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Climate science ‘is beyond argument’

March 17, 2014 in Arctic, Business, Carbon, Climate deniers, Deep Ocean, Economy, Fish, Food security, Global Ocean Commission, Ice Loss, Marine ecology, Ocean acidification, Ocean Warming, Polar ice, Pollution, Science

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Not as sunny as it seems: The ocean is under attack on many fronts, with climate change foremost among them Image: kein via Wikimedia Commons

Not as sunny as it seems: The ocean is under attack on many fronts, with climate change foremost among them
Image: kein via Wikimedia Commons

By Alex Kirby

The Global Ocean Commission says climate change is one of the key threats to the health of the world’s marine life, which it says faces multiple pressures in a warming world.

HONG KONG, 17 March - South Africa’s former Finance Minister, Trevor Manuel, has derided those who deny the scientific argument that climate change is an urgent problem caused largely by human activity.

He told journalists here: “The science is now incontrovertible. There are a few people in the world who deny it, but they are mainly in lunatic asylums.”

Mr Manuel is one of three co-chairs of the Global Ocean Commission, a panel of global leaders who have just ended a meeting here to finalise the proposals they will present to the United Nations in June.

The meeting agreed that another key threat to the world’s oceans is overfishing and the subsidies which help to make it possible. It says this, and the other factors causing ocean degradation, threaten the food security of as many as 500 million people.

It is deeply worried about pollution. With plastic remains now so pervasive that they are found even in deep seafloor sediments, Mr Manuel said, it sometimes seemed that “you might as well not bother to buy seafood at all – just buy the plastic bag it comes in and eat that.”

Shells corroded

The Commission says climate change threatens the oceans in three main ways: by raising the temperature of the water; by reducing its oxygen content; and by increasing its acidity. Antarctic pteropods, small sea snails also known as sea butterflies, are already being found with severely corroded shells because of acidification, and larger creatures, including bigger shellfish and corals, are likely to be seriously affected.

Another of the co-chairs, José María Figueres, the former president of Costa Rica, told the Climate News Network the Commission was concerned at the prospect of exploitation of the high seas in the Arctic as the region’s sea ice continues to melt.

He said: “Beyond Arctic countries’ EEZs (exclusive economic zones stretching 200 nautical miles from the coast), the melting will leave us with a doughnut-shaped hole in the Arctic high seas, which are not under international control.

“Some nations are now looking to explore there for fish, minerals, valuable biodiversity and other resources. I believe we should not go down that route.

We should listen to the science and follow the precautionary principle, keeping this pristine area off-limits for exploitation until we understand the consequences.

Coalition builders

“We’re already pushing the high seas to the limit. We don’t need to push them over the edge by a lack of proper precaution in the Arctic.”

He said: “The jury is still out on whether we have 20 or 30 years ahead as a window of opportunity to act. But why wait? Listen to the science, which is overwhelming, and to the economics, which are sound.”

Describing the Commission as “not just a bunch of treehuggers, but a group that’s grounded itself in good sound economics”, Mr Figueres said the recommendations it planned to present to the UN on 24 June would represent about 20% of its work. The other 80% would involve building coalitions around each recommendation: there are expected to be no more than 10 in total.

The Commission’s third co-chair is the UK’s former Foreign Secretary, David Miliband. He told the Network: “Answers that sit on a shelf are a waste of time, and people who are positively inclined to protect the oceans are held back by institutional inertia.

“But the interplay between climate change and ocean damage is rising, and it very much needs to. The science of most of the last half-century shows us how we’ve been playing tricks with nature.” – Climate News Network

US urges fishing ban in melting Arctic

February 24, 2014 in Adaptation, Arctic, Fish, Indigenous peoples, Marine ecology, Ocean Warming

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A US Coastguard vessel patrols the Arctic Ocean: Once the ice goes, the trawlers will not be far behind Image: PA1 Timothy Tamargo via Wikimedia Commons

A US Coast Guard vessel patrols the Arctic Ocean: Once the ice goes, the trawlers will not be far behind
Image: PA1 Timothy Tamargo via Wikimedia Commons

By Alex Kirby

Washington is urging countries that share the Arctic to ban commercial fishing in the offshore Arctic Ocean, something that will soon be possible for the first time in human history as the ice melts.

LONDON, 24 February – The countries that ring the Arctic Ocean will soon face a dilemma: can they risk commercial fishing fleets shooting their nets in those soon-to-be-ice-free seas?

Before long – quite possibly before mid-century – the Arctic Ocean will be free of ice during part of each summer, scientists are now saying confidently. For better or worse that will open up huge opportunities for shipping and hydrocarbon exploitation. And for the first time in recorded history it will allow the fishing boats access to whatever has lived undisturbed until now beneath the ice.

A three-day meeting began today in Nuuk, the capital of Greenland, where US officials are hoping to persuade the other nations which border the Arctic Ocean to introduce a moratorium on high seas fishing there (the other members of the group are Canada, Russia and Norway).

David Benton, of the US Arctic Research Commission (USARC), said the Americans were proposing an agreement “that would close the international waters of the Arctic Ocean to commercial fishing until there is a good scientific foundation on which to base management of any potential fishing”.

All coastal countries control fisheries within 200 miles of their own coastlines. The high seas beyond that limit belong to no country and can be protected only by international agreement.

Once the five Arctic nations have agreed a fishing moratorium, Benton said, they would then approach other countries with major commercial fishing fleets, such as China, Japan and Korea, to negotiate full protection for the central Arctic Ocean.

Previous ban

The Arctic was experiencing a fairly rapid rate of change, said Benton, as the permanent ice melted. “That’s potentially causing large changes in the ecosystem, but we don’t understand what’s going on up there. If we want to do things right, this is the approach we should be taking.”

In 2009, the US adopted its own Arctic Fishery Management Plan, closing American waters north of Alaska to commercial fishing until scientific research proves that the fishery is sustainable. Scott Highleyman, director of the international Arctic program for the Pew Charitable Trusts, said that had been a precaution that took account of the way warming was changing the Arctic ecosystem faster than science could keep up with it.

He told the Los Angeles Times: “There are no stock surveys or scientific assessments for fish there. You don’t want to fish a place where you don’t know the fish population dynamics. Any time we’ve done that, it led to catastrophic overfishing.” One example, Highleyman said, is the New England Atlantic cod fishery, which was shut down in the 1980s due to overfishing, costing 50,000 jobs.

An open letter to the Arctic governments, signed by 2,000 scientists from around the world, says that if the Ocean is overfished that will damage species that live there, including seals, whales and polar bears, and the people who use them for food.

“Until recently, the region has been covered with sea ice throughout the year, creating a physical barrier to the fisheries,” the scientists wrote. “A commercial fishery in the central Arctic Ocean is now possible and feasible.” – Climate News Network

Equatorial fish feel the heat

February 12, 2014 in Adaptation, Fish, Food security, Indonesia, Marine ecology, Ocean Warming, Warming, Wildlife

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Weaving through the coral: Small fish like these are important sources of food for larger reef species Image: D. Dixson

Weaving through the coral: Small fish like these are important sources of food for larger reef species
Image: D. Dixson

By Alex Kirby

Many species of fish living near the Equator are sensitive to variations in heat and will not thrive in the warmer oceans of the future, scientists in Australia have found.

LONDON, 12 February – Lying in a hot bath may be a pleasant experience, because you can always get out when you’ve had enough. For some of the fish that swim in equatorial seas, though, that is not an option: climate change threatens to make the water not just uncomfortable, but unendurable.

An international team of researchers based in Australia reports in Global Change Biology that the rapid pace of climate change is threatening the future of some of the fish which live near the Equator.

Over a 14-day period the team tested four species of damsel fish and two of cardinal fish. They say: “Our results indicate that low-latitude reef fish populations are living close to their thermal optima and may be more sensitive to ocean warming than higher-latitude populations.”

“Our studies found that one species of fish could not even survive in water just 3°C warmer than it lives in now”, says the lead author of the study, Dr Jodie Rummer from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University in Queensland.

Dr Rummer and her colleagues studied six common species living on coral reefs near the Equator. She says many species in this region experience only a very narrow range of temperatures throughout their lives, and so are probably adapted to perform best at those temperatures.

The world’s oceans are projected to warm by 2-3°C by the end of this century. “Such an increase in warming leads to a loss of performance”, Dr Rummer said. “Already, we found four species of fish are living at or above the temperatures at which they function best.”

Breeding compromised

The team measured the rates at which fish use oxygen across different temperatures – at rest and during maximal performance. The results showed that in warmer water fish lose their ability to perform properly. In the wild this would limit activities crucial to survival, such as evading predators, finding food, and finding the energy to breed.

With many of the Earth’s equatorial wild populations now living close to their thermal limits, there will be serious consequences if some – like the fish the researchers studied – cannot adapt to the speed at which the oceans are warming.

The response of many species to increasing warmth is to migrate to somewhere that suits them better, which could help to drain the equatorial oceans of fish which play a key role there. Dr Rummer suggests there will be declines in fish populations as species move away from the Equator to find refuge in areas with more agreeable temperatures.

“This will have a substantial impact on the human societies that depend on these fish,” she says. Many developing countries are in the equatorial zone, and fish are central to the livelihoods and survival of millions of people, including many in Indonesia and south-east Asia.

With rapid climate change, the scientists say, understanding the link between an organism and its environment is crucial to developing management strategies to conserve biodiversity and to allow the sustainable use of marine fisheries. This is especially urgent for ensuring food security for people. – Climate News Network

Shellfish feel impact of more acid seas

January 22, 2014 in Adaptation, Algae, Carbon Dioxide, Fish, Greenhouse Gases, Marine ecology, Ocean acidification, Predation, USA

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Low oxygen and rising acidity in the oceans spell trouble for some species of scallop Image: By Jeremy Keith from Brighton & Hove, UK

Low oxygen and rising acidity in the oceans spell trouble for some species of scallop
Image: By Jeremy Keith from Brighton & Hove, UK, via Wikimedia Commons

By Tim Radford

Researchers in the US have discovered that several more marine species are being damaged by the effects of the increasing acidity of the oceans, a direct consequence of greenhouse gas emissions.

LONDON, 22 January – Ocean acidification brings fresh problems for Californian native oysters. Like some creature from a horror movie, a driller killer threatens Ostrea lurida, the Olympia oyster that dwells in the estuaries of western North America.

Many species are likely to face problems as pH levels (which measure how acid a liquid is) change and ocean chemistry begins to alter as the world warms and ever more dissolved carbon dioxide flows into the sea and adds to its acidity.

Researchers have observed that coral skeletons are affected and larval oysters find it more difficult to build their first shell structures. The change towards greater acidity seems to trigger learning difficulties in juvenile rockfish  and make it harder for the conch snail to leap out of the way of a predator’s poisoned dart. And three separate research papers bring yet more bad news for yet more sea creatures.

Eric Sanford and colleagues at the University of California, Davis, report in the Proceedings of the Royal Society B that under more acid water conditions, the Olympia oyster experiences a 20% increase in drilling predation.

Researchers conducted a direct experiment involving oysters reared in normal conditions, oysters reared in water high in dissolved carbon dioxide, and an invasive predator from a distant ocean called Urosalpinx cinerea, the Atlantic oyster drill. Their assumption was that bivalves (creatures with a hinged shell) in more acid water would grow thinner shells, and that drilling predators would selectively choose the victims that would be easiest to drill into.

Problems multiply

It didn’t work quite like that – the experimental oysters did not have thinner shells. But these oysters were victims all the same. They were 30% to 40% smaller than the control group of oysters in the other tank “and these smaller individuals were consumed at disproportionately greater rates”, the authors say. The invasive snails, on the other hand, were not bothered by the change in water pH.

The results indicate, say the researchers, that ocean acidification “can negatively affect the early life stages of Olympia oysters.” They have been subjected already to overfishing, disease, habitat loss, pollution and hypoxia, when water is so rich in nutrients that it becomes starved of oxygen and turns into a dead zone where nothing much can survive for long. Extra vulnerability to an invasive driller killer is, the scientists carefully say in non-emotive language, “a relatively novel stressor for this species.”

Hypoxia, too, turns out to be a problem made worse by carbon dioxide. Low oxygen waters are already acidified waters, say Christopher Gobler of Stony Brook University in the US and colleagues in the Public Library of Science journal PLOS One.

They report that a combination of low oxygen and low pH led to higher rates of death and slower growth for young bay scallops and hard clams than expected from either individual factor. “Low oxygen zones in coastal and open ocean ecosystems have expanded in recent decades, a trend that will accelerate with climatic warming”, says Gobler.

Threat to algae

“There is a growing recognition that low oxygen regions of the ocean are also acidified, a condition that will intensify with rising levels of atmospheric CO2 due to the burning of fossil fuels causing ocean acidification. Hence the low oxygen, low pH conditions used in this study will be increasingly common in the world’s oceans in the future.”

And ocean acidification is not just making life good for predators and bad for the prey, it could be threatening to alter the basic biodiversity of the sea. Sophie McCoy of the University of Chicago reports in Ecology Letters that she and Cathy Pfister looked at the dynamics of coralline algae that live around Tatoosh Island, Washington, on the Pacific coast of the US.

These little creatures, like oysters, grow calcium carbonate skeletons. In previous observations in which four species were transplanted to these waters, one species called Pseudolithophyllum muricatum emerged as the undisputed winner. In the 1980s, its skeleton grew twice as thick as its competitors’.

In the latest round of tests, there was no clear winner: no species was dominant, and P. muricatum won less than 25% of the time – a response, the authors think, to changes in the pH of the sea water just in the last 12 years.

The total energy available to the organisms was the same, but their responses were different: those that needed to make more calcium carbonate tissue were under more stress than those that did not.

This experiment was a “real world” test rather than a laboratory experiment. “Field sites like Tatoosh are unique because we have a lot of historical ecological data going back decades,” said McCoy. “I think it is really important to use that in nature to understand what is going on.” – Climate News Network

Researchers study shellfish success

December 24, 2013 in Adaptation, Antarctic, Europe, Fish, Marine ecology, Ocean acidification

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Scottish musel beds: The European research will be globally relevant Image: Copyright and courtesy of SAMS

Scottish mussel beds: The European research will be globally relevant
Image: Copyright and courtesy of SAMS

By Alex Kirby

The British Antarctic Survey is leading a research programme aimed at helping the European fishing industry and monitoring the effects of climate change on several shellfish species.

LONDON, 24 December – If you like the occasional plate of grilled scallops or fancy an oyster now and then, read on and ponder. The health of several species of European shellfish is under threat.

The bad news is that the shellfish face an uncertain future as the oceans become warmer and more acidic because of the changing climate. But there is some better news too: the European Union is funding an international research team to work out how these changes will affect several species vital to the European fishing economy and to marine biodiversity.

Scientists do not fully understand how shellfish like oysters, mussels, scallops and clams produce their shells, or how a change in environment will affect their populations. To address this the EU is funding a €3.6 million (£3 m) programme called CACHE (Calcium in a Changing Environment). Shellfish are an important part of the European marine economy which provides an estimated 5.4 million jobs.

Coordinated from the British Antarctic Survey (BAS) in Cambridge, UK, the programme will research how the animals produce their shells. The scientists will also try to identify populations which are resilient to climate change.

These relatively small animals are important as part of the wider pattern of marine biodiversity. And, as they make their shells from calcium carbonate, they also help to absorb the greenhouse gas CO2 from seawater.

Biotech applications

The risk to them comes from their dependence on calcium carbonate – a substance which dissolves under acidic conditions.  As the oceans become warmer and more acidic their shells will either thin, or the animals will have to expend more energy on producing thicker shells.  This will affect their population sizes and the quality of their flesh, directly affecting fisheries and consumers.

How shellfish produce their shells also matters to the biotech industry, which is interested in imitating (in a process known as bio-mimicry) the way in which shellfish take a soluble compound like calcium to make solid, robust structures.

A better understanding of this could reduce the carbon footprint of producing construction materials and create the potential for “fixing” CO2 into the building process.

The species the research team is looking at are the king scallop, the Pacific oyster, the blue mussel and the soft shell clam. It will also study the native oyster to help conservation plans, as it is listed as a priority species in the UK.

Iceberg protection

Dr Melody Clark of BAS, the programme coordinator, told the Climate News Network: “The programme is driven by the science. We really don’t know the fundamentals of how shellfish respond to changing environments.

“We do know that, in response to environmental conditions, they can change how much shell they produce, for example growing thicker shells in response to predators. In the Antarctic, inter-tidal limpets grow much thicker shells than sub-tidal ones, because they are bashed by icebergs.

“And we don’t know just how they make their shells, whether with calcium from their food, or from the seawater.

“On bio-mimicry, this research may let us start to develop ways of producing more robust structures without carbon, and with little energy.

“We’re researching shellfish in European waters, but we’re recruiting the researchers worldwide, and the results will be relevant beyond Europe.” – Climate News Network

Acid oceans harm more species

December 3, 2013 in Fish, Marine ecology, Ocean acidification

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A water melon sea urchin in Srdinian waters: Acid seas do not help larval digestion Image: Marco Busdraghi via Wikimedia Commons

A water melon sea urchin in Sardinian waters: Acid seas do not help larval digestion
Image: Marco Busdraghi via Wikimedia Commons

By Tim Radford

As climate change warms the world’s oceans, they are becoming more acidic. Researchers in Europe and the US have found the rising acidity is bad news for several species.

LONDON, 3 December – The chemistry of the oceans is changing. And it isn’t just the corals and the baby oysters that are unhappy. It makes juvenile rockfish really anxious, and it upsets the digestion of sea urchins.

The pH (a measure of acidity – the lower the pH, the more acid the water) of the planet’s oceans is dropping rapidly, largely because the carbon dioxide levels in the atmosphere are increasing. Since carbon dioxide dissolves in water to form carbonic acid, the seas are responding to global change.

The first and clearest victims are likely to be the corals, which are adapted to a specific value of pH in the oceans, but there have also been problems reported by oyster farmers.

Now Martin Tresguerres of the University of California, San Diego reports in the Proceedings of the Royal Society B that at least one species of juvenile fish responds badly to the changes in ocean chemistry.

There is a natural aspect to ocean acidification – submarine volcanoes discharge carbon dioxide and turn the deep seas around them to a kind of fizzing champagne, and upwelling ocean currents can occasionally deliver a stressful level of lower pH sea water to blight fishing waters.

But Tresguerres reports that he and colleagues subjected young Californian rockfish to the kind of water chemistry predicted as atmospheric carbon levels rise, and then measured their behaviour in response to changes of light in the aquarium, and to an unfamiliar object in the tank.

Stomach problems

What the researchers found was that the lower pH had a pronounced effect on one of the fish neuroreceptors linked to anxiety, and this effect lasted for at least seven days after the little creatures were returned to normal sea water. The change was not permanent: normal responses seemed to return after 12 days.

Meanwhile, across the Atlantic, Meike Stumpp of the University of Gothenburg in Sweden has been looking at how sea urchin larvae respond to altered pH in the seas. She and colleagues report in Nature Climate Change that they too tweaked the seawater chemistry, to discover that digestion took longer and was less effective, a bit of a problem for any young creature – especially one hardly a fifth of a millimeter in length – in the competitive world of the oceans.

“My measurements demonstrated a very strong pH dependency”, she said. “The enzymes in the sea urchins’ stomachs are optimised to function at very high pH – which is different from the situation in mammals, where stomach pH is acidic and enzymes work best at low pH.”

The implications are that as pH levels fall, life will become a great deal more problematic for at least some key marine species. And the likelihood of change is increasing. Scientists of the International Geosphere-Biosphere Programme  recently allotted a “very high” confidence level to a set of simple findings.

One was that humans were indeed making the seas more acidic, another was that the capacity of the oceans to absorb carbon dioxide would fall with increasing acidity, and a third was that the impact of this change in water chemistry would be felt for centuries. They also had “high confidence” that cold water corals and mollusc communities would be affected. – Climate News Network

UK waters grow cooler – and more acid

November 28, 2013 in Fish, Marine ecology, Natural Variability, Ocean acidification, Ocean Warming, United Kingdom

EMBARGOED until 0001 GMT on Thursday 28 November

Heading out... catches of Atlantic cod, and other cold water species, have halved Image: Peter from Edinburgh, Scotland, UK via Wikimedia Commons

Heading out… catches of Atlantic cod, and other cold water species, have halved
Image: Peter from Edinburgh, Scotland, UK via Wikimedia Commons

By Alex Kirby

A comprehensive report on the state of the seas around the United Kingdom says ocean acidification is probably increasing faster than for the last 300 million years.

LONDON, 28 November – Dipping your toes in the waters around Britain has grown marginally less inviting: in the last few years the seas have grown slightly colder.

Against the background of a continued warming trend, this blip is explained by scientists as an example of the climate’s tendency sometimes to go “off trend”, and to show clear variations from the norm.

UK researchers say the average UK coastal sea surface temperature in the last decade was lower in 2008-2012 than in 2003-2007, an example of short-term variability which they say is at odds with temperature records which “continue to show an overall upward trend“.

The finding – perhaps not surprising, given the slower pace of atmospheric warming in recent years – is reported by the Marine Climate Change Impacts Partnership (MCCIP) and is published in its latest Report Card, which assesses how climate change is affecting UK waters.

MCCIP, launched in 2005, is a partnership between scientists, the UK Government and its agencies, non-governmental organisations and industry.

Local consequences

For the first time the report looks at Arctic sea-ice coverage, and agrees that a long-term decline is clearly apparent, with sea-ice extent retreating and the ice becoming thinner as temperatures rise. It says the overall warming trend of recent decades is expected to continue.

It emphasises the importance of local-scale impacts, describing the movement of fish species and how non-native species are expanding their range.

It says: “International commercial landings from the north-east Atlantic of species identified as warm-adapted (e.g. grey gurnard, red mullet, hake) have increased 250% in the last 30 years, while landings of cold-adapted species (e.g. cod, haddock, whiting) have halved.”

The report also identifies a possible trend to smaller fish: “”Evidence is emerging that fish body-size is affected by climate change. For example, warm, lower-oxygen conditions favour smaller individuals, and by 2050 the average fish weight could be reduced by 14-24%.

Accelerating acidity

“However, there are multiple drivers of changes in size distributions including the known effects of fishing.”

One cause of change the report identifies with high confidence is growing ocean acidification. It says: “The current rate of increase in acidity… is probably more rapid now than any time in the last 300 million years.”

The researchers say changes to primary fish production are expected throughout the UK, with southern regions (for instance the Celtic Sea and English Channel) becoming up to 10% more productive and northern regions (like the central and northern North Sea) up to 20% less so.

But they acknowledge “some challenges” in identifying the impacts of climate change. These challenges are caused by difficulties in distinguishing both between short-term variability and long-term trends, and between climate influences and other pressures.

Over 150 scientists from 55 UK science organisations contributed to the report, which covers a range of 30 marine and coastal topics. The detailed peer-reviewed briefings on all the topics covered in the summary series are available online.  The 2013 Report Card and the 33 topic reports will be available online shortly after publication. – Climate News Network