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Hundreds of methane plumes spotted on sea floor

Hundreds of methane plumes spotted on sea floor | Marine Science and Environment |

Plumes of bubbles streaming from hundreds of newly discovered sea-floor seeps between North Carolina and Massachusetts are likely to contain methane and could be adding as much as 90 tonnes of the planet-warming gas to the atmosphere or overlying waters each year, research published Sunday in Nature Geoscience suggests.


An estimated two-thirds of the emissions emanate from sediments at depths where methane-rich ices may be decomposing due to warming waters along the ocean bottom, the researchers say. Effects of these plumes on climate and ocean chemistry are not yet clear, but could extend well beyond the plumes themselves.


The bubble streams showed up on sonar scans of the sea floor taken between September 2011 and August 2013 during oceanographic expeditions ranging from Cape Hatteras in North Carolina to Georges Bank off Cape Cod. Altogether, researchers analysed data covering a 94,000-square-kilometre arc (an area about the size of Indiana or Hungary) that includes the edge of the continental shelf and the steep slope just seaward of it, says co-author Adam Skarke, a geologist at Mississippi State University in Starkville. Within a distance of about 950 kilometres, the team found about 570 bubble plumes — an astounding number considering that scientists had previously reported only a handful in the region, he notes.


Although some of the plumes extended hundreds of metres above the ocean floor, the bubbles emanating from deep-water sources typically dissolved into the sea long before they could breach the surface, says Skarke.


“I’m not that surprised that people haven’t seen these things before,” says Tim Minshull, an oceanographer at the University of Southampton, UK, who was not involved in the work. “These features are quite narrow, sometimes just a few metres across, and the ocean’s a big place.”


Researchers have not yet collected samples of the bubbles, says Carolyn Ruppel, a geophysicist with the US Geological Survey in Woods Hole, Massachusetts, and a co-author on the study. Nevertheless, they are presumed to contain methane because of their sources, she notes. Some of the shallow-water seeps are likely to be in now-submerged areas that were methane-producing wetlands during the most recent ice age, when sea levels were more than 100 metres lower than they are today.


However, many of the sources along the continental slope lie at cold depths in which ices have formed at high pressures within sea-floor sediments, which once trapped methane produced by microbes living there. These ices may now be slowly breaking down because of the warming of overlying waters, says Skarke. At least one previous study2 has hinted that warming waters are destabilizing methane-rich ices at moderate depths farther south along the US Atlantic coast.


Sampling the bubbles, along with the waters in and around the plumes, will help scientists to estimate the effects of the methane emissions, says Skarke. The gas reacts with, and thereby diminishes, dissolved oxygen, a process that creates carbon dioxide that will tend to acidify surrounding waters.


“This is a very careful study that lays the groundwork for further research,” says Ronald Cohen, a geologist at the Carnegie Institution for Science in Washington DC, who was not involved in the study. Among other things, he notes, “scientists would like to know what these sources are, how much methane they’re producing, and how those sources vary over time.”


Although Skarke and his colleagues suspect that warming waters may be boosting rates of methane emission, the amounts of carbonate minerals seen at some deep sites visited by remotely operated vehicles — which are created by methane-munching microbes and typically accumulate at less than 5 centimetres per 1,000 years — suggest that some of the seeps have been active for a millennium or more.

This article is reproduced with permission and was first published on August 24, 2014.

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Pushing frontiers of deep sea exploration

Pushing frontiers of deep sea exploration | Marine Science and Environment |

Marine scientists are delighted with the latest video footage of life and death from the deepest, most mysterious region of the ocean. One has described it as the best they have yet collected. A deep sea probe shot the videos in April and May during an expedition that plumbed the 10,000m depths of the Kermadec Trench, northeast of New Zealand.

The images reveal the hunting strategy of a large enigmatic fish, the swimming style of a gigantic deep sea crustacean and new information on the activities of the world's deepest living fish. These are new insights on the behaviour of marine animals which inhabit one of the most extreme and inhospitable realms of the planet - the ocean depth range between 6,000m to 11,000m where the floor of the abyss plunges into great troughs, known as ocean trenches.

Oceanographers call it the hadal zone. At its lowest point, the pressure reaches one tonne per square centimetre and the temperature drops to one degree C. The technical challenges to sending manned and unmanned submersibles into this environment mean that a sizeable portion of the planet's sea floor remains terra incognito.

According to Andy Bowen, chief engineer at the Woods Hole Oceanographic Institution (WHOI) in the US: "The hadal zone… represents an area somewhat equivalent to that of North America. So it's a substantial area of the ocean that is essentially unexplored." Marine biologist Alan Jamieson of the University of Aberdeen in Scotland regards this as an unacceptable gap in our knowledge of the ocean ecosystem.

"The hadal zone is 45% of the ocean's depth range. So the entire discipline of deep sea biology has concentrated on the shallowest 50% and that seems wrong," he said. Jamieson led the team which collected the latest video material. He talks about the expedition and its discoveries in the science radio series Into the Abyss on BBC Radio 4.

His spectacular images are some consolation for a technical disaster during the scientific voyage: The catastrophic implosion at 10km depth of the US$3.1m submersible robot, Nereus. Nereus was the world's most advanced deep sea research vehicle - designed and built at Woods Hole. Nereus was lost during only its second mission in the hadal zone.

The expedition was the first to attempt to study systematically an ocean trench at the different depths across its entire width. It was the inaugural mission of an international research programme called Hades - Hadal Ecosystem Studies. The scope of that project is much reduced with the destruction of Nereus at the bottom of the Kermadec Trench.


Trenches exist where tectonic plates of ocean crust collide. One great raft of crust is slowly descending into the Earth's interior beneath the edge of the other plate. At the surface, the junction between them is the trench - a broadly V-shaped feature which can run thousands of kilometres in length. The deepest is the Mariana Trench with a floor as deep as 11,000 metres at one location.

The Hollywood film maker Cameron visited its lowest point, Challenger Deep, in 2012. Cameron's submarine mission cost millions of dollars and he reported seeing little in the way of interesting creatures. Alan Jamieson's new video images came at much cheaper price. The videos were captured during several deployments of a device called a hadal lander. A lander is relatively simple piece of hardware: lights and cameras within a pressure-resistant housing. It also carries a pole on which a dead fish is secured. The bait lures hadal creatures into the camera's field of view, once the whole contraption has been dropped to the sea floor.

In the recent Kermadec expedition, the Aberdeen team began their deployments in the relative shallows. At 1,554m depth, the lander and its mackerel lure pulled in a mass of squirming eels of two species: large arrow tooth eels and smaller snubnose eels. The video camera caught the last few seconds of existence for a snubnose eel. In the frenzy of scavenging, a large arrow tooth grabbed the smaller species and carried it off, undulating backwards, into the darkness. "That was a direct kill," said Alan Jamieson.

Even at 1,500 metres, food parcels like the one delivered by the lander are few and far between. Fish detect its odour and emerge from the enveloping darkness to converge on the feast. All species in this environment will scavenge but the new footage creepily shows that a feeding frenzy is also an opportunity for predation.


Another revelation about deep sea hunting behaviour came with a deployment to the upper slopes of the trench itself at 5100 metres. Eel-like fish called cusk eels are frequently spotted at this depth, and deeper. The deep dwelling cusk eels, Bassozetus sp, grow up to one metre in length.


Alan Jamieson said that on previous expeditions, he often saw cusk eels come to the bait but he never saw them do anything interesting. This time the lander caught several occasions when they burst into action in what Jamieson described as some of the best video sequences he's ever taken. The fish's glum-looking, tight-lipped face opens up to form a submarine vacuum cleaner.


The cusk eel holds its position at the bait and waits for the odour of dead fish to attract crustaceans called amphipods. Amphipods are the most abundant of free-swimming creatures in the deepest depths. Dr Jamieson theorises that cusk eels only spring into action when amphipods large enough to bother with swims close. When the fish somehow detects their proximity, its mouth springs wide open in a split second, sucking up the amphipod in a rush of water.


Deeper in the trench, there is an amphipod species which has nothing to fear from fish. This creature is unofficially known as the Supergiant - its scientific name is Alicella gigantea. The Kermadec expedition this year captured the first footage of the Supergiant swimming. On this occasion, the animal was caught, brazenly ploughing through a shoal of pink snailfish at 7,243 metres below the surface.


Most members of the amphipod group are small, typified by the species many of us are likely to have encountered: the sand hoppers which ping out of disturbed seaweed on the beach. The adult Supergiant is colossal compared to any other amphipod species. On previous expeditions in the Kermadec and Japan trenches, individuals brought up in deep sea traps have measured as long as 28 centimetres, almost one foot.

Marine biologists speculate that Supergiants evolved gigantic size as a defence against predation. At some point in the past, their ancestors had the luck to develop mutations in genes which regulate growth. Another adaptation to this environment are food stores in their bodies, according to marine biologist Ashley Rowden at New Zealand's National Institute of Water and Atmospheric Research. He said that Supergiants which have been brought to the surface feel as though they are made of wax.

"The belief is that the waxy materials are a food storage source for times when there isn't food for those Supergiants to exist on. They are able to use what they've stored from a previous big feast." Sharing the Middle Trench depth range with the Super Giants are the snailfish - the deepest living fish known. They have the appearance of large tadpoles made of pink jelly. They are semi-transparent. The lights of the hadal camera illuminate orange blobs within their bodies. These blobs are their livers.

Snailfish feed on small amphipods. The greatest depth at which they have been seen is 7,700 metres. The fish (Notoliparis kermadecensis) in the Kermadec Trench look more or less identical to those seen in the Japan Trench way to the north. However genetic analyses show they are different species and not that closely related to one another. They are closer cousins of the shallower water snailfish species in their respective parts of the world.


On this and previous expeditions, snailfish have been brought to the surface in traps. According to Ashley Rowden, the jelly-like consistency makes a snailfish hard to handle. "It's like handling a water-filled condom. It slips around in your hand and you're not quite sure which bit you should be holding so that it doesn't drop to the deck."


The latest footage of snailfish in their natural environment reveals them to be more numerous and more energetic than the scientists had supposed. Alan Jamieson says the snailfish had also appeared to be wedded to the sea floor. The new video reveals them disporting in mid water around a precipitous cliff of volcanic rock. The water depth here was 7,669 metres.


"We always thought that when you get down to those depths, you'd be lucky if you saw one or two, eking out an existence in this really deep water but we've been very, very surprised to see so many being so active," said Alan Jamieson. "The more I do this the more I don't consider the very deepest parts of the ocean as that different (from the rest of it). They are not weird and 'out there'…. They are just an extension of every other marine environment."

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Tags reveal Chilean devil rays are among ocean's deepest divers

Tags reveal Chilean devil rays are among ocean's deepest divers | Marine Science and Environment |

A new study shows that devil rays plunge nearly 2km below the ocean surface, making some of the deepest and fastest dives ever observed in the sea. Scientists tracked 15 of the large, winged fish, previously thought to be surface dwellers, for several months. In between their icy dives, they appear to bask near the surface to warm up.

The findings, published in Nature Communications, offer an explanation for a mysterious mass of blood vessels, thought to keep the ray's brain warm. The front part of the animal's skull is stuffed with a sponge-like mesh of large and small arteries. This network, called a rete mirabile, was described in the devil rays 30 years ago.

During the day, the rays would spend time up at the surface—presumably heating up—immediately before, and then again, after a deep dive. How else might these animals be dealing with the cold temperatures of the deep ocean?


A previous study in the 1970s found that several species of devil rays possess a physiological adaptation —well-developed blood vessels around the cranial cavity that essentially serve as heat exchange systems. At the time, it was hypothesized that the rays must be using this adaptation to cool down rather than warm up.


"Rays were always seen in very warm water up at the surface, so why would they need an adaptation for cold water? Once we looked at the dive data from the tags, of course it made perfect sense that the rays have these systems. Sometimes they're down diving for two or three hours in very cold water—two to three degrees Celsius (35.6 to 37.4 degrees Fahrenheit)," Thorrold said.


While it's not certain what the rays are doing at these depths, the dive profiles suggest that they're foraging on large numbers of fish that live in deeper waters. "There's an enormous amount of biomass in the deep ocean that we're only starting to understand the significance of," said co-author Camrin Braun, a graduate student in the MIT/WHOI Joint Program in Oceanography. "This paper suggests that devil rays are aware of and regularly exploit this resource, which demonstrates an unexpected new link between the surface and deep ocean."

Devil rays are coming under increasing pressures from fishing, particularly in the Indian and Pacific Oceans. Manta gill rakers are targeted for Chinese medicine, and their cartilage is used as filler in shark fin soup. "Ultimately, answering whether these animals depend on the deep layers of the ocean for their feeding and survival could have major implications for their management and that of oceanic habitats," added co-author Pedro Afonso, a researcher at the Institute of Marine Research (IMAR) at the University of the Azores and the Laboratory of Robotics and Systems in Engineering and Science (LARSyS).

Little is known about the life span of devil rays or at what age they reproduce. Like other large rays, devil rays are thought to have just one pup born per litter about every two years. "With those kinds of low reproductive rates, any type of mortality is going to have a big impact on the species," Thorrold said. "We don't know enough about devil rays to even know if we should be worried about their status. There are lines of evidence to suggest we ought to be worried, or at least that we should be trying to learn more about the biology and ecology of these rays."

Via Gaye Rosier
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England's marine conservation network is worse than useless

England's marine conservation network is worse than useless | Marine Science and Environment |

0.000001 – one hundred thousandth – is a number so small that to most people it seems like nothing at all. Yet four and a half years since the Marine Act of 2009 came into force – legislation that was heralded as the saviour of UK seas – this is the sum total of UK waters that is protected from all fishing for the purpose of nature conservation.


The Marine Act is that rare thing: a law supported by all political parties. The sea is dear to so many of us it transcends ideology. In the run up to the law's enactment, there was widespread recognition that the seas were in trouble. Fisheries were in decline, once rich habitats had been stripped by two centuries of destructive fishing, and formerly abundant species had been brought to the verge of disappearance. Five such endangered species are featured on a set of stamps issued this month by the Royal Mail: sturgeon, common skate, spiny dogfish, conger eel and wolffish. There are dozens more.


Recognising the emerging crisis, coastal nations of the world committed in 2002 at the World Summit on Sustainable Development to establish national networks of marine protected areas by 2012. The Marine Act established the legal framework for a UK marine protected area network that would be comprehensive and representative of the full spectrum ofmarine life, complementing more narrowly targeted EU directives.


In a spirit of optimism, work began in 2010 to build an English network of protected areas by 2012 (Scotland and Northern Ireland have passed domestic versions of the Marine Act and are working to longer timetables).


In late 2012, 127 marine conservation zones and 65 reference areas (places to be protected from all fishing) were recommended to the government. If implemented in full and protected fully from damaging activities, this would be a world-class network. It would lay the foundation for a spectacular resurgence of life in the sea and boost the prosperity of marine industries, including fishing. So the reaction was one of widespread dismay when the government announced in late 2013 that it would only establish 27 marine conservation zones and not a single reference area.


nder pressure from conservation bodies, tens of thousands of citizens and a group of 86 leading scientists, the government announced that there would be two more tranches of marine conservation zones to complete the network by 2016. In the first, a further 37 sites are now under consideration.


But this is where marine policy unravels comprehensively. None of the 27 conservation zones declared in 2013 have yet received any new protection. My students and I have probed Department for Environment, Food and Rural Affairs, the Marine Management Organisation and various inshore fisheries and conservation authorities and it seems that virtually no new protection is on offer. In fact they seem to be falling over themselves to reassure the fishing industry that the zones will be open to business as usual. Even in the few small places where protection from certain fishing methods is being (reluctantly) entertained the measures will be entirely voluntary.


Which begs the question: what was the point? Why spend upwards of £10m to create an elaborate network of paper parks? Why have a law that permits mandatory protection and leave protection to the goodwill of users?


As a professional marine scientist with 25 years' experience researching the effects of marine protected areas worldwide, I think this leaves us in a worse position than before the Marine Act was conjured into being. Before there was nothing and we knew it. Now there is the illusion of protection. The person in the street will think the sea is well looked after at last, but there is still nothing. This network is worse than useless. Marine conservation policy has drifted far off its original course.


There is abundant evidence from places where other nations have been less hesitant, that marine protected areas work well when they are fully protected from fishing, and produce little benefit at all if left open to destructive fishing methods like bottom trawling and scallop dredging. No amount of official reassurance or obfuscation on marine conservation zones (they are beginning to seem like the same thing) can alter this fact. In the sea as in many walks of life, there is no free lunch. You get what you pay for. Benefits will only flow from protected areas where a high level of protection is given, backed by law, and enforced with determination.


There is still a way to rescue this sinking ship. The government should give full protection from all mobile fishing gears to the entirety of every zone they create, and place a significant fraction of them off limits to all fishing. It is the only way we can hope to restore the vitality, diversity and productivity of our seas, and offer a chance of recovery for endangered fish like the common skate, wolffish and sturgeon.

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How big data is providing pearls of wisdom for Tasmanian oyster farmers

How big data is providing pearls of wisdom for Tasmanian oyster farmers | Marine Science and Environment |

Big data has the potential to transform the way natural resources are managed but, despite small scale successes, Australia lacks a clear strategy.


It takes human senses to appreciate the wonders of Australia’s natural environment. But it is machine intelligence that may prove critical to our ability to manage it. Numerous projects around Australia are now using advanced data analytics techniques (also known as big data) to better understand and manage the complexity of natural systems. Modern analytical techniques – particularly the capability to analyse and compare vast sets of data simultaneously – are delivering new capabilities to understand how natural systems work.

The hope is that through better understanding the interplay of different systems through data it may be possible to manage natural resources in a way that is both more efficient and more sustainable. This is the intention of Sense-T, a sensing and data analysis project currently being developed in Tasmania by the CSIRO, University of Tasmania and numerous supporting parties including environmental groups and farmers.

It is using vast volumes of data already collected by the state to better manage its natural resources, while augmenting this with new sensor-based data sets to provide specific details. The four projects currently underway cover beef and dairy production, viticulture, aquaculture and water management, and have even seen researchers attaching sensors to oysters to collect data for farm management.

Sense-T’s director, Ros Harvey, says where possible the projects will re-purpose existing data sources for new purposes, such as using environmental monitoring data to improve farming methods. “And we are looking at repurposing production optimisation data from our agricultural projects and repurposing that for environmental reporting,” Harvey says. “If we repurpose individual farm-level data and aggregate it up, can it become a really important source of environmental monitoring that can be used for public policy purposes?”

Sense-T’s oyster farming project for instance is taking existing data on inflows into water catchments and using this to help farmers determine when environmental pollutants will move in and out of their farming areas, helping them better determine the optimal times for harvesting.

In Tasmania’s north-east, a water catchment management program is providing farmers with real-time information on the health of waterways to reduce the number of times a year that farmers are issued with orders to stop drawing water for environmental reasons.


“We were working with the community to develop a dashboard that allows that community to actually understand what is happening with the environmental flows in the river that they are drawing irrigation from,” Harvey says. Vital to the success of Sense-T is a partnership with Sirca, a not-for-profit organisation focused on financial research and innovation, but whose big data crunching capabilities have proven adaptable to the needs of Sense-T.

The concept of using big data for environmental purposes is only just beginning to be understood within the public sector. While the Australian public service big data strategy does make reference to the use of analytics to monitor environmental issues, activity today is being driven by individual departments or research projects.


But nationwide examples do exist. One of the biggest users of big data for environmental management is the Bureau of Meteorology (BoM), which also makes available large data sets for external analysis. This includes past weather and climate information from its weather stations, with many popular data sets available free of charge. The BoM has also been a key contributor to CRCSI (Cooperative Research Centre for Spatial Information), and specifically to a project that is using archival data from the Landsat satellites. This includes information on characteristics of the earth’s surface taken at a resolution of 25 metres and refreshed every 16 days stretching back to 1987. 

According to CRCSI’s business development and research manager, Philip Tickle, this information is vital in helping land managers understand changes in ground cover and water. “A landholder will be able to bring in a boundary of a paddock or farm and get the average ground cover for the last 30 years and how it compares to neighbours,” Tickle says.

What makes this possible is use of the National Computing Infrastructure at the Australian National University, which provides the computational grunt to crunch the petabytes of data that the Landsat archives contain. “Something that might have taken three to five years’ worth of computing two or three years ago can basically be run overnight now,” Tickle says.

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Marine science: challenges for a growing 'blue economy'

Marine science: challenges for a growing 'blue economy' | Marine Science and Environment |

AUSTRALIA 2025: How will science address the challenges of the future? In collaboration with Australia’s chief scientist Ian Chubb, we’re asking how each science discipline will contribute to Australia now and in the future. Written by luminaries and accompanied by two expert commentaries to ensure a broader perspective, these articles run fortnightly and focus on each of the major scientific areas. In this instalment we dive into marine science.


Why are our oceans important to us? How is our health, the health of the environment, the strength of our economy and indeed, our future, dependent on the seas? How can marine science help us, collectively, to sustainably develop our marine-based industries and at the same time protect our unique marine ecosystems so that they can be appreciated and enjoyed by future generations?


In many ways, Australia is defined by the oceans that surround us. We have the third largest ocean territory in the world. The majority of our trade travels by sea, vast offshore oil and gas resources earn vital export income and offer a long term, cleaner energy source than coal and our fisheries and aquaculture industries provide healthy food.


We are custodians of two magnificent marine World Heritage Areas – the Great Barrier Reef and Ningaloo Reef – and we are a nation that loves to sit by, swim, surf, dive, fish and sail in the (mostly) clean waters and healthy marine ecosystems that surround our continent.


Australia’s affinity with our ocean estate is perhaps best exemplified by the fact that 85% of our population lives within 50km of the coast. Marine industries contributed approximately A$42 billion to our economy in 2010. This is projected to grow to approximately A$100 billion by 2025 with the expansion of current industries and development of new opportunities in areas such as renewable energy. As a nation we will increasingly be dependent on our “blue economy” for our future prosperity.


In addition to their economic and aesthetic value, our oceans also provide a suite of essential “ecosystem services” – most importantly in their role within the global climate system. Since the end of the 18th century, about 30% percent of human-induced carbon dioxide emissions have been taken up by the oceans while over the past 50 years, they have absorbed about 90% of the extra heat generated through the impacts of the greenhouse effect. The moderating influence of the oceans as our planet warms, and their very strong influences on our island continent’s weather, impact on every Australian, every day.


If Australia, and indeed the world at large, is to continue to enjoy and grow the benefits accrued from our oceans, we need to face up to and meet a number of significant (and in some cases urgent) challenges.

Australia’s marine science community recently collaborated with governments, not-for-profit organisations and the private sector to produce the report Marine Nation 2025: Marine Science to Support Australia’s Blue Economy.


Marine Nation 2025 outlined six, interconnected “grand challenges” facing Australia, each of which has a significant marine dimension with gaps in understanding or requirement for tools that can be addressed by marine science:


1) sovereignty, security, natural hazards: needs improved operational oceanographic forecasting and increased effort on fine-scale hydrographic data and charts.


2) energy security: needs support for developing energy resources, particularly liquid natural gas and renewable energy and research to support carbon sequestration.


3) food security: needs research to support a booming aquaculture industry, as well as data and tools to improve management of wild-catch fisheries.


4) biodiversity conservation and ecosystem health: needs environmental baselines, effective indicators of ecosystem health to guides national marine environmental monitoring, and tools to predict impacts of development on marine biodiversity.


5) dealing with changing climate: needs enhanced understanding and skill in prediction of the impacts of sea level rise, increasing sea temperature and ocean acidification and the role of the ocean as a carbon sink.


6) optimal resource allocation: needs integrated social, economic and environmental information and tools to assist transparent, robust and accountable decision-making.


The multidisciplinary nature of marine science, the geographic scale and connectedness of marine systems, and the complexity of the challenges above mean that in the majority of cases no one institution (or in the case of industry, one company) can build the evidence base or tools required to adequately address these challenges, even at local scales.

Thus, a dedicated and coordinated effort across our national marine science community, governments and industry is required.


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Antarctica's ice losses double

Antarctica's ice losses double | Marine Science and Environment |

Antarctica is now losing about 160 billion tonnes of ice a year to the ocean - twice as much as when the continent was last surveyed. The new assessment comes from Europe's Cryosat spacecraft, which has a radar instrument specifically designed to measure the shape of the ice sheet.


The melt loss from the White Continent is sufficient to push up global sea levels by around 0.43mm per year. Scientists report the data in the journal Geophysical Research Letters. The new study incorporates three years of measurements from 2010 to 2013, and updates a synthesis of observations made by other satellites over the period 2005 to 2010. Cryosat has been using its altimeter to trace changes in the height of the ice sheet - as it gains mass through snowfall, and loses mass through melting.


The study authors divide the continent into three sectors - the West Antarctic, the East Antarctic, and the Antarctic Peninsula, which is the long finger of land reaching up to South America. Overall, Cryosat finds all three regions to be losing ice, with the average elevation of the full ice sheet falling annually by almost 2cm.


In the three sectors, this equates to losses of 134 billion tonnes, 3 billion tonnes, and 23 billion tonnes of ice per year, respectively. The East had been gaining ice in the previous study period, boosted by some exceptional snowfall, but it is now seen as broadly static in the new survey.


As expected, it is the western ice sheet that dominates the reductions.

Scientists have long considered it to be the most vulnerable to melting.

It has an area, called the Amundsen Sea Embayment, where six huge glaciers are currently undergoing a rapid retreat - all of them being eroded by the influx of warm ocean waters that scientists say are being drawn towards the continent by stronger winds whipped up by a changing climate.


About 90% of the mass loss from the West Antarctic Ice Sheet is going from just these few ice streams. At one of them - Smith Glacier - Crysosat sees the surface lowering by 9m per year.


"CryoSat has given us a new understanding of how Antarctica has changed over the last three years and allowed us to survey almost the entire continent," explained lead author Dr Malcolm McMillan from the NERC Centre for Polar Observation and Modelling at Leeds University, UK. "We find that ice losses continue to be most pronounced in West Antarctica, along the fast-flowing ice streams that drain into the Amundsen Sea. In East Antarctica, the ice sheet remained roughly in balance, with no net loss or gain over the three-year period," he told BBC News.


Cryosat was launched by the European Space Agency in 2010 on a dedicated quest to measure changes at the poles, and was given a novel radar system for the purpose. It has two antennas slightly offset from each other. This enables the instrument to detect not just the height of the ice sheet but the shape of its slopes and ridges. This makes Cryosat much more sensitive to details at the steep edges of the ice sheet - the locations where thinning is most pronounced. It also allows the satellite to better detect what is going on in the peninsula region of the continent where the climate has warmed rapidly over the past 50 years.


"The peninsula is extremely rugged and previous satellite altimeters have always struggled to see its narrow glaciers. With Cryosat, we get remarkable coverage - better than anything that's been achieved before," said Prof Andy Shepherd, also of Leeds University.


The GRL paper follows hard on the heels of two studies that have made a specific assessment of the future prospects for the Amundsen Sea Embayment. One of these reports concluded that the area's glaciers were now in an irreversible retreat. The other paper, considering one of the glaciers in detail, suggested the reversal process could take several hundred years to be completed.


A loss of all the ice in the six glaciers would add about 1.2m to global sea level. This is still a small fraction of the total sea-level potential of Antarctica, which holds something like 26.5 million cubic km ice (or 58m of sea-level rise equivalent). But the continent has been largely insulated from some of the warming influences taking place elsewhere in the world and it is important, say scientists, to keep a check on any changes that are occurring, and the speed with which they are happening.


Prof Duncan Wingham proposed the Cryosat mission and is its principal investigator. He told BBC News: "We lack the capability to predict accurately how the Amundsen ice streams will behave in future. "Equally, a continuation or acceleration of their behaviour has serious implications for sea level rise. This makes essential their continued observation, by Cryosat and its successors."


And Prof David Vaughan of the British Antarctic Survey was not involved in the Cryosat survey. He commented: "The increasing contribution of Antarctica to sea-level rise is a global issue, and we need to use every technique available to understand where and how much ice is being lost. "Through some very clever technical improvements, McMillan and his colleagues have produced the best maps of Antarctic ice loss we have ever had. Prediction of the rate of future global sea-level rise must be begin with a thorough understanding of current changes in the ice sheets - this study puts us exactly where we need to be."

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Human litter found in Europe's deepest ocean depths

Human litter found in Europe's deepest ocean depths | Marine Science and Environment |

Bottles, plastic bags, fishing nets and other human litter have been found in Europe's deepest ocean depths, according one of the largest scientific surveys of the seafloor to date. Scientists used video and trawl surveys to take nearly 600 samples from 32 sites in the Atlantic and Arctic oceans and the Mediterranean Sea, from depths of 35 metres to 4.5 kilometres. They found rubbish in every Mediterranean site surveyed, and all the way from the continental shelf of Europe to the mid-Atlantic ridge, around 2,000km from land.


Plastic was the most common type of litter found on the seafloor, accounting for 41%, while rubbish associated with fishing activities (discarded net and fishing lines) made up 34%. Glass, metal, wood, paper and cardboard, clothing, pottery and unidentified materials were also documented.


Jonathan Copley, senior lecturer in marine ecology at the University of Southampton, who did not take part in the study, said: "This very important research confirms what most of us who work in the deep ocean have noticed for quite some time – that human rubbish has got there before us.


"But this paper presents an analysis of the kinds of rubbish, what is common where, and what sort of activities are having the most impact in terms of rubbish reaching the deep ocean in different regions. People are piecing this together on a global scale to appreciate how widespread this problem is potentially."


As more of Europe's deep seafloor is being explored, litter is being revealed as far more widespread than previously thought. While individual studies have used trawling to quantify the amount of litter in particular areas or remotely operated vehicles to study the types ofwaste, this paper is the first to analyse the patterns of distribution and abundance of litter across different underwater geographical settings and depths.


The most dense accumulations of litter were found in deep underwater canyons, and the lowest density on continental shelves and ocean ridges, according to the international study involving 15 European organisations.


Dr Kerry Howell, associate professor at Plymouth University's Marine Institute, who took part in the study, said: "This survey has shown that human litter is present in all marine habitats, from beaches to the most remote and deepest parts of the oceans. Most of the deep sea remains unexplored by humans and these are our first visits to many of these sites, but we were shocked to find that our rubbish has got there before us."


Litter disposal and accumulation in the marine environment is one of the fastest growing threats the health of the world's oceans, with an estimated 6.4m tonnes of litter entering the oceans each year.

Plastics are by far the most abundant material, introducing toxic chemicals that can be lethal to marine fauna and break down into "microplastics" that have become the most abundant form of solid-waste pollution on Earth. Plastic pollution has also been found to be changing microbial processes in the ocean.


Besides the visible impact of marine pollution, litter can be mistaken as food and ingested by a wide variety of marine organisms. Entanglement in derelict fishing gear – known as "ghost fishing" – is a serious threat to mammals, turtles, birds and corals. Floating litter also facilitates the transfer of alien species to new habitats.


Scientists said one interesting discovery made in the study related to seafloor deposits of clinker – the residue of burnt coal dumped by steam ships from the late 18th century onwards. Marine biologist Dr Eva Ramirez-Llodra said: "We have known that clinker occurs on the deep-sea bed for some time, but what we found was the accumulation of clinker is closely related with modern shipping routes, indicating that the main shipping corridors have not been altered in the last two centuries."

The report also showed the path that materials such as plastics can take, originating from coastal and land sources and being carried along continental shelves and slopes into deep water.


Dr Veerle Huvenne, seafloor and habitat mapping team leader at the National Oceanography Centre, Southampton, said: "Submarine canyons form the main connection between shallow coastal waters and the deep sea. Canyons that are located close to major coastal towns and cities, such as the Lisbon canyon offshore Portugal, or the Blanes canyon offshore Barcelona, can funnel litter straight to water depths of 4,500m or more."


The paper, Marine litter distribution and density in European Seas, from the shelves to deep basins, was published in the journal PLOS ONE.

The study was led by the University of the Azores, and is a collaboration between the Mapping the Deep Project led by Plymouth University and the Hermione Project, coordinated by the National Oceanography Centre, Southampton.

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Agreement reached on deep sea mining

Agreement reached on deep sea mining | Marine Science and Environment |

Plans to open the world's first mine in the deep ocean have moved significantly closer to becoming reality. A Canadian mining company has finalised an agreement with Papua New Guinea to start digging up an area of seabed. The controversial project aims to extract ores of copper, gold and other valuable metals from a depth of 1,500m.

However, environmental campaigners say mining the ocean floor will prove devastating, causing lasting damage to marine life. The company, Nautilus Minerals, has been eyeing the seabed minerals off Papua New Guinea (PNG) since the 1990s but then became locked in a lengthy dispute with the PNG government over the terms of the operation.

Under the agreement just reached, PNG will take a 15% stake in the mine by contributing $120m towards the costs of the operation.


Mike Johnston, chief executive of Nautilus Minerals, told BBC News: "It's a taken a long time but everybody is very happy." "There's always been a lot of support for this project and it's very appealing that it will generate a significant amount of revenue in a region that wouldn't ordinarily expect that to happen."

The mine will target an area of hydrothermal vents where superheated, highly acidic water emerges from the seabed, where it encounters far colder and more alkaline seawater, forcing it to deposit high concentrations of minerals. The result is that the seabed is formed of ores that are far richer in gold and copper than ores found on land.

Mr Johnston said that a temperature probe left in place for 18 months was found to have "high grade copper all over it".


For decades, the idea of mining these deposits - and mineral-rich nodules on the seabed - was dismissed as unfeasible because of the engineering challenge and high cost. But the boom in offshore oil and gas operations in recent years has seen the development of a host of advanced deep sea technologies at a time when intense demand for valuable metals has pushed up global prices.

The mine, known as Solwara-1, will be excavated by a fleet of robotic machines steered from a ship at the surface. The construction of the largest machine, a Bulk Cutter weighing 310 tonnes, has just been completed by an underwater specialist manufacturer, Soil Machine Dynamics (SMD), based in Newcastle, UK. The plan is to break up the top layer of the seabed so that the ore can be pumped up as a slurry.

The agreement with PNG now clears the way for Nautilus to order a specialist vessel to manage the operation. Mining itself could start within five years.


Environmental campaigners have long argued that seabed mining will be hugely destructive and that the precise effects remain unknown.

Richard Page, oceans campaigner for Greenpeace, said: "The emerging threat of seabed mining is an urgent wake-up call for the need to protect the oceans.


"The deep ocean is not yet mapped or explored and so the potential loss of fauna and biospheres from mining is not yet understood.

"Only 3% of the oceans and only 1% of international waters are protected, which makes them some of the most vulnerable places on earth - what we desperately need is a global network of ocean sanctuaries."

According to Nautilus, the mine will have a minimal environmental footprint, covering the equivalent of about 10 football fields and focusing on an area which is likely to be rapidly re-colonised by marine life.


Mr Johnston said: "It's a resilient system and studies show that life will recover in 5-10 years. An active venting site 1km to the southeast has the same bugs and snails and the current will carry the bugs and snails to the mine site. We expect it to recover quite quickly."


But this will be the first attempt to extract ore from the ocean floor, so the operation - and the company's assurances about the impacts - will be watched closely. So far, 19 licences to search for seabed minerals have been awarded by the International Seabed Authority, the UN body policing this emerging industry.

The International Seabed Authority (ISA), which has welcomed the Nautilus Minerals agreement with Papua New Guinea, is currently drawing up guidelines for the environmental management of future seabed mining. Michael Lodge of the ISA told the BBC: "This is a very exciting opportunity and we are looking forward to learning from the tests of the new machine, which is a world first and should give us some valuable insights into technical feasibility and environmental impact."


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Mystery of 'ocean quacks' solved

Mystery of 'ocean quacks' solved | Marine Science and Environment |

The mystery of a bizarre quacking sound heard in the ocean has finally been solved, scientists report. The noise - nicknamed "the bio-duck" - appears in the winter and spring in the Southern Ocean. However, its source has baffled researchers for decades. Now acoustic recorders have revealed that the sound is in fact the underwater chatter of the Antarctic minke whale.

The findings are published in the Royal Society journal Biology Letters.

Lead researcher Denise Risch, from the US National Oceanic and Atmospheric Administration (Noaa) Northeast Fisheries Science Center in Massachusetts, said: "It was hard to find the source of the signal.

"Over the years there have been several suggestions... but no-one was able to really show this species was producing the sound until now."


The strange sound was first detected by submarines about 50 years ago. Those who heard it were surprised by its quack-like qualities. 

Since then, the repetitive, low frequency noise has been recorded many times in the waters around the Antarctic and western Australia. Suggestions for its source have ranged from fish to ships.

The researchers now say they have "conclusive evidence" that the bio-duck is produced by the Antarctic minke whale.


In 2013, acoustic recorders were attached to two of the marine mammals and recorded the whales making the strange noise.

Dr Risch said: "It was either the animal carrying the tag or a close-by animal of the same species producing the sound." The researchers do not yet know under what circumstances the minke whales make their distinctive vocalisations, although the sounds that were recorded were produced close to the surface and before the mammals made deep dives to feed.


The team says solving this long-standing mystery will help them to learn more about these little-studied animals. Dr Risch said: "Identifying their sounds will allow us to use passive acoustic monitoring to study this species. "That can give us the timing of their migration - the exact timing of when the animals appear in Antarctic waters and when they leave again - so we can learn about migratory patterns, about their relative abundance in different areas and their movement patterns between the areas."

The team will be analysing data from the PALAOA station, the Alfred Wegener Institute's (AWI) permanent acoustic recording station in Antarctica, which has been recording in the Southern Ocean continuously in the last few years.


This is not the only acoustic puzzle that scientists have recently shed light on. Another baffling low frequency noise - called The Bloop - turned out to be the sound of Antarctica's ice cracking.

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Jamaicans battling invasive lionfish numbers with knife and fork

Jamaicans battling invasive lionfish numbers with knife and fork | Marine Science and Environment |

ABC News reports that Jamaica's National Environment and Planning Agency is reporting a 66 percent drop in sightings of lionfish in coastal waters with depths of 75 feet (23 meters) four years after a national campaign to slash numbers of the candy striped predator.


The invasive predator has been wreaking havoc on reefs and decimating native juvenile fish and crustaceans. Dayne Buddo, a Jamaican marine ecologist who focuses on marine invaders at the Caribbean island's University of the West Indies, attributes much of the local decrease in sightings to a growing appetite for their fillets. He told ABC News that Jamaican fishermen have jumped on the lionfish trade, selling their fillets at local markets.  He said the practice was in stark contrast to a few years ago, when island fishermen "didn't want to mess" with the exotic fish because of their barbs, which can deliver a painful sting. 


"After learning how to handle them, the fishermen have definitely been going after them harder, especially spear fishermen. I believe persons here have caught on to the whole idea of consuming them," Buddo told ABC News. Lionfish are a tropical native of the Indian and Pacific oceans. It is likely the fish were introduced into the alien waters of the Carribean and Atlantic through the pet trade.   


Governments, conservation groups and dive shops across the affected areas have been sponsoring fishing tournaments and other efforts to go after the notoriously slow-swimming lionfish in an effort to protect already endangered habitats. The U.S. National Oceanic and Atmospheric Administration launched a campaign in 2010 urging the U.S. public to "eat sustainable, eat lionfish!"


While encouraging, population control of the fish around coastal shallow water areas does not mean the fast-breeding species will be eradicated from the Carribean and Atlantic. Large, football-sized lionfish are caught daily in fishing pots set in deeper water - where spear fisherman and recreational divers do not usually swim, according to ABC News. 


Despite the end of a four-and-a-half-year national lionfish project financed by the Global Environment Program, targeted efforts to remove the lionfish from Jamaican waters are ongoing. "I don't think we'll ever get rid of it, but I think for the most part we can control it, especially in marine protected areas where people are going after it very intensively and consistently," Buddo said.


While fishing and marketing of lionfish for consumption could well be a temporary measure, it is currently the best solution for the problem. 

Scientists are continuing to research how lionfish numbers are kept in check in their natural habitat. 


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IPCC report: ‘Climate change is happening and no one in the world is immune’

IPCC report: ‘Climate change is happening and no one in the world is immune’ | Marine Science and Environment |

The negative effects of climate change are already beginning to be felt in every part of the world and yet countries are ill-prepared for the potentially immense impacts on food security, water supplies and human health, a major report has concluded.


In the most comprehensive study yet into the effects of rising levels of carbon dioxide in the atmosphere, the UN’s Intergovernmental Panel on Climate Change (IPCC) warns that global warming could undermine economic growth and increase poverty.


The IPCC found that the negative impacts of climate change have already extended beyond any potential benefits of rising temperatures and that they will worsen if global-average temperatures continue to rise by the expected lower limit of 2C by 2100 – and will become potentially catastrophic if temperatures rise higher than 4C.


In a blunt and often pessimistic assessment of climate-change impacts – the fifth assessment since 1990 – the IPCC scientists give a stark warning about what the world should expect if global temperatures continue to rise as predicted without mitigation or adaptation. “In recent decades, changes in climate have caused impacts on natural and human systems on all continents and across the oceans,” says the report Climate Change 2014 Impacts, Adaptation and Vulnerability, formally released early this morning by the IPCC after a final editorial meeting in Yokohama, Japan.

“Throughout the 21st century, climate-change impacts are projected to slow down economic growth, make poverty more difficult, further erode food security, and prolong existing and create new poverty traps, the latter particularly in urban areas and emerging hot spots of hunger,” the report states.


Scientists in Britain said it is the clearest warning yet of what could happen if the world continues to prevaricate over cuts in emissions.  “Climate change is happening, there are big risks for everyone and no place in the world is immune from them,” said Professor Neil Adger of Exeter University, one of the many lead authors of the report.


Nearly 2,000 experts from around the world contributed to the report, written by 436 authors and edited by 309 lead authors and review editors of the IPCC’s working group II. It was by far the most detailed investigation to date of the global impacts of climate change – extending from oceans to mountains and from the poles to the equator.


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Beaked whale is deep-dive champion

Beaked whale is deep-dive champion | Marine Science and Environment |

Cuvier's beaked whales are likely to be the most extreme breath-holders among marine mammals. A satellite tag attached to one of these animals, swimming off the coast of California, recorded a dive to nearly 3km below the ocean surface that lasted 137 minutes. This performance exceeds that for any southern elephant seal, which is also known to be an extreme breath-holder.

The Cuvier's record-breaking dive is reported in the journal Plos Biology.

Erin Falcone is a research biologist with the Cascadia Research Collective in Washington State, US, which led the research project. She told BBC News that beaked whales had very high levels of the myoglobin protein in their muscles, to the point where the tissues appeared almost black. This functions like haemoglobin in the blood, allowing the whales to store much higher levels of oxygen, and thus breathe less frequently while remaining active.

"One key adaptation that seems to allow beaked whales to dive more deeply than other species is a dramatic reduction in air spaces within their bodies," she added. "It is the presence of air spaces within the body that would crush a human at a fraction of the depths these whales can dive. "Reduction in air spaces not only makes them more 'crush resistant', but also likely serves to reduce the uptake of dissolved gases into their tissues - which can lead to decompression sickness or 'the bends'."

Cuvier's beaked whales have long been recognised as expert divers, but their precise abilities have been uncertain because of the paucity of data detailing their behaviour in the wild. The Cascadia group and colleagues managed to put tags on eight animals, collecting over 3,700 hours of diving data.

This information covered more than 1,000 individual deep-dives, averaging depths of 1,400m; and some 5,600 shallow dives, averaging about 275m down. The prevalent behaviour, says the team, is for a single deep foraging dive followed by a series of shallow dives. The time spent at the surface in between each dive can be very short - just a few minutes. The deepest recorded dive was to 2,992m, lasting 137.5 minutes, beating the maximum duration for a diving marine mammal of 2,388m, for a duration of 120 minutes, reported for a southern elephant seal.

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Deep-sea octopus broods eggs for over four years—longer than any known animal

Deep-sea octopus broods eggs for over four years—longer than any known animal | Marine Science and Environment |

Researchers at the Monterey Bay Aquarium Research Institute (MBARI) have observed a deep-sea octopus brooding its eggs for four and one half years—longer than any other known animal. Throughout this time, the female kept the eggs clean and guarded them from predators. This amazing feat represents an evolutionary balancing act between the benefits to the young octopuses of having plenty of time to develop within their eggs, and their mother’s ability to survive for years with little or no food.


Every few months for the last 25 years, a team of MBARI researchers led by Bruce Robison has performed surveys of deep-sea animals at a research site in the depths of Monterey Canyon that they call “Midwater 1.” In May 2007, during one of these surveys, the researchers discovered a female octopus clinging to a rocky ledge just above the floor of the canyon, about 1,400 meters (4,600 feet) below the ocean surface. The octopus, a species known as Graneledone boreopacifica, had not been in this location during their previous dive at this site in April.


Over the next four and one-half years, the researchers dove at this same site 18 times. Each time, they found the same octopus, which they could identify by her distinctive scars, in the same place. As the years passed, her translucent eggs grew larger and the researchers could see young octopuses developing inside. Over the same period, the female gradually lost weight and her skin became loose and pale.


The researchers never saw the female leave her eggs or eat anything. She did not even show interest in small crabs and shrimp that crawled or swam by, as long as they did not bother her eggs. 


The last time the researchers saw the brooding octopus was in September 2011. When they returned one month later, they found that the female was gone. As the researchers wrote in a recent paper in the Public Library of Science (PLOS ONE), “the rock face she had occupied held the tattered remnants of empty egg capsules.”


After counting the remnants of the egg capsules, the researchers estimated that the female octopus had been brooding about 160 eggs.

Most female octopuses lay only one set of eggs and die about the time that their eggs hatch. The eggs of Graneledone boreopacificaare tear-drop-shaped capsules the size of small olives. As the young develop inside the eggs, they require plenty of oxygen. This means that the female octopus must continuously bathe the eggs in fresh, oxygenated seawater and keep them from being covered with silt or debris. The female must also guard her eggs vigilantly to prevent them from being eaten by predators.

Because the young octopus spend so much time in their eggs, by the time they hatch they are fully capable of surviving on their own and hunting for small prey. In fact, the newborns of G. boreopacifica are larger and better developed than the hatchlings of any other octopus or squid.


In their recent paper, the researchers point out that octopus eggs, like those of other invertebrates, develop more slowly in cold water. The seawater near the ocean floor at the Midwater 1 site is about three degrees Celsius (37 degrees Fahrenheit), which is typical for the depths of Monterey Canyon.


Given this chilly environment, it’s not surprising that octopuses are not the only deep-sea animals to brood their young for long periods of time. One type of mysid (a shrimp relative that is abundant in depths of Monterey Canyon) carries its eggs for 20 months and goes without food the whole time. Like octopus hatchlings, the young of this shrimp also emerge from their eggs as fully developed miniature adults.



Such long brooding times present an evolutionary challenge, especially for animals such as octopus, which do not live very long. As the authors noted in their paper, “The trade-off within the reproductive strategy of deep-living octopods is between the mother’s ability to endure a long brooding period and the competitiveness of her hatchlings. Graneledone boreopacifica produces hatchlings that are very highly developed, which gives them the advantage of a high potential for survival.”


This research suggests that, in addition to setting records for the longest brooding time of any animal,Graneledone boreopacifica may be one of the longest lived cephalopods (a group that includes octopuses, squids, and their relatives). Most shallow-water octopuses and squids live just a year or two.


“The ultimate fate of a brooding female octopus is inevitably death,” the researchers wrote, “but in this first example from the deep sea, brooding also confers an extension of adult life that greatly exceeds most projections of cephalopod longevity.”


Although long-term observations of deep-sea animals are rare, the researchers propose that extended brooding periods may be common in the deep sea. Such extended life stages would need to be taken into account in assessing the effects of human activities on deep-sea animals. In any case, this strategy has apparently worked for Graneledone boreopacifica—it is one of the most common deep-sea octopuses in the Northeastern Pacific.

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Female shrimps are more aggressive

Female shrimps are more aggressive | Marine Science and Environment |

Female snapping shrimps are more aggressive than males, frequently snapping their deadly claws at each other, a study has shown. Researchers in the US had expected male shrimps - which brandish a larger snapping claw - to behave more aggressively.

But despite their smaller claw size, females snapped more often when defending their territory. 


Findings are published in the journal Ethology. "We're so used to seeing animals in which males have larger weapons than females: bigger antlers, bigger teeth, bigger horns... And in many of these species, males are more aggressive than females," said Dr Melissa Hughes, from the College of Charleston in South Carolina, US who led the study.


"Males, more so than females, benefit from being aggressive and having large weapons, in species where males compete for females." Snapping shrimps are sometimes called pistol shrimps and use their larger claw - the major chela - as a deadly weapon to kill prey and opponents. They can kill enemies with a direct snap, and are known to stun potential food with a jet of bubbles by rapidly closing their larger claw. The snapping sound of this bubble blast collapsing gave the animals their name.


The researchers wanted to see how different sexes use their claws to defend their territory. They collected two species of snapping shrimp, Alpheus heterochaelis and Alpheus angulosus, and studied same-sex and opposite-sex interactions in test chambers. The shrimps were allowed to become residents in a burrow, before being faced with intruder shrimps. The researchers filmed these interactions and counted the number of snaps - a sign of aggression - by each shrimp.


In both species, female shrimps contradicted the researchers' expectations by snapping more overall, and behaving more aggressively towards other females. Males were equally aggressive to both male and female intruders. Dr Hughes admitted the reasons for females' more aggressive behaviour are unclear. "Female aggression has not been studied nearly as much, and so we don't understand it nearly as well," she told BBC Nature.


"One possibility here is that females are competing with each other for males, either through direct competition fighting over males, or by defending large territories so that the distance between females is too large for one male to easily move between multiple females."


There are over 400 species of snapping shrimp. The crustaceans use their two distinct claws for different functions, and if they lose their larger claw in battle, the smaller one transforms into their snapping claw, and a new one grows where the snapper used to be. "These are incredibly cool animals that nearly no one has ever heard of," commented Dr Hughes.



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Obama to expand marine reserves and crack down on seafood black market

Barack Obama used his executive powers as president on Tuesday to create the world's largest marine sanctuary, banning commercial fishing, mining and oil exploration in a vast expanse of the Pacific.

The move – which saw Obama once again bypass an unwilling Congress to advance his environmental agenda – could potentially put nearly 800,000 sq miles in the south-central Pacific off-limits to commercial exploitation.


In a related measure, the White House announced a new task force to crack down on illegal fishing operations and black market seafood making its way to US supermarkets. "We can protect our oceans for future generations," Obama said in a brief video address to an international ocean summit at the US State Department.


Seeking to deflect an anticipated Republican backlash against his use of his executive authority, Obama said he was following the lead of earlier presidents by expanding an existing protection zone. “Like Presidents Clinton and Bush before me I am going to use my authority as president to protect some of our most precious marine landscapes, just like we do for mountains and rivers and forests,” Obama told the summit.


The marine sanctuary under consideration would vastly expand the areas protected around the Pacific Remote Islands Marine National Monument, which was originally established by George Bush. The area, around seven uninhabited islands and atolls under US control, contains some of the most pristine marine environments in the world, the White House said in a statement. The statement said Obama would decide on the final geographic scope of the protection zone after consulting scientists, conservation experts, and fishing interests.


But the Washington Post which had an early look at the announcement, said the sanctuary could extend up to 780,000 square miles, doubling the area of ocean under protection. Obama was also convening a task force to fight unreported and illegal fishing, the White House said. Officials said rogue trawlers undermine government's efforts to manage fish stocks. Scientists estimate about one of every five fish is caught illegally, robbing up to $23bn a year from legitimate commercial fishing operations around the world.


The task force would work on coming up with a comprehensive strategy to end pirate fishing by the end of 2014, the White House advisor, John Podesta, said. In addition to the economic and environmental costs, he said rogue fishing operations were a security threat – “vectors for criminals who traffic in guns, drugs and other human beings”.


The task force will look at requiring fishing vessels to install transponders to track their movements at sea and the source of seafood that ends up in US supermarkets. “Customers will know exactly who caught it, where and when,” the secretary of state, John Kerry, told the summit.


The twin announcements from the White House were intended to spur action from government officials, business leaders and environmental groups attending the ocean summit. “For this effort to succeed, it has to be bigger than any one country,” Obama said. Moments after his video address, the actor Leonardo DiCaprio told the summit he would donate an additional $7m over the next two years to “meaningful” ocean protection. The actor had earlier given about $2m to the Oceana conservation group.


On Monday, Kiribati's president, Anote Tong, said the Pacific island nation would close off an ocean area the size of California to commercial exploitation by the end of this year. Tong said the ban on commercial fishing in the 157,630-sq-mile area protected area would help speed the recovery of tuna and other fish stocks. The marine protection area Obama was proposing was originally envisaged by Bush. In his last two weeks in the White House, Bush used his executive powers as president to set up marine sanctuaries in three areas in the Pacific.


Obama was now considering expanding one of those areas, near Wake Island and six other uninhabited atolls. The Pew Charitable Trusts estimated the move could potentially expand the area Bush protected by a factor of nine to some 780,000 sq miles. Expanding other sanctuaries designated by Bush, such as the Northern Mariana Islands, would increase the area to 1.5m sq miles, according to Pew.


But the move was in some ways symbolic. Because the islands are uninhabited, there is very little fishing in the area Obama proposes to protect, and no indication mining or drilling is imminent. However, scientists say bigger marine sanctuaries are easier to enforce and allow more species to recover.


More than 350 scientists this week signed on to a letter to the White House urging Obama to expand marine sanctuaries to up to 20% of each ocean region under US control. Conservation groups praised Obama's move, as well as his proposals for tracking seafood. Scientists believe as much as a third of the wild-caught seafood sold in US is landed by illegal fishing trawlers, undermining efforts to sustainably manage stocks

The Oceana conservation group said the task force was “a historic step forward” to stop illegal fishing and seafood fraud.


“Tracking where, when and how our seafood is caught, and ensuring that this basic information follows the product through each step in the supply chain, will help to eliminate seafood fraud and the illegal fishing it can disguise,” the group said in a statement. Other environmental groups praised the action on illegal fishing, but urged Congress to implement a treaty that would put identification numbers on all fishing vessels and curb landings of illegal fish catches.


“As one of the top seafood importers in the world, the US has a responsibility to ensure that every fish bought in our stores, markets, and restaurants is fully traceable to where it was legally caught,” the World Wildlife Fund said.

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Unsustainable shrimp a jumbo problem

Unsustainable shrimp a jumbo problem | Marine Science and Environment |

Ahead of World Oceans Day on June 8, a UBC researcher discusses how shrimp trawling ‘clear cuts’ the ocean floor. Project Seahorse researcher Sarah Foster says most of the shrimp we eat are unsustainably harvested. For every kilogram of tropical shrimp caught through trawling the bottom of the ocean, 10 kilograms of other marine life is killed. To protect ocean health, Foster argues that we have to be smart about the shrimp we eat.


Each year around World Oceans Day my family and friends ask what they can do to make a difference to the health of our oceans. My answer: don’t eat shrimp or prawns–unless you know they have been sustainably sourced. Most aren’t.


Almost all shrimp you buy or get served come from tropical trawl fisheries. This fishing technique “clear cuts” the ocean floor, catching shrimp and everything else in its path. An average of 10 kilos of other marine life is captured and killed for every kilo of tropical shrimp landed. Some of this “other catch” or “bycatch” is kept and sold, but most is turned into fishmeal or fish oil for fertilizer and aquaculture practices. Many of these species could be sources of food for humans but reducing them to plant or animal feed redirects key protein sources away from the people who need it.


The total area of seabed trawled each year is nearly 150 times the area of forest that is clear cut. We criticize clear cutting forests so why don’t we fuss about clear cutting the ocean floor?


Most shrimp farming is as bad, if not worse, as bottom trawling. Shrimp ponds have destroyed thousands of kilometres of coastal habitats around the world, particularly mangroves, which serve as nurseries to many marine species and help buffer coastal communities from powerful storms. Shrimp farming also pollutes adjacent waters with chemicals and waste, and the salt from the ponds can turn productive land into a desert.


Something has to make trawlers change their practice. By buying and eating sustainably sourced shrimp you can help provide the incentive. Shrimp trawlers around the world now carry Turtle Excluder Devices because the U.S. won’t import their shrimp if they don’t, although implementation remains a huge challenge.


Let’s give fisheries an incentive to protect the rest of the bycatch species. Be smart about the shrimp you eat. Thankfully in Canada this is easier than in many places. Most of Canada’s shrimp fisheries are considered to be ecologically sustainable with minimal bycatch. Canada is home to one of the most sustainable prawn fisheries in the world – the B.C. spot prawn fishery. This fishery uses traps that do not result in as much bycatch or habitat damage. We also have programs like Oceans Wise that tell you if the shrimp you want to buy for the barbecue or order in a restaurant won’t harm the oceans they come from.


Yes, you will pay more for the shrimp you eat but the oceans will pay less for your choices. Your gain is that you will be able to appreciate and eat other marine life for much longer.

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MH370 spur to 'better ocean mapping'

MH370 spur to 'better ocean mapping' | Marine Science and Environment |

Scientists have welcomed the decision to make all ocean depth data (bathymetry) gathered in the search for missing Malaysia Airlines flight MH370 publicly available. A detailed survey of 60,000 sq km of seabed is to be undertaken to help refine the hunt for the lost jet.

The depth and shape of Earth's ocean floor is very poorly known. Leading researchers say the MH370 example should be a spur to gather much better data elsewhere in the world. The search has been hampered by the lack of a high-resolution view of the bed topography west of Australia. This was apparent on the very first dive made by an autonomous sub investigating possible sonar detections of the aircraft's cockpit voice and flight data recorders.

It was forced to cut short the mission because it encountered depths that exceeded its operating limit of 4,500m. There are places thought to exceed 7,800m. Australian Transportation Safety Board (ATSB) officials said this week that an area in the southern Indian Ocean the size of Tasmania would now be subject to a full survey using multibeam echo sounders (MBES). A Chinese navy vessel, Zhu Kezhen, has already started on the project. It will be joined by a commercial ship in June, with the work likely to take three months. Drs Walter Smith and Karen Marks have assessed the paucity of bathymetric data in the region in an article for EOS Transactions, the weekly  magazine of the American Geophysical Union. The pair work for the US National Oceanic and Atmospheric Administration (Noaa).

They say only two publicly accessible data-acquisition sorties have been conducted close to where search vessels made possible black box detections, and "both expeditions occurred prior to the use of modern multibeam echo sounders, so depth measurements were collected by single, wide-beam echo sounders that recorded on analogue paper scrolls, the digitizing of which is often in error by hundreds of metres".


Modern MBES uses GPS to precisely tie measurements to a particular location. The equipment can not only sense depth very accurately (to an error typically of 2%), but can also return information on seafloor hardness - something that would be important in looking for wreckage in soft sediment.


Just 5% of a vast region, 2,000km by 1,400km, which includes the search locality, has any sort of direct depth measurement, Smith and Marks say.

The rest - 95% - is covered by maps that are an interpolation of satellite data. These have a resolution no better than 20km. Maps of the arid surface of Mars are considerably better.


"The state of knowledge of the seafloor in the MH370 search area, although poor, is typical of that in most of Earth's oceans, particularly in the Southern Hemisphere," the pair write. "In many remote ocean basins the majority of available data are celestially navigated analogue measurements because systematic exploration of the oceans seems to have ceased in the early 1970s, leaving the ocean floors about as sparsely covered as the interstate highway system covers the United States.

"When these sparse soundings are interpolated by satellite altimetry, the resulting knowledge of seafloor topography is 15 times worse in the horizontal and 250 times worse in the vertical than our knowledge of Martian topography." Smith and Marks hope that the detailed survey work now being conducted in the search for MH370 will be a catalyst to gather better data in other parts of the globe.

High-resolution bathymetry has myriad uses. "Better knowledge of the ocean floor means better knowledge of fish habitats. This is important for marine conservation, and could help us find biological resources including new medicines," Dr Smith told BBC News. "It means also a better ability to assess the mineral resource potential of the seabed. And it means better knowledge of the obstacles to flow that cause turbulence and mixing in the oceans.

"We need this mixing and circulation information to make good models of future climate. All of these things depend on knowing the topography of the sea floor." The Australian Joint Agency Coordination Centre, which disseminates all information on the hunt for MH370, confirmed that the MBES survey data would be publicly available.

"The bathymetry data gathered in the course of the search for MH370 will become the property of the Australian Government. Recognising the importance of that data, it will be made available to the public via both Australian and international databases," the JACC told the BBC.

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Wild beluga whales pass hearing test

Wild beluga whales were found to have hearing comparable with whales in captivity, which sets up a baseline test for hearing damage in other whales in noisy waters. Christopher Intagliata report.


Beluga whales live in the world's cold northern seas, where they endure months of perpetual darkness.   “So they have to use sound, rather than sight, in order to find their way around.” That's Aran Mooney, a marine biologist at Woods Hole Oceanographic Institution, in Massachusetts. He says belugas have really fast hearing, too: “Sound underwater travels five times faster than it does in air. And so those guys have to basically perceive and utilize sound five times faster than we do.”  


He and his colleagues traveled to Bristol Bay, Alaska, to test belugas' hearing in the wild. They captured seven belugas for routine physicals. And played them a series of frequencies, while measuring the whales' brain activity with electrodes.   Turns out the whales' hearing was sharp, and similar to that of captive belugas. Which means they could appreciate sound ranging from about 4 kilohertz to 150—a frequency nearly eight times higher than the upper limit of our ears. The results are in The Journal of Experimental Biology. [Manuel Castellote et al, Baseline hearing abilities and variability in wild beluga whales (Delphinapterus leucas)]  


The older belugas tested in this survey still had decent hearing too. But that might not be the case for belugas living in noisier Cook Inlet, near Anchorage.   “There's a lot of military activities, a lot of commercial activities in Cook Inlet, and those animals are known to be declining at a rate of about two percent per year. And we think noise is a major stressor to those animals.”   And now that researchers know what wild belugas should be able to hear, they can test Cook Inlet belugas—to see whether that underwater noise is, literally, deafening.

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It Took Just One Revolutionary Idea To Finally Catch The Elusive Giant Squid On Film

It Took Just One Revolutionary Idea To Finally Catch The Elusive Giant Squid On Film | Marine Science and Environment |

The giant squid may be one of the most hard-to-glimpse creatures in the oceans. Since at least the 1500s, rumors have circulated that such a sea creature existed with "a head like a man ... and a dress of scarlet like a monk's cloak," according to the Smithsonian's Ocean Portal.


Five hundred years later, scientists knew this creature was a giant squid, but they were hardly any closer to seeing one live. "Most of what we know comes from dead carcasses that floated to the surface and were found by fishermen," the Smithsonian said.


Finally, in 2006, scientists pulled one up to the surface, after luring it with bait, and caught it on film. But it was not until last year that scientists finally caught the first video of the giant squid in its natural habitat, seen in the footage at


Marine scientist Edith Widder, who was on the team that found the squid, gave the inside scoop in her 2013 TED talk, detailed below. To get the footage, the team had to completely transform the way it approached deep-ocean investigations. It would never have happened without a simple but revolutionary idea: "focusing on attracting animals instead of scaring them away," Widder said at a Mission Blue event.


This idea helped her score an invite to the Squid Summit and a proposition from marine explorer Mike deGruy to hunt for the giant squid. To get the squid on camera, they had to be as unobtrusive in the water as possible. Specifically, they had to use quiet vehicles.

In her talk, Widder explained why no one yet had seen the squid:

So my suspicion was that it might have something to do with the amount of noise [the vehicles] make. So I set up a hydrophone on the bottom of the ocean, and I had each of these fly by at the same speed and distance and recorded the sound they made.


Instead of using large, loud submersibles, Widder and a team created Medusa, a small, minimalist setup designed for remote squid filming. It has only the necessary features: a camera and a glowing blue lure designed to mimic a jellyfish, which they named e-jelly. It also has red lighting that's invisible to most deep-sea creatures but lights up the scene for us humans.


The setup has no motor, just 2,000 feet of line connecting it to the surface. It floats around with ocean currents and monitors what's happening deep underwater. With Medusa, the team was able to entice the giant squid with the glowing lure, not because the squid eat the jellyfish that glow blue but because their blue glow is a defense that signals a predator is near.


And a jelly's predator is a giant squid's prey, according to Widder.

"What really wowed me about that was the way it came in up over the e-jelly and then attacked the enormous thing next to it, which I think it mistook for the predator on the e-jelly," she said. "Exploration is the engine that drives innovation. Innovation drives economic growth. So let's all go exploring," Widder said.


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New approach to managing marine ecosystems

Ways to manage natural resources have been under development for decades, driven by an increasing need to understand the effect of man-made impacts on ecosystems. Often, it has been assumed that management could be based on the population dynamics of an individual species but new research shows how in the marine environment whole ecosystems need to be assessed individually rather than benchmarked against all other ecosystems.


Even where two systems share physical characteristics, but are in different ocean basins, the research found that the individual systems required respective management approaches. Only when ecosystems are similar in type and share a location, for example, may a single approach suit both ecosystems.


The new study published today in PLOS ONE found that ecosystem traits—such as type (for example lagoon, estuary or bay), size, depth and location—need to be taken in to account when assessing an ecosystem's environmental status or health. The study also found that the structure and function of ecosystems differ from one to the next, posing more challenges to managing marine resources.


"This paper (Global patterns in ecological indicators of marine food webs: a modelling approach) is among the first to analyse a large variety of models from different systems in an organised and systematic way," said lead author Dr Sheila Heymans, who is also head of the ecology department at the Scottish Association for Marine Science (SAMS). "It presents the largest meta-analysis of the structural and functional indicators of marine food webs to date and adds to the general theory of marine food web dynamics and its use for ecosystem conservation and management.


Food webs show the interaction between species at different feeding levels and consequently show the flow of energy and matter in ecosystems. These predator-prey interactions are a main regulator of ecosystem dynamics, and they contribute to the way ecosystems respond to natural and human impact such as fishing, habitat degradation or environmental forces.


Food web models are simplified representations of natural systems, which help us understand how biodiversity and ecosystems respond to changes. Creating food web models typically calls for quantitative modelling, integrating food web dynamics and external factors such as environmental change or fishing.


This paper analysed 105 published marine food web models representing ecosystems from coastal lagoons to the deep sea in all the world's oceans, and from past and recent timeframes to find out whether there were general patterns in ecological traits of marine food webs. Uniquely, this paper included statistical analyses to address the variation and uncertainty thrown up by all the different model strategies and structures used in those 105 publications. The study posed new and advanced analyses on the key species concept.

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Some corals adjusting to rising ocean temperatures, Stanford researchers say

Some corals adjusting to rising ocean temperatures, Stanford researchers say | Marine Science and Environment |

Research led by Stanford scientist Steve Palumbi reveals how some corals can quickly switch on or off certain genes in order to survive in warmer-than-average tidal waters.

To most people, 86-degree Fahrenheit water is pleasant for bathing and swimming. To most sea creatures, however, it's deadly. As climate change heats up ocean temperatures, the future of species such as coral, which provides sustenance and livelihoods to a billion people, is threatened.


Through an innovative experiment, Stanford researchers led by biology Professor Steve Palumbi have shown that some corals can – on the fly – adjust their internal functions to tolerate hot water 50 times faster than they would adapt through evolutionary change alone. The findings, published April 24 in Science, open a new realm of possibility for understanding and conserving corals.


"The temperature of coral reefs is variable, so it stands to reason that corals should have some capacity to respond to different heat levels," said Palumbi, director of Stanford's Hopkins Marine Station and a senior fellow at the Stanford Woods Institute for the Environment. "Our study shows they can, and it may help them in the future as the ocean warms."

Coral reefs are crucial sources of fisheries, aquaculture and storm protection. Overfishing and pollution, along with heat and increased acidity brought on by climate change, have wiped out half of the world's reef-building corals during the past 20 years. Even a temporary rise in temperature of a few degrees can kill corals across miles of reef.


American Samoa presents a unique case study in how corals might survive a world reshaped by climate change. Water temperatures in some shallow reefs there can reach 95 degrees Fahrenheit, enough to kill most corals. To find out how native corals survive the heat, researchers in Palumbi's lab transplanted colonies from a warm pool to a nearby cool pool and vice versa.


The researchers found that, over time, cool-pool corals transplanted to the hot pool became more heat-tolerant. Although these corals were only about half as heat-tolerant as corals that had been living in the hot pool all along, they quickly achieved the same heat tolerance that could be expected from evolution over many generations. Corals, like people, have adaptive genes that can be turned on or off when external conditions change. The corals Palumbi's group studied adjusted themselves by switching on or off certain genes, depending on the local temperature.


These findings make clear that some corals can stave off the effects of ocean warming through a double-decker combination of adaptation based on genetic makeup and physiological adjustment to local conditions.


"These results tell us that both nature and nurture play a role in deciding how heat-tolerant a coral colony is," Palumbi said. "Nurture, the effect of environment, can change heat tolerance much more quickly – within the lifetime of one coral rather than over many generations." 


Palumbi cautioned that corals' heat-adaptive characteristics do not provide a magic bullet to combat climate change. They can't respond to indefinite temperature increases and they could be compromised by stressors such as acidification and pollution. Still, if it holds true for most corals, this adaptive ability could provide a "cushion" for survival and might give coral reefs a few extra decades of fighting back the harsh effects of climate change, Palumbi said.

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GPS trackers shed light on lives of little penguins

GPS trackers shed light on lives of little penguins | Marine Science and Environment |

Australian researchers are strapping satellite tracking technology to little penguins to shed light on their marine environment. A team of scientists from Macquarie University has teamed up with researchers at Sydney's Taronga Zoo to carry out the study.

The researchers are attaching GPS trackers and accelerometers to the penguins to work out where they are searching for food. It is technology commonly found in most smartphones, with the accelerometer monitoring the penguin's orientation and movement. The scientists are studying the zoo's captive colony as well as the wild population found at Montague Island off the far south coast of NSW.

The project is part of a larger multispecies study aiming at identifying important marine hotspots and improving the management and zoning of marine parks. The scientists are looking at how suitable certain breeding sites will be in the future due to food availability.

Macquarie University PhD student Gemma Carroll is leading the research. "If we can understand where they're feeding now and why those areas are important places for penguins to feed we can understand how, if the environment changes, those places that might be important might change as well," Ms Carroll said.

Taronga Zoo's David Slip says the species is extremely vulnerable to habitat change. "Managing the resources are really important to make sure there's enough for seals and penguins but also enough for us," Dr Slip said. "If their food moves off shore then they have to go further and it means it's a lot longer to get back to their chicks."

Macquarie University's Professor Rob Harcourt, who specialises in marine predators, says the research provides a window into an unknown world. "By working out exactly where they're going, what they're feeding upon and what the constraints are of those feeding then we'll be able to provide a lot more information," he said.

The study has already uncovered some interesting findings on the penguins' not so little appetites. One Taronga little penguin ate 22 pilchards in five minutes. The scientists are looking to collect at least another two years of data on the wild animals. Their hope it that the project will eventually be expanded into the long term to help measure oceanographic change in South Eastern Australia.

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Hagfish slime mystery unravelled by Canadian scientists

Hagfish slime mystery unravelled by Canadian scientists | Marine Science and Environment |

esearchers at the University of Guelph have figured out what makes the slime secreted by the hagfish so strong, hoping it can lead to the commercial development of stronger fibres.  Prof. Douglas Fudge and his team used electron microscopes and 3D imaging to examine the cell structure of the gelatinous substance produced by the prehistoric bottom-dwelling fish.

They found that 15-centimetre-long protein threads are coiled in a pattern resembling skeins of yarn, which grow and fill the cells.

The threads are an "incredibly strong" super fibre, lead researcher Prof. Douglas Fudge said. And when stretched, the protein molecules "snap into different arrangements, becoming stronger and tougher."


They have proved stronger than any synthetic versions attempted so far.

The researchers hope clues as to how they're made could help scientists develop better ones, which could one day have commercial uses.

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Palau's plans to ban commercial fishing could set precedent for tuna industry

Palau's plans to ban commercial fishing could set precedent for tuna industry | Marine Science and Environment |

The Pacific island-nation of Palau is close to kicking all commercial fishing vessels out of its tropical waters. The move will single-handedly section off more than 230,000 sq miles of ocean, an area slightly smaller than France, to create one of the world's largest marine reserves. The sanctuary, which Palauan President Thomas Remengesau Jr announced at the United Nations last month, would also sit inside the world's last healthy stand of lucrative, tasty tuna.


Giving fishing vessels the boot is bold for any nation, but perhaps more so for Palau, a smattering of 300 islands east of the Philippines. Tuna,America's favorite finned fish, is a regional boon worth an estimated $5.5bn. Commercial fishing, largely by boats from Japan and Taiwan,represents $5m annually – or 3.3% of GDP – to Palau. But still, the island state says it will allow existing fishing licenses to expire.


The move, hailed by ocean conservationists, sets a worrying precedent for the tuna industry. While the commercial catch inside Palau is minimal, captains covet the freedom to chase warm-blooded, migratory tuna across jurisdictions. If Palau goes through with the plan, it will mark the first time a nation has completely banned fishing vessels from its entire Exclusive Economic Zone.


"Our concern is not so much a practical one as it is a concern with the precedent of closing areas with no scientific basis for it," says Brian Hallman, executive director of the American Tunaboat Association.

"The migratory range of tunas is vast, covering the waters of many countries and the high seas. So the only way to conserve stocks is by international treaty arrangements and this is already being done."


Palau's decision to act alone could be seen as a warning to the fishing industry to take the sustainability concerns of smaller, fish-rich nations more seriously and to work with these countries on more nimble and responsive solutions.


Palau currently works with seven of its island neighbors to co-operatively manage a large swath of ocean. Jointly, these eight nations set fishing quotas and sustainability standards to manage nearly a third of the world's tuna stock. Balancing both conservation and business, the alliance became the first group of countries certified by the Marine Stewardship Council for managing its tuna grounds sustainably.


But this arrangement hinges on allowing more-sustainable fishing inside member waters. If Palau bans commercial fishing, it's unclear how this will impact the broader regional effort. "There's nothing in these agreements that require we allow fishing in our waters," Remengesau says in a telephone interview. "It's all about the regional area. Our conservation efforts would ensure that the stocks are healthy and that they gain in economic value as they move out of our territorial waters into other waters."

When it comes down to it though, banning commercial boats simply appears to be in Palau's interests. Even though the bulk of commercial fishing in the region focuses on tuna, sharks are frequently hauled in as bycatch. Yanking sharks out of the sea directly hits Palau's biggest moneymaker: the $85m dive tourism industry.

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