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Subantarctic seabed creatures and past climate

Subantarctic seabed creatures and past climate | Marine Science and Environment | Scoop.it
A new marine biodiversity study in one of the largest Marine Protected Areas in the world reveals the impact of environmental change on subantarctic seabed animals and answers big questions about the extent of South Georgia’s ice sheet during the Last Glacial Maximum around 20,000 years ago. 

 Reporting this week in the Journal of Biogeography researchers at British Antarctic Survey (BAS) describe how colonies of seabed creatures, such as sea sponges – that play an important role in absorbing and storing carbon from the atmosphere – can take thousands of years to recover from major glaciation events. 
 
A key ambition for the study was to use biology to investigate two conflicting theories about the extent of ice cover during the period when the ice sheet was at its greatest extent. Whilst some researchers estimate the sheet was largely confined to fjords around the subantarctic island of South Georgia, others suggest it could have extended across the continental shelf. 

 This new study suggests an intermediate cover. The ice sheet probably extended over most of the continental shelf (covering an area of 40,000km2), but some of the eastern sector and troughs in the shelf appear to have remained ice free. There is evidence that seabed creatures survived in the ice-free zones whilst in other areas they were removed by grounded ice. 

 The scientists used an underwater camera lander and a trawl to survey seabed fauna around the continental shelf. They found the fauna was richer at the edge where the advancing ice sheet had transported boulders, rocks and sediments (areas known as moraines). This process could have potentially bulldozed all seabed life off the continental shelf. Only animals at the outer edge, on these moraines, were able to survive.

Lead author David Barnes, from BAS, says: “Biology can tell us a lot about ice sheet extent during the last glaciation and the survival of ocean ecosystems. Remarkably it seems that most seabed species, especially the less mobile ones, have not moved far back to recolonize the coast the inner shelf and coastal areas despite having thousands of years to recover. Only the more mobile species such as Antarctic sea spiders and brittle-stars have managed to make their way back. It is reasonable to conclude that most of the continental shelf is still undergoing recolonisation 20,000 years after the grounded ice started to retreat.” 

Co-author, Chester Sands, a molecular ecologist at BAS, says there are considerable implications for marine conservation: “This study gives us a clearer understanding about this important Southern Ocean ecosystem. This subantarctic region is biologically diverse and an important habitat for rare and endemic species. Long-term conservation monitoring plans will benefit from this new knowledge.” 

Funding for this research came from the UK’s Darwin Initiative. Deployments of the underwater camera and trawls took place during the 2011 and 2013 research cruises of the RRS James Clark Ross. The paper: “Biodiversity signature of the Last Glacial Maximum at South Georgia, Southern Ocean” by David Barnes, Chester Sands, Oliver Hogg, Ben Robinson, Rachel Downey and James Smith is published by the Journal of Biogeography.
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Mass coral death drives efforts to identify resilient reefs

Mass coral death drives efforts to identify resilient reefs | Marine Science and Environment | Scoop.it

It has been a bleak year for the world’s coral. Ecologists have watched in horror as unusually warm ocean temperatures have prompted corals to ‘bleach’, or expel the symbiotic algae that provide much of their food. The result has been death and damage to reefs from Kiribati in the Pacific to the Indian Ocean's Maldives. With such episodes projected to occur more often even if climate change is mitigated, researchers are redoubling efforts to identify the factors that can make a reef resilient to harsh conditions. 


An analysis published this week in Nature points to some answers1. The study identifies 15 ‘bright spots’ where ecosystems are in a much better shape than researchers had predicted they should be. These include unpopulated, unfished regions such as the Chagos Islands in the Indian Ocean, and areas that are close to towns and where fishing takes place — such as Kiribati and the Solomon Islands, also in the Pacific. The study also pinpoints 35 ‘dark spots’ where conditions were surprisingly poor, such as Montego Bay in Jamaica and Lord Howe Island between Australia and New Zealand.


The research team, led by Joshua Cinner, a social scientist who studies coral-reef systems at the Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University in Townsville, Australia, based its analysis on data that describe conditions at more than 2,500 reefs. The researchers used information on a reef’s habitat, depth, nearby human population and amount of fishing to model how many fish could live at each site. The bright spots shared several characteristics, including high levels of local engagement in resource management, high dependence on local marine resources, and protective cultural taboos — such as excluding fishers from outside the local village. 


 Cinner’s work also suggests that the proximity of urban centres is a key driver of change in marine systems. It can damage reef systems that seem to be performing well to the naked eye, such as sites in the northwestern Hawaiian Islands that are part of a well-policed marine reserve but are still classified as a dark spot. “Marine reserves will never be enough,” says Cinner, who presented his results on 6 June at a meeting in London organized by the Central Caribbean Marine Institute. Instead, he says, the creation and maintenance of reserves should be coupled with other efforts to reduce threats to reefs. 


 Emily Darling, a marine conservation scientist at the Wildlife Conservation Society, an environmental group in New York, calls the study impressive. “It’s absolutely a novel approach that brings together ecological and social information, and bridges approaches from human health and development to conservation,” she says. “Identifying what conditions create bright spots is incredibly hopeful for coral-reef conservation and sustainable fisheries.” 


Cinner's work was among a number of coral studies presented at last week's meeting, which aimed to shake up the community of scientists who study corals, and catalyse a push for solutions to the avert the decline of these ecosystems. Terry Hughes, director of the coral-reef centre at James Cook University, says that the 2016 bleaching events have given researchers new motivation to seek solutions. “They’re seeing a level of damage they haven’t seen before.” He argues that current methods to promote reef sustainability are falling short. Even Australia’s Great Barrier Reef, widely considered to be the best-managed reef ecosystem in the world, is suffering. 


The latest estimate from Hughes’s centre, released on 30 May, suggests that this year’s bleaching has killed 35% of corals at 84 survey sites on the northern and central Great Barrier Reef. Gareth Williams, who researches remote reefs from Bangor University, UK, told the meeting that modelling work currently under review suggests that even if the world manages to reduce its greenhouse-gas emissions, many reefs will bleach annually by 2030. Corals can recover from mild to moderate bleaching, but severe bleaching is deadly and repeated bleaching will likely cause drastic changes to the ecosystem in the long term.“I don’t think we can save them all,” Williams said. “Some reefs are just going to go. Investing in those will be a waste of time and resources.” 


Many participants at the meeting agreed that the research community needs to shift from cataloguing the decline of reefs to finding ways to encourage their resilience to climate change. “We’ve stood by for the last 25 years trying to understand what’s happening and watching coral reefs die globally,” said Carrie Manfrino, research director at the Cayman Islands-based Central Caribbean Marine Institute, which organized the meting. What’s needed now, she told the audience, is “to establish a new road map that can give us a future”. 


 Tom Frazer, a meeting attendee and director of the School of Natural Resources and Environment at the University of Florida in Gainsville, says that it is a positive sign that there are some reefs that have proven to be resilient to human-induced change or to have recovered from disturbances such as bleaching or cyclones. “These are bright spots and provide hope for the future,” said Frazer — adding that social factors such as behavioural change and innovative governance for marine systems are going to be “absolutely essential” to saving reefs. 


 Nature doi:10.1038/nature.2016.20080

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Experiment 'turns waste CO2 to stone'

Experiment 'turns waste CO2 to stone' | Marine Science and Environment | Scoop.it
Scientists think they have found a smart way to constrain carbon dioxide emissions - just turn them to stone. The researchers report an experiment in Iceland where they have pumped CO2 and water underground into volcanic rock. 

Reactions with the minerals in the deep basalts convert the carbon dioxide to a stable, immobile chalky solid. Even more encouraging, the team writes in Science magazine, is the speed at which this process occurs: on the order of months. "Of our 220 tonnes of injected CO2, 95% was converted to limestone in less than two years," said lead author Juerg Matter from Southampton University, UK. "It was a huge surprise to all the scientists involved in the project, and we thought, 'Wow! This is really fast'," he recalled on the BBC's Science In Action programme.

With carbon dioxide concentrations in the atmosphere marching ever upwards and warming the planet, researchers are keen to investigate so called "carbon capture and storage" (CCS) solutions. Previous experiments have seen pure CO2 injected into sandstone, or deep, salty aquifers. Chosen sites - which have included disused oil and gas wells - have relied on layers of impermeable capping rocks to hold down the carbon dioxide. But the fear is always that the CO2 could find a way to leak back out into the atmosphere.

The Carbfix project on Iceland, on the other hand, seeks to solidify the unwanted carbon in place. Working with the Hellisheidi geothermal power plant outside Reykjavik, it combined the waste CO2 with water to make a slightly acidic liquid that was then sent hundreds of metres down into the volcanic basalts that make up so much of the North Atlantic island. The low pH water (3.2) worked to dissolve the calcium and magnesium ions in the basalts, which then reacted with the carbon dioxide to make calcium and magnesium carbonates. 

Cores drilled into the experimental site pulled up rock with the tell-tale white carbonates occupying the pore spaces. The researchers also tagged the CO2 with carbon-14, a radioactive form of the element. In this way, they were able to tell if any of the injected CO2 was leaking back to the surface or finding its way out through a distant watercourse. No such escape was detected. 

"This means that we can pump down large amounts of CO2 and store it in a very safe way over a very short period of time," said study co-author Martin Stute from Columbia University's Lamont-Doherty Earth Observatory, US. "In the future, we could think of using this for power plants in places where there's a lot of basalt - and there are many such places." Dr Matter added: "You can find basalts on every continent and, certainly, you can find them offshore because all the oceanic crust - so below the seafloor - is all basaltic rocks. In terms of the availability of basaltic rocks to take care of CO2 emissions globally - no problem."

There is, however, the issue of cost. Capture of the CO2 at power stations and other industrial complexes is expensive, and without incentives it is currently deemed to be uneconomic. The infrastructure needed to pump the gas to the burial site also has to be considered. And in the case of the Carbfix approach, a substantial amount of water is required. Only something like 5% of the mass sent underground is CO2. 

Christopher Rochelle is an expert on CCS at the British Geological Survey and was not involved in the Iceland experiment. He said Carbfix underlined the importance of moving beyond modelling and lab studies to real-world demonstrations. Only by doing this can the technology readiness be properly assessed. "We need to do more field-scale tests, like this one in Iceland, to better understand the types of processes that are ongoing and how fast they work," he told BBC News. "Here, they injected into reactive rocks and the minerals precipitated relatively quickly and are then unable to migrate anywhere. That's great, but the rocks under Iceland are different to those under the North Sea, for example. So the approach that is taken is going to have to vary depending on where you are. We are going to need a portfolio of techniques." The Hellisheidi geothermal power station has now moved beyond the experiment reported in Science magazine and is routinely injecting CO2 into the subsurface in larger quantities. 

The company is also burying hydrogen sulphide - another byproduct from the plant. This benefits the locals who have had to suffer the occasional waft of rotten eggs coming over their properties.
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Ocean Floor Geology Revealed

Ocean Floor Geology Revealed | Marine Science and Environment | Scoop.it

Scientists from the University of Sydney’s School of Geosciences, Australia, have led the creation of the world’s first digital map of the seafloor’s geology. The composition of the seafloor, covering 70 percent of the Earth’s surface, has been mapped after the most recent map was hand drawn in the 1970s. Published in Geology, the map will help scientists better understand how our oceans have responded, and will respond, to environmental change. It also reveals the deep ocean basins to be much more complex than previously thought.


The deep ocean floor is a graveyard with much of it made up of the remains of microscopic sea creatures called phytoplankton thriving in sunlit surface waters. The composition of these remains can help decipher how oceans have responded in the past to climate change. A special group of phytoplankton called diatoms produce about a quarter of the oxygen we breathe and make a bigger contribution to fighting global warming than most plants on land. Their dead remains sink to the bottom of the ocean, locking away their carbon.


The new seafloor geology map demonstrates that diatom accumulations on the seafloor are nearly entirely independent of diatom blooms in surface waters in the Southern Ocean. This disconnect demonstrates that the researchers, amongst them co-author  Professor Dietmar Muller from the University of Sydney, understand the carbon source, but not the sink. More research is needed to better understand this relationship.


This research opens the door to future marine research voyages aimed at better understanding the workings and history of the marine carbon cycle. Australia’s new research vessel Investigator is ideally placed to further investigate the impact of environmental change on diatom productivity. Some of the most significant changes to the seafloor map are in the oceans surrounding Australia.

 

Dr Dutkiewicz and colleagues analysed and categorised around 15,000 seafloor samples – taken over half a century on research cruise ships to generate the data for the map.  She teamed with the National ICT Australia (NICTA) big data experts to find the best way to use algorithms to turn this multitude of point observations into a continuous digital map. The digital data and interactive map are freely available as open access resources.

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Tomorrow's farmers may take more fruitful dives for crops

Tomorrow's farmers may take more fruitful dives for crops | Marine Science and Environment | Scoop.it

We raise crops on land. Could we do the same underwater? Use the oceans to provide alternative sources of plant production where land is not as kind? Why not? asked Fast Company. "The temperature doesn't fluctuate, so there's no frost. Aphids can't get anywhere near the plants, the pumped-in atmosphere is CO2-rich. And the plants—apparently—love it.

 

A number of sites this month have been looking at an underwater greenhouse growing strawberries and other types of food. They are growing off the coast of Italy in a greenhouse 20 feet under water.

 

Placement off the coast in Italy is able to take advantage of some of the sea's natural properties to grow plants, leveraging constant temperatures and high amounts of carbon dioxide. The structures are described by The Washington Post as "balloon-like biospheres" —their shape of the greenhouses allows for water to constantly evaporate and replenish the plants. "What's more, the high amounts of carbon dioxide act like steroids for the plants, making them grow at very rapid rates."

 

The greenhouse is anchored to the floor of the sea just off the coast of Noli, said Robert Gebelhoff , who covers health and science news for The Washington Post. The air of the greenhouse stands at 79 degrees with humidity hovering around 83 percent, he said.

 

In addition to strawberries, other edibles growing there are basil, lettuce and beans. These biospheres, said The Washington Post, are complete with live Web streaming and sensors. They are collecting data realtime on oxygen and carbon dioxide levels.

 

Glenn McDonald, writing in Discovery News, described the biospheres too. The five structures, he said, "resemble old-fashioned diving bells. Air is trapped under a transparent dome suspended beneath the waves, with rings of shelving along the interior housing soil beds for fruits and vegetables."

 

This botanical facility is called Nemo's Garden. The project is operated as part of the Ocean Reef Group, a family-run group of two companies based out of San Marcos, California, and Genova, Italy. Sergio Gamberini is CEO of Ocean Reef and head of the Nemo's Garden Project.

 

With a local government permit, the group is allowed to set up biospheres for four months in a year, from May to September. What's next: The company has several plans, one of which is to launch a crowdfunding campaign to support further development. McDonald in Discovery News said the group has plans to expand the program with other crops, especially mushrooms, which the researchers anticipate would thrive in the humid environment.


Read more at: http://phys.org/news/2015-07-tomorrow-farmers-fruitful-crops.html#jCp

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A Southern Indian Ocean database of hydrographic profiles obtained with instrumented elephant seals - Nature

A Southern Indian Ocean database of hydrographic profiles obtained with instrumented elephant seals - Nature | Marine Science and Environment | Scoop.it

Abstract

 

The instrumentation of southern elephant seals with satellite-linked CTD tags has offered unique temporal and spatial coverage of the Southern Indian Ocean since 2004. This includes extensive data from the Antarctic continental slope and shelf regions during the winter months, which is outside the conventional areas of Argo autonomous floats and ship-based studies. This landmark dataset of around 75,000 temperature and salinity profiles from 20–140 °E, concentrated on the sector between the Kerguelen Islands and Prydz Bay, continues to grow through the coordinated efforts of French and Australian marine research teams. The seal data are quality controlled and calibrated using delayed-mode techniques involving comparisons with other existing profiles as well as cross-comparisons similar to established protocols within the Argo community, with a resulting accuracy of ±0.03 °C in temperature and ±0.05 in salinity or better. The data offer invaluable new insights into the water masses, oceanographic processes and provides a vital tool for oceanographers seeking to advance our understanding of this key component of the global ocean climate.

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Huge marine reserve for Pitcairn

Huge marine reserve for Pitcairn | Marine Science and Environment | Scoop.it

The UK is to establish the largest, continuous marine reserve in the world, around the Pitcairn Islands. The Pacific zone will cover 834,000 sq km (322,000 sq miles) - more than twice the land area of the British Isles. The intention is to protect the wealth of ocean life from illegal fishing activities.


A satellite "watchroom" has been established to monitor vessel activity, and to gather the information needed to prosecute unauthorised trawling. The announcement of the reserve came in Chancellor George Osborne's pre-election Budget. The Pew Charitable Trusts and the National Geographic Society, who campaign on the need for marine reserves, welcomed the news.


NatGeo explorer and TV presenter Paul Rose told BBC News: "Ocean leadership like this from our government is exactly right. It protects the pristine waters of our overseas territories and sets an example to the rest of the world, giving hope and encouragement to future generations. Thank you UK government."

 

The UK already had the largest continuous, fully protected marine reserve in the world - around the Chagos Islands in the Indian Ocean. This area, established in 2010, is 640,000 sq km in size. (The US Pacific Remote Islands Marine National Monument is larger at 1.2 million sq km but is not continuous). Conservationists believe such zones are an essential component in the toolbox of measures required to tackle the colossal trade in "dark fish".


It is thought as many as one in five fish are landed outside of national or international regulations. The value of this trade could exceed more than $20bn (£13bn; 17bn euros) a year, according to some estimates. Much of the theft is perpetrated by industrial-scale pirate operations that think the vast expanse of the oceans can hide their behaviour.

 

Some of the confidence to establish reserves leans on new satellite technologies that are able now to track and follow the pirates. This is being done in the new watchroom, established at the Satellite Applications Catapult in Harwell, Oxfordshire. It is a partnership between the Catapult and Pew, and is called Project Eyes on the Seas.

 

Its smart systems not only track vessels but analyse their movements. And by incorporating additional data, such as sea conditions and probable fish locations, Project Eyes can make predictions about what the vessels are likely to be doing. Algorithms provide automated alerts.

 

In conjunction with the Pitcairn designation, the Swiss-based Bertarelli Foundation has agreed to fund the watchroom for the next five years. Project Eyes, which has been in a demonstration phase until now, will immediately go into full operation. It is expected to provide support for other reserves as well.

 

Jo Royle, who manages Pew's Global Ocean Legacy campaign in the UK, said: "There is talk from the UK government that they will now designate Ascension Island. They're talking to islanders to understand their marine resource needs. "We're also trying to get South Sandwich Islands designated as well. And this year could be a big year because Chile are talking about designating Easter Island, and Palau are talking about designating the waters around themselves. The issue is rising up the political agenda."

 

The Pitcairns are one of the most remote island groups in the world.

The British Overseas Territory comprises four islands - Pitcairn itself, Henderson, Oeno and Ducie. Pitcairn is the main island with a population of about 60 people. Famously, most of the inhabitants are descended from crewmembers of the mutinous British Royal Navy's Bounty ship, who settled the area with their Tahitian companions in 1790.


A survey of the waters around the islands shows they are not particularly productive in terms of the high-value pelagic species. Tuna fishing, for example, takes place well to the north. But there is concern that if illegal operations do move into the immediate waters around the Pitcairns, they could decimate the marine life that does exist there very rapidly.


The waters' main claim to special status is really their pristine nature. The range of species that occupy the complex community of hard and soft corals is impressive. These include two species found nowhere else on Earth: a species of squirrelfish and the many-spined butterfly fish. Also, the area is home to many important bird species, such as the Henderson petrel (endangered), whose only known breeding spot in the world is on Henderson Island.

 

The UK government said it would proceed with the designation of Pitcairn on the basis that all the satellite monitoring arrangements are put properly in place, and that any naval costs can be accommodated within existing departmental expenditure limits.

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Fiddler crabs build 'temples of love'

Fiddler crabs build 'temples of love' | Marine Science and Environment | Scoop.it

It's not enough for a male dancing fiddler crab to have a big claw. If he wants a mate, he also needs to build a sandy temples on his burrow.

 

On sandy beaches around the world, some male fiddler crabs spend up to two days building a 'temple of love'  on top of their burrows. They only build the hood-shaped sand structures during courting season, when they attract more females. But that's not the only reason. The little temples also help the crabs find their way back to their own burrows. That means a male with a hood can explore much further afield.

 

Fiddler crabs have terrible eyesight, so a male on a trip must remember the way back to his burrow, says lead author Tae Won Kim from the Korea Institute of Ocean Science and Technology. But if the male gets it wrong or is thrown off course, he can use his temple as a landmark to find the way home.

 

As a result, he has more freedom of movement to find and court females. So building the temple is worth the time and effort. To discover this, Kim compared the mating success of maledancing fiddler crabs in Panama with and without these hood-like structures. He also added artificial hoods to male burrows that didn't have them, and removed hoods from those who had built them.

 

Dancing fiddlers are one of 18 fiddler crab species that build structures, varying from vertical mud pillars to mud domes. The dancing fiddlers' temples, or hoods, are the largest relative to the crab's body size. Between 10 and 40% of males build them.

 

Female fiddlers prefer males that have large claws and that wave them around a lot. They are particularly choosy, often fleetingly visiting up to 20 different burrows before choosing a mate. But these are dangerous journeys, as the female is vulnerable to predators like great-tailed grackles.

 

Stopping off at a burrow keeps her safe, says co-author John Christy of the Smithsonian Research Institute in Panama. Naturally, she prefers burrows with hoods and will often stay at one to lay her eggs. Previous research by Christy's team suggests she even prefers burrows with hoods if the males are not at home.

 

Christy has been studying fiddler crabs for almost four decades, to find out about the mechanisms of sexual selection: how males outcompete each other to attract females. The hood-like temples, he says, are a strange case because they have not just evolved to impress females.

 

The males make the hoods to get more freedom of movement, so they can do a better job of attracting females. But the females are attracted to males with hoods for safety reasons, not because those males are necessarily better.

 

The female response to the hoods is more about their own survival and about preserving their young, rather than about finding the best male.Males have evolved to make the hoods, not because females prefer them, but because they are useful to the males, says Christy.

 

The new study is published in the journal Animal Behaviour.

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New automated method for classifying the deep sea floor

New automated method for classifying the deep sea floor | Marine Science and Environment | Scoop.it

Researchers at the National Oceanography Centre (NOC) have developed a new, automated method for classifying hundreds of kilometres of the deep sea floor, in a way that is more cost efficient, quicker and more objective than previously possible.

 

Currently there is very little information about the geographic distribution of life on the sea floor. This is largely because of the practical difficulty in accessing creatures which live at such a great depth in the ocean.

 

However, this research soon to be published in the journal Marine Geology, reveals a new method of estimating this distribution using a combination of: submarine mapping technology, statistics and a ‘landscape’ ecology technique called ‘Niche Theory’, which is generally used on land.  

 

The Niche Theory states that biodiversity is driven by spatial variability in environmental conditions, i.e. the greater the range of habitats, the greater the biodiversity. The lead author of this study, Khaira Ismail from the University of Southampton, has used this concept to create broad-scale, full coverage maps of the sea floor. The objective of these maps is to estimate the location of biodiversity hotspots, by identifying areas where the deep-sea landscapes are relatively more varied.  

 

Dr Veerle Huvenne, from the NOC, said “by informing us of where to look and where to plan more detailed surveys, this new method will help to make our deep-sea research more targeted and efficient, by advancing our understanding of life in the deep ocean, which at the moment is still very limited.” These maps cover areas approximately 200km across, and have pixel sizes around 25m.

 

They are created using information on the topography and sediment type of the sea floor, collected from a multi-beam echo sounder and a side scan sonar, respectively.  The resulting map is then analysed in order to break down the sea floor into a series of zones, using statistical analysis to identify distinct ‘geomorphological terrains’ in an objective and repeatable way.  

 

Khaira said “using statistical methods to identify these ‘terrain zones’ allows us to be more objective than if we were picking them out by hand. This objectivity means that the results are consistent and repeatable, which allows different areas of the sea floor to be compared more easily.” 

 

This research forms part of the €1.4M European Research Council funded CODEMAP project, and was applied in the Lisbon-Setúbal and Cascais Canyons, off the Portuguese coast. These submarine canyons were classified into six marine ‘seascapes’, based on their geomorphological features. 

 

Future work will use submarine robot cameras to take photos and videos of life in the deep-sea areas that have been subjected to this mapping technique. This will allow researchers to start to identify new deep sea habitats. 

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New species and surprising findings in the Mariana Trench

New species and surprising findings in the Mariana Trench | Marine Science and Environment | Scoop.it

The Mariana Trench located in the Western Pacific near Guam hosts the deepest place on earth, and has been the focus of high profile voyages to conquer its deepest point, Challenger Deep. A recent expedition to the Trench onboard Research Vessel Falkor targeted multiple depths and found active thriving communities of animals. The expedition set many new records such as the deepest rock samples ever collected and new species including the deepest fish ever recorded.

This month an international team have returned from the first detailed study of the Mariana Trench aboard Schmidt Ocean Institute's research vessel Falkor. This Hadal Ecosystem Studies (HADES) expedition, led by co-chief scientists Jeff Drazen and Patty Fryer of the University of Hawaii, departed from other deep-sea trench research by sampling a broad spectrum of environments using five deep sea vehicle systems called landers at specifically targeted depths from 5000 m - 10,600 m (16,404 ft. – 34,777 ft.). 

 

Rather than solely focusing on the deepest point in the Mariana Trench, a concerted effort was made to gain a better understanding of the interplay between life and geologic processes across the entire hadal zone.  Dr. Jeff Drazen, co-chief scientist expressed the drive behind this method "Many studies have rushed to the bottom of the trench, but from an ecological view that is very limiting.  It's like trying to understand a mountain ecosystem by only looking at its summit".

 

The findings from this research will help to answer important questions about Earth's largest and least explored habitat, including what organisms live there and how life adapts to these extreme conditions, and how much carbon in the atmosphere reaches the deep sea and if it affects the food chains there.

 

New species were discovered on this expedition that will provide insight into the physiological adaptations of animals to this high-pressure environment. Several records for deepest living fish, either caught or seen on video were broken.  Setting the final record at 8,143 m, was a completely unknown variety of snailfish, which stunned scientists when it was filmed several times during seafloor experiments. The white translucent fish had broad wing-like fins, an eel-like tail and slowly glided over the bottom. Dr. Alan Jamieson stated that "when findings and records such as these can be broken so many times in a single trip, we really do get the feeling we are at the frontier of marine science."


Additionally, the deepest rock samples ever obtained from the inner slope of the trench represent some of the earliest volcanic eruptions of the Mariana island arc. These rocks can provide significant information on the geology of the trench system.

Wendy Schmidt, co-founder and Vice President of Schmidt Ocean Institute was delighted with the success of the expedition. "Rarely, do we get a full perspective of the ocean's unique deep environments. The questions that the scientists will be able to answer following this cruise will pave the way for a better understanding of the deep sea, which is not exempt from human impact."

 

Falkor is now back in the Mariana Trench conducting research that will complement the previous expedition and continue to explore this unique environment.

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Deep-sea asphalt mounds found off West African coast

Deep-sea asphalt mounds found off West African coast | Marine Science and Environment | Scoop.it

Scientists have discovered a large area of the deep seabed strewn with mounds of asphalt off the coast of Angola, hosting rich animal life.

 

This is the first such discovery in the Atlantic proper or in the Southern Hemisphere, and the first time the creatures living around them have been studied in detail. It arises from a long-term collaboration between energy company BP and scientists at NERC's National Oceanography Centre (NOC).

 

The researchers found at least 21 kinds of deep-water creature living around the tarry structures, including octopuses, blobfish, sea stars and coral-like sea fans. 'It seems to be a very rich animal community - the asphalt provides a hard surface for them to attach themselves to, so animals like sponges can get a foothold,' says Dr Daniel Jones of NOC, the study's lead author.

 

He adds that these rare habitats may turn out to be important for how animals are distributed across the ocean floor, perhaps as stepping-stones that allow species to move into new areas and enable genetic material to flow across widely-dispersed populations.

BP experts first noticed the structures while searching the seabed for signs of energy deposits with the potential for exploitation. The asphalt mounds identified cover 3.7 square kilometres and sit around 2km beneath the surface. Closer investigation with remotely-operated subs revealed more than 2,000 mounds. Some are just inches from side to side; others are hundreds of metres across.

 

The BP staff alerted researchers at NOC, with whom they have a long-standing collaboration. The scientists examined the geological data and the images from BP's robots in an effort to understand the variety of living things around these structures, and their wider importance for marine biodiversity.


'This work is a real example of the benefits of collaboration between NERC scientists and industry,' says Jones, noting that experts at BP and its contractor Fugro joined NOC staff in writing the paper. 'We get access to BP's high-quality data, while BP gets information that can support its efforts to improve the environmental management of its operations.'

 

The mounds form when heavy, tarry hydrocarbons ooze up from beneath the sea floor and harden into asphalt much like the stuff that's used to surface roads. Only a handful of other examples are known, and those only since 2004, when a much larger 'tar volcano' came to light in the Gulf of Mexico. They are related to cold seeps - best known as places on the seabed where lighter hydrocarbons like methane leak into the water - in fact, both kinds of undersea fluid flow are found at the Angola site, leading the scientists to suspect that different parts of the same flow of hydrocarbons are somehow being separated on the journey up to the seafloor, with the lighter part emerging as a cold seep and the heavier forming asphalt mounds.

 

'With modern high-resolution mapping technology, it's getting much easier to spot these structures, so it's very likely we'll find more, but they're certainly not common,' says Jones. 'At the moment we have limited information about the ecological role they play, but they obviously support a broad community of organisms and it'd seem sensible to manage them carefully until we know more.'

 

The study appears in Deep Sea Research 1 and is open access.

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Study to use Google data search analytics to understand marine networks

Study to use Google data search analytics to understand marine networks | Marine Science and Environment | Scoop.it

Scientists at Heriot-Watt University will use the kind of computing algorithms more commonly associated with Google search engines to uncover and record the complex relationships which exist across Scotland's Marine Protected Areas.

'Graph theory' as it is known, underpins many computerised applications. It is used, for example, in internet and telephone network design, optimising emergency service response times, Facebook degrees of separation and Google ranking techniques.

 

A new study by the University will use computer models to map ocean currents and larvae movement around Scotland's coast after which the graph theory algorithm-based approach will be used to analyse the data. It is hoped it will reveal how individual protected areas connect and how important that connectivity is to marine species such as protected cold-water corals and other reef-forming species such as flame shells, horse mussels and serpulid worms.


Ecosystems cannot exist in isolation. Many marine creatures, as adults, live fixed to the sea bed, but these sedentary populations are linked through the production of larvae which drift on the ocean currents, like seeds on the wind, before settling, allowing colonisation of new areas and recovery of damaged populations.

Dr Alan Fox who has recently joined the School of Life Sciences on a Daphne Jackson Fellowship, will work with Professor Murray Roberts and Professor David Corne, to study this connectivity.

 

"Application of graph theory to marine conservation networks will help identify important sites and pathways, find gaps and optimise the network for marine protection," said Dr Fox. "Longer term, combined with monitoring, network characteristics will help determine the essential properties of successful marine protection and feed in to protected area network design worldwide."

 

Professor David Corne, Director of Enterprise, Impact and Innovation in Heriot-Watt University's School of Mathematical & Computer Sciences said, "Viewing the MPA network through a 'complexity science' lens enables us to discover significant problems or opportunities that would otherwise be missed; Alan's work could lead to an entirely new approach to identify MPAs, providing stakeholders with more confidence in their ability to ensure the protection of vulnerable species."

 

In July the Scottish Government designated 30 new MPAs in Scotland's seas to help protect marine species and habitats, from sponges on the deep seabed to dolphins and basking sharks. These MPAs join existing protected areas around the coast forming a developing network where damaging activities will be managed to allow marine life to thrive. To obtain maximum benefit scientists need to know how well the protected areas will function as a complete network.

 

Professor Murray Roberts, co-ordinator of Heriot-Watt University's new Lyell Centre for Earth and Marine Science and Technology said, "Marine ecosystems have never been under as much stress as they are now. We are seeing the effects of warmer temperatures and ocean acidification changing the oceans at unbelievably rapid rates. There's real concern that additional pressures from things like over-fishing and pollution may push marine ecosystems too far – and that's why properly integrated networks of marine protected areas are more important now than ever before. "It's these protected places that hold the best hope for ecosystems to recover and help provide the larvae and juveniles that will spread to other areas."

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Gravity map traces ocean circulation

Gravity map traces ocean circulation | Marine Science and Environment | Scoop.it

Scientists use gravity data to produce what they say is the most accurate space view yet of global ocean currents and the speed at which they move.

 

The information has been drawn from a range of satellites, but in particular from the European Space Agency's Goce mission.

This platform, which operated from 2009 to 2013, made ultra-precise measurements of Earth's gravity. It has detailed the role this force plays in driving ocean circulation.


The new model - presented at a Goce conference at the Unesco HQ in Paris, France - will be of fundamental importance to climate modellers, because it is the mass movement of water that helps to transport heat around the globe. Goce carried instrumentation capable of sensing very subtle changes in Earth's gravitational tug. This pull varies ever so slightly from place to place because of the uneven distribution of mass inside the planet.


Scientists used these observations to construct what is called a "geoid", which essentially describes the "level surface" on an idealised world.

It is the shape the oceans would adopt if there were no winds, no currents and no tides to disturb them. By comparing this geoid with measurements of sea-surface height made by other spacecraft, researchers can see where water has become piled up.


And it is water's desire always to "run downhill" that is a major influence on the direction and speed of currents - although atmospheric winds and the Earth's rotation are of course critical partners in the overall picture.

Clearly visible in the map at the top of this page are the Agulhas Current flowing down the African coast; the Gulf Stream running across the Atlantic; the Kuroshio Current that sweeps south of Japan and out into the North Pacific; as well as the Antarctic Circumpolar Current, and the system of currents that hug the Equator. In places, these great trains of water move in excess of 1m per second.

 

The new Goce model of ocean circulation has been checked and integrated with the point measurements from drifting buoys. This has helped capture some of the smaller-scale features in the currents that lie beyond the capabilities of satellites, even one that made as highly resolved observations as the Esa mission.

"Goce has really made a breakthrough for the estimation of ocean currents," said Marie-Helene Rio from the Italian National Research Council's Institute of Atmospheric Sciences and Climate.

"The mission objective in terms of geoid [measurement] has been achieved at 1-2cm accuracy at 100km resolution, and in terms of ocean currents this translates into an error that is less than 4cm/s."

Scientists can now add in data collected about sea temperature to calculate the amount of energy the oceans move around the Earth.

Computer models that try to forecast future climate behaviour have to incorporate such details if they are to run more realistic simulations.

The 5th International Goce User Workshop this week will be looking at the many other applications that came out of the satellite's mission.

Mapping gravity variations can yield information about ice mass loss in the Antarctic, and the deep-Earth movements that give rise to great quakes.

 

Goce was dubbed the "Ferrari of space" because of its sleek looks and the fact that it was assembled in Italy. When operational, it was the lowest flying scientific satellite in the sky, making observations at an altitude of just 224km during its late phases.


This allowed the spacecraft to better sense the tiny gravity variations, but meant it had to constantly thrust an electric engine to stay aloft.

When the xenon fuel for this engine was exhausted in November 2013, Goce succumbed to the force it had been sent up to study and fell back to Earth. Eyewitnesses saw surviving debris fall into the South Atlantic, just off the tip of South America, south of the Falkland Islands.

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Life thriving on UK's biggest underwater mountains

Life thriving on UK's biggest underwater mountains | Marine Science and Environment | Scoop.it

Life is thriving on the UK's tallest underwater mountains, an expedition has revealed. Scientists used robotic submersibles to dive more than 2,000m beneath the waves to explore four seamounts off the west coast of Scotland. The footage revealed vast coral reefs, and an array of crustaceans and fish living in the cold, dark waters. The team also collected thousands of samples, and believe many species may be new to science. Dr Kerry Howell, a deep sea biologist at Plymouth University, told BBC News: "Lots of people think of the deep sea as being a sort of desert of mud. "And in fact these mountain structures are far from that - [there are] so many animals, so much life."


The Deep Links project team, a collaboration between Plymouth University, the University of Oxford, the Joint Nature Conservation Committee and the British Geological Survey, spent six weeks at sea onboard the RSS James Cook. Of the four underwater mountains they explored, the biggest - the Anton Dohrn - stands at 1,700m tall. It would dwarf Ben Nevis, which has a peak of 1,344m - yet it is totally submerged. The scientists say until now these unique habitats have been little explored.


Dr Howell explained: "We don't know very much about the underwater mountains off the coast of the UK. We went there initially in 2005, and that was the first time anyone had taken cameras there. But the footage wasn't great and technology has moved on since then. "So this time we were able to take really sophisticated robots there with HD film, and get really fantastic quality images."


The scientists were able to control the Isis Remotely Operated Vehicle (ROV) from the deck of the ship, to record video, take photos and scoop up samples as it explored the deep. They also deployed Autosub 6000, an autonomous robot, to map the mountains. "You see the sea floor coming out of the gloom, and you don't know what you are going to find," said Dr Michelle Taylor, a deep sea biologist from the University of Oxford. "This is the first time that anybody has seen this sea mount, has seen the animals that live on this seamount, how they live, what they live on, who lives with them - and that's really exciting."


The team found brightly coloured cold-water coral reefs that stretched for many kilometres. Some of the species were several metres high, while others were thought to be thousands of years old. They discovered huge sponge gardens crammed with tiny animals, crustaceans, including deep-sea crabs and shrimps, basket stars, sea anemones, and many fish species, including lepidions and chimaeras, which are related to sharks. It will take the team many months to analyse all of the footage and carefully examine the specimens they collected. Even at this stage, they expect there could be many species new to science. The team found that overall the seamounts were in good condition, with most designated as Marine Protected Areas. However, the scientists still found signs of human impact, including litter and trawl marks, and they are concerned about how climate change may affect these habitats in the future. Dr Taylor said: "It's very important to understand what lives in these locations because they might change - and they might change forever."


Dr Howell added that the reefs were among the best she had ever seen. "These mountains are British, they are in British waters - and they support such an amazing diversity of life," she told the BBC. "And the fact the UK has its own coral reefs, people don't appreciate that. "These reefs are enormous and in really great condition - [they are] so beautiful, so important - and I really hope that people can appreciate what they have on their doorstep."

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Marine life quickly recovered after global mass extinction

Marine life quickly recovered after global mass extinction | Marine Science and Environment | Scoop.it

Reptiles rapidly invaded the seas soon after a global extinction wiped out most life on Earth, according to a new study led by University of California, Davis, researchers.


Global climate change—likely triggered by massive volcanic eruptions—killed off more than 95 percent of all species about 250 million years ago, at the end of the Permian period. Land reptiles colonized the ocean in just 3.35 million years at the beginning of the Triassic, a speedy recovery in geologic time, the researchers report today (June 13) in the journal Scientific Reports. "Our results fit with the emerging view that the recovery was faster than previously thought," said study co-author Ryosuke Motani, professor of paleobiology at UC Davis' Department of Earth and Planetary Sciences. 


The research was led by Wanlu Fu, now of the Laboratory of Orogenic Belt and Crustal Evolution at Peking University. Fu conducted the research while an in-residence doctoral student working with study co-author Isabel Montañez, professor of geochemistry at UC Davis. Co-authors include scientists from the University of Wisconsin and the University of Milan in Italy. The fossils and rock samples were collected from Majiashan in Chaohu, South China. 


The oldest marine reptile fossils appeared 248.81 million years ago, the most precise date yet, according to the study. These pioneering marine reptiles, including the dolphin-like ichthyosaurs and sauropterygians, went on to rule the Mesozoic seas during the era of the dinosaurs. Ocean mixing led to recovery At the same time, there were major changes in ocean chemistry and carbon cycling, the team found. Vertical mixing of oceanic water had stopped during or soon after the mass extinction, causing widespread depletion of oxygen in the oceans. 


Carbon isotopes in the Majiashan rock layers suggest the oldest marine reptiles appeared just after a return to healthy ocean circulation, which could have prompted the ecosystem recovery, the researchers suggest. The rocks recorded more vigorous mixing of ocean waters, which would have brought nutrient-rich waters to the surface to fuel tiny organisms at the bottom of the ocean's food chain. "We attribute the biotic recovery and initiation of a new marine ecosystem to the final breakdown of this ocean stratification and the return to an oxygenated ocean," Montañez said. 


The carbon isotopes varied on a timescale of 405,000 years and 100,000 years, the study reports. These carbon cycles correspond to Earth's orbital eccentricity, in which the Earth's orbit shifts from more circular to more elliptical and back. These orbital wobbles also provided a means to precisely date the first occurrence of Mesozoic marine reptiles. 


 Read more at: http://phys.org/news/2016-06-marine-life-quickly-recovered-global.html#jCp

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DNV GL in Largest Underwater CO2 Release Study

DNV GL in Largest Underwater CO2 Release Study | Marine Science and Environment | Scoop.it

The largest ever controlled release of carbon dioxide from an underwater pipeline is to be conducted at DNV GL’s full-scale Spadeadam Testing and Research Centre as part of an international Joint Industry Project (JIP) called Sub-C-O2.


Scheduled to start in early 2016, the planned release will mark the second phase of experiments at the Spadeadam test site, which is situated in remote Ministry of Defence land in Cumbria, UK. The tests are designed to increase industry understanding about environmental and safety effects of underwater CO2 releases from pipelines, DNV GL explained.

 

The eventual aim is to develop safety guidelines for offshore CO2 pipelines, which are expected to proliferate as carbon capture, utilisation and storage (CCUS) technology is eventually installed to mitigate CO2 emissions from power plants and large industrial sources. CO2 transported in offshore pipelines is also being used for enhanced oil and gas recovery.

 

“Combining knowledge of the consequences of underwater release with the probabilities of these events occurring will enable developers to improve designs and reactive measures to manage such events,” said Russell Cooper, technical services manager at National Grid.

 

The British electricity and gas company has test drilled a subsea CO2 storage site offshore UK. Its work has helped to demonstrate significant storage potential in the southern North Sea, DNV GL wrote.It is participating in Sub-C-O2 alongside Norway’s Gassnova, Brazil’s Petrobras, the UK government’s Department of Energy and Climate Change, and DNV GL. Italy’s Eni plans to join the DNV GL-led JIP in 2016.


The first experiment at Spadeadam involves small-scale, controlled CO2 releases from a three-inch nominal bore pipeline in a 8.5-metre diameter, three-metre deep water tank. Launched in September 2015, this phase was scheduled to complete by December, the same year, the company noted.

 

“Underwater cameras and other measurement techniques show us the configuration and characteristics of the plume of released gas, whether it reaches the surface, and what happens there,” said Dr Mohammad Ahmad from DNV GL’s office in Groningen, the Netherlands, who project manages the JIP. We also measure water temperature, pressure, water pH and dispersing CO2 concentration. The experiments will provide valuable information on the effects of the plume below the surface, and on the level of any toxic gases in the air above.”


The second experimental phase running for three months from early 2016 will involve releases in a 39-meter diameter, 12-metre deep pond at Spadeadam to study the effects of depth on measured and observed parameters. “This is a huge pond,” Ahmad said. “It is the largest experimental investigation to date of underwater CO2 releases. It is designed around what is known about underwater natural gas [methane] leaks. We will be curious to see if and when we may get CO2 hydrates collecting on pipework.”


Spadeadam is one of a network of 18 laboratories and testing centres operated by DNV GL on three continents. “The world class team and facilities at Spadeadam have made DNV GL our ‘go to’ organisation throughout our extensive programme of experiments to understand the requirements of CO2 transportation,” Cooper said.

The JIP was conceived and initiated by DNV GL’s Groningen office, and designed in collaboration with Spadeadam. Other offices in Oslo, Norway, and London, UK, have conducted physical modelling for the project, DNV GL said.

 

Experimental findings are shared periodically with JIP participants so that next steps can be refined. Testing at Spadeadam will conclude by June 2016. Even larger-scale, controlled testing in the natural environment may subsequently take place. “We are considering a number of locations,” Ahmad said.

 

The ultimate goal, as with many DNV GL-led JIPs, is the publication of a recommended practice or industry standard. “The evolution of best practice, based on a sound understanding of the consequences of underwater releases, will greatly help the nascent CCUS industry to build public confidence and assist the rollout out of a vital carbon abatement technology,” Cooper said.

 

“It will be valuable for risk assessment,” Ahmad added. “This sometimes requires adjustments to the assumptions of computer models for gas dispersion, and for that you need data from experiments on this scale. The contribution of data from Spadeadam to improving risk models will be the main input to developing safety guidelines for offshore CO2 pipelines.”

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Carbon Dioxide Pools Discovered in Aegean Sea

Carbon Dioxide Pools Discovered in Aegean Sea | Marine Science and Environment | Scoop.it
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The location of the second largest volcanic eruption in human history, the waters off Greece’s Santorini are the site of newly discovered opalescent pools forming at 250 meters depth. The interconnected series of meandering, iridescent white pools contain high concentrations of carbon dioxide (CO2) and may hold answers to questions related to deepsea carbon storage as well as provide a means of monitoring the volcano for future eruptions.

 

“The volcanic eruption at Santorini in 1600 B.C. wiped out the Minoan civilization living along the Aegean Sea,” said Woods Hole Oceanographic Institution (WHOI) scientist Rich Camilli, lead author of a new study published today in the journal Scientific Reports. “Now these never-before-seen pools in the volcano’s crater may help our civilization answer important questions about how carbon dioxide behaves in the ocean.”

The pools range in size from 1 to 5 meters diameter, and scientists believe they are ephemeral, appearing and disappearing like a rain pool in the dessert.

 

Camilli and his colleagues from the University of Girona, National and Kapodistrian University of Athens, Institut de Physique du Globe de Paris, and Hellenic Centre for Marine Research, working in the region in July 2012, used a series of sophisticated underwater exploration vehicles to locate and characterize the pools, which they call the Kallisti Limnes, from ancient Greek for “most beautiful lakes.” A prior volcanic crisis in 2011 had led the researchers to initiate their investigation at a site of known hydrothermal activity within the Santorini caldera. During a preliminary reconnaissance of a large seafloor fault the University of Girona’s autonomous underwater vehicle (AUV) Girona 500 identified subsea layers of water with unusual chemical properties.

 

Following the AUV survey, the researchers then deployed HCMR’s Thetis human occupied vehicle. The submersible’s crew used robotic onboard chemical sensors to track the faint water column chemical signature up along the caldera wall where they discovered the pools within localized depressions of the caldera wall. Finally, the researchers sent a smaller remotely operated vehicle (ROV), to sample the pools’ hydrothermal fluids.

 

“We’ve seen pools within the ocean before, but they’ve always been brine pools where dissolved salt released from geologic formations below the seafloor creates the extra density and separates the brine pool from the surrounding seawater,” said Camilli. “In this case, the pools’ increased density isn’t driven by salt – we believe it may be the CO2 itself that makes the water denser and causes it to pool.”

 

Where is this CO2 coming from? The volcanic complex of Santorini is the most active part of the Hellenic Volcanic Arc. The region is characterized by earthquakes caused by the subduction of the African tectonic plate underneath the Eurasian plate. During subduction, CO2 can be released by magma degassing, or from sedimentary materials such as limestone which undergo alteration while being subjected to enormous pressure and temperature.

 

The researchers determined that the pools have a very low pH, making them quite acidic, and therefore, devoid of calcifying organisms. But, they believe, silica-based organisms could be the source of the opal in the pool fluids.

 

Until the discovery of these CO2-dense pools, the assumption has been that when CO2 is released into the ocean, it disperses into the surrounding water. “But what we have here,” says Camilli, “is like a ‘black and tan’ – think Guinness and Bass – where the two fluids actually remain separate” with the denser CO2 water sinking to form the pool.

 

The discovery has implications for the build up of CO2 in other areas with limited circulation, including the nearby Kolumbo underwater volcano, which is completely enclosed. “Our finding suggests the CO2 may collect in the deepest regions of the crater. It would be interesting to see,” Camilli said, adding it does have implications for carbon capture and storage. Sub-seafloor storage is gaining acceptance as a means of reducing heat-trapping CO2 in the atmosphere and lessening the acidifying impacts of CO2 in the ocean. But before fully embracing the concept, society needs to understand the risks involved in the event of release.

 

Temperature sensors installed by the team revealed that the Kallisti Limnes were 5°C above that of surrounding waters. According to co-author Javier Escartin, “this heat is likely the result of hydrothermal fluid circulation within the crust and above a deeper heat source, such as a magma chamber.” These temperatures may provide a useful gauge to study the evolution of the system. Escartin added that “temperature records of hydrothermal fluids can show variations in heat sources at depth such as melt influx to the magma chamber. The pool fluids also respond to variations in pressure, such as tides, and this informs us of the permeability structure of the sub-seafloor.” Changes in the pools’ temperature and chemical signals may thus complement other monitoring techniques as useful indicators of increased or decreased volcanism.

 

This European – American research collaboration was funded through support from the EU Eurofleets program, Institut de Physique du Globe de Paris, Hellenic Centre for Marine Research, the US National Science Foundation, and NASA’s astrobiology program (ASTEP) which supports autonomous technology development to search for life on other planets. “From a technology perspective, it was a big step forward,” Camilli said.

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Dead Zones Found in Tropical North Atlantic

Dead Zones Found in Tropical North Atlantic | Marine Science and Environment | Scoop.it

A team of German and Canadian researchers have discovered areas with extremely low levels of oxygen in the tropical North Atlantic, several hundred km off the coast of West Africa. The levels measured in these ‘dead zones,’ inhabitable for most marine animals, are the lowest ever recorded in Atlantic open waters. The dead zones are created in eddies, large swirling masses of water that slowly move westward. Encountering an island, they could potentially lead to mass fish kills. The research was published 30 April 2015 in Biogeosciences, an open access journal of the European Geosciences Union (EGU).

 

Dead zones are areas of the ocean depleted of oxygen. Most marine animals, like fish and crabs, cannot live within these regions, where only certain microorganisms can survive. In addition to the environmental impact, dead zones are an economic concern for commercial fishing, with very low oxygen concentrations having been linked to reduced fish yields in the Baltic Sea and other parts of the world.

 

According to lead-author Johannes Karstensen, a researcher at GEOMAR, the Helmholtz Centre for Ocean Research in Kiel, Germany, “the minimum levels of oxygen now measured are some 20 times lower than the previous minimum, making the dead zones nearly void of all oxygen and unsuitable for most marine animals.”

Dead zones are most common near inhabited coastlines where rivers often carry fertilizers and other chemical nutrients into the ocean, triggering algae blooms. As the algae die, they sink to the seafloor and are decomposed by bacteria, which use up oxygen in this process. Currents in the ocean can carry these low-oxygen waters away from the coast, but a dead zone forming in the open ocean had not yet been discovered.

 

The newly discovered dead zones are unique in that they form within eddies, large masses of water spinning in a whirlpool pattern. “The few eddies we observed in greater detail may be thought of as rotating cylinders of 100 to 150 km in diameter and a height of several hundred metres, with the dead zone taking up the upper 100 m or so,” explains Karstensen. The area around the dead-zone eddies remains rich in oxygen.

 

“The fast rotation of the eddies makes it very difficult to exchange oxygen across the boundary between the rotating current and the surrounding ocean. Moreover, the circulation creates a very shallow layer – of a few tens of meters – on top of the swirling water that supports intense plant growth,” explains Karstensen. This plant growth is similar to the algae blooms occurring in coastal areas, with bacteria in the deeper waters consuming the available oxygen as they decompose the sinking plant matter. “From our measurements, we estimated that the oxygen consumption within the eddies is some five times larger than in normal ocean conditions.”

 

The eddies studied in the Biogeosciences article form where a current that flows along the West African coast becomes unstable. They then move slowly to the west, for many months, due to the Earth’s rotation. “Depending on factors such as the [eddies’] speed of rotation and the plant growth, the initially fairly oxygenated waters get more and more depleted and the dead zones evolve within the eddies,” explains Karstensen. The team reports concentrations ranging from close to no oxygen to no more than 0.3 ml of oxygen per liter of seawater. These values are all the more dramatic when compared to the levels of oxygen at shallow depths just outside the eddies, which can be up to 100 times higher than those within.

 

The researchers have been conducting observations in the region off the West African coast and around the Cape Verde Islands for the past seven years, measuring not only oxygen concentrations in the ocean but also water movements, temperature and salinity. To study the dead zones, they used several tools, including drifting floats that often got trapped within the eddies. To measure plant growth, they used satellite observations of ocean surface color.

 

Their observations allowed them to measure the properties of the dead zones, as well as study their impact in the ecosystem. Zooplankton – small animals that play an important role in marine food webs – usually come up to the surface at night to feed on plants and hide in the deeper, dark waters during the day to escape predators. However, within the eddies, the researchers noticed that zooplankton remained at the surface, even during the day, not entering the low-oxygen environment underneath.

 

“Another aspect related to the ecosystem impact has a socioeconomic dimension,” says Karstensen. “Given that the few dead zones we observed propagated less than 100 km north of the Cape Verde archipelago, it is not unlikely that an open-ocean dead zone will hit the islands at some point. This could cause the coast to be flooded with low-oxygen water, which may put severe stress on the coastal ecosystems and may even provoke fish kills and the die-off of other marine life.”

 

To read the original paper, click here.

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The Iron Snail

The Iron Snail | Marine Science and Environment | Scoop.it

The Museum has recently received specimens of the enigmatic deep-sea vent snail, Chrysomallon squamiferum, the scaly-foot snail. In this post, Dr Chong Chen explains why this species is so extraordinary.

 

This is no ordinary snail. First of all, it lives in deep-sea hydrothermal vents in the Indian Ocean, more than 2,500 metres deep, just beside black smokers that are churning out superheated water exceeding 350°C. Second, it is the only known gastropod with a suit of scale armour. Thirdly, the scales as well as the shell are mineralised with iron sulfide. That’s right – these snails make a skeleton out of iron, and are the only animal so far known to do so.

 

Hydrothermal vents were first discovered in the Galápagos Rift as recently as 1977. This is just off the Galápagos Islands whose fauna famously inspired Charles Darwin in the development of his theory of natural selection. Vents are deep-sea ‘hot springs’ fuelled by geological activity; the hot erupting fluid is usually acidic and contains various metals, as well as hydrogen sulfide. This is what makes rotten eggs smell bad, and is toxic to most organisms. Some bacteria, however, are able to use it to produce energy in a process known as chemosynthesis.


Over geological timescales many remarkable organisms have adapted to live in these ‘toxic utopia’, and flourish by exploiting the energy produced by these bacteria. The scaly-foot snail has also harnessed the power of chemosynthesis, housing endosymbiotic bacteria – bacteria living inside another creature to mutual benefit – in an enlarged part of its gut. This produces the energy it needs. In another words – it has a food factory inside its body and doesn’t even need to feed! This is likely the reason it can grow to about 45mm in size, when most of its close relatives without endosymbionts are only 15mm or smaller.


Scaly-foot snails were first discovered in 2001, at the Kairei vent field in the Indian Ocean. Its discovery came as a great surprise as even among those animals specialised for living at vents, it was very, very strange. And cool. Although the shell of a snail is well-known to be modified into a great variety of forms, this is not the case with hard parts on the foot, and apart from an operculum (the ‘trap-door’ serving as a lid when the animal retracts to its shell) no other gastropods have other mineralised structures on the foot. Yet C. squamiferum has thousands of scales!

 

The shell, although not particularly exciting in form, isn’t exactly ordinary either as the outermost layer is made of iron sulfide. And so are the scales. So this entire animal is covered in iron compound, mainly pyrite (FeS2, or ‘Fool’s gold’) and greigite (Fe3S4). As greigite is magnetic, the animal actually sticks to magnets. The function of the scales is postulated to be either protection or detoxification but their true use remains a mystery.

 

So why blog about the ‘scaly-foot’ now, if it has already been known to science for more than a decade? Well, actually, despite numerous studies and publications on its strange biology this species has never been formally described and named, until now. A recent paper by Dr Chong Chen (Department of Zoology, University of Oxford) and colleagues finally gave it the scientific name you see here –Chrysomallon squamiferum.

 

The Museum received a set of five specimens as part of the description process, which will serve as key references for scientists who wish to study this extraordinary species in the future.

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Cardiff tidal energy lagoon 'could power every home in Wales'

Cardiff tidal energy lagoon 'could power every home in Wales' | Marine Science and Environment | Scoop.it
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www.bionautic.com's curator insight, March 5, 2015 7:23 AM

A “tidal lagoon” capable of powering all the homes in Wales could be built off the Cardiff coast, under Government-backed plans for a series of tidal electricity schemes around the UK. Green energy company Tidal Lagoon Power on Monday began the official planning process for the proposed 14-mile seawall, which would stretch from Cardiff to Newport and cost up to £6bn.


The company is already developing plans for a smaller pilot scheme in Swansea Bay and also wants to build four other large-scale lagoons – at Newport, West Cumbria, Colwyn Bay and Bridgwater Bay. It says the fleet of six lagoons could together generate 8 per cent of the UK’s needs for 120 years. The Government has already thrown its weight behind the plans,naming the Swansea Bay Tidal Lagoon in the National Infrastructure Plan last year. The £1bn scheme, which involves a six-mile sea wall, is currently awaiting a decision, due by June, on its planning application.


Ed Davey, the energy secretary - who could take the planning decision before the general election - told the BBC he was “very excited by the prospect of tidal power”, describing it as “really useful”. Ministers are preparing to enter into negotiations with Tidal Lagoon Power over subsidies for the Swansea project, which would be paid for through levies on consumer energy bills.

Citizens Advice has warned that the plans are “appalling value for money” and urged the Government not to “squander” bill-payers’ cash on the project.

 

Electricity from Swansea would be more expensive than that from any other major green energy project in the UK to date, the consumer charity warned. The developer admits the scheme would be “expensive” initially but claims that the cost of electricity from the second, larger scheme in Cardiff would be cheaper, on a par with power from the proposed Hinkley Point C nuclear plant. It is seeking subsidies for the first 35 years of the project, to recoup its construction costs and turn a profit, but says that thereafter the energy would be very cheap.


Each lagoon would generate power for about 14 hours a day, as water passes through turbines embedded in the sea walls.

Gates in the lagoon walls would be closed to keep water out as the tide rises, then opened soon after high tide, allowing water to rush in and turn the turbines. Gates would then be shut, keeping the water in until soon after low tide, when they would be opened to let the water out and turn the turbines again. The proposed Cardiff scheme’s annual output would be equivalent to the electricity used by all homes in Wales in a year, the company said.


It began the first formal stages of preparing for a planning application on Monday and says it aims to submit a full application in 2017. If approved, it could start generating power in 2022. Developers say tidal power is reliable, unlike wind energy, and that a series of lagoons around the coast could capitalise on different tidal times to ensure power around the clock.


Tidal Lagoon Power has also caused controversy with plans to quarry rocks for the lagoons in Cornwall, where its sister company wants to reopen the disused Dean Quarry and ship the rocks out via a new jetty and breakwater that would be built in a recently-designated Marine Conservation Zone. Mark Shorrock, Chief Executive of Tidal Lagoon Power: “We have the best tidal resource in Europe and the second best worldwide. We now have a sustainable way to make the most of this natural advantage.”




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Evolution 'favours big sea beasts'

Evolution 'favours big sea beasts' | Marine Science and Environment | Scoop.it

The animals in the ocean have been getting bigger, on average, since the Cambrian period - and not by chance. That is the finding of a huge new survey of marine life past and present, published in the journal Science.

 

It describes a pattern of increasing body size that cannot be explained by random "drift", but suggests bigger animals generally fare better at sea. In the past 542 million years, the average size of a marine animal has gone up by a factor of 150.

 

It appears that the explosion of different life forms near the start of that time window eventually skewed decisively towards bulkier animals. Today's tiniest sea critter is less than 10 times smaller than its Cambrian counterpart, measured in terms of volume; both are minuscule crustaceans. But at the other end of the scale, the mighty blue whale is more than 100,000 times the size of the largest animal the Cambrian could offer: another crustacean with a clam-like, hinged shell.

 

The idea that natural selection might lead to animal lineages gradually gaining weight is far from new. It is set out in a proposal known as Cope's rule, after American fossil specialist Edward Drinker Cope. 19th-Century palaeontologists noticed that the ancient ancestors of modern mammals often tended to be smaller; horses, for example, can be traced to the dog-sized Eohippus genus of 50 million years ago.

 

The pattern is not consistent across the animal kingdom, however. Most groups of dinosaurs got bigger until they died out - but the birds that evolved from them grew smaller and lighter with the necessity of flight. Dr Noel Heim, from Stanford University in California, set out to give Cope's rule its most thorough test yet - in the vast realm of the ocean.

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Jellyfish 'can sense ocean currents'

Jellyfish 'can sense ocean currents' | Marine Science and Environment | Scoop.it

Jellyfish can sense the ocean current and actively swim against it, according to a study that involved tagging and tracking the creatures. The research, by an international team, could help scientists work out how jellyfish form "blooms".


These blooms may comprise between hundreds and millions of jellyfish, and can persist in a given area for months. It remains unclear just how the jellyfish sense changes in water, the paper in Current Biology journal says. The scientists, including researchers from Swansea University and Deakin University in Warnambool, Australia, tagged 18 large barrel jellyfish (Rhizostoma octopus) in the Bay of Biscay, off the coast of France.


The team caught the jellyfish and fitted them with loggers that measured acceleration and body orientation. Lead researcher Prof Graeme Hays from Deakin University said it was "really easy" to attach the tags. "We loop a cable tie around the peduncle that joins the swimming bell to the trailing arms," he explained. "It takes seconds, and the tag stays on indefinitely." At the same time, the researchers used floating sensors to monitor and measure the ocean currents.


This showed that the jellyfish were able actively to swim against the current, apparently in response to feeling themselves drift. In a second part of the study, the researchers used their data to create a realistic simulation of the movement of a bloom of jellyfish in the ocean. This showed, said Prof Hays, that "active and directed swimming helps maintain blooms", by keeping jellyfish in a particular area rather than allowing them to be dispersed or washed ashore by the currents.


"With this knowledge of their behaviour we can start to have some predictive capability for bloom dynamics," the scientist told BBC News. What is not yet clear is how exactly the jellyfish work out which way to travel. The scientists think the animals might sense the current across the surface of their bodies. They also speculate that the jellyfish might use the Earth's magnetic field to navigate - an ability seen in some other migrating marine species, including sea turtles.


One ultimate aim of studying and tracking swimming jellyfish is to improve the forecasting of jellyfish blooms, which have increased in frequency over the past decade, disrupting fisheries and stinging swimmers. Perhaps troublingly, these results show that swimming against the current helps hold blooms together, even in areas when currents are strong.

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Deep sea mining is the future in Papua New Guinea

Deep sea mining is the future in Papua New Guinea | Marine Science and Environment | Scoop.it

The world’s first deep-sea mine will open in 2018 in the waters off Papua New Guinea, with purpose-built machinery to extract precious metals from the sea bed.

 

In the territorial waters of Papua New Guinea (PNG), at a project known as Solwara 1, Nautilus Minerals has been granted the first lease to mine the deep sea for metals. With scarcity in resources around the world and countries needing more and more metals to sustain everyday life, mining the ocean floor is being looked at as a way to meet this demand.


Nautilus holds approximately 450,000 km2 of highly prospective exploration acreage in the western Pacific – in PNG, the Solomon Islands, Fiji, Vanuatu and Tonga, as well as in international waters in the eastern Pacific. Nautilus Minerals has been given a mining licence by the PNG government for its Solwara 1 site, and production will begin in 2018.


Advances in technology and the development of a legislative framework by the International Seabed Authority have made what was once thought of as impossible a reality. Mike Johnston, CEO at Nautilus Minerals, says: “Technology offshore has exploded within the oil and gas industry. The oil and gas industry is spending $300-$400billion a year on offshore petroleum technology. We are using those lessons.


“We have had all of this potential. The technological improvements we have seen over the last 40 or 50 years have allowed us to keep going into deeper and deeper water.” Soil Machine Dynamics (SMD), which has been developing technologies for the subsea oil and gas sector since the 1980s, will be providing the vehicles to be used for the mine.


Mike Jones, managing director at SMD, says: “We have worked closely with Nautilus to develop three vehicles that will be remotely operated to extract and collect minerals from the mine. There are significant challenges to create a mining system that will reliably operate more than a mile deep on a seafloor terrain of peaks and valleys. We have taken machinery used daily in land mining and tunnelling and married it with our know-how in subsea robotics.

“The individual machines weigh about the same as 20 London buses. Each is designed to carry out the specific tasks to build the mine-site roads and benches; extract the ore through cutting; and then deliver it to a huge subsea pump that brings it to the surface. The operation of the machines is directed from a control centre on the vessel. Here, pilots and co-pilots monitor and control each vehicle using the sonar and camera images that are relayed from each vehicle via an umbilical link.”

 

Resources being mined on land are becoming scarcer. The demand for copper is doubling every 15 to 20 years, as countries such as China and India industrialise. Preliminary discoveries have shown that resources on the seafloor are enormous. Johnston says: “Why would we want to continue to stress our planet and try to feed the world from the 30 per cent of the planet we can inhabit and ignore the other 70 per cent? That makes absolutely no sense whatsoever.


“Looking at the ocean, there are very large deposits of seafloor massive sulphides (SMSs), copper, nickel, cobalt and polymetallic nodules. And they are very high-grade compared with land-based deposits. On land the copper grade is now on average 0.6 per cent.

“SMS deposits have copper grades alone of nearly eight per cent, plus they contain around five or six grams of gold, which is a higher grade than most gold mines on land. Then if you look at the nodules, the deposits have grades of more than one per cent copper and more than one per cent nickel, 26 per cent manganese, and nearly 0.3 per cent cobalt. There is more copper on the sea floor than all the reserves on land.”

 

As this is the first commercial deep-sea mining project, Nautilus has been receiving interest from governments, authorities and other companies to see how it can be done environmentally safely and economically. Johnston says: “The trick is to do it right, which is what we are trying to do. We have been watched very closely and most people you talk to will tell you we are doing it right.”

Johnston explains the carbon footprint of deep-sea mining is smaller than on land. He says: “We are going to great lengths to make it, environmentally, one of the smallest footprints of any operation anywhere in the world.

 

“There is only so much recycling we can do, and there is only so much we can do on land. If mines get bigger, the footprints are getting even more enormous, the strip ratios are getting higher and higher. With seafloor mining, the footprints are very small and it is highly scalable. Once you do the first one and learn the lessons, the next one will be even better and then you will be able to do debt finance and people will want to be able to provide that finance.”

Countries in the western Pacific want to know more about the project as a way of helping to sustain their development.

 

“We are talking to a lot of governments in the western Pacific – smaller nations which are interested in it because they do not have any other opportunities,” Johnston says. “They only have a bit of fishing and that is about it. “Some of these countries do not even have a tourism industry as they are too remote. Exporting resources on the sea-floor is something they are interested in doing, so long as it is done right. A lot of them are watching and speaking to the PNG government to try to learn about it.


“The PNG government is a very supportive partner for us, and over the last six months they have worked really hard to get these final deals secured, bring us into production and make it happen.”

In partnership with SMD, Nautilus Minerals is pioneering the development of undersea mining. Governments, authorities and companies are already looking to it for guidance on how deep-sea extraction can be achieved safely and economically.

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Life from 'deepest drill' revealed

Life from 'deepest drill' revealed | Marine Science and Environment | Scoop.it

Life uncovered by the deepest-ever marine drilling expedition has been analysed by scientists. The International Ocean Discovery Program (IODP) found microbes living 2,400m beneath the seabed off Japan. The tiny, single-celled organisms survive in this harsh environment on a low-calorie diet of hydrocarbon compounds and have a very slow metabolism.


The findings are being presented at the America Geophysical Union Fall Meeting. Elizabeth Trembath-Reichert, from the California Institute of Technology, who is part of the team that carried out the research, said: "We keep looking for life, and we keep finding it, and it keeps surprising us as to what it appears to be capable of."


The IODP Expedition 337 took place in 2012 off the coast of Japan’s Shimokita Peninsula in the northwestern Pacific. From the Chikyu ship, a monster drill was set down more than 1,000m (3,000ft) beneath the waves, where it penetrated a record-breaking 2,446m (8,024ft) of rock under the seafloor.

 

Samples were taken from the ancient coal bed system that lies at this depth, and were returned to the ship for analysis. The team found that microbes, despite having no light, no oxygen, barely any water and very limited nutrients, thrived in the cores. To find out more about how this life from the "deep biosphere" survives, the researchers set up a series of experiments in which they fed the little, spherical organisms different compounds.


Dr Trembath-Reichert said: "We chose these coal beds because we knew there was carbon, and we knew that this carbon was about as tasty to eat, when it comes to coal, as you could get for microbes.

"The thought was that while there are some microbes that can eat compounds in coal directly, there may be smaller organic compounds – methane and other types of hydrocarbons - sourced from the coal that the microbes could eat as well."

 

The experiments revealed that the microbes were indeed dining on these methyl compounds. The tests also showed that the organisms lived life in the slow lane, with an extremely sluggish metabolism. They seem to use as little energy as possible to get by.

 

The researchers are now trying to work out if there are lots of different kinds of microbes living in the coal beds or whether there is one type that dominates. They also want to find out how the microbes got there in the first place. "Were these microbes just in a swamp, and loving life in a swamp, because there is all sorts of carbon available, oxygen, organic matter... and then that gets buried?" pondered Dr Trembath-Reichert. "It could be that they didn’t get a chance to escape – they couldn’t exactly walk out. So is it that they were there to begin with and then they could maintain life? "Or were they like microbes that were able to travel down to those depths from the surface?"


The discovery of vast ecosystems of microbes deeper and deeper underground is causing scientists to reassess the role that these organisms play in the carbon cycle. Because these organisms take in hydrocarbons and expel methane, a greenhouse gas, as a waste product, they may be having a greater impact on the system that governs the Earth’s climate than was previously thought.

The findings also have implications for the hunt for life on other planets.

 

If life can survive in the most extreme conditions on Earth, perhaps it has found a way to cope with harsh environments elsewhere in the cosmos.

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Key Role for NOC in Major European Marine Science Project

The National Oceanography Centre (NOC) is to play a leading role in the largest marine science project that the European Commission has ever funded. The EUR20 million AtlantOS project, due to start in January 2015 and led by Professor Dr Martin Visbeck (GEOMAR), will bring together a wide spectrum of scientific disciplines from over 60 research organisations across the world in order to enhance the efficiency of Atlantic ocean observation procedures. The project is to run for 51 months.

 

 By fundamentally restructuring and integrating the existing, loosely-coordinated Atlantic ocean monitoring activities, as well as filling in the gaps, the multi-disciplinary AtlantOS project will result in more efficient, more complete and lower cost information delivery. The result is expected to have benefits ranging from improved safety planning for coastal communities in the event of oil spills, to better implementation of marine policies and more accurate weather forecasting for offshore energy.

 

AtlantOS will improve the readiness of existing ocean observing networks and data systems, as well as strengthening Europe’s contribution to the Global Ocean Observing System. Within this project, NOC will be playing the integral role of linking coastal and offshore systems through sea level work and coastal biogeochemical projects, as well as coordinating field observations, creating products to aid weather prediction and leading the development of new observation technologies, techniques and systems to deliver data on all priority parameters.

 

Dr Matt Mowlem, who leads technology developments in NOC and AtlantOS, expects that AtlantOS will support the development of technologies and techniques. It will also address the current lack of data for chemical and biological process in ocean observing, which should enable a step-change in our ability to understand and manage this unique environment.

 

Professor Ian Wright, who is the Director of Science and Technology at NOC, observed that this type of project “is central to the NOC’s ambitions in developing in situ and persistent observing of multiple ocean parameters within a context of working with strong European partners.”

 

The AtlantOS project has received funding from the European Commission through the first ‘Blue Growth’ Horizon2020 call, which aims to promote growth in the ocean economy through innovation and the improved sharing of data. The project will last 51 months.

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