By 2300, climate change may cause fishery yields to decline by as much as 20% around the globe, and by as much as 60% in the North Atlantic, a new modeling study suggests.
The study primarily attributes this decline to a lack of ocean mixing, such that nutrients sink into the deep ocean instead of staying at the ocean surface; such alterations to ocean mixing would ultimately drive a decline in fish populations near the surface, the authors say. Climate change models consistently estimate that fisheries will decline by the end of this century, yet there have been few efforts to explore what changes might occur beyond 2100. Here, J. Keith Moore and colleagues used modeling to explore the effects of climate change on fisheries under a "business-as-usual" scenario whereby carbon emissions continue apace, at the same level as they are now.
The Southern Ocean currently experiences mixing between the bottom and top oceanic layers, delivering such a substantial amount of nutrients to the surface that an abundance flows into other oceans. However, simulations by Moore et al. suggest that a combination of changing winds and warmer upper oceanic layers, plus a poleward shift of nutrient upwelling in the Antarctic, will cause an increased portion of nutrients to sink into the deeper layer of the ocean and become trapped there (for example, the amount of phosphate being upwelled will be reduced by 41%, the model estimates). This will reduce the delivery of nutrients to other oceanic areas, they note. While ocean warming and stratification will increase globally, deep mixing in the North Atlantic will be particularly reduced, the authors find. They note that the long-term effects of these changes mean that fisheries will be reduced for a thousand years or more.
A new partnership between Global Fishing Watch and NOAA matches night-time imagery with monitoring data from fishing vessels.
Arufura Sea, January, 2018. Vessel Monitoring System (VMS) data from Indonesia is shown in the Global Fishing Watch map as yellowish dots. This image is overlayed with data from NOAA's satellite-based Visible Infrared Imaging Radiometer Suite (VIIRS) which detects many vessels not broadcasting VMS. VIIRS-detected vessels are shown here as blue sailboats. Credit: Global Fishing Watch 2018.
Global Fishing Watch has entered into a new data-sharing partnership with the U.S. National Oceanic and Atmospheric Administration (NOAA) to improve understanding of the activity of fishing vessels in Indonesian waters. Through the partnership, Global Fishing Watch and NOAA are matching Vessel Monitoring System (VMS) data from the Indonesian government with NOAA's satellite based Visible Infrared Imaging Radiometer Suite (VIIRS), which reveals the locations of brightly lit vessels at night. The idea is to identify fishing vessels that are not picked up by other monitoring systems and to test and refine the use of VIIRS for identifying and distinguishing different types of fishing vessels.
By cross matching VMS from Indonesia with VIIRS, the team found that roughly 80 percent of VIIRS detections could not be correlated to a vessel broadcasting VMS. The vast majority of these vessels are likely to be fishing vessels using bright lights to attract fish. While a small number may be other types of vessels, most ships do not use lights bright enough for detection. This work indicates that the addition of VIIRS data can greatly enhance transparency in commercial fishing in Indonesia.
The team believes most of the VIIRS detections are from fishing vessels not required to carry VMS because they are under the 30 gross ton (GT) threshold established by the government of Indonesia. It is also possible that some vessels detected only by VIIRS meet the size requirement but have switched off their VMS or have a faulty device. Another possibility is that VIIRS is detecting foreign boats that are not carrying VMS because they are poaching from Indonesian waters.
On the left, blue boats represent vessels detected by NOAA's satellite-based Visible Infrared Imaging Radiometer Suite (VIIRS) over the Arufura Sea on January, 2018. On the right, yellow dots represent active fishing vessels using Indonesia's Vessel Monitoring System plotted on the Global Fishing Watch map. About 80 percent of VIIRS-detected vessels do not broadcast VMS, and so combining the two data sources provides a more complete picture of fishing activity in Indonesia. Credit: Global Fishing Watch 2018.
"I'm excited for this opportunity to see the dark fleet," said David Kroodsma, Global Fishing Watch Research Program Director. The dark fleet being a common term used to describe vessels that don't show up in vessel monitoring systems and therefore are said to operate in the dark. "NOAA's VIIRS data shows us vessels we can't see by any other means and helps us to gain a more complete picture of fishing activity."
Global Fishing Watch detects nearly all large fishing vessels in Indonesian waters by combining Indonesia's VMS data and publicly broadcast AIS data which is required on vessels exceeding 300 GT. Global Fishing Watch can even tell when vessels turn off their monitoring devices. But the system is unable to see vessels when they are not broadcasting either AIS or VMS. Incorporating VIIRS, which represents a completely new source of data, into the Global Fishing Watch database and, eventually, the public mapping platform, will reveal the activity of even more of the world's commercial fishing fleet.
To cross match VMS and VIIRS, NOAA's Earth Observation Group developed an orbital model that predicts the probable location of each VMS-broadcasting vessel at the time of the VIIRS data collection. The model checks the predicted location against the actual VIIRS detections to define matches. Prior to the partnership with Global Fishing Watch, NOAA had access to two months of Indonesia VMS data, which they used to develop their cross-matching algorithm.
The partnership with Global Fishing Watch has provided three years-worth of Indonesian VMS data, which NOAA has now matched to its VIIRS vessel detections. In addition, the partnership has provided NOAA with valuable information on vessel gear types and identification numbers in the VMS records.
Arufura Sea, January, 2018. Comparing Vessel Monitoring System (VMS) data from Indonesia with satellite-based Visible Infrared Imaging Radiometer Suite (VIIRS) data reveals a more complete picture of fishing activity in Indonesia. Credit: Global Fishing Watch 2018.
This new data is enabling NOAA to calculate the frequency of VIIRS boat detections for the different fishing gear types and to work towards a calibration for estimating wattage from the VIIRS detected radiance. "When I saw what Global Fishing Watch could provide in the data, I said, Wow, that could really help us a lot, because we don't have access to this information in any other way," said Chris Elvidge, NOAA's Earth Observation Group Lead. His team is creating an atlas of fishing grounds for Indonesia using the three years of VMS provided by Global Fishing Watch and multiple years of VIIRS data.
Global Fishing Watch is able to provide the VMS data because of its partnership with Indonesia, which began publicly sharing their VMS through the Global Fishing Watch platform in June 2017. They are the first nation to take such bold steps toward transparency, and Peru has recently signed an MOU to do the same.
Now that Global Fishing Watch has access to the VIIRS boat detection data they can vastly expand the number of fishing boat records reported in the public database. In addition, it would be possible to cross match VMS or AIS data with VIIRS boat detections to identify "dark vessels" which may be fishing illegally. The combined data sources could also be analyzed to detect clusters of fishing boats straddling international boundaries, or fishing in Marine Protected Areas.
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.
Indigenous fisher spearfishing in Indonesia. Credit: Swansea University.
Writing in the Journal Fish & Fisheries, Dr Richard Unsworth of Swansea University (together with colleagues at Cardiff University and Stockholm University) examine the global extent to which these meadows of underwater plants support fishing activity.
"Wherever seagrass exists in proximity to people, our research finds that it's used as a key targeted fishing habitat" said Dr Unsworth, who is based at Swansea University's Biosciences department.
"Our research is for the first time recording how globally extensive the use of seagrass meadows as a fishery habitat is. In developing countries this activity tends to have a major significance for daily food supply and general livelihoods. In developed countries the role of this activity is more for recreation or species specific targeted fisheries (e.g. clams)."
Dr Nordlund from Stockholm University added "The ecological value of seagrass meadows is irrefutable, yet there loss continues at an accelerating rate. Now there is growing evidence globally that many fisheries associated to seagrass are unrecorded, unreported and unmanaged, leading to a tragedy of the seagrass commons".
In their article, the researchers highlight that because of their nearshore, shallow water distribution in sheltered environments seagrass meadows make great places to fish in all conditions. This leads to high intensity of fishing effort often all year round.
The authors have studied seagrass fisheries all around the world from the Philippines, to Zanzibar, Indonesia, the Turks & Caicos Islands and locations in the Mediterranean. They have found many similarities in the types of fishing gear used the major animal families that are fished and the extent of effort focused in these sensitive habitats.
Even in small seagrass meadows in Wales fishers can be seen targeting shrimp at low tide and placing gill nets to catch Bass. By providing a three-dimensional structure in an otherwise barren sea, seagrasses provide the perfect hiding place for fish and invertebrates such as crabs, shrimp and clams. This abundance of animal life is what attracts fishers.
"It is important that more recognition is given to the value of these habitats for supporting fisheries as they're being damaged and degraded globally." said Dr Cullen-Unsworth (Cardiff University), one of the co-authors who is also director of the marine conservation charity Project Seagrass who are working to highlight the importance and plight of these sensitive marine habitats.
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."
Fish biomass up to five times greater compared to unprotected zones at northernmost reefs.
This is the Agincourt Reef, Great Barrier Reef, Queensland, Australia. Credit: Robert Linsdell (CC-BY).
Protected zones of the Great Barrier Reef benefit fish even at the relatively lightly-fished northern reefs, according to a study published November 8, 2017 in the open-access journal PLOS ONE by Carolina Castro-Sanguino from the University of Queensland, Australia, and colleagues.
The Australian Great Barrier Reef Marine Park is the largest network of marine reserves in the world, and includes both 'no fishing' ('no-take') and 'no-entry' zones as well as fished areas. The authors of the present study analyzed the effect of such policies in the relatively lightly-fished northernmost regions. They measured, counted and calculated the biomass of commonly-fished species found at 31 northern, central and southern reefs in the area north of Cooktown, as well as assessing the seabed habitat at these sites.
The authors found that fish biomass was up to five times greater in protected zones which prevented fishing, whether they had 'no-take' or 'no-entry' policies. The most remote northern reefs had greater fish biomass than more southern zones, regardless of the zones' policies, and the authors speculate that poaching may be common in southern reserves. They also found indication that fishers may frequently operate at reserves' boundaries to exploit the increased fish biomass in these reserves.
The specific seabed habitat of different reefs had a strong effect on the amounts and types of fish found, making it impossible for the researchers to discern any distinct effects of 'no-take' versus 'no-entry' policies. Nonetheless, they did find clear differences in biomass between protected and unprotected areas, despite this region being generally fished relatively lightly. They state that this illustrates the high sensitivity to fishing of many species, reinforcing the case for their protection.
"Even in remote reef habitats, marine reserves increase the biomass of exploited fish but detecting these benefits can be challenging because the state of corals also varies across some management zones and these patterns also affect fishes," says Castro-Sanguino. "We also conclude that fishing is most intense near reserve borders leading to a reduction of biomass just outside reserves."
The Khaled bin Sultan Living Oceans Foundation designed the study in consultation with PJM and implemented the collection of the data, curation and quality control of data in collaboration with the co-authors. They also funded CCS to undertake the analysis and collaborated on the preparation of the manuscript. This study was a component of the Khaled bin Sultan Living Oceans Foundation Global Reef Expedition (2011-2015).
A new 6 million euro project funded by the EU's Horizon 2020 program examines jellyfish as a commercial product.
Cotylorhiza tuberculata is sometimes called the fried egg jellyfish. Credit: Tihomir Makovec.
Global climate change and the human impact on marine ecosystems have led to dramatic decreases in the number of fish in the ocean. It has also had an unforseen side effect: because overfishing decreases the numbers of jellyfish competitors, their blooms are on the rise.
The GoJelly project, coordinated by the GEOMAR Helmholtz Centre for Ocean Research, Germany, would like to transform problematic jellyfish into a resource that can be used to produce microplastic filters, fertilizer or fish feed. The EU has just approved funding of EUR 6 million over 4 years to support the project through its Horizon 2020 programme.
Rising water temperatures, ocean acidification and overfishing seem to favor jellyfish blooms. More and more often, they appear in huge numbers that have already destroyed entire fish farms on European coasts and blocked cooling systems of power stations near the coast. A number of jellyfish species are poisonous, while some tropical species are even among the most toxic animals on earth.
"In Europe alone, the imported American comb jelly has a biomass of one billion tons. While we tend to ignore the jellyfish there must be other solutions," says Jamileh Javidpour of GEOMAR, initiator and coordinator of the GoJelly project, which is a consortium of 15 scientific institutions from eight countries led by the GEOMAR Helmholtz Centre for Ocean Research in Kiel.
The project will first entail exploring the life cycle of a number of jellyfish species. A lack of knowledge about life cycles makes it almost impossible to predict when and why a large jellyfish bloom will occur. "This is what we want to change, so that large jellyfish swarms can be caught before they reach the coasts," says Javidpour.
At the same time, the project partners will also try to answer the question of what to do with jellyfish once they have been caught. One idea is to use the jellyfish to battle another, man-made threat.
"Studies have shown that the mucus from jellyfish can bind microplastic. Therefore, we want to test whether biofilters can be produced from jellyfish. These biofilters could then be used in sewage treatment plants or in factories where microplastic is produced," the GoJelly researchers say.
Jellyfish can also be used as fertilizers for agriculture or as aquaculture feed. "Fish in fish farms are currently fed with captured wild fish, which does not reduce the problem of overfishing, but increases it. Jellyfish as feed would be much more sustainable and would protect natural fish stocks," says the GoJelly team.
Chrysaora hysoscella, also called the compass jellyfish, is common in the waters of the Atlantic and the Mediterranean. Credit: Tihomir Makovec.
Another option is using jellyfish as food for humans. "In some cultures, jellyfish are already on the menu. As long as the end product is no longer slimy, it could also gain greater general acceptance," said Javidpour. Finally yet importantly, jellyfish contain collagen, a substance very much sought after in the cosmetics industry.
Project partners from the Norwegian University of Science and Technology, led by Nicole Aberle-Malzahn, and SINTEF Ocean, led by Rachel Tiller, will analyse how physical characteristics (hydrography, temperature), biological characteristics (abundance, biomass, ecology, reproduction) and biochemical parameters (stoichiometry, food quality) affect the initiation of jellyfish blooms.
Based on a comprehensive analysis of triggering mechanisms, origin of seed populations and ecological modeling, the researchers hope to be able to make more reliable predictions on jellyfish bloom formation of specific taxa in the GoJelly target areas. This knowledge will allow sustainable harvesting of jellyfish communities from various Northern and Southern European populations.
This harvest will provide a marine biomass of unknown potential that will be explored by researchers at SINTEF Ocean, among others, to explore the possible ways to use the material.
A team from SINTEF Ocean's strategic program Clean Ocean will also work with European colleagues on developing a filter from the mucus of jellyfish that will capture microplastics from household products (which have their source in fleece sweaters, breakdown of plastic products or from cosmetics, for example) and prevent these from entering the marine ecosystem.
Finally, SINTEF Ocean will examine the socio-ecological system and games, where they will explore the potentials of an emerging international management regime for a global effort to mitigate the negative effects of microplastics in the oceans.
"Jellyfish can be used for many purposes. We see this as an opportunity to use the potential of the huge biomass drifting right in front of our front door," Javidpour said.
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."
"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.
When the Fukushima power plant released large quantities of radioactive materials into nearby coastal waters following Japan's massive 2011 earthquake and tsunami, it raised concerns as to whether eating contaminated seafood might impair human health--not just locally but across the Pacific.
A new study by an international research team shows that those concerns can now be laid to rest, at least for consumption of meat from migratory marine predators such as tuna, swordfish, and sharks.
The team focused on cesium, a silvery metal with a large number of radioactive isotopes. Two of these, 134Cs and 137Cs, form when uranium fuel breaks down in nuclear reactors. The cesium isotopes are of particular concern because they were discharged in large quantities following the disaster, exhibit relatively long half-lives (2.1 and 30 years respectively), and tend to accumulate in the muscle tissues that people like to eat.
However, the team's sampling of tissues from predatory fishes and other large vertebrates collected across the northern Pacific between 2012 and 2015 revealed no detectable levels of 134Cs, and 137Cs concentrations that were generally consistent with background levels from aboveground nuclear testing during the 1940s and 50s. They collected the animals from waters near Japan, Hawaii, and California.
Lead author Daniel Madigan of Harvard University says, "Our measurements and associated calculations of how much radioactive cesium a person would ingest by eating this seafood shows that impacts to human health are likely to be negligible. For marketed fish to be restricted from trade, the cesium levels would have to be more than 1,600 times higher than in any samples we measured."
Co-author Kevin Weng, an assistant professor at William & Mary's Virginia Institute of Marine Science, participated in the study by collecting fish samples in waters around Oahu and a remote seamount. He says, "Go ahead and eat some sushi! Our work shows that radioactivity from the Fukushima disaster is very low in open-ocean vertebrates."
Also contributing to the study were Zofia Baumann and Nicholas Fisher of Stony Brook University; Owyn Snodgrass, Heidi Dewar, and Peter Dutton of NOAA's Southwest Fisheries Science Center; Michelle Berman-Kowalewski of the Channel Islands Cetacean Research Unit; and Jun Nishikawa of Tokai University.
The researchers undertook their analysis partly in response to earlier studies by Madigan and colleagues showing elevated levels of radioactive cesium in bluefin and albacore tuna caught off the California coast shortly after the Fukushima disaster--evidence that these fishes had swum almost 6,000 miles in less than two months. (It took ocean currents more than two years to deliver much-diluted cesium from Fukushima to those same waters.)
Although this early work focused on the utility of cesium isotopes as a happenchance tool that could help scientists characterize migratory patterns among a group of heavily exploited commercial fishes, public attention focused on perceived risks to human health.
"The earlier studies showed extremely low risks from cesium to anyone eating these migratory species, but public concern persisted," says Weng. That concern also expanded to include not only the species of tuna in which cesium had been measured, but to other fishes, marine mammals, and sharks.
"People were very concerned about North Pacific salmon, halibut and scallops off British Columbia, and sea lions in Southern California," says Madigan. "There was even information on the Internet that 'the Pacific is dead'."
"One goal of our study," he says, "was to put these perceived risks in context by surveying a broad range of vertebrate species across the entire North Pacific for the presence or absence of Fukushima-derived radiocesium. Our results, which show very low or undetectable levels in these animals, are important both for public perception of seafood safety and for scientific understanding of radionuclide transfer."
The authors suggest that scientists and funding agencies should look for at least one silver lining in any future nuclear or industrial accidents. "We can and should use future point sources of contamination, radioactive or otherwise, to shed new light on migratory dynamics of pelagic species that are poorly understood, heavily exploited, or of high conservation concern," says Madigan. "But we would need to act quickly, within that narrow opportunistic timespan."
The Oceans Meetings brings together a panel of experts and country leaders committed to the oceans' future.
The Portuguese Minister of the Sea hosts more than 50 country delegations and international organizations
Speakers include Carlos Moedas, European Commissioner for Research, Science and Innovation and Vladimir Ryabinin, Executive Secretary of the Intergovernmental Oceanographic Commission (IOC-UNESCO)
Countries are committed to change our oceans' governance practices
By the initiative of the Portuguese Government and of the Minister of the Sea, Ana Paula Vitorino, the Oceans Meeting will be held in Lisbon between 7th and 8th September. More than 50 country delegations and international organizations will attend the international forum. During the Oceans Meeting the following events will take place: a high-level meeting with ministers and government representatives, an international conference and business meetings. The Oceans Meeting gives a new expression to a global movement led by Portugal, which is intended to be extended to more countries with oceanic connections and who are fully aware of the need to preserve the resources of the sea and contribute to a better maritime environment. Through an interdisciplinary approach, the primary objective of this event is to bring together experts and political leaders to discuss common international policies for the Ocean. Oceans' pollution is one of the top priority problems that needs to be addressed. The abusive and undue use of the sea as a garbage dump as well as other inorganic products, represent serious risks to the subsistence of marine fauna and flora. Most importantly, they constitute a threat to human life that must be fought while preserving the oceans and the well-being of people.
Portugal, a country with long maritime traditions and with an ongoing process of extension of its continental shelf, has responsibilities and obligations in guaranteeing the sustainability of the oceans. Therefore, the country wants to lead a high level international movement that works toward the sustainable use of the oceans, in an inclusive and joint manner.
A polluted and improperly used sea, with higher concentrations of heavy materials and plastic particles, means less oxygen in the air that we breathe and a lower quality of the marine resources that we consume.
Marine pollution has a direct impact on human life through chemicals, toxins and on other harmful microparticles in the ocean water.
The international conference taking place in parallel to the forum's inter-ministerial meeting will focus on the topic «Oceans and Human Health» and will feature the interventions of Carlos Moedas, European Commissioner for Research, Science and Innovation and Vladimir Ryabinin, Executive Secretary of the Intergovernmental Oceanographic Commission (IOC-UNESCO).
Leonor Beleza, President of the Champalimaud Foundation, Lora Fleming, Director of the European Centre for Environment and Human Health and Lasse Gustavsson, Executive Director in Europe for Oceana, are others of the renowned experts attending the conference.
The high-level speakers present in Lisbon reveal the importance of the oceans' sustainability topic. Their presence also shows that there is a growing awareness of the need to take urgent measures that can defend the sea from the abuses and pressures of a modern society, that thinks in the immediate and does not project itself in the future.
«Portugal is conscious of the risks posed to the oceans. We are creating a mobilizing movement for maritime countries that understand the importance of clean oceans and that, together, can develop the necessary measures to leave future generations a healthier and more productive sea», says the Minister of the Sea, Ana Paula Vitorino.
«This is not rhetoric, we want action in a movement that will expand in the future to countless other countries with concerns about the sustainable use of the oceans», she added.
The inter-ministerial meeting, chaired by Ana Paula Vitorino, will be attended by ministers from various coastal states, namely the CPLP, from Mediterranean countries as well as from Europe and the North Atlantic. At the end, a declaration of intent will be adopted by the countries represented at the Lisbon meeting.
«We have a responsibility to safeguard the future of the oceans. By doing so, we are contributing to a better human development», said the Minister of the Sea, Ana Paula Vitorino, stressing the importance of the Oceans Meeting bringing together more than 50 country delegations and international organizations committed to the future of the oceans and, consequently, of humanity.
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.