Constantine Alexander's Journal: May 2017

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May 2017

05/31/2017

More frequent extreme ocean warming could further endanger albatross

Black-browed albatross are large seabirds that breed on sub-Antarctic islands during the austral summer. Like many other long-lived species, black-browed albatrosses lay just one egg during breeding season. Photo by Henri Weimerskirch, Centre d'Etudes Biologiques de Chize.

As Earth warms due to human-caused climate change, extreme climatic events like heat waves, droughts, and spikes in ocean temperatures have increased and are projected to become even more common by the end of this century.

As scientists grapple with the behavioral, ecological and evolutionary impacts of extreme climatic events, the journal Philosophical Transactions of the Royal Society B created a special June issue to explore what is known on the topic and pioneer new approaches to this challenging and rapidly expanding field of study. The issue, which was published online May 8, 2017, was co-edited by Wood Hole Oceanographic institution (WHOI) biologist Stephanie Jenouvrier.

"The ecological effects that these extreme climatic events will have on already stressed ecosystems are not known," says Jenouvrier, a population biologist, "but understanding the impacts is crucial to future conservation efforts."

In addition to her role as co-editor, Jenouvrier is also co-author of a study featured in the special issue, which examines how extreme ocean warming events further stress an already declining population of black-browed albatross in the French Southern and Antarctic Lands.

"Previous studies on the effects of climate change on ecosystems have mainly focused on changes in mean temperature--the average temperature during a given time period," says Jenouvrier.

By looking at average temperatures from year-to-year, scientists can identify trends to determine if temperatures are warming, staying the same or getting colder and study how these trends affect ecosystems. However, because the trend reflects average temperatures, it "smoothes out" variability and extreme events and the dramatic effects those events can have on species and ecosystems. It is the effect of such variability and extreme events in ocean temperature on an albatross population that Jenouvrier and her team were determined to study.

"Changes in variability can have very different consequences on population dynamics for both animals and plants," Jenouvrier says.

To assess impacts to albatrosses, Jenouvrier and her coauthors from the Centre d'Etudes Biologiques de Chizé in France, examined sea surface temperature data and records of extreme warming events since 1978 on albatrosses breeding at Kerguelen Island. To do so, they developed computer demographic models to compare the effects of changes in both the mean (average) sea surface temperature and the sea surface temperature variability on the population growth and proportion of age groups within the population.

A change in temperature variability leads to more frequent warmer and colder events while a change in the temperature mean increases the occurrence of warmer events but decreases the occurrence of colder events. The researchers found that changes in the variation of ocean temperatures had a threefold effect on the growth rate of the albatross population compared to changes in just mean ocean temperature. Increasing variation of ocean temperatures--temperatures that range well below or above the optimum for the species--leads to population decline, while increasing the mean (average) of ocean temperatures result in population increase.

Although, more frequent hotter extreme events will lead to population decline, a change in the mean leads to more frequent warmer events that favor this specific population because the optima value for albatross is actually warmer than the current historical temperature. In other words, the effect of extreme events can be buffered when species live in cooler than optimal environments, providing a kind of "climate safety margin" for those species.

"In this case, the historical mean (or average) of sea surface temperatures was lower than the optimal temperature for this species," explains Jenouvrier. "If the mean temperature warms, these albatrosses will experience temperatures that will be more often at or near the optimum range for the species, so these changes in mean will buffer the negative effects of the extreme warming events."

However, even for those species that do experience a buffering effect from the climate safety margin, it's likely to be only temporary as future temperatures continue to rise beyond their optimal temperature range, she adds.

The researchers also studied impacts of extreme events on various age groups of the albatross population. Both models --one which increased temperature mean and the other the variation of sea surface temperatures--in younger populations: an impact with potentially important conservation implications for the species because younger birds are most likely to be those caught in long-line fishing hooks.

"In this special issue of the journal, we developed a roadmap to both advance the research and incorporate what has been learned from related fields," Jenouvrier adds. "Understanding the behavioral, ecological and evolutionary impacts of extreme climatic events is crucial when these events are rapidly increasing in frequency and intensity due to global climate change."

Citation: Martijn van de Pol, Stéphanie Jenouvrier, Johannes H. C. Cornelissen & Marcel E. Visser; Behavioural, ecological and evolutionary responses to extreme climatic events: challenges and directions; Philosophical Transactions of the Royal Society B: Biological Sciences, 2017; 372 (1723): 20160134 DOI: 10.1098/rstb.2016.0134.

Contact: Erika Fitzpatrick
Woods Hole Oceanographic Institution

Posted at 05:56 AM in Biodiversity, Climate Change, Marine Environment, Science | Permalink | Comments (0)

05/27/2017

Marine species distribution shifts will continue under ocean warming

Changes impact local fishing communities, resource management.

Credit: IUCN

Scientists using a high-resolution global climate model and historical observations of species distributions on the Northeast U.S. Shelf have found that commercially important species will continue to shift their distribution as ocean waters warm two to three times faster than the global average through the end of this century. Projected increases in surface to bottom waters of 6.6 to 9 degrees F (3.7 to 5.0 degrees Celsius) from current conditions are expected.

The findings, reported in Progress in Oceanography, suggest ocean temperature will continue to play a major role in where commercially and recreationally important species will find suitable habitat. Sea surface temperatures in the Gulf of Maine have warmed faster than 99 percent of the global ocean over the past decade. Northward shifts of many species are already happening, with major changes expected in the complex of species occurring in different regions on the shelf, and shifts from one management jurisdiction to another. These changes will directly affect fishing communities, as species now landed at those ports move out of range, and new species move in.

"Species that are currently found in the Mid-Atlantic Bight and on Georges Bank may have enough suitable habitat in the future because they can shift northward as temperatures increase," said lead author Kristin Kleisner, formerly of the Northeast Fisheries Science Center (NEFSC)'s Ecosystems Dynamics and Assessment Branch and now a senior scientist at the Environmental Defense Fund. "Species concentrated in the Gulf of Maine, where species have shifted to deeper water rather than northward, may be more likely to experience a significant decline in suitable habitat and move out of the region altogether."

The researchers used bottom trawl survey data collected between 1968 and 2013 on the shelf to estimate niches for 58 demersal and pelagic species. A high-resolution global climate model known as CM2.6, developed by the NOAA Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton, New Jersey, was used to generate projections of future surface and bottom ocean temperatures across the region. The future temperatures were then used to project where marine species would find suitable habitat.

"Similar studies in the past used a coarse model with a roughly 100-kilometer or 62-mile ocean resolution, while the new model has a 10-kilometer or 6.2-mile ocean resolution, making the simulation of oceanic and atmospheric features much more accurate," said Vincent Saba of the NEFSC's Ecosystems Dynamics and Assessment Branch, who works at GFDL and is a co-author of the study.

Saba has compared the difference between the coarse model and the new high-resolution model as being similar to the difference between an old standard definition television set and today's ultra high definition screens.

Researchers looked at species distributions in spring and fall in the Gulf of Maine on the northern part of the Northeast Shelf and those on the southern end, from Georges Bank to the Mid-Atlantic Bight. They also examined what the shifting distributions might mean for fishing communities by looking at the current and potential future distance between the main fishing port in each state and the center of the distribution of suitable thermal area for the top-landed species by weight in each state.

Key northern species including Acadian redfish, American plaice, Atlantic cod, haddock, and thorny skate may lose thermal habitat, while spiny dogfish and American lobster may gain. Projected ocean warming in the Gulf of Maine may create beneficial conditions for American lobster populations, and they may continue to be accessible to fishing ports in the region.

In contrast, species like monkfish, witch flounder, white hake and sea scallops may remain accessible to major local fishing ports but could experience strong declines in habitat due to ocean warming. Atlantic cod, which is at the southern end of its range, may find suitable thermal habitat off the shelf entirely or in more northern waters in Canada.

In states south of New York, the distance to the centers of species distribution from ports may increase for some species, including summer flounder, which is currently the third most-landed species in Virginia. In North Carolina, the distance from ports to the center of distribution may increase for all six of the top landed species. Among the top six species landed in Virginia, only Atlantic croaker and striped bass are projected to have more suitable habitat.

"Warming waters may have a positive effect on smooth dogfish, Atlantic croaker, and striped bass in the southern part of the Northeast Shelf, with increases in suitable habitat in terms of area and species abundance, " Kleisner said. "But these species are also shifting northward and the bulk of the biomass of some species may be further from the main ports in southern states, making it more costly for fishermen to access these species. Conversely, as species move into new regions, fishermen may have new opportunities."

The projections indicate that as species shift from one management jurisdiction to another, or span state and federal jurisdictions, increased collaboration among management groups will be needed to set quotas and establish allocations.

"These changes will depend on the pace of climate change and on the ability of species to adapt or shift elsewhere to maintain a preferred habitat," said Kleisner. "We did not examine fishing pressure, species interactions and other factors that may influence future distributions. However, given the historical changes observed on the Northeast Shelf over the past five decades and confidence in the projection of continued ocean warming in the region, it is likely there will be major changes within this ecosystem."

"Those changes will result in ecological, economic, social, and natural resource management challenges throughout the region," Kleisner said. "It is important to understand large-scale patterns in these changes so that we can plan for and mitigate adverse effects as much as possible."

Citation: Kristin M. Kleisner, Michael J. Fogarty, Sally McGee, Jonathan A. Hare, Skye Moret, Charles T. Perretti, Vincent S. Saba; Marine species distribution shifts on the U.S. Northeast Continental Shelf under continued ocean warming; Progress in Oceanography, Volume 153, April 2017, Pages 24–36; DOI: 10.1016/j.pocean.2017.04.001.

Contact: Shelley Dawicki
NOAA Northeast Fisheries Science Center

Posted at 02:18 AM in Climate Change, Fisheries, Marine Environment, Science | Permalink | Comments (0)

05/23/2017

Arctic warming to increase Eurasian extreme cold events

This is a sketch map of the possible physical process between Arctic warming and Eurasian cold events. Credit: Dr. Yao Yao.

In recent years, Arctic warming and extreme events have attracted widespread attention of the world. Recently, Dr. YAO Yao and Prof. LUO Dehai from the Institute of Atmospheric Physics investigated the impact of Ural blocking (UB) on Eurasian extreme cold events in response to Arctic warming and obtained some interesting findings.

The intensity, persistence of UB-related Eurasian cold anomalies, according to LUO and his collaborators from USA and Australia, depend strongly on the strength and vertical shear (VS) of the mean background westerly wind (MWW) over mid-high latitude Eurasia related to Barents and Kara Seas (BKS) warming. The large BKS warming since 2000 weakens the meridional temperature gradient, MWW and VS, which increases quasi-stationarity and persistence of the UB (rather than its amplitude), and then leads to more widespread Eurasian cold events and further enhances the BKS warming. LUO and his coauthors also examined the physical mechanism behind the observational result using an UNMI model.

"The cooling over Central Asia occurs mainly during 2000-2015 and is related to the quasi-stationary and persistent UB," said LUO, "the Northern Hemisphere winter warming hiatus observed in the recent decade (2000-2015) is likely associated with the quasi-stationary and persistent UB linked to the background Arctic warming or sea ice loss over the BKS. In particular, cold (warm) extremes are more persistent over Central Asia (BKS) for weak MWW or VS winters than for strong ones. "

Citation: Yao Yao and Dehai Luo; Increased Quasi Stationarity and Persistence of Winter Ural Blocking and Eurasian Extreme Cold Events in Response to Arctic Warming; Journal of Climate (24 April 2017); DOI: 10.1175/JCLI-D-16-0261.1.

Contact: Zheng Lin
Institute of Atmospheric Physics, Chinese Academy of Sciences

Posted at 12:18 AM in Climate Change, Environment, Science | Permalink | Comments (0)

05/20/2017

Sequestering blue carbon through better management of coastal ecosystems

USU ecologist Trisha Atwood publishes in Frontiers in Ecology and the Environment.

Focusing on the management of carbon stores within vegetated coastal habitats provides an opportunity to mitigate some aspects of global warming. Trisha Atwood from Utah State University's Watershed Sciences Department of the Quinney College of Natural Resources and the Ecology Center has collaborated with several co-authors from Australia, including lead author Peter Macreadie from Deakin University, in an article published in the May 2017 issue of Frontiers in Ecology and the Environment.

"If we are going to fight off climate change not only do we need to cut CO2 emissions," Atwood states. "But we also need to protect and restore natural carbon sinks like coastal wetlands."

Although vegetated coastal ecosystems occupy only 0.2 percent of the ocean's surface, they play a disproportionately large role in the capture and retention of global carbon. As a result, bio sequestration in vegetated coastal habitats, a process that takes up atmospheric CO2 and stores it for millennia in marine soils (e.g. blue carbon), is emerging as one of the most effective methods for long-term carbon storage.

Researchers are learning how to increase the sequestration of the blue carbon. Historically, resource managers have relied on best-management practices to protect and restore vegetated coastal habitats. Researchers now theorize that incorporating catchment-level management strategies in addition to the preservation of shoreline vegetation can help keep global warming to under 2 degreesC. These highly productive vegetated coastal habitats, including seagrasses, tidal marshes and mangroves, provide the best opportunities to capture and retain marine-based carbon.

Three key environmental processes influence blue carbon sequestration: nutrient inputs, bioturbation and hydrology. When these processes are altered by human actions, such as eutrophication of coastal ecosystems, it can result in large amounts of CO2 and methane being released back into the atmosphere. Managing these three processes provides the best option to protect the carbon with its' long-term storage capacity.

"Wetlands have a tremendous capacity for storing carbon long-term," Atwood said. "This research highlights three ways in which we can protect and improve this capacity."

She and her co-authors demonstrate that these actions have the potential to profoundly alter rates of carbon accumulation and retention in vegetated coastal habitats around the globe.

Citation: Nielsen Daniel A, Kelleway Jeffrey J, Atwood Trisha B, Seymour Justin R, Petrou Katherina, Connolly Rod M, Thomson Alexandra CG, Trevathan-Tackett Stacey M, Ralph Peter J ; Can we manage coastal ecosystems to sequester more blue carbon? Frontiers in Ecology and the Environment, 15(4): 206–213 (10 April 2017); DOI: 10.1002/fee.1484.

Contact: Trisha Atwood
Utah State University

Posted at 01:44 AM in Climate Change, Environment, Marine Environment, Science, Sustainable Development | Permalink | Comments (0)

05/19/2017

New coral reef fish species shows rare parental care behavior

Among the hundreds of species of damselfish, only a few protect and care for their young; a newly discovered species raises the number from three to four.

Altrichthys alelia (Alelia's damselfish) is a new species of damselfish discovered in the Philippines. Unlike most coral reef fish, in this species the parents care for their young. Credit: Giacomo Bernardi.

The vast majority of coral reef fish produce large numbers of young that disperse into the ocean as larvae, drifting with the currents before settling down on a reef. Giacomo Bernardi, a professor of ecology and evolutionary biology at UC Santa Cruz, studies reef fish that buck this trend and keep their broods on the reef, protecting the young until they are big enough to fend for themselves.

On a recent trip to the Philippines, Bernardi and his graduate students discovered a new species of damselfish that exhibits this unusual parental care behavior. Out of about 380 species of damselfish, only three brood-guarding species were known prior to this discovery. Bernardi's team had gone to the Philippines to study two of them, both in the genus Altrichthys, that live in shallow water off the small island of Busuanga. On the last day of the trip, the researchers went snorkeling in a remote area on the other side of the island from their study site.

"Immediately, as soon as we went in the water, we saw that this was a different species," Bernardi said. "It's very unusual to see a coral reef fish guarding its babies, so it's really cool when you see it."

Genetic tests on the specimens they collected confirmed that it is a new species, which the researchers named Altrichthys alelia (Alelia's damselfish, derived from the names of Bernardi's children, Alessio and Amalia, who helped with his field research). A paper on the new species was published May 18 in the journal ZooKeys.

Parental care dramatically improves the chances of survival for the offspring. According to Bernardi, less than one percent of larvae that disperse into the ocean survive to settle back on a reef, whereas survival rates can be as high as 35 percent for the offspring of the Altrichthys species. Yet the parental care strategy remains rare among reef fish.

"It's a huge fitness advantage, so why don't they all do that? There must also be a huge disadvantage," Bernardi said.

One big disadvantage is that the young are unable to colonize new sites far from the home reef of their parents. As a result, brood-guarding species (the technical term is "apelagic" species, because they don't have a pelagic, ocean-going phase) tend to occur in highly restricted areas, which leaves them more vulnerable to extinction.

"I suspect that species evolve this strategy regularly, and they are successful until there is some change to the local habitat, and then the whole population gets wiped out," Bernardi said. "These are very fragile species. The Banggai cardinalfish is one that was discovered just a few years ago in a small area in Indonesia, and it's already on the endangered species list."

Citation: Giacomo Bernardi, Gary C. Longo & T.E. Angela L. Quiros; Altrichthys alelia, a new brooding damselfish (Teleostei, Perciformes, Pomacentridae) from Busuanga Island, Philippines; ZooKeys, 2017; 675: 45; DOI: 10.3897/zookeys.675.12061.

Contact: Tim Stephens
University of California - Santa Cruz

Posted at 03:56 AM in Biodiversity, Marine Environment, Science | Permalink | Comments (0)

05/18/2017

Dams are major driver of global environmental change

Water reservoirs created by damming rivers could have significant impacts on the world's carbon cycle and climate system that aren't being accounted for, a new study concludes.

The study, conducted by researchers at the University of Waterloo and the Université libre de Bruxelles, appears in Nature Communications. It found that man-made dam reservoirs trap nearly one-fifth of the organic carbon moving from land to ocean via the world's rivers. While they can act as a significant source or sink for carbon dioxide, reservoirs are poorly represented in current climate change models.

"Dams don't just have local environmental impacts. It's clear they play a key role in the global carbon cycle and therefore the Earth's climate," said Philippe Van Cappellen, a Canada Excellence Research Chair in Ecohydrology at Waterloo and the study's co-author. "For more accurate climate predictions, we need to better understand the impact of reservoirs."

There are currently in excess of 70,000 large dams worldwide. With the continuing construction of new dams, more than 90 per cent of the world's rivers will be fragmented by at least one dam within the next 15 years.

The study's researchers used a novel method to determine what happens to organic carbon traveling down rivers and were able to capture the impact of more than 70 per cent of the world's man-made reservoirs by volume. Their model links known physical parameters such as water flow and reservoir size with processes that determine the fate of organic carbon in impounded rivers.

"With the model used in this study, we can better quantify and predict how dams affect carbon exchanges on a global scale," said Van Cappellen, a professor in Waterloo's Department of Earth and Environmental Sciences.

In similar recent studies, the group of researchers also found that ongoing dam construction impedes the transport of nutrients such as phosphorus, nitrogen and silicon through river networks. The changes in nutrient flow have global impacts on the quality of water delivered to wetlands, lakes, floodplains and coastal marine areas downstream.

"We're essentially increasing the number of artificial lakes every time we build a dam," said Taylor Maavara, lead author and a PhD student at Waterloo. "This changes the flow of water and the materials it carries, including nutrients and carbon."

Citation: Taylor Maavara, Ronny Lauerwald, Pierre Regnier & Philippe Van Cappellen; Global perturbation of organic carbon cycling by river damming; Nature Communications, 2017; 8: 15347; DOI: 10.1038/ncomms15347.

Contact: Matthew Grant
University of Waterloo

Posted at 02:13 AM in Environment, Renewable Energy, Science | Permalink | Comments (0)

05/17/2017

Travel distances of juvenile fish key to better conservation

Largest study of larval dispersal to inform optimal sizing and spacing of marine reserves.

As part of the largest, most comprehensive study of larval dispersal ever conducted, scientists were able to determine that most of the juvenile clownfish stayed relatively close to home, settling at mean distances of 10-15 kilometers from their natal reefs. Photo by Simon Thorrold, Woods Hole Oceanographic Institution.

Marine reserves -- sections of the ocean where fishing is prohibited--promote coral reef sustainability by preventing overfishing and increasing fish abundance and diversity. But to be effective, they need to be sized right, and in a way that accounts for how far juvenile fish travel away from their parents after spawning.

Scientists at the Woods Hole Oceanographic Institution (WHOI), along with researchers from Australia, France, and Saudi Arabia, have successfully measured the dispersal distances of two coral reef fish species across a 3,000 square mile section of the ocean -- an area the size of Yellowstone National Park. The study, published in the May 8, 2017, issue of the journal Nature Ecology & Evolution, marks the largest, most comprehensive study of larval dispersal ever conducted and has important implications for the sizing and spacing of marine reserves.

"How far fish will disperse in their lifetimes is critical when you start thinking about how marine reserves should be designed," said Simon Thorrold, co-author of the study and a senior scientist at WHOI. "This is the first time we've been able to measure dispersal distances on spatial scales that are relevant to marine reserves, which means we can now provide data that informs management on optimal spacing and sizing."

Size matters

Marine reserves come in many shapes and sizes. But if a reserve is too small, it can't accommodate enough larvae to sustain populations. And if it's too big, larvae will simply stay within the confines of the reserve without contributing to surrounding fisheries -- a critical secondary role marine reserves need to play to improve fisheries management.

To get a read on fish dispersal in the past, scientists relied on population genetics approaches that lacked the power to measure dispersal over space and time scales relevant to protected areas of the ocean. More recently, ecologists have turned to computer-generated models of water currents to track particles through virtual oceans. According to Thorrold, this approach also has limitations since there was no way to verify the accuracy of the models. "The software can generate a lot of cool-looking graphs, but it was impossible to test the skill of those models in any real way."

How far fish will disperse in their lifetimes is critical when you start thinking about how marine reserves should be designed, according to WHOI biologist Simon Thorrold, co-author of the new study. The research team found that butterflyfish dispersed further than clownfish, averaging distances of 43-64 kilometers before settling into their new habitats. Photo by Simon Thorrold, Woods Hole Oceanographic Institution.

An empirical approach

To overcome these limitations, Thorrold and his colleagues took direct measurements of dispersal distances in the field. They collected DNA samples from thousands of adult and juvenile clownfish and butterflyfish throughout Kimbe Bay, Papua New Guinea, in 2009 and 2011. The entire sampling process occurred underwater, with the 30-person science team spending thousands of man-hours on SCUBA over several weeks in the field each year.

When the scientists returned to the lab, they used DNA parentage analysis, a sequencing technique that allowed them to match the juveniles up with their parents based on the DNA samples and spawning and settlement location data. From that, they were able to determine that most of the juvenile clownfish stayed relatively close to home, settling at mean distances of 10-15 kilometers from their natal reefs. The butterflyfish dispersed further, averaging distances of 43-64 kilometers before settling into their new habitats.

"Since we knew the respective locations of the adults and babies, we were able to come up with the exact linear distances that the larvae had dispersed. We're no longer talking about estimates," said Thorrold.

Benefits beyond design

In addition to helping inform the design of protected areas, the measurements can help to test the ability of reserves to perform key conservation functions. For example, one way a marine reserve network may improve fish population sustainability is through the so-called "rescue effect." In theory, if fish in a reserve suffer catastrophic mortality, the reserve can be repopulated by larvae from other reserves within the network. Thorrold and colleagues were able to track larvae from one reserve to another in the study area, confirming that rescue effect is likely to occur in real-world reserve networks.

The dispersal measurements could also allow fisheries managers to monitor the effectiveness of existing reserves, helping answer the question of whether or not a particular reserve is contributing to fish populations beyond its boundaries. This, according to Thorrold, has been a big unknown.

"If you can trace larvae from one reserve to a place that's fished, you can come up with a direct measure of how many fish the reserve is contributing to exploited populations beyond the reserve," he said. "This helps when trying to convince fishermen that networks of marine reserves are a good management tool."

Future work

According to Thorrold, as coral reef seascapes continue to face pressure from man-made stressors, marine reserves will continue to serve as an important conservation management tool. As such, it will become increasingly important to be able to provide direct measurements of larval dispersal, and find ways to apply the information to other regions of the ocean.

"The next thing we are working on is developing a coupled bio-physical model of the area that will allow us to take the results from this study and generalize them to other coral reef seascapes around the world," he said. "Limited resources for ocean management, particularly in the developing world, means that we need to maximize the chances of successful conservation outcomes from these efforts. These types of scientific insights will be critical for ongoing efforts to promote resilience of coral reef ecosystems in the face of human exploitation and climate change."

Citation: Glenn R. Almany, Serge Planes, Simon R. Thorrold, Michael L. Berumen, Michael Bode, Pablo Saenz-Agudelo, Mary C. Bonin, Ashley J. Frisch, Hugo B. Harrison, Vanessa Messmer, Gerrit B. Nanninga, Mark A. Priest, Maya Srinivasan, Tane Sinclair-Taylor, David H. Williamson & Geoffrey P. Jones; Larval fish dispersal in a coral-reef seascape; Nature Ecology & Evolution 1, Article number: 0148 (08 May 2017); DOI:10.1038/s41559-017-0148.

This research was supported by Australian Research Council, the King Abdullah University of Science and Technology, and the National Science Foundation.

Contact: Lonny Lippsett
Woods Hole Oceanographic Institution

Posted at 02:33 AM in Biodiversity, Marine Environment, Protected Areas, Science | Permalink | Comments (0)

05/16/2017

No escaping ocean plastic: 37 million bits of litter on one of world's remotest islands

The beaches of one of the world's most remote islands have been found to be polluted with the highest density of plastic debris reported anywhere on the planet, in a study published in the prestigious US scientific journal Proceedings of the National Academy of Sciences.

Despite being uninhabited and located more than 5000 kilometres from the nearest major population centre, Henderson Island is littered with an estimated 37.7 million pieces of plastic.

Part of the UK's Pitcairn Islands territory, the island is so remote that it's only visited every five to ten years for research purposes, but its location near the centre of the South Pacific Gyre ocean current makes it a focal point for debris carried from South America or deposited by fishing boats.

During the most recent scientific expedition to the island led by the British nature conservation charity RSPB, the study's lead author, IMAS researcher Dr Jennifer Lavers, found the beaches littered by up to 671 items per square metre, the highest density ever recorded.

"What's happened on Henderson Island shows there's no escaping plastic pollution even in the most distant parts of our oceans," Dr Lavers said.

"Far from being the pristine 'deserted island' that people might imagine of such a remote place, Henderson Island is a shocking but typical example of how plastic debris is affecting the environment on a global scale.

"Based on our sampling at five sites we estimated that more than 17 tonnes of plastic debris has been deposited on the island, with more than 3570 new pieces of litter washing up each day on one beach alone.

"It's likely that our data actually underestimates the true amount of debris on Henderson Island as we were only able to sample pieces bigger than two millimetres down to a depth of 10 centimetres, and we were unable to sample along cliffs and rocky coastline."

Dr Lavers said most of the more than 300 million tonnes of plastic produced worldwide each year is not recycled, and as it's buoyant and durable it has a long-term impact on the ocean.

"Plastic debris is an entanglement and ingestion hazard for many species, creates a physical barrier on beaches to animals such as sea turtles, and lowers the diversity of shoreline invertebrates.

"Research has shown that more than 200 species are known to be at risk from eating plastic, and 55 per cent of the world's seabirds, including two species found on Henderson Island, are at risk from marine debris," Dr Lavers said.

Citation: Jennifer L. Lavers and Alexander L. Bond; Exceptional and rapid accumulation of anthropogenic debris on one of the world’s most remote and pristine islands; Proceedings of the National Academy of Sciences of the United States (May 15, 2017); DOI: 10.1073/pnas.1619818114.

Contact: Andrew Rhodes
University of Tasmania - Institute for Marine and Antarctic Studies

Posted at 05:02 AM in Environment, Environmental Disasters, Marine Environment, Science | Permalink | Comments (0)

What could be the importance of marine and coastal cultural ecosystem services

This is a geographical location of marine and coastal CES assessments. Credit: Rodrigues et al. 2017.

A detailed scientific literature review published in the open access journal One Ecosystem confirmed that research on marine and coastal cultural ecosystem services is scarce compared to other ecosystem service categories, revealing curious insights and identifying major knowledge gaps.

Available knowledge is not only primarily focused on local and regional sociocultural or economic assessments, but is also mostly coming from Western Europe and North America (USA and Canada). Largely underrepresented, the Global South has only a few studies in South America, Madagascar, and China. Remarkably, no marine and coastal cultural ecosystem services assessments were found in any country of the African continent.

"Such research bias narrows the understanding of social-ecological interactions to a western cultural setting, undermining the role of other worldviews in the understanding of a wide range of interactions between cultural practices and ecosystems worldwide" explain the study authors led by João Garcia Rodrigues.

In addition to this regional bias, the authors have identified clusters of co-occurring drivers of change affecting marine and coastal habitats and their cultural ecosystem services. Damming, land reclamation, tourism and industrial fishing were among the identified drivers of change.

The main knowledge gaps found were the lack of integrated valuation assessments; linking the contribution of cultural ecosystem service benefits to human well-being; assessing more subjective and intangible classes; identifying the role of open-ocean and deep-sea areas in providing these services; and understanding the role of non-natural capital in the co-production of cultural ecosystem services. "Research priorities should be aimed at filling these knowledge gaps" explain the authors.

Overcoming such challenges can result in more balanced decisions that will ultimately contribute to more sustainable interactions between humans and the marine environment. The authors highlight that "cultural ecosystem services are strong motivations for people to embrace sustainability, and hence their inclusion in environmental decision-supporting mechanisms can contribute to a more sustainable future for marine and coastal ecosystems".

Citation: Garcia Rodrigues J, Conides A, Rivero Rodriguez S, Raicevich S, Pita P, Kleisner K, Pita C, Lopes P, Alonso Roldán V, Ramos S, Klaoudatos D, Outeiro L, Armstrong C, Teneva L, Stefanski S, Böhnke-Henrichs A, Kruse M, Lillebø A, Bennett EM, Belgrano A, Murillas A, Sousa Pinto I, Burkhard B and Villasante S (2017); Marine and Coastal Cultural Ecosystem Services: knowledge gaps and research priorities; One Ecosystem 2: e12290; DOI: 10.3897/oneeco.2.e12290.

Contact: João Garcia Rodrigues
Universidade de Santiago de Compostela

Posted at 03:24 AM in Environment, Marine Environment, Science | Permalink | Comments (0)

05/13/2017

Who swims where?

An international research team has compared global distribution maps of marine species and has developed recommendations for how to further improve the two extensive databases providing publicly available delineations of marine species occurrence. Information about species' occurrences is the crucial basis for ecological studies as well as for policy decisions required to ensure the survival of endangered species. The researchers also developed a Web app that people can use to overlay the maps from both databases in order to compare them - around 250 species have been recorded in the app. University of Freiburg biologist Dr. Kristin Kaschner was involved in the work that the team published in the scientific journal PLOS ONE.

Currently, research and policy predominantly rely on two sources for the large scale distribution of marine species: the International Union for Conservation of Nature (IUCN) creates the maps based on experts' knowledge for the individual species while AquaMaps, a tool and online marine atlas developed by Kaschner, generates occurrence maps fusing a predictive modelling approach. Together the databases include 24,586 species: 22,889 are in AquaMaps and 4,027 are in IUCN, with an intersection of only 2,330 species included in both.

Due to the varying methodologies, the delineation of a specific species' distribution can differ greatly. For many of the well-studied species, the maps produced by both databases aligned very well. But for others, however, there are irregularities: in the IUCN maps, for instance, the presence of coral in deep waters is overestimated. Some of the computer-generated AquaMaps maps, on the other hand, of which only 5.7 percent have been checked by experts, show breaks on the edges of the prognosticated distribution areas, indicating a possible need for improving the algorithm.

The Web app enables the comparison between maps drawn from both extensive databases for the global distribution of sea animals as seen here by the example of the Atlantic white-sided dolphin. Source: http://ohi-science.nceas.ucsb.edu/plos_marine_rangemaps.

„With our results we want to offer an impulse to deepen the cooperation between species experts and species distribution modelers," says Kaschner. „The goal is to offer scientists, policy-makers and representatives in civil society the best possible basis for decision-making when it comes to protecting endangered species and biodiversity in our planet's oceans."

Citation: Casey C. O'Hara, Jamie C. Afflerbach, Courtney Scarborough, Kristin Kaschner, and Benjamin S. Halpern; Aligning marine species range data to better serve science and conservation; PLOS ONE (May 3, 2017); DOI: 10.1371/journal.pone.0175739.

This study was supported by funding from the Gordon and Betty Moore Foundation.

Interactive Web App.

Contact: Dr. Kristin Kaschner
University of Freiburg