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Something peculiar is happening in the azure waters off the rocky cliffs of Ischia, Italy. There, streams of gas-filled volcanic bubbles rising up to the surface are radically changing life around them by making seawater acidic. Stanford researchers studying species living near these gassy vents have learned what it takes to survive in acidic waters, providing a glimpse of what future oceans might look like as they grow more acidic.

Volcanic carbon dioxide seeps from the ocean floor near Ischia, Italy [Credit: Pasquale Vassallo, Stazione Zoologica Anton Dohrn]

Their findings, published in Nature Communications, suggest that ocean acidification driven by human-caused carbon dioxide emissions could have a larger impact than previously thought.

"When an organism's environment becomes more acidic, it can dramatically impact not only that species, but the overall ecosystem's resilience, function and stability," said Stanford marine biologist Fiorenza Micheli, lead author on the paper. "These transformations ultimately impact people, especially our food chains."

A natural laboratory

Most ocean acidification studies to date have taken place in laboratories, making it impossible to assess how whole ecosystems comprised of multiple, interacting species would be affected. The real-life laboratory provided researchers an opportunity to examine dozens of species, from sea urchins to marine snails, that live in areas of different acidity along Ischia's volcanic carbon dioxide vents. In addition to studying how species diversity changed with acidification, they analyzed species traits, such as diet and growth, that influence how well the ecosystem performs. For example, sea snails were smaller in more acidic water, as their shells take longer to grow and are thinner and more brittle. These harmful effects on sea snails, a key food for animals higher up in the food chain, may affect fish populations.

Overall, the researchers found that the active venting zones with the most acidic waters were home to not only the least number of species, but also the lowest amounts of "functional diversity" – the range of ecosystem-support services or roles that each species can provide.

"Studying the natural carbon dioxide vents in Ischia allowed us to unravel which traits from different species, like snail shell strength, were more vulnerable to ocean acidification. These results illuminate how oceans will function under different acidification scenarios in the future," said lead author Nuria Teixidó, a marine biologist from Stazione Zoologica Anton Dohrn in Italy, who was a visiting researcher at Stanford during the research.

Acidification in the waters of Ischia displaced long-lived species, such as corals, that form habitat for other species – a process already often witnessed on reefs across the world. The researchers also found that high levels of carbon dioxide and more acidity favored species with short life spans and fast turnover as they are the only species that can resist these environmental conditions. This change could lead to further diversity loss and instability in the oceans, as biodiversity tends to increase an ecosystem's stability.

Biodiversity loss is mapped along a natural CO2 gradient [Credit: Nuria Teixidó, Stazione Zoologica Anton Dohrn]

A broader application

Localized case studies such as Ischia can shed light on how future global environmental conditions may affect ocean life. Beyond losing biodiversity, ocean acidification will threaten food security for millions of people who depend on seafood, along with tourism and other ocean-related economies.

"The effects of ocean acidification on whole ecosystems and their functioning are still poorly understood," said Micheli, a professor of biology. "In Ischia, we have gained new insights into what future oceans will look like and what key services, like food production and coastal production, will be lost when there is more carbon dioxide in the water."

Author: Nicole Kravec | Source: Stanford University [December 11, 2018]

NOAA's annual report card on the Arctic, released today at the American Geophysical Union fall meeting in Washington, D.C., measures the changing climate of the polar region including warmer air and ocean temperatures and declines in sea-ice that are driving shifts in animal habitats.

Eyeing the Arctic: The southern Greenland town of Narsaq. Photo taken during a NASA Operation IceBridge flight April 26, 2018 [Credit: NASA/Joe MacGregor]

Now in its 13th year, the 2018 Arctic Report Card is a peer-reviewed report that provides an annual status update on the region and compares these observations to the long-term record. It was compiled from the research of 81 scientists working for governments and academia in 12 nations. This information can be used to inform decisions by local, state and federal leaders as Arctic residents confront the challenges and opportunities posed by a rapidly changing climate and ecosystem.

"The environmental changes in the Arctic underscore why NOAA continues to invest in Arctic research and activities, which improve the nation's economic competitiveness, national security, and the sustainable management of natural resources," said retired Navy Rear Adm. Timothy Gallaudet, Ph.D., acting under secretary of commerce for oceans and atmosphere at NOAA, who led the news conference to release the report card. "This report will also help guide NOAA's priorities in better understanding the role of the Arctic in climate change and extreme weather; sustaining and growing fisheries; and supporting adaptation and economic opportunities in the region."


This year's report shows that the Arctic region experienced the second-warmest air temperatures ever recorded; the second-lowest overall sea-ice coverage; lowest recorded winter ice in the Bering Sea; and earlier plankton blooms due to early melting of sea ice in the Bering Sea.

In addition to annual updates on ocean temperature, snow cover, tundra greenness and melting on the Greenland Ice Sheet, the report card also includes reports on multi-year environmental changes, including a long-term population decline of the region's iconic wildlife species, the caribou. Other multi-year essays focused on the expansion northward of toxic harmful algae and significant concentrations of microplastic pollution that are transported by ocean currents into the Arctic Ocean from other parts of the global ocean.

Declining Arctic sea ice: The 2018 Arctic Report Card found the Arctic region had the second-lowest overall sea-ice coverage on record. The map shows the age of sea ice in the Arctic ice pack in March 1985 (left) and March 2018 (right) . Ice that is less than a year old is darkest blue. Ice that has survived at least 4 full years is white [Credit: Maps were provided by NOAA Climate.gov and based on data provided by Mark Tschudi./University of Colorado/ CCAR (NOAA Climate.gov)]

This report card is just one of many aspects of NOAA's role in the Arctic region. NOAA, alongside many partners, is monitoring Arctic conditions, pioneering innovative technologies, and creatively collecting data and other scientific information.

For example, new technology is revolutionizing our understanding of the Arctic's changing environment, beginning to fill critical gaps in ocean and atmospheric observations. This technology is unmanned, fast, cost-effective, sturdy enough to withstand icy temperatures, and able to collect quality data for lengthy periods. Further, NOAA Polar-orbiting satellites fly over the Arctic 28 times daily, collecting data vital to improve weather forecasts, help fisheries increase catch, and support safe, efficient navigation in challenging waters. Additionally, as Arctic waters become increasingly ice-free, and commerce and other interests grow, NOAA is working to update nautical charts and calculate tide and current predictions.

Source: National Oceanic and Atmospheric Administration (NOAA) [December 11, 2018]

Small, local patches of habitat could be playing a much bigger role in conserving biodiversity than you think, according to new research.

Eastern rosella at Edithvale wetland [Credit Wayne Butterworth]

The global study just published in the Proceedings of the National Academy of Sciences looked at the conservation values of vegetation patches in 27 countries on four continents, and considered their size and distance to other habitat.

The results were surprising according to lead researcher Professor Brendan Wintle from Melbourne University.

"Compared to large and well connected habitat areas, small and isolated patches of habitat have generally been treated as not very important to conservation," said Professor Wintle. "What we have found, however, is that small and isolated habitat areas are very important to the survival of many rare and endangered species."

"The environment is suffering a death by a thousand cuts," Wintle continued. "We need to re-think vegetation management regulations and policies that allow small patches of vegetation to be destroyed."

Co-author Dr. Sam Veloz, Climate Adaptation Group Director at Point Blue Conservation Science, added "We have many existing processes in place to fund restoration or conservation activities that are largely focused on large patches of habitat. While it's important to continue these efforts, our paper emphasizes that small but important habitat patches should be included in an overall conservation portfolio."

An example from the paper explored suitable habitat for four songbird species in California and Oregon (the streaked horned lark, savannah sparrow, Western meadowlark and the Oregon vesper sparrow). Research showed that highly fragmented parts of the study areas for each species contain habitat patches of very high conservation value. And the four species studied have ranges primarily in those small, isolated patches.

Dr. Heini Kujala from the University of Melbourne, another co-author, said that once you start considering how much habitat is left for a species, small patches can be very valuable.

"Small habitat patches can sometimes be the last pieces of a once widespread habitat. For species that rely on this type of habitat that makes them very important," said Dr. Kujala.

"Definitely we are not saying that it is an improvement to cut up big habitat areas into smaller pieces, rather that many of the small pieces that we have left are really important for conservation."

The study's authors hope that the research will raise awareness among planners, land managers, scientists, and the community about the value of small vegetation patches.

Source: University of Melbourne [December 11, 2018]

Barely living "zombie" bacteria and other forms of life constitute an immense amount of carbon deep within Earth's subsurface -- 245 to 385 times greater than the carbon mass of all humans on the surface, according to scientists nearing the end of a 10-year international collaboration to reveal Earth's innermost secrets.

A nematode (eukaryote) in a biofilm of microorganisms. This unidentified nematode (Poikilolaimus sp.) from Kopanang gold mine in South Africa, lives 1.4 km below the surface [Credit: Gaetan Borgonie, Extreme Life Isyensya, Belgium]

On the eve of the American Geophysical Union's annual meeting, scientists with the Deep Carbon Observatory today reported several transformational discoveries, including how much and what kinds of life exist in the deep subsurface under the greatest extremes of pressure, temperature, and low nutrient availability.

Drilling 2.5 kilometers into the seafloor, and sampling microbes from continental mines and boreholes more than 5 km deep, scientists have used the results to construct models of the ecosystem deep within the planet.

With insights from now hundreds of sites under the continents and seas, they have approximated the size of the deep biosphere -- 2 to 2.3 billion cubic km (almost twice the volume of all oceans) -- as well as the carbon mass of deep life: 15 to 23 billion tonnes (an average of at least 7.5 tonnes of carbon per cu km subsurface).

The work also helps determine types of extraterrestrial environments that could support life.

Among many key discoveries and insights:

- The deep biosphere constitutes a world that can be viewed as a sort of "subterranean Galapagos" and includes members of all three domains of life: bacteria and archaea (microbes with no membrane-bound nucleus), and eukarya (microbes or multicellular organisms with cells that contain a nucleus as well as membrane-bound organelles)

- Two types of microbes -- bacteria and archaea -- dominate Deep Earth. Among them are millions of distinct types, most yet to be discovered or characterized. This so-called microbial "dark matter" dramatically expands our perspective on the tree of life. Deep Life scientists say about 70% of Earth's bacteria and archaea live in the subsurface

- Deep microbes are often very different from their surface cousins, with life cycles on near-geologic timescales, dining in some cases on nothing more than energy from rocks

- The genetic diversity of life below the surface is comparable to or exceeds that above the surface

- While subsurface microbial communities differ greatly between environments, certain genera and higher taxonomic groups are ubiquitous -- they appear planet-wide

- Microbial community richness relates to the age of marine sediments where cells are found -- suggesting that in older sediments, food energy has declined over time, reducing the microbial community

- The absolute limits of life on Earth in terms of temperature, pressure, and energy availability have yet to be found. The records continually get broken. A frontrunner for Earth's hottest organism in the natural world is Geogemma barossii, a single-celled organism thriving in hydrothermal vents on the seafloor. Its cells, tiny microscopic spheres, grow and replicate at 121 degrees Celsius (21 degrees hotter than the boiling point of water). Microbial life can survive up to 122°C, the record achieved in a lab culture (by comparison, the record-holding hottest place on Earth's surface, in an uninhabited Iranian desert, is about 71°C -- the temperature of well-done steak)

- The record depth at which life has been found in the continental subsurface is approximately 5 km; the record in marine waters is 10.5 km from the ocean surface, a depth of extreme pressure; at 4000 meters depth, for example, the pressure is approximately 400 times greater than at sea level

- Scientists have a better understanding of the impact on life in subsurface locations manipulated by humans (e.g., fracked shales, carbon capture and storage)

Candidatus Desulforudis audaxviator (the purplish, blue rod-shaped cells straddling orange carbon spheres) is a species of bacteria that survives on hydrogen. Scientists found it living within a fluid and gas-filled fracture 2.8 km beneath Earth's surface at a mine near Johannesburg, South Africa. The genus name Desulforudis comes from the Latin for "from sulfur"  and "rod," noting its shape and its ability to get energy from sulfates. And audaxviator? From Jules Verne's Journey to the Center of the Earth, and a message in Latin deciphered by Verne's protagonist, Professor Lidenbrock, which read  in part: "descend, bold traveler, and attain the center of the Earth" [Credit: Greg Wanger, California Institute of Technology, USA, and Gordon Southam University of Queensland, Australia]

Ever-increasing accuracy and the declining cost of DNA sequencing, coupled with breakthroughs in deep ocean drilling technologies (pioneered on the Japanese scientific vessel Chikyu, designed to ultimately drill far beneath the seabed in some of the planet's most seismically-active regions) made it possible for researchers to take their first detailed look at the composition of the deep biosphere.

There are comparable efforts to drill ever deeper beneath continental environments, using sampling devices that maintain pressure to preserve microbial life (none thought to pose any threat or benefit to human health).

To estimate the total mass of Earth's subcontinental deep life, for example, scientists compiled data on cell concentration and microbial diversity from locations around the globe.

Led by Cara Magnabosco of the Flatiron Institute Center for Computational Biology, New York, and an international team of researchers, subsurface scientists factored in a suite of considerations, including global heat flow, surface temperature, depth and lithology -- the physical characteristics of rocks in each location -- to estimate that the continental subsurface hosts 2 to 6 × 10^29 cells.

Combined with estimates of subsurface life under the oceans, total global Deep Earth biomass is approximately 15 to 23 petagrams (15 to 23 billion tonnes) of carbon.

Says Mitch Sogin of the Marine Biological Laboratory Woods Hole, USA, co-chair of DCO's Deep Life community of more than 300 researchers in 34 countries: "Exploring the deep subsurface is akin to exploring the Amazon rainforest. There is life everywhere, and everywhere there's an awe-inspiring abundance of unexpected and unusual organisms.

"Molecular studies raise the likelihood that microbial dark matter is much more diverse than what we currently know it to be, and the deepest branching lineages challenge the three-domain concept introduced by Carl Woese in 1977. Perhaps we are approaching a nexus where the earliest possible branching patterns might be accessible through deep life investigation.

"Ten years ago, we knew far less about the physiologies of the bacteria and microbes that dominate the subsurface biosphere," says Karen Lloyd, University of Tennessee at Knoxville, USA. "Today, we know that, in many places, they invest most of their energy to simply maintaining their existence and little into growth, which is a fascinating way to live.

"Today too, we know that subsurface life is common. Ten years ago, we had sampled only a few sites - the kinds of places we'd expect to find life. Now, thanks to ultra-deep sampling, we know we can find them pretty much everywhere, albeit the sampling has obviously reached only an infinitesimally tiny part of the deep biosphere."

"Our studies of deep biosphere microbes have produced much new knowledge, but also a realization and far greater appreciation of how much we have yet to learn about subsurface life," says Rick Colwell, Oregon State University, USA. "For example, scientists do not yet know all the ways in which deep subsurface life affects surface life and vice versa. And, for now, we can only marvel at the nature of the metabolisms that allow life to survive under the extremely impoverished and forbidding conditions for life in deep Earth."

"A decade ago, we had no idea that the rocks beneath our feet could be so vastly inhabited. Experimental investigations told us that microbes could potentially survive to great depth; at that time, we had no evidence, and this has become real ten years later. This is simply fascinating and will surely foster enthusiasm to look for the biotic-abiotic fringe on Earth and elsewhere," said Isabelle Daniel, University of Lyon 1, France.

This is a species of Methanobacterium, which produces methane. Found in samples from a buried coal bed 2 km below the  Pacific Ocean floor off the coast of Japan, this specimen was retrieved during an Integrated Ocean Drilling Program  (now the International Ocean Discovery Program) expedition aboard the Drilling Vessel Chikyu. Bar represents 10 μm (micrometers, or 0.0004 inch) [Credit: Hiroyuki Imachi (Japan Agency for Marine-Earth Science and Technology (JAMSTEC)]

Among the many remaining enigmas of deep life on Earth:

Movement: How does deep life spread -- laterally through cracks in rocks? Up, down? How can deep life be so similar in South Africa and Seattle, Washington? Did they have similar origins and were separated by plate tectonics, for example? Or do the communities themselves move? What roles do big geological events (such as plate tectonics, earthquakes; creation of large igneous provinces; meteoritic bombardments) play in deep life movements?

Origins: Did life start deep in Earth (either within the crust, near hydrothermal vents, or in subduction zones) then migrate up, toward the sun? Or did life start in a warm little surface pond and migrate down? How do subsurface microbial zombies reproduce, or live without dividing for millions to tens of millions of years?

Energy: Is methane, hydrogen, or natural radiation (from uranium and other elements) the most important energy source for deep life? Which sources of deep energy are most important in different settings? How do the absence of nutrients, and extreme temperatures and pressure, impact microbial distribution and diversity in the subsurface?

"Even in dark and energetically challenging conditions, intraterrestrial ecosystems have uniquely evolved and persisted over millions of years. Expanding our knowledge of deep life will inspire new insights into planetary habitability, leading us to understand why life emerged on our planet and whether life persists in the Martian subsurface and other celestial bodies,"  according to Fumio Inagaki, Japan Agency for Marine-Earth Science and Technology.

"While we are far from being able to quantify it, we believe Deep Life has an important impact on global biogeochemical cycles and chemical equilibria in habitable rocks. Deep Life plays a role in aquifer quality, for example, or carbon capture and storage (CCS). Unfortunately, the deep biosphere is very poorly considered in engineering operations carried out in the subsurface. We recently demonstrated the high reactivity of deep biota to CO2 injections (CCS), which ultimately led to the bioclogging of the injection well, and surrounding reservoir," adds Benedicte Menez, Institut de Physique du Globe de Paris, France.

Source: Deep Carbon Observatory [December 10, 2018]

The future of the world's coral reefs is uncertain, as the impact of global heating continues to escalate. However, according to a study published in Nature Climate Change, the response of the Great Barrier Reef to extreme temperatures in 2017 was markedly different to one year earlier, following two back-to-back bouts of coral bleaching. Remarkably, corals that bleached and survived 2016 were more resistant in 2017 to a recurrence of hot conditions.

Researchers found that the response of corals to heat stress during the second of two unprecedented back-to-back bleaching events on the Great Barrier Reef was markedly different from the first [Credit: Tane Sinclair-Taylor]

"Dead corals don't bleach for a second time. The north lost millions of heat-sensitive corals in 2016, and most of the survivors were the tougher species. As a result of bleaching, the mix of species is changing very rapidly," said lead author Prof Terry Hughes, Director of the Australian Research Council Centre of Excellence for Coral Reef Studies (Coral CoE), headquartered at James Cook University.

"We were astonished to find less bleaching in 2017, because the temperatures were even more extreme than the year before," he said.

The new research highlights the extent of damage, or "geographic footprint" of multiple coral bleaching events across the 2,300 km length of the world-heritage listed area.

The back-to-back heatwaves bring the total number of mass bleaching events on the Great Barrier Reef to four over the past two decades (in 1998, 2002, 2016 and 2017). The scientists found that only 7% of the Great Barrier Reef escaped bleaching entirely since 1998, and after the 2017 event, 61% of reefs have now been severely bleached at least once.

During an underwater survey, a researcher records the bleaching severity of a massive Porites coral colony on the Great Barrier Reef [Credit: Justin Marshall]

"We found, using the National Oceanic and Atmospheric Administration's (NOAA) satellite-based coral bleaching tools, that corals in the north of the Great Barrier Reef were exposed to the most heat stress in 2016. A year later, the central region saw the most prolonged heating," said co-author Dr Mark Eakin, from NOAA's Coral Reef Watch program, in Maryland, USA.

The southern third of the Great Barrier Reef was cooler in both years due to local weather conditions, and escaped with only minor bleaching.

"It's only a matter of time before we see another mass-bleaching event, triggered by the next marine heatwave, driven by global heating," said co-author Dr Andrew Hoey of Coral CoE at James Cook University. "One of the worst possible scenarios is we'll see these southern corals succumb to bleaching in the near future."

"The outcome in 2017 depended on the conditions experienced by the corals one year earlier. We called that 'ecological memory,' and show that these repeating events are now acting together in ways that we didn't expect," said Prof Hughes.

"We've never seen back-to-back mass coral bleaching before on the Great Barrier Reef, in two consecutive summers. The combined footprint has killed close to half of the corals on two-thirds of the world's largest reef system," said Dr Hoey.

"We need urgent global action on greenhouse emissions to save the world's coral reefs. Australia should be -- but regrettably isn't -- at the forefront of tackling global heating," said Prof Hughes.

Source: ARC Centre of Excellence in Coral Reef Studies [December 10, 2018]

The new study, which detected bacteria from humans in the genus Salmonella and Campylobacter in Antarctic and Subantarctic marine birds, reveals the fragility of polar ecosystems and warns about the risk of massive deaths and extinctions of local fauna populations due pathogens.

These zoonotic agents, which cause common infections in humans, are caught by scavenger marine birds in contact with humans or livestock, and spread around the southern ocean [Credit: Jacob González-Solís/University of Barcelona-IRBio]

Reverse zoonosis: when the human species infects other living beings

Explorers, whalers, scientists -and lately, tourists-, are examples of human collectives that moved to the furthest regions of the planet. Some studies have claimed for years that there had been cases of reverse zoonosis, that is, infections humans give to other living beings. Despite some previous signs, scientific studies on zoonotic agents in the Antarctic and Subantarctic areas have been fragmented. Therefore, evidence is spread and not completely convincing in this field.

The new study, published in the journal Science of the Total Environment, studies the potential transmission of bacteria from humans to marine bird populations in four areas of the Antarctic and Subantarctic ecosystems. "Chronology and potential pathways for reverse zoonosis in these ecosystems are complex and difficult to study, but it seems they can be clearly related to the proximity of the fauna to inhabited areas and the presence of research stations", says Professor Jacob González-Solís, from the Department of Evolutionary Biology, Ecology and Environmental Sciences of the UB and IRBio.

Antibiotic-resistant bacteria in polar ecosystems

The study confirms the first evidence of reverse zoonosis related to the presence of human-origin bacteria Salmonella and Campylobacter in polar fauna. One of the warning signs was, in particular, the identification of Campylobacter strains, which are resistant to ciprofloxacin and enrofloxacin (common antibiotics in medicine and veterinary).

"Finding common Campylobacter genotypes in human species or livestock was the definite hint to prove that humans can be introducing pathogens in these regions", says Marta Cerdà-Cuéllar, researcher at the IRTA-CReSA. "These Salmonella and Campylobacter strains, which are a common cause for infections in humans and livestock, do not usually cause death outbreaks in wild animals. However, the emerging or invasive pathogens that arrive to highly sensitive populations -such as the Antarctic and Subantarctic fauna- could have severe consequences and cause the local collapse and extinction of some populations".

Northen and Southern Hemisphere: migrating route for marine birds and pathogens

The study shows the risk of reverse zoonosis is higher in areas that are closer to inhabited areas, such as the Flakland Islands, and probably the Tristan da Cunha archipelago. In this situation, the biological connectivity between Antarctic and Subantarctic communities through marine birds is a factor that would speed up the circulation of zoonotic agents among the ecosystems from different latitudes.

"This could be the case, for instance, of the Subantarctic parasite Stercorarius antarcticus: a scavenger marine bird could get the pathogen and spread it from Subantarctic latitudes to the Antarctica", says González-Solís.

Polar areas: not all the biodiversity is protected

The Antarctic Treaty protocol on Environmental Protection sets a series of principles that can be applied to human activity in Antarctica to reduce the human footprint in the white continent. However, some Subantarctic areas -which are also the habitat of birds such as the brown skua or the giant petrel- are not protected by the protecting regulation and could become the entrance for pathogen agents in polar ecosystems.

"Our results show it is easier for humans to introduce pathogen agents in the pristine areas in the Antarctica. As a result, pathogens entering the furthest ecosystems in the Southern Hemisphere could be a serious threat for the future of wildlife. Therefore, it is essential to adopt biosecurity measures to limit the human impacts in the Antarctica", notes Jacob González-Solís.

Source: University of Barcelona [December 10, 2018]

Dolphins in the northern Adriatic contain high levels of PCBs – highly toxic chemicals banned in the 1970s and 1980s – and are passing the pollutant to their young, according to new research led by a marine scientist at the University of St Andrews.

Credit: Tilen Genov/ University of St Andrews

An international team of researchers evaluated PCB and other organochlorine contaminants in bottlenose dolphins (Tursiops truncatus) living in the Gulf of Trieste (northern Adriatic Sea), the northernmost part of the Mediterranean Sea and one of the most human-impacted areas in the Mediterranean.

They found that, overall, 87.5% of dolphins had PCB concentrations above the toxicity threshold for the onset of physiological effects in marine mammals, while 65.6% had concentrations above the highest threshold published for marine mammals based on reproductive impairment in seals. Such high contaminant levels are of concern, particularly in combination with other threats to dolphins, including bycatch in fisheries, disturbance by boat traffic, and prey depletion.

The research, published in the journal Science of the Total Environment, involved Morigenos – Slovenian Marine Mammal Society (Slovenia), the Sea Mammal Research Unit at the University of St Andrews (UK), the Zoological Society of London's Institute of Zoology (UK), the Centre for Environment, Fisheries and Aquaculture Science (CEFAS, UK) and the Institute of Marine Sciences of the Italian National Research Council (Italy).

Credit: Genov et al, Morigenos – Slovenian Marine Mammal Society (Slovenia)

Tilen Genov, lead author of the study and a Ph.D. student at the University of St Andrews, said:

"We have been studying these dolphins for over 16 years, so we know most of them well. Through long-term re-sighting histories of identified individuals, we were able to link PCB levels in individual dolphins to parameters such as sex, reproductive output and social group membership.

"The research showed that males have significantly higher pollutant concentrations than females. This is because females offload a substantial amount of their toxicological burden to their young through gestation and lactation.

Credit: Tilen Genov/ University of St Andrews

"That is also why females that have not yet had calves had significantly higher concentrations than those that had previously produced at least one calf. Such results are expected based on our knowledge of mammal physiology, but it is not very common to demonstrate this phenomenon in wild whales and dolphins."

Dr. Paul Jepson, co-author of the study and specialist wildlife veterinarian at the Zoological Society of London's Institute of Zoology, said:

"This is another study showing high or very high levels of a very toxic and persistent pollutant – PCBs – in European dolphins. PCBs have the ability to cause diseases like cancer and can also suppress reproduction."

Source: University of St Andrews [December 10, 2018]

A UMass Boston professor and his colleagues have published new research showing that feeding on human junk food may be altering the course of evolution in Darwin's finches.

Finches eat off a plate in an urban area of the Galapagos [Credit: K. Gotanda]

Assistant Professor of Evolutionary Biology Luis De León says feeding on human foods is weakening natural selection on ground finch beaks, which is what drives the formation of new species in the wild. These findings, published in the journal Evolutionary Applications, suggest that the seemingly harmless activity of feeding birds might be altering the course of evolution in the iconic Darwin’s finches in the Galápagos islands.

“If we continue to feed finches, we’re not only affecting the individual species, but the processes that lead to the formation of new species,” De León said. “We’re getting in the way of evolution.”

Galápagos finches are famed for being the inspiration behind Charles Darwin’s pioneering work on evolution. They are an example of adaptive radiation, an evolutionary process that produces new species from a single, rapidly diversifying lineage. Their common ancestor arrived on the Galápagos about two million years ago, and since then Darwin's finches have evolved into more than a dozen recognized species differing in body size, beak shape, and feeding behavior.

De León and fellow researchers from UMass Amherst, Universidad San Francisco de Quito, McGill University, and Norwegian University of Science and Technology were on Santa Cruz Island when they found two forms of medium ground finches — a small and large version — while studying beak size at an isolated, pristine site.

When they repeated the same set of measurements at a nearby urban site, the distinction between the two beak sizes was not present. Studying data collected by other researchers in the 1970s, the researchers could see the two types of medium ground finches had been present in the area before, but something had changed in the last 40-50 years.

They hypothesized that the change might have to do with urbanization and the rapidly increasing human population in that area. In particular, the introduction of novel foods brought by humans.

Finches eat from an egg crate left by the researchers [Credit: University of Massachusetts Boston]

Using egg crates filled with natural seeds and human junk food — chips, cookies, and rice — the researchers tested to see if the finches were in fact feeding on human food and what their preference was, weighing the food before and after to see how much was eaten.

De León said they found that finches in the urban area were almost exclusively feeding on human food. When the experiment was repeated at an isolated site in nature, the finches ignored the trays.

They found that "urban" finches feed on human junk foods, and in fact prefer these foods over their natural diet. This indicates that ongoing urbanization in the Galápagos is eroding the ecological differences that originally drove the formation of species in Darwin's finches.

“In contrast to their natural diet, the finches are changing their diet to human junk food,” De León said. “We know one way finches diversify and become new species is by specializing in different food types. All three or four species of ground finches at urban sites on Santa Cruz Island seem to be converging onto the same junk food diet. If that’s the case, the selection pressures that would be naturally  keeping them apart would be weakening, possibly leading to the collapse of the adaptive radiation of ground finches.”

Researchers also found a strong preference for human foods at EG Beach, a non-urban site visited by tourists located 12 kilometers away from the town of Puerto Ayora. This suggests that human behavior, rather than human population density, is the main driver of finches’ preference for human food, expanding the impacts of urbanization beyond city centers.

Now that the researchers know that finches are changing their diets to human junk food, they need to look at the consequences for the actual evolution of the species on this island.

“When thinking about preserving biodiversity in general, we often focus on preserving individual species,” he said. “What we show with this work is we also need to consider preserving the processes that lead to the formation of species.”

Assistant Professor of Evolutionary Biology Luis De León studies Darwin's finches [Credit: University of Massachusetts Boston]

De León and a PhD student will return to the Galapagos in January.

De León said they will continue to do more genetic analysis, looking at whether there is an increase in gene flow across the four species of ground finch. Now that the birds are eating the same diet, researchers want to know if they are also interbreeding.

Elaine Montes, a second-year PhD student at UMass Boston who is working with De León, will look at the physiological consequences of human junk food on Galapagos finches by analyzing telomeres, a long chain of repetitive DNA at the end of every chromosome that can shorten due to stress and aging.

“We want to see whether they have a shorter life span than birds in nature,” he said.

De León has worked at UMass Boston for two years. He received his PhD at McGill University, where he started his work on Galapagos finches 14 years ago.

“It’s a fascinating place. Every species is so unique; it captures your imagination. You can imagine how Darwin was fascinated by looking at all those species,” he said. “I feel privileged to essentially walk in Darwin’s footsteps.”

Author: Crystal Valencia | Source: University of Massachusetts Boston [December 03, 2018]

The International Union for Conservation of Nature's (IUCN) Red List of Threatened Species is a powerful tool for researchers and policymakers working to stem the tide of species loss across the globe. But adding even a single species to the list is no small task, demanding countless hours of expensive, rigorous and highly specialized research.

This map shows the predicted levels of risk to more than 150,000 species of plants located worldwide. Using vast amounts of open-access data, the researchers trained a machine learning algorithm to assign a probability that a given species would qualify for at-risk designation on the International Union for the Conservation of Nature's Red List of Threatened Species. Warmer colours denote areas with larger numbers of potentially at-risk species, while cooler colours denote areas with low overall predicted risk [Credit: Anahí Espíndola and Tara Pelletier]

As a result of these limitations, a large number of known species have not yet been formally assessed by the IUCN and ranked in one of five categories, from least concern to critically endangered. This deficit is quite apparent in plants: Only about 5 percent of all currently known plant species appear on IUCN's Red List in any capacity.

A new method co-developed by Anahí Espíndola, an assistant professor of entomology at the University of Maryland, uses the power of machine learning and open-access data to predict species that could be eligible for at-risk status on the IUCN Red List. The research team created and trained a machine learning algorithm to assess more than 150,000 species of plants from all corners of the world, making their project among the largest assessments of conservation risk to date. According to the results, more than 10 percent of these species are highly likely to qualify for an at-risk IUCN classification.

The algorithm is a predictive model that can be applied to any grouping of species at any scale, from the entire globe to a single city park. Espíndola and her colleagues published their findings online in the Proceedings of the National Academy of Sciences on December 3, 2018.

"Our method isn't meant to replace formal assessments using IUCN protocols. It's a tool that can help prioritize the process, by calculating the probability that a given species is at risk," Espíndola said. "Ultimately, we hope it will help governments and resource managers decide where to devote their limited resources for conservation. This could be especially useful in regions that are understudied."

Espíndola and her collaborators built their predictive model using open-access data from the Global Biodiversity Information Facility (GBIF) and the TRY Plant Trait Database. Lead author Tara Pelletier, an assistant professor of biology at Radford University, worked together with Espíndola to perform the machine learning analysis.

Espíndola and Pelletier then trained the model using GBIF and TRY data from the relatively small group of plant species already on the IUCN Red List. This allowed the researchers to assess and fine-tune the model's accuracy by checking its predictions against the listed species' known IUCN risk status. The Red List sorts non-extinct species into one of five classification categories: least concern, near-threatened, vulnerable, endangered and critically endangered.

The researchers then applied the model to the many thousands of plant species that remain unlisted by IUCN. According to the results, more than 15,000 of the species--roughly 10 percent of the total assessed by the team--have a high probability of qualifying as near-threatened, at a minimum.

Espíndola and her colleagues mapped the data and noted several major geographical trends in the model's predictions. At-risk species tended to cluster in areas already known for their high native biodiversity, such as the Central American rainforests and southwestern Australia. The model also flagged regions such as California and the southeastern United States, which are home to a large number of endemic species, meaning that these species do not naturally occur anywhere else on Earth.

"When I first started thinking about this project, I suspected that many regions with high diversity would be well-studied and protected. But we found the opposite to be true," Espíndola said. "Many of the high-diversity areas corresponded to regions with the highest probability of risk. When we saw the maps, we were surprised it was that clear. Endemic species also tend to be more at risk because they are usually confined to smaller areas."

The model also flagged a few surprising areas not typically known for their biodiversity, such as the southern coast of the Arabian Peninsula, as having a high number of at-risk species. Some of the most imperiled regions have not received enough attention from researchers, according to Espíndola. She hopes that her method can help to fill in some of these knowledge gaps by identifying regions and species in need of further study.

"Let's say you wanted to assess every species of wild bee on one continent. So you do the assessment and find that only one species is at risk. Now you've used all those resources to identify an area with low risk, which is still helpful, but not ideal when resources are limited. We want to help prevent that from happening," Espíndola said. "Our analysis was global, but the model can be adapted for use at any geographic scale. Everything we've done is 100 percent open access, highlighting the power of publicly-available data. We hope people will use our model--and we hope they point out errors and help us fix them, to make it better."

The research paper was published online in the Proceedings of the National Academy of Sciences.

Source: University of Maryland [December 03, 2018]

The research, led by the University of Plymouth, examined the uptake of nanoparticles by a commercially important mollusc, the great scallop (Pecten maximus). After six hours exposure in the laboratory, billions of particles measuring 250nm (around 0.00025mm) had accumulated within the scallop's intestines. However, considerably more even smaller particles measuring 20nm (0.00002mm) had become dispersed throughout the body including the kidney, gill, muscle and other organs.

These are some of the scallops used as part of the current research [Credit: University of Plymouth]

The study is the first to quantify the uptake of nanoparticles at predicted environmentally relevant conditions, with previous research having been conducted at far higher concentrations than scientists believe are found in our oceans.

Dr Maya Al Sid Cheikh, Postdoctoral Research Fellow at the University of Plymouth, led the study. She said: "For this experiment, we needed to develop an entirely novel scientific approach. We made nanoparticles of plastic in our laboratories and incorporated a label so that we could trace the particles in the body of the scallop at environmentally relevant concentrations. The results of the study show for the first time that nanoparticles can be rapidly taken up by a marine organism, and that in just a few hours they become distributed across most of the major organs."

Professor Richard Thompson OBE, Head of the University's International Marine Litter Research Unit, added: "This is a ground breaking study, in terms of both the scientific approach and the findings. We only exposed the scallops to nanoparticles for a few hours and, despite them being transferred to clean conditions, traces were still present several weeks later. Understanding the dynamics of nanoparticle uptake and release, as well as their distribution in body tissues, is essential if we are to understand any potential effects on organisms. A key next step will be to use this approach to guide research investigating any potential effects of nanoparticles and in particular to consider the consequences of longer term exposures."

A scan showing particles accumulated within the scallop's gills (GI), kidney (K), gonad (GO), intestine (I), hepatopancreas (HP) and muscle (M) [Credit: University of Plymouth]

Accepted for publication in the Environmental Science and Technology journal, the study also involved scientists from the Charles River Laboratories in Elphinstone, Scotland; the Institute Maurice la Montagne in Canada; and Heriot-Watt University.

It was conducted as part of RealRiskNano, a £1.1million project funded by the Natural Environment Research Council (NERC). Led by Heriot-Watt and Plymouth, it is exploring the effects which microscopic plastic particles can have on the marine environment.

In this study, the scallops were exposed to quantities of carbon-radiolabeled nanopolystyrene and after six hours, autoradiography was used to show the number of particles present in organs and tissue.

It was also used to demonstrate that the 20nm particles were no longer detectable after 14 days, whereas 250nm particles took 48 days to disappear.

Ted Henry, Professor of Environmental Toxicology at Heriot-Watt University, said: "Understanding whether plastic particles are absorbed across biological membranes and accumulate within internal organs is critical for assessing the risk these particles pose to both organism and human health. The novel use of radiolabelled plastic particles pioneered in Plymouth provides the most compelling evidence to date on the level of absorption of plastic particles in a marine organism."

Source: University of Plymouth [December 03, 2018]

Scientists are worried about the platypus, with a national risk assessment led by UNSW Professor Richard Kingsford suggesting declines of up to 30 percent.

A UNSW-led project has raised concerns about the decline of platypus populations [Credit: Taronga Zoo: G Anderson]

Mounting evidence that platypus populations are falling has concerned scientists who are nearing the end of a three-year national survey of the iconic species.

The UNSW-led Australian Research Council-funded project has compiled a comprehensive database of the distribution and abundance of the platypus over the last two centuries, combining this with data from systematic capture surveys to conduct a national risk assessment for the species.

"We have great concerns about the future survival of this unique species," says project leader Professor Richard Kingsford, director of the UNSW Centre for Ecosystem Science.

New research reveals the extinction of plant or animal species from extreme environmental change increases the risk of an 'extinction domino effect' that could annihilate all life on Earth.

Virtual earths modelling shows an 'extinction domino effect' risk ten times higher than forecast, indicating rising global temperatures due to climate change could wipeout entire species [Credit: Flinders University]

This would be the worst-case scenario of what scientists call 'co-extinctions', where an organism dies out because it depends on another doomed species, with the findings published in the journal Scientific Reports.

Think of a plant's flower pollinated by only one species of bee -- if the bee becomes extinct, so too will the plant eventually.

"Even the most resilient species will inevitably fall victim to the synergies among extinction drivers as extreme stresses drive ecosystems to collapse." says lead author Dr Giovanni Strona of the European Commission's Joint Research Centre based in Ispra in northern Italy.

Researchers from Italy and Australia simulated 2,000 'virtual earths' linking animal and plant species. Using sophisticated modelling, they subjected the virtual earths to catastrophic environmental changes that ultimately annihilated all life.

Examples of the kinds of catastrophes they simulated included runaway global warming, scenarios of 'nuclear winter' following the detonation of multiple atomic bombs, and a large asteroid impact.

"What we were trying to test is whether the variable tolerances to extreme global heating or cooling by different species are enough to explain overall extinction rates,"


"But because all species are connected in the web of life, our paper demonstrates that even the most tolerant species ultimately succumb to extinction when the less-tolerant species on which they depend disappear."

"Failing to take into account these co-extinctions therefore underestimates the rate and magnitude of the loss of entire species from events like climate change by up to 10 times," says co-author Professor Bradshaw of Flinders University in South Australia

Professor Bradshaw and Dr Strona say that their virtual scenarios warn humanity not to underestimate the impact of co-extinctions.

"Not taking into account this domino effect gives an unrealistic and exceedingly optimistic perspective about the impact of future climate change", warns Professor Bradshaw.

It can be hard to imagine how the demise of a small animal or plant matters so much, but the authors argue that tracking species up to total annihilation demonstrates how the loss of one can amplify the effects of environmental change on the remainder.

"Another really important discovery was that in the case of global warming in particular, the combination of intolerance to heat combined with co-extinctions mean that 5-6 degrees of average warming globally is enough to wipe out most life on the planet", says Dr Strona.

Professor Bradshaw further warns that their work shows how climate warming creates extinction cascades in the worst possible way, when compared to random extinctions or even from the stresses arising from nuclear winter.

Source: Flinders University [November 29, 2018]

Ancient wildfires played a crucial role in the formation and spread of grasslands like those that now cover large parts of the Earth, according to scientists at Penn State and the Smithsonian National Museum of Natural History.

Outcrops in Pakistan provided paleosol, or fossil soil samples, used to test the role of fire in the spread of grasslands nearly 10 million years ago [Credit: Anna K. Behrensmeyer]

A new study links a large rise in wildfires nearly 10 million years ago, in the late Miocene, with a major shift in vegetation on land, as indicated by carbon isotopes of plant biomarkers found in the fossil record. Frequent, seasonal fires helped turn forested areas into open landscapes, and drove the expansion of grasslands, the researchers said.

The team developed an innovative approach to test the role of fire in the rise of early grasslands. They analyzed tracers of ancient leaves and of burned organic matter left behind in paleosols, or fossil soils, in northern Pakistan.

"The tools we use are molecules and biomarkers produced by organisms in Earth history and preserved in rocks," said Allison Karp, a graduate student in geosciences at Penn State and lead author on the paper. "We can use these as clues to figure out what was happening with climate and ecology in the past."

The new technique has broad implications as a tool for scientists seeking to answer questions about past vegetation and climate change, the researcher said.

This shows that the tool can pinpoint the location of a fire where it occurred, according to Karp. "In a paleosol record you are really capturing an integrated picture of what was happening when the soil was forming," she said.

The researchers recently reported their findings in the Proceedings of the National Academy of Sciences. Katherine Freeman, Evan Pugh University Professor of Geosciences at Penn State and Karp's adviser, is a co-author on the paper.

"This is one of the biggest ecological changes in the last 66 million years," said Karp. "None of the open grassland systems we have today existed before this transition. It was a very different looking world, especially in sub-tropical places like Pakistan."

Scientists have long studied the rise of C4 grasslands, named after plants that evolved a new way to handle photosynthesis that allows them to thrive in dry, tropical conditions and with lower amounts of carbon dioxide. These plants include modern crops like corn and sugarcane.

A drop in global carbon dioxide levels was once believed to be behind the rise of C4 grasslands. More recent research has shown that the grasses spread at different rates on different continents, indicating that regional factors, like rain patterns -- and potentially fire -- played important roles. But there had been little direct evidence that linked a rise in wildfires to this transition.

"We were interested in reconstructing fire and the expansion of grasslands in the same geologic record to see if we could find proxy evidence of the role fire played," Karp said. "We now have a nice line of observational evidence to compare to what the models have said."

Karp and her collaborators used polycyclic aromatic hydrocarbons (PAHs), found in paleosols, as fire proxies. PAHs are chemicals that are created by the burning of organic matter like wood and plants. They also are naturally found in coal and crude oil.

PAHs increased five-fold across the study area while evidence of conifer trees declined and ultimately disappeared. The heavily forested landscape opened up in two stages. Around 10 million years ago, forests were replaced by more fire-prone, open woodlands or grasslands, and between six and eight million years ago, C4 grasslands became dominant just as the quantity of fire signatures sharply increased.

Modern fire ecology can explain the process. Grasses grow faster than trees after a fire and they also help create conditions ripe for subsequent fires, promoting open landscapes. In the late Miocene, wet seasons brought on by monsoon conditions encouraged plant growth, which in turn created more fuel for fires during hot, dry seasons in Pakistan.

"The role fire played in the expansion and evolution of grassland systems in deep time is important because understanding how fire has maintained systems in the past can help us predict what may happen to these important systems in the future as climate continues to change," Karp said.

The new fire marker approach could be used to examine landscape-scale interactions between fire and vegetation for other geographic regions and climactic transitions, like glacial-interglacial transitions or catastrophic climate-change events, researchers said.

Author: Matthew James Carroll | Source: Pennsylvania State University [November 28, 2018]