Constantine Alexander's Journal

Man-made fibres and plastic found in the deepest living organisms

Animals from six of the deepest places on Earth found to contain man-made fibres and plastic in their stomachs, scientists have shown.

By Newcastle University.

A study, led by Newcastle University’s Dr Alan Jamieson, has uncovered evidence that not only have plastics now reached the deepest chasms of our oceans but they are being ingested by the animals that live there.

Revealing their findings as part of Sky Ocean Rescue - a campaign to raise awareness of how plastics and pollution are affecting our seas - the team tested samples of crustaceans found in the ultra-deep trenches that span the entire Pacific Ocean - the Mariana, Japan, Izu-Bonin, Peru-Chile, New Hebrides and Kermadec trenches.

These range from seven to over 10 kilometres deep, including the deepest point, Challenger Deep in the Mariana Trench, at a staggering 10,890 metres deep.

Using state-of-the-art facilities at Newcastle University and Shimadzu UK Ltd in Milton Keynes, the team examined 90 individual animals and found ingestion of plastic ranged from 50% in the New Hebrides Trench to 100% at the bottom of the Mariana Trench.

The fragments identified include semi-synthetic cellulosic fibres, such as Rayon, Lyocell and Ramie, which are all microfibres used in products such as textiles, to Nylon, polyethylene, polyamide, or unidentified polyvinyls closely resembling polyvinyl alcohol or polyvinylchloride - PVA and PVC.

Research lead Dr Jamieson, said: “We published a study earlier this year showing high levels of organic pollutants in the very deepest seas and lots of people asked us about the presence of plastics, so we decided to have a look. The results were both immediate and startling. This type of work requires a great deal of contamination control but there were instances where the fibres could actually be seen in the stomach contents as they were being removed. We felt we had to do this study given the unique access we have to some of the most remote places on earth, and we are using these samples to make a poignant statement about mankind’s legacy."

 

Surface to seafloor

Using deep-sea ‘landers’ developed by Dr Jamieson, the technology free-falls to the ocean floor and carries out a variety of monitoring and sampling tasks. The technology has been used at locations around the globe and the team’s deepest landers have been dropped over 200 times around the Pacific Trenches.

There is now an established appreciation of plastic pollution in our oceans and the detrimental effects this has on marine organisms. An estimated 300 million tonnes of plastic now litters the oceans, with more than 5 trillion plastic pieces weighing over 250,000 tons currently floating on the surface.

Although the majority of marine litter can be observed floating on the surface, the degradation and fragmentation of plastics will ultimately result in sinking to the underlying deep-sea habitats, where opportunities for dispersal become ever more limited.

A 'Lander' developed by Dr Jamieson. Credit: Newcastle University

“Deep-sea organisms are dependent on food raining down from the surface,” explains Dr Jamieson, “which in turn brings any adverse components, such as plastic and pollutants with it. The deep sea is not only the ultimate sink for any material that descends from the surface, but it is also inhabited by organisms well adapted to a low food environment and these will often eat just about anything. This study has shown that man-made microfibres are culminating and accumulating in an ecosystem inhabited by species we poorly understand, cannot observe experimentally and have failed to obtain baseline data for prior to contamination. These observations are the deepest possible record of microplastic occurrence and ingestion, indicating it is highly likely there are no marine ecosystems left that are not impacted by anthropogenic debris.”

The ocean is losing its breath

In broadest view yet of world's low oxygen, scientists reveal dangers and solutions.

Low oxygen caused the death of these corals and others in Bocas del Toro, Panama. The dead crabs pictured also succumbed to the loss of dissolved oxygen. Credit: Arcadio Castillo/Smithsonian.

In the past 50 years, the amount of water in the open ocean with zero oxygen has gone up more than fourfold. In coastal water bodies, including estuaries and seas, low-oxygen sites have increased more than 10-fold since 1950. Scientists expect oxygen to continue dropping even outside these zones as Earth warms.

To halt the decline, the world needs to rein in both climate change and nutrient pollution, an international team of scientists including Lisa Levin, a biological oceanographer at Scripps Institution of Oceanography at the University of California San Diego, asserted in a new paper published Jan. 4 in Science.

"Oxygen is fundamental to life in the oceans," said Denise Breitburg, lead author and marine ecologist with the Smithsonian Environmental Research Center. "The decline in ocean oxygen ranks among the most serious effects of human activities on the Earth's environment."

"It's a tremendous loss to all the support services that rely on recreation and tourism, hotels and restaurants and taxi drivers and everything else," said Levin. "The reverberations of unhealthy ecosystems in the ocean can be extensive."

The study came from a team of scientists from GO2NE (Global Ocean Oxygen Network), a new working group created in 2016 by the United Nation's Intergovernmental Oceanographic Commission. The review paper is the first to take such a sweeping look at the causes, consequences and solutions to low oxygen worldwide, in both the open ocean and coastal waters. The article highlights the biggest dangers to the ocean and society, and what it will take to keep Earth's waters healthy and productive.

The Stakes

"Approximately half of the oxygen on Earth comes from the ocean," said Vladimir Ryabinin, executive secretary of the International Oceanographic Commission that formed the GO2NE group. "However, combined effects of nutrient loading and climate change are greatly increasing the number and size of 'dead zones' in the open ocean and coastal waters, where oxygen is too low to support most marine life."

In areas traditionally called "dead zones," like those in Chesapeake Bay and the Gulf of Mexico, oxygen plummets to levels so low many animals suffocate and die. As fish avoid these zones, their habitats shrink and they become more vulnerable to predators or fishing. But the problem goes far beyond "dead zones," the authors point out. Even smaller oxygen declines can stunt growth in animals, hinder reproduction and lead to disease or even death. It also can trigger the release of dangerous chemicals such as nitrous oxide, a greenhouse gas up to 300 times more powerful than carbon dioxide, and toxic hydrogen sulfide. While some animals can thrive in dead zones, overall biodiversity falls.

Climate change is the key culprit in the open ocean. Warming surface waters make it harder for oxygen to reach the ocean interior. Furthermore, as the ocean as a whole gets warmer, it holds less oxygen. In coastal waters, excess nutrient pollution from land creates algal blooms, which drain oxygen as they die and decompose. In an unfortunate twist, animals also need more oxygen in warmer waters, even as it is disappearing.

People's livelihoods are also on the line, the scientists reported, especially in developing nations. Smaller, artisanal fisheries may be unable to relocate when low oxygen destroys their harvests or forces fish to move elsewhere. In the Philippines, fish kills in a single town's aquaculture pens cost more than $10 million. Coral reefs, a key tourism attraction in many countries, also can waste away without enough oxygen.

Some popular fisheries could benefit, at least in the short term. Nutrient pollution can stimulate production of food for fish. In addition, when fish are forced to crowd to escape low oxygen, they can become easier to catch. But in the long run, this could result in overfishing and damage to the economy.

Low-oxygen zones are spreading around the globe. Red dots mark places on the coast where oxygen has plummeted to 2 milligrams per liter or less, and blue areas mark zones with the same low-oxygen levels in the open ocean. Credit: GO2NE working group. Data from World Ocean Atlas 2013 and provided by R. J. Diaz.

Winning the War: A Three-Pronged Approach

To keep low oxygen in check, the scientists said the world needs to take on the issue from three angles:

Address the causes: nutrient pollution and climate change. While neither issue is simple or easy, the steps needed to win can benefit people as well as the environment. Better septic systems and sanitation can protect human health and keep pollution out of the water. Cutting fossil fuel emissions not only cuts greenhouse gases and fights climate change, but also slashes dangerous air pollutants like mercury.

Protect vulnerable marine life. With some low oxygen unavoidable, it is crucial to protect at-risk fisheries from further stress. According to the GO2NE team, this could mean creating marine protected areas or no-catch zones in areas animals use to escape low oxygen, or switching to fish that are not as threatened by falling oxygen levels. Improve low-oxygen tracking worldwide. Scientists have a decent grasp of how much oxygen the ocean could lose in the future, but they do not know exactly where those low-oxygen zones will be. Enhanced monitoring, especially in developing countries, and numerical models will help pinpoint which places are most at risk and determine the most effective solutions.

"This is a problem we can solve," Breitburg said. "Halting climate change requires a global effort, but even local actions can help with nutrient-driven oxygen decline." As proof Breitburg points to the ongoing recovery of Chesapeake Bay, where nitrogen pollution has dropped 24 percent since its peak thanks to better sewage treatment, better farming practices and successful laws like the Clean Air Act. While some low-oxygen zones persist, the area of the Chesapeake with zero oxygen has almost disappeared. "Tackling climate change may seem more daunting," she added, "but doing it is critical for stemming the decline of oxygen in our oceans, and for nearly every aspect of life on our planet."

Citation: Denise Breitburg, Lisa A. Levin, Andreas Oschlies, Marilaure Gregoire, Francisco P. Chavez, Daniel J. Conley, Veronique Garcon, Denis Gilbert, Dimitri Gutierrez, Kirsten Isensee, Gil S. Jacinto, Karin E. Limburg, Ivonne Montes, S.W.A. Naqvi, Grant C. Pitcher, Nancy N. Rabalais, Michael R. Roman, Kenneth A. Rose, Brad A. Seibel, Maciej Telszewski, Moriaki Yasuhara & Jing Zhang; Declining oxygen in the global ocean and coastal waters; Science, Vol. 359, Issue 6371, eaam7240 (5 January 2018); DOI: 10.1126/science.aam7240.

Contact: Rob Monroe
University of California - San Diego

 

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Fish and ships: Vessel traffic reduces communication ranges for Atlantic cod, haddock

Maps showing (a) locations of the three recording sites within Massachusetts Bay and Stellwagen Bank National Marine Sanctuary north of Cape Cod in relation to the adjacent coast of Massachusetts, (b) AIS vessel tracks over the three-month recording period for both the Atlantic cod winter spawning site and the haddock winter spawning site within a 10 nautical mile radius. White lines mark the boundaries of Stellwagen Bank National Marine Sanctuary.
Location of the Spring Cod Conservation Zone, the site of the Atlantic cod spring spawning recording location.
Location of the Atlantic cod winter spawning recording location.
Location of the haddock winter spawning recording location.
Port of Boston traffic separation scheme.
Maps created in ArcMAP 10.3.1 by Jenni Stanley of NOAA Fisheries/NEFSC and Mike Thompson of NOAA/SBNMS

NOAA scientists studying sounds made by Atlantic cod and haddock at spawning sites in the Gulf of Maine have found that vessel traffic noise is reducing the distance over which these animals can communicate with each other. As a result, daily behavior, feeding, mating, and socializing during critical biological periods for these commercially and ecologically important fish may be altered, according to a study published in Scientific Reports.

Three sites in Massachusetts Bay, two inside Stellwagen Bank National Marine Sanctuary (SBNMS) and one inshore south of Cape Ann, were monitored for three months by researchers at the Northeast Fisheries Science Center (NEFSC) laboratory in Woods Hole, Mass. and at the sanctuary offices in Scituate, Mass. Vocalizations, such as Atlantic cod grunts and haddock knocks, were recorded by bottom-mounted instruments at each site during spawning in winter and spring.

"We looked at the hourly variation in ambient sound pressure levels and then estimated effective vocalization ranges at all three sites known to support spawning activity for Gulf of Maine cod and haddock stocks," said Jenni Stanley, a marine research scientist in the passive acoustics group at the NEFSC and SBNMS and lead author of the study. "Both fluctuated dramatically during the study. The sound levels appear to be largely driven by large vessel activity, and we found a signification positive correlation with the number of Automatic Identification System (AIS) tracked vessels at two of the three sites."

AIS is an automatic tracking system, used on ships and by vessel traffic services. It provides information on a vessel, such as its unique identification number, position, course and speed, which can be displayed on a shipboard radar or electronic chart display.

Ambient sounds - those in the surrounding environment - include animals vocalizing, physical sounds such as wind and water movement or geological activity, and human-produced sound from ships and marine construction. Many marine animals use ambient sound to navigate, to choose where to settle, or to modify their daily behaviors including breeding, feeding and socializing.

Cod grunts were present for 100 percent of the spring days and 83 percent of the winter days. Haddock knocks were present for 62 percent of the winter days within the three-month sampling period. However, ambient sound levels differed widely at the three sites, both on an hourly and daily time scale. The Atlantic cod winter spawning site, nearest the Boston shipping lanes, had the highest sound levels, while the Atlantic cod spring spawning site inshore south of Gloucester, Mass. had the lowest. Sound levels in the haddock winter spawning site, further offshore in the sanctuary, were in the middle of the range detected in the study.

Marine Autonomous Recording Units, or MARUs, used to record sound on the ocean floor. Photo credit: NOAA Fisheries/NEFSC

Study data were also used to calculate the estimated distance a fish vocalization would be heard at each of the spawning sites. The effective radius ranged widely, from roughly 4 to 70 feet, and was largely dependent on the number of tracked vessels within a 10 nautical mile radius of the recording sites.

Lower-level, chronic exposure to increased ambient sound from human activities is one of the most widespread, yet poorly understood, factors that could be changing fish behavior. If they cannot hear as well as they need to, then sound signals from other fish can be lost, compromised, or misinterpreted in ways that can cause a change in behavior. Since Atlantic cod, for example, vocalize to attract mates and listen for predators, not hearing those signals could potentially reduce reproductive success and survival.

"Anthropogenic sound in certain ocean regions has increased considerably in recent decades due to various human activities such as global shipping, construction, sonar, and recreational boating," Stanley said. "As ocean sound increases, so does the concern for its effects on populations of acoustic signalers, which range from invertebrates to marine mammals. We don't know if or to what extent specific species can adapt or adjust their acoustic signals to compete in this environment."

In addition to Stanley, other researchers involved in the study were Sofie Van Parijs at the NEFSC's Woods Hole Laboratory and Leila Hatch at Stellwagen Bank National Marine Sanctuary.

Citation: Jenni A. Stanley, Sofie M. Van Parijs & Leila T. Hatch; Underwater sound from vessel traffic reduces the effective communication range in Atlantic cod and haddock; Scientific Reports 7, Article Number: 14633 (7 November 2017); DOI: 10.1038/s41598-017-14743-9.

Contact: Shelley Dawicki
NOAA Northeast Fisheries Science Center

 

Marine turtles dying after becoming entangled in plastic rubbish

This is a live leatherback turtle entangled in fishing ropes which increases drag, Grenada 2014. Credit: Kate Charles, Ocean Spirits.

Hundreds of marine turtles die every year after becoming entangled in rubbish in the oceans and on beaches, including plastic 'six pack' holders and disgarded fishing gear.

The rise in plastic refuse in the ocean and on beaches is killing turtles of all species, with a disproportionate impact on hatchlings and young turtles, research by the University of Exeter shows.

A world-wide survey covering the major oceans where turtles live found that found that 91 per cent of the entangled turtles were found dead. They also suffered serious wounds from entanglement, leading to maiming, amputation or choking. Others that survived were forced to drag disgarded rubbish or debris with them.

The survey found turtles are being tangled up in lost fishing nets, plastic twine and nylon fishing line, as well as six pack rings from canned drinks, plastic packaging straps, plastic balloon string, kite string, plastic packaging and discarded anchor line and seismic cable. Turtles were also discovered entangled in discarded plastic chairs, wooden crates, weather balloons and boat mooring line.

The research, published in Endangered Species Research, sheds light on the true threat of plastic pollution to marine turtles, which, other research has shown, also eat plastic rubbish, and marine creatures caught up in it.

Professor Brendan Godley. Professor of Conservation Science and Director of the Centre for Ecology & Conservation at the University of Exeter's Penryn campus and the lead author warned that as plastic pollution increases more and more turtles are likely to become entangled.

Mortality from entanglement has increased substantially over the last century, as with marine mammals and birds.

84 per cent of the 106 experts surveyed on the Atlantic, Pacific Caribbean, Mediterranean and Indian ocean coast, who responded said they had found turtles tangled in rubbish, including plastic debris and lost or disgarded fishing gear.

The report concluded that, based on the survey results, that more than 1000 turtles are likely to die due to entanglement. But the figure is likely to be a 'gross underestimation' of the scale of the threat to turtles. Not all dead turtles strand on beaches, especially young animals, and some decay at sea. Some of the experts surveyed said that not all stranded turtles are found and that some are removed by local people to eat.

This is a Drowned Green turtle entangled in ghost nets in Uruguay. Credit: Karumbe.

Hatchlings and young sea turtles are particularly susceptible to getting tangled up in lost or disgarded fishing gear or floating debris. Juvenile turtles ride on ocean currents to zones where floating rubbish and debris is concentrated creating an 'ecological trap'. They also 'set up home' near floating debris and can remain there for years.

Professor Godley, the lead author, said the mortality rate from becoming tangled up in human refuse was, in practice, likely to be far higher than 1,000 turtles a year estimated by the limited survey.

"Plastic rubbish in the oceans, including lost or disgarded fishing gear which is not biodegradable, is a major threat to marine turtles. We found, based on beach strandings, that more than 1000 turtles are dying a year after becoming tangled up, but this is almost certainly a gross underestimate. Young turtles and hatchings are particularly vulnerable to entanglement," he said.

"Experts we surveyed found that entanglement in plastic and other pollution could pose a long term impact on the survival of some turtle populations and is a greater threat to them than oil spills. We need to cut the level of plastic waste and purse biodegradable alternatives if we are to tackle this grave threat to turtles' welfare."

The Exeter University research team, which included two research students Emily Duncan and Zara Botterell who work in conjunction with Plymouth Marine Laboratory, surveyed experts who rescue and rehabilitate stranded turtles in 43 countries, to find out if they had discovered turtles which had been tangled up. They also found 23 reports of entangled turtles in peer-reviewed publications, magazines, newspapers and reports.

All species of turtle were found entangled, but Olive Ridley turtles are the most likely species to get tangled up. The species nests in the hundreds of thousands. It forages in areas where marine debris can aggregate. It may also be attracted to feeding on marine rubbish, including disgarded fishing tackle.

Most entanglements recorded were in lost or discarded fishing gear known as 'ghost fishing' rope, nets and lines. Since the 1950s the fishing industry has replaced natural fibres such as cotton, jute and hemp with synthetic plastic materials such as nylon, polyethylene and polypropylene which doesn't biodegrade in water.

The report concludes: "Entanglement with anthropogenic plastic materials, such as discarded fishing gear, as well as land based sources, is an under reported and under researched threat to marine turtles."

But it points out some communities are actively working to rescue turtles that get tangled up. Fishermen in Sicily volunteer to take part in the rescue of turtles in difficulty at sea and on beaches, and are trained to transfer them to rescue centres.

Citation: Duncan EM, Botterell ZLR, Broderick AC, Galloway TS, Lindeque PK, Nuno A, Godley BJ; REVIEW: A global review of marine turtle entanglement in anthropogenic debris: a baseline for further action; Endangered Species Research Vol. 34: 431-448 (December 11, 2017); DOI: 10.3354/esr00865.

Contact: Marie Woolf
University of Exeter

 

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Study finds ways to avoid hidden dangers of accumulated stresses on seagrass

Hundreds of millions of cubic meters of vital seagrass meadows worldwide can potentially be at risk of collapse from accumulated effects of repeated dredging and natural stress.

QUT Research Fellow Dr. Paul Wu is part of a research team working towards saving seagrass from dredging. Photo by Anthony Weate/QUT Marketing & Communication.

A new QUT-led study has found ways to detect hidden dangers of repeated stresses on seagrass using statistical modelling.

The research, published by the Journal of Applied Ecology, found cumulative maintenance dredging which affected the light on the sea floor increased risks on seagrass survival. It found, globally, seagrass meadows can be at risk of collapse from accumulated effects of repeated dredging and natural stress.

However, lead researcher QUT's Dr Paul Wu said maintenance dredging programs of one or two weeks (common in Queensland) were unlikely to impact seagrass.

• Seagrass provide shelter and food to marine life, including at-risk species like dugongs and green turtles
• Globally, hundreds of millions of cubic metres of sediment are dredged annually
• Dredging repeated every 1, 2 or 3 years, or for three months or more duration, needs careful management to avoid a loss of resilience
• Latest research builds on recently released research pinpointing 'ecological windows' for timing of dredging

"Our model predicts ahead of time how much repeated stress is too much," Dr Wu said. "Our results show dredging can be successfully managed to maintain healthy seagrass meadows in the absence of other disturbances. The research isn't about stopping dredging. It's about being able to predict how resilient the seagrass will be by incorporating environmental conditions such as storms, cyclones and run-off from agriculture." Dr Wu said port authorities and coastal developers could use the research to support a risk-informed management strategy.

 

Coastal development is commonly associated with dredging, which presents a hazard to ecosystem health via stressors including light degradation and water quality reduction.

"Generally, dredging repeated every one, two or three years, or of three months duration or more, needs careful management to avoid a loss of seagrass resilience," Dr Wu said.

Dr Wu said the development of a risk modelling approach, based on a Bayesian Network, was a tool increasingly applied in ecology.

The findings of the study are specific to hazards and environmental conditions for individual sites.

"For instance, dredging repeated every one, two or three years on a Halophila meadow at Hay Point was predicted to be at risk of losing resilience," he said.

"We developed 960 hazard scenarios including frequency of dredging durations of between one to six months and the level of light stress and the month when dredging occurred."

Dr Wu is an Associate Investigator with the ARC Centre of Excellence for Mathematical and Statistical Frontiers (ACEMS) within QUT's Mathematical and Statistical Sciences Faculty.

Citation: Paul Pao-Yen Wu, Kathryn McMahon, Michael A. Rasheed, Gary A. Kendrick, Paul H. York, Kathryn Chartrand, M. Julian Caley, Kerrie Mengersen; Managing seagrass resilience under cumulative dredging affecting light: Predicting risk using dynamic Bayesian networks; Journal of Applied Ecology, 2017; DOI: 10.1111/1365-2664.13037.

Contact: Debra Nowland, Queensland University of Technology

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Pacific Island countries could lose 50 to 80% of fish in local waters under climate change

Pacific Island nations are highly dependent on fisheries as a food source and for employment. Image by Quentin Hanich.

Many Pacific Island nations will lose 50 to 80 percent of marine species in their waters by the end of the 21st century if climate change continues unchecked, finds a new Nippon Foundation-Nereus Program study published in Marine Policy. This area of the ocean is projected to be the most severely impacted by aspects of climate change.

"Under climate change, the Pacific Islands region is projected to become warmer, less oxygenated, more acidic, and have lower production of plankton that form the base of oceanic food webs," said lead author Rebecca Asch, Nereus Program alumnus and Assistant Professor at East Carolina University. "We found that local extinction of marine species exceeded 50 percent of current biodiversity levels across many regions and at times reached levels over 80 percent."

The Pacific Islands region is the warmest of the global ocean. It's also an area where there is less seasonal variability -- it more or less feels like summer all year. Because there are no drastic seasons, the animals in the tropical Pacific may find changing conditions to be more of a shock.

"Additional warming will push ocean temperature beyond conditions that organisms have not experienced since geological time periods in this region," said co-author Gabriel Reygondeau, Nereus Fellow at UBC. "Since no organisms living in the ocean today would have time to adapt to these warmer conditions, many will either go extinct or migrate away from the western Pacific, leaving this area with much lower biodiversity."

Climate change will be strongly felt in the Pacific Islands, including impacts on fisheries, sea level rise, and extreme weather events. Image by Quentin Hanich.

The authors examined the effects of climate change on more than a thousand species, including those that live on reefs and those that live in open-water habitats. Both groups underwent declines in local biodiversity, but the rates of decline were higher for the open-water species.

These changes would be detrimental to Pacific Islanders, who are highly dependent on marine species for food, economic opportunities, and cultural heritage. Additional threats come from sea level rise and increasing major storms. Also, these are often developing countries with less resources available for societal adaptations to climate change.

"One hopeful point is that the extent of these changes in biodiversity and fisheries was dramatically reduced under a climate change scenario where greenhouse gas emissions were close to what would be needed for achieving the Paris Climate Agreement" said co-author William Cheung, Nereus Director of Science. "As a result, these changes in oceanic conditions are not inevitable, but instead depend on the immediate actions of all countries to materialize their commitment to limit greenhouse gas emissions as is being discussed in COP23 in Bonn, Germany, this week."

Citation: Rebecca G. Asch, William W.L. Cheung, Gabriel Reygondeau; Future marine ecosystem drivers, biodiversity, and fisheries maximum catch potential in Pacific Island countries and territories under climate change; Marine Policy, 2017; DOI: 10.1016/j.marpol.2017.08.015.

Contact: Lindsay Lafreniere
Nippon Foundation-Nereus Program

 

Climate change, sparse policies endanger right whale population

Right whale with her calf. Credit: NOAA.

North Atlantic right whales - a highly endangered species making modest population gains in the past decade - may be imperiled by warming waters and insufficient international protection, according to a new Cornell University analysis published in Global Change Biology.

North Atlantic right whales' preferred cuisine is copepods that thrive in cool waters, such as the Gulf of Maine, said author Erin Meyer-Gutbrod, who conducted the work as a doctoral student and postdoctoral researcher in the laboratory of Charles Greene, professor of oceanography and co-author on the paper.

Scientists once relied on continuous plankton sampling to track the copepods, but the National Oceanic and Atmospheric Administrations' National Marine Fisheries Service discontinued the program, preventing researchers from observing ecosystem changes as they occur.

In the past several years, a smaller portion of the right whale population has been seen in the Gulf of Maine as it has warmed, and the whales have been spotted farther north than usual, in the Canadian Gulf of St. Lawrence, likely in search of the small crustaceans, she said.

Because whales used to be rare in the Gulf of St. Lawrence, northern waterways lack whale protection policies. Without adequate policies the whales are at greater risk from ship traffic and commercial fishing gear.

"Right whales are a highly endangered species with approximately 500 animals remaining," said Meyer-Gutbrod, who now works at the Marine Science Institute at the University of California, Santa Barbara. "This crisis signals a major shift in the whale population's recovery, corresponding to a loss of 3 percent of the right whale population."

"There is a very important interaction between climate change and anthropogenic mortality factors," said Greene. "We must extend whale protections to prevent a major decline in the population."

Citation: Meyer-Gutbrod EL and Greene CH; Uncertain recovery of the North Atlantic right whale in a changing ocean; Global Change Biology (2017) 00:1-10; DOI: 10.1111/gcb.13929.

Contact: Jeff Tyson
Cornell University

 

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A solution to fisheries overharvesting

U of G researchers have developed a model that allows fisheries to net enough to meet rising consumer demand while ensuring adequate income and replenishment of natural stocks.

There are fewer fish in the sea - literally. Consumer demand and inadequate scientific information has led to overharvesting, reducing fish species and fish stocks around the world. But University of Guelph researchers have identified a possible solution. They have developed a model that allows fisheries to net enough to meet rising consumer demand while ensuring adequate income and replenishment of natural stocks. The research was published today in Proceedings of the National Academy of Sciences.

"We know fish are getting rarer," said John Fryxell, a U of G integrative biology professor and lead author of the paper.

Many commercial fisheries are threatened by overharvesting. For example, the collapse of once-abundant cod stocks in the North Atlantic led to a federal fishing moratorium on the species in the 1990s. Managers and fisheries are hampered by a lack of information, from overall population numbers to data on how fast fish grow and reproduce. As the global population increases and demand for fish protein rises - particularly in developing countries - more fisheries are chasing smaller fish populations in hopes of recouping higher prices for their efforts. This further threatens fish stocks that are already being over-exploited, Fryxell said. Finding the "sweet spot" - where the world's fisheries can function all the while protecting natural fish stocks - was the goal of the new model.

"It gives fisheries and conservation managers a tool for balancing those competing demands," he said.

They developed the model using information about landed fish catches and prices for any species to determine by how much a given fishery has been overharvested. Basically, the model encourages fisheries to reduce short-term harvests in order to realize higher long-term yields without sacrificing economic return.

"The model is based on the premise that it's just as profitable to have high catches and low prices as high prices and lower catches," said Fryxell.

That strategy also helps ensure a more sustainable fishery over the long term, he said. Supportive policy changes might include introducing tariffs that make it less profitable to fish low-yielding, high-priced species. Or managers might encourage fish farming to provide alternative protein sources and push down prices of wild stocks, he said.

"We'd have a better world where the fishery is making money, and we're feeding more people with more fish in the ocean."

The research also connects the world's fisheries with U of G's Food From Thought project, Fryxell said.

"It's Food From Thought in a renewable rather than a managed context - how choices impact production, how we manage to make production more sustainable and still provide enough food." Co-authors are integrative biology professor Kevin McCann and other researchers at University of Guelph, McGill University, the University of Washington, and Fisheries and Oceans Canada.

Citation: John M. Fryxell, Ray Hilborn, Carling Bieg, Katrine Turgeon, Amanda Caskenette & Kevin S. McCann; Supply and demand drive a critical transition to dysfunctional fisheries; Proceedings of the National Academy of Sciences, 2017; DOI: 10.1073/pnas.1705525114.

Contact: Prof. John Fryxell
University of Guelph

 

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Scientists find new source of radioactivity from Fukushima disaster

The research team sampled eight beaches in Japan within 60 miles of the crippled Fukushima Dai-ichi Nuclear Power Plant and found high levels of radioactive cesium discharged from the 2011 accident in the brackish groundwater beneath the beaches. The cesium did not constitute a public health concern, but it showed how radioactive material can be transported far from accidents sites, where it attaches to and is stored by sand grains. Photo by Souichiro Teriyaki, Kanazawa University.

By Woods Hole Oceanographic Institution.

Scientists have found a previously unsuspected place where radioactive material from the Fukushima Dai-ichi nuclear power plant disaster has accumulated--in sands and brackish groundwater beneath beaches up to 60 miles away. The sands took up and retained radioactive cesium originating from the disaster in 2011 and have been slowly releasing it back to the ocean.

"No one is either exposed to, or drinks, these waters, and thus public health is not of primary concern here," the scientists said in a study published October 2 in the Proceedings of the National Academy of Sciences. But "this new and unanticipated pathway for the storage and release of radionuclides to the ocean should be taken into account in the management of coastal areas where nuclear power plants are situated."

The research team,Virginie Sanial, Ken Buesseler, and Matthew Charette of Woods Hole Oceanographic Institution and Seiya Nagao of Kanazawa University, hypothesize that high levels of radioactive cesium-137 released in 2011 were transported along the coast by ocean currents. Days and weeks after the accident, waves and tides brought the cesium in these highly contaminated waters onto the coast, where cesium became "stuck" to the surfaces of sand grains. Cesium-enriched sand resided on the beaches and in the brackish, slightly salty mixture of fresh water and salt water beneath the beaches.

But in salt water, cesium no longer "sticks" to the sand. So when more recent waves and tides brought in salty seawater from the ocean, the brackish water underneath the beaches became salty enough to release the cesium from the sand, and it was carried back into the ocean.

"No one expected that the highest levels of cesium in ocean water today would be found not in the harbor of the Fukushima Dai-ichi nuclear power plant, but in the groundwater many miles away below the beach sands," said Sanial.

The new study revealed a previously unsuspected pathway for radioactive material to be transported, stored for years, and subsequently released far from the site where it was initially discharged. llustration by Natalie Renier, Woods Hole Oceanographic Institution.

The scientists estimated that the amount of contaminated water flowing into the ocean from this brackish groundwater source below the sandy beaches is as large as the input from two other known sources: ongoing releases and runoff from the nuclear power plant site itself, and outflow from rivers that continue to carry cesium from the fallout on land in 2011 to the ocean on river-borne particles. All three of these ongoing sources are thousands of times smaller today compared with the days immediately after the disaster in 2011.

The team sampled eight beaches within 60 miles of the crippled Fukushima Dai-ichi Nuclear Power Plant between 2013 and 2016. They plunged 3- to 7-foot-long tubes into the sand, pumped up underlying groundwater, and analyzed its cesium-137 content. The cesium levels in the groundwater were up to 10 times higher than the levels found in seawater within the harbor of the nuclear power plant itself. In addition, the total amount of cesium retained more than 3 feet deep in the sands is higher than what is found in sediments on the seafloor offshore of the beaches.

Cesium has a long half-life and persists in the environment. In their analyses of the beaches, the scientists detected not only cesium-137, which may have come from the Dai-ichi plant or from nuclear weapons tested in the 1950s and1960s, but also cesium-134, a radioactive form of cesium that can only come only from the 2011 Fukushima accident.

The researchers also conducted experiments on Japanese beach samples in the lab to demonstrate that cesium did indeed "stick" to sand grains and then lost their "stickiness" when they were flushed with salt water.

"It is as if the sands acted as a 'sponge' that was contaminated in 2011 and is only slowly being depleted," said Buesseler.

"Only time will slowly remove the cesium from the sands as it naturally decays away and is washed out by seawater," said Sanial.

"There are 440 operational nuclear reactors in the world, with approximately one-half situated along the coastline," the study's authors wrote. So this previously unknown, ongoing, and persistent source of contamination to coastal oceans "needs to be considered in nuclear power plant monitoring and scenarios involving future accidents."

Citation: Virginie Sanial, Ken O. Buesseler, Matthew A. Charette, and Seiya Nagao; Unexpected source of Fukushima-derived radiocesium to the coastal ocean of Japan; PNAS (October 2, 2017); DOI: 10.1073/pnas.1708659114.

 

Hurricane exposes and washes away thousands of sea turtle nests

Hurricane Irma storm surge takes heavy toll on one of world's most important nesting areas.

Hurricane Irma took a devastating toll on incubating sea turtle nests in the Archie Carr National Wildlife Refuge, one of the most important loggerhead and green turtle nesting sites in the world, according to new estimates from the UCF Marine Turtle Research Group.

Researchers found significant dune erosion that swept away some nests and exposed the eggs of others. It was a record year for green turtle nesting along the refuge's beaches in southern Brevard County, but storm surge due to hurricane Irma destroyed many unhatched loggerhead and green turtle nests. University of Central Florida researchers estimate that of nests laid through the end of September, more than half of the season's green turtle nests and a quarter of loggerhead nests were lost.

Both species are listed as threatened under the U.S. Endangered Species Act, and Florida hosts the majority of both species' U.S. nests. The section of the Archie Carr National Wildlife Refuge monitored by UCF hosts about a third of the Florida's green turtle nests.

"Last year with Hurricane Matthew, we lucked out because it was a low green turtle year," said Kate Mansfield, assistant professor and director of the UCF Marine Turtle Research Group, noting that green turtles typically have alternating high and low nesting years. "This year was an extraordinarily exciting year for green turtle nesting, breaking all previous records within the refuge and continuing the conservation success story for the species. Unfortunately, we had another big hurricane this year, highlighting the need for continued conservation efforts in the area."

Green turtles set a new record in 2017, laying 15,744 nests in the sands of the 13 miles of the Brevard County portion of the Archie Carr National Wildlife Refuge monitored by UCF. An estimated 8,830 of those were lost to the storm. Green turtles nest later in the season than other species, so many of their eggs hadn't hatched by the time Irma hit. Some 56 percent of total green nests were lost, an estimated 81 percent of those that were still incubating.

Along the same stretch of beach, loggerheads laid 9,690 nests in 2017, but most had already hatched when Irma passed through the region. Still, an estimated 2,290 loggerhead nests were lost. That's 24 percent of the total loggerhead nests and 91 percent of those that were still incubating when hurricane-driven storm surge came ashore.

The refuge is located at the northern extent of dense leatherback nesting in Florida, but the species nest in far fewer numbers, laying just 23 nests in 2017 within the portion of the refuge monitored by UCF. But they nest earlier than greens and loggerheads, and all of the leatherback nests had finished incubating before the hurricane.

UCF also monitors another 16.4 miles of beaches north of the wildlife refuge, at Patrick Air Force Base and in central Brevard County. Considerably fewer nests are laid there than in the Archie Carr National Wildlife Refuge, but the numbers are still high compared to many other parts of the country. On those beaches, an estimated 642 of 2,251 green turtle nests and 831 of 6,229 loggerhead nests were lost due to the hurricane.

The UCF Marine Turtle Research Group also found evidence that some green turtle hatchlings have emerged since the hurricane. And some turtles have continued to come ashore and lay new nests. Within the wildlife refuge, 466 new green turtle nests and eight new loggerhead nests were laid in September following Irma. Along the other UCF-monitored beaches, 72 new green nests and three new loggerhead nests were laid. Still, the nests aren't out of danger.

"Green turtles are still nesting, but recent extremely high tides have likely wiped out many of those new nests, too," said Erin Seney, an assistant research scientist with the UCF group. "The good news is that the nesting habits of sea turtles do protect them from large-scale nest loss and make them more resilient to this kind of event. They lay multiple nests per nesting season, roughly every other year for 30 years or more."

UCF researchers have run a sea turtle monitoring and research program on the beaches of the Archie Carr National Wildlife Refuge in southern Brevard County for 35 years. Their findings about sea turtle nesting activity are among the reasons the refuge was created in 1991. Last year, the university and the U.S. Fish and Wildlife Service signed a landmark agreement that formalized UCF's use of refuge facilities and established a protocol that will allow UCF to build research facilities and a plan that will give UCF oversight of the facilities for 40 years or more.

Nest Counts and Loss Estimates

UCF's portion of the Archie Carr National Wildlife Refuge (21 km) - nest totals through Sept. 30

• Loggerheads - 9,690 nests (8 new since Irma)
• Green turtles* - 15,744 nests (466 new since Irma)
• Leatherbacks - 23 nests (0 new since Irma)
• *Green turtle total is a new record, breaking the previous record of 12,905 green turtle nests in 2015.

Estimated Irma-related nest loss on UCF's portion of the Archie Carr National Wildlife Refuge

• Loggerheads - 2,299 nests lost (=91% of nests that were still incubating, 24% of nests laid through Sept. 30)
• Green turtles (nest latest in the season) - 8,830 nests lost (=81% of nests that were still incubating, 56% of nests laid through Sept. 30)
• Leatherbacks (nest earliest in the season) - 0 nests lost

UCF's "other beaches" (PAFB and Central Brevard - combined 26.5 km) - combined nest totals through Sept. 30

• Loggerheads - 6,229 nests (3 new since Irma)
• Green turtles - 2,251 nests (72 new since Irma)
• Leatherbacks - 6 nests (0 new since Irma)

Estimated Irma-related nest loss on PAFB+Central Brevard

• Loggerheads - 831 nests lost (=96% of nests that were still incubating, 13% of nests laid through Sept. 30)
• Green turtles - 642 nests lost (=51% of nests that were still incubating, 29% of nests laid through Sept. 30)
• Leatherbacks - 0 nests lost

To support sea turtle research at UCF, please visit this link.

Contact: Rachel Williams
University of Central Florida