moderate to severe lung disease was five times more likely in the Barataria Bay dolphins, with symptoms including lung masses and consolidation. The researchers also found that 25 percent of the Barataria Bay dolphins were significantly underweight and the population overall had very low levels of adrenal hormones, which are critical for responding to stress.

The researchers examined alternative hypotheses for the dolphins’ disease conditions, such as exposure to other man-made chemicals that have previously been measured in high concentrations in marine mammals and also associated with impacts on health.  Blubber samples from the Barataria Bay dolphins, however, showed relatively low concentrations for the broad suite of chemicals measured, including PCBs and commonly detected persistent pesticides, as compared to other coastal dolphin populations.

Based on the findings from the 2011 dolphin health study, researchers performed three additional health assessments in 2013 as part of theDeepwater Horizon NRDA. The studies were repeated in Barataria Bay and Sarasota Bay, and also expanded to Mississippi Sound, including both Mississippi and Alabama waters. Results from these more recent health assessments are still pending.

Researchers conducting the NRDA studies are collaborating closely with the team conducting an Unusual Mortality Event (UME) investigation in the northern Gulf of Mexico under the Marine Mammal Protection Act. Investigations of this type follow stranding events that are unexpected, involve a significant die-off and demand an immediate response.  The observed increase in the number of dolphin strandings now includes more than 1,050 animals that have stranded along the Gulf Coast from the Texas/Louisiana border through Franklin County, Florida. Ninety-four percent of these animals have stranded dead.

The UME investigation, spanning from February 2010 to present, is the longest UME response since 1992, and includes the greatest number of stranded dolphins in an UME in the Gulf of Mexico. Dr. Teresa Rowles, lead for the Marine Mammal Health and Stranding Response Program and a co-author on the dolphin health publication, indicates that “these dolphin health studies will contribute significant information for both the NRDA and the UME investigation as we compare disease findings in the wild, living dolphins to the pathologies and analyses from the dead animals across the northern Gulf.”

NOAA

Offshore wind farm foundations could alter seafloor ecosystems of the North Sea

By Science for Environment Policy

The planned expansion of offshore wind farms in the German Bight of the North Sea will provide hard surfaces in what is currently a soft-bottom habitat. This could see an increase in the numbers of some species, such as mussels, which attach themselves to these hard structures, in turn leading to increased numbers of fish and crabs specialised to this habitat, new research suggests.

Offshore wind turbine foundations provide a surface for some animals, such as mussels, to grow on, and foraging grounds or shelter from predators for larger animals, including fish and crabs. In areas such as the North Sea, where the sea floor is mainly soft sand or mud, the provision of such 'hard' habitats changes the type of species able to survive there, potentially having an effect on the wider ecosystem.

This research was carried out in the German Bight, where the construction of 5000 wind turbines is planned over the next 20 years. Researchers undertook two separate studies; one of marine invertebrates, such as mussels and sea anemones, and another of larger, more mobile animals, such as fish and crabs. In the first study, during 2005-2007, divers studied species on the foundations of a research platform. This platform was purposely built to measure biological and physical factors relevant to the construction of wind farms and its foundations were very similar to those of wind turbines.

The three most common types of invertebrate found were the blue mussel (Mytilus edulis); anthozoans (a group of animals including corals and sea anemones) and the amphipod Jassa (tube-building, shrimp-like creatures). At 1 m depth, the foundations were thickly covered by blue mussels; at 20-28 m depth, anthozoans dominated, together with Jassa and the pink-hearted hydroid Tubularia (an anthozoan).

The researchers estimate that a yearly average of 4300 kg of biomass accumulated on the underwater structure. Furthermore, about 75% of the colonising invertebrates were blue mussels. As the mussels die, the shells fall to the seabed, creating additional hard surfaces for colonisation, increasing numbers further still. Five thousand wind turbines could turn this area into a biomass hotspot, the authors conclude.

In the second study, undertaken during 2007-2009, the researchers focused on larger animals and compared species found on the soft seabed, on shipwrecks and on the research platform. Fifteen different groups of species were found on the research platform, 16 around shipwrecks and 11 on the soft seabed. The types of species on the platform and shipwrecks were similar; the most common species was the edible crab (Cancer pagurus). However, the species found on the seabed were substantially different from both the wrecks and the platform.

Three species were found only on wrecks and the platform; these were the edible crab, the velvet crab (Necora puber) and the sea-scorpion fish (Taurulus bubalis). The researchers estimated that the construction of the planned wind farms could increase numbers of edible crabs by 1.1 million, the number of velvet crabs by 970 000 and the number of sea-scorpions by 200 000.

The researchers conclude that the planned developments may have a large effect on seafloor ecosystems. However, they concede that many facts remain unclear, for example, working wind turbines will vibrate slightly, whereas the trial platform does not, and it is not clear how this might affect seafloor species.

Sources: 

• Krone, R., Gutow, L., Brey, T. et al. (2013). Mobile demersal megafauna at artificial structures in the German Bight – Likely effects of offshore wind farm development. Estuarine, Coastal and Shelf Science. 125: 1-9. DOI: 10.1016/j.ecss.2013.03.012.

•  Krone, R., Gutow, L., Joschko, T.J., et al. (2013). Epifauna dynamics at an offshore foundation - Implications of future wind power farming in the North Sea. Marine Environmental Research. 85: 1-12. DOI: 10.1016/j.marenvres.2012.12.004.

Contact: Roland Krone