Archive for September, 2012

Tiny fossils hint at effects of ocean acidification

Sediment-bound specimens allow comparison of ancient and present responses to changing oceans.

Monterey, California

A rare find of stunningly intact fossils of prehistoric plankton will allow researchers to study how the tiny marine organisms cope with rising acidity in the oceans.

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Acidifying ocean threatens ecosystems and US economy – congress learns about the potential impacts of ocean acidification

In a briefing hosted by Senator Maria Cantwell (D-WA), Representative Norm Dicks (D-WA), and Representative Don Young (R-AK), scientists shared their research about the impending ecological and economic consequences of increasing ocean acidity.

Acidification is caused by the ocean absorbing increasing amounts of carbon dioxide from the atmosphere. This causes both direct and indirect harm to marine life. Marine species that build their structures out of calcium carbonate (oysters, corals, etc.) are most vulnerable to ocean acidification and by extension, the organisms, jobs, and economies that depend on them are also threatened. Shellfish farms in the Pacific Northwest have reported negative impacts to oyster production due to acidic ocean waters. As acidification increases, it is expected to have profound consequences on fisheries and the coastal communities which rely on healthy marine ecosystems.

Continue reading ‘Acidifying ocean threatens ecosystems and US economy – congress learns about the potential impacts of ocean acidification’

Hot, sour, and breathless

This week, 572 scientists gathered in Monterey for the Third International Symposium on the Oceans in a High CO2 World. The numbers mark a sharp increase from the first symposium in 2004 in Paris where the community of ocean acidification scientists numbered only 124. And, this time, the mood was more urgent.  Atmospheric CO2 is entering the ocean and it is acidifying fast… the ocean is 30% more acidic than prior to industrialization. Combine this with rising ocean temperatures and decreasing oxygen levels (which cause dead zones) and, in the words of Swedish scientist Sam Dupont, you have an ocean that is increasingly, “hot, sour and breathless,” for its inhabitants. What these changes mean – from effects on plankton to shellfish and fish to entire marine ecosystems – was the subject of the meeting.

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International coordination centre for ocean acidification

Major international symposium closes with launch of new international coordination centre and announcement of an X-Prize for Ocean Health
Ocean in a High-CO2 World Symposium Monterey, California, USA, 27 September 2012 Continue reading ‘International coordination centre for ocean acidification’

Differential acid–base regulation in various gills of the green crab Carcinus maenas: effects of elevated environmental pCO2

Euryhaline decapod crustaceans possess an efficient regulation apparatus located in the gill epithelia, providing a high adaptation potential to varying environmental abiotic conditions. Even though many studies focussed on the osmoregulatory capacity of the gills, acid–base regulatory mechanisms have obtained much less attention. In the present study, underlying principles and effects of elevated pCO2 on acid–base regulatory patterns were investigated in the green crab Carcinus maenas acclimated to diluted seawater. In gill perfusion experiments, all investigated gills 4–9 were observed to up-regulate the pH of the hemolymph by 0.1 – 0.2 units. Anterior gills, especially gill 4, were identified to be most efficient in the equivalent proton excretion rate. Ammonia excretion rates mirrored this pattern among gills, indicating a linkage between both processes. In specimen exposed to elevated pCO2 levels for at least 7 days, mimicking a future ocean scenario as predicted until the year 2300, hemolymph K+ and ammonia concentrations were significantly elevated, and an increased ammonia excretion rate was observed. A detailed quantitative gene expression analysis revealed that upon elevated pCO2 exposure, mRNA levels of transcripts hypothesized to be involved in ammonia and acid–base regulation (Rhesus-like protein, membrane-bound carbonic anhydrase, Na+/K+-ATPase) were affected predominantly in the non-osmoregulating anterior gills.

Continue reading ‘Differential acid–base regulation in various gills of the green crab Carcinus maenas: effects of elevated environmental pCO2’

Socio-economic impacts of ocean acidification in the Mediterranean Sea

Ocean acidification appears as another environmental pressure associated with anthropogenic emissions of carbon dioxide. This paper aims to assess the likely magnitude of this phenomenon in the Mediterranean region. This involves translating expected changes in ocean chemistry into impacts, first on marine and coastal ecosystems and then, through effects on services provided by these to humans, into socio-economic costs. Economic market and non-market valuation techniques are needed for this purpose. Important sectors affected are tourism and recreation, red coral extraction, and fisheries (both capture and aquaculture production). In addition, the costs associated with the disruption of ecosystem regulating services, notably carbon sequestration and non-use values will be considered. Finally, indirect impacts on other economic sectors will have to be estimated. The paper discusses the framework and methods to accomplish all of this, and offers a preliminary, qualitative overall assessment.

Continue reading ‘Socio-economic impacts of ocean acidification in the Mediterranean Sea’

Ocean acidification can mess with a fish’s mind

In more acidic waters clown fish wander too far from safety, sea snails fail to avoid prey

Monterey, Calif.—Mental problems at sea? Fish and mollusks could begin to have them—thanks to rising CO2 levels. Some of the resulting behaviors are odd, some compromising, and they reveal just how fundamentally carbon emissions are affecting our increasingly fragile Earth.

As humans emit more carbon dioxide into the atmosphere, more of the gas is absorbed by the oceans, gradually making the water more acidic. Numerous studies in recent years have documented how lower pH (higher acidity) can make it harder for shellfish and tiny organisms to form shells or internal skeletons and to reproduce. The acidity often forces the organisms to expend extra energy to counteract ill effects on their metabolisms as well. But now scientists are finding that lower pH can also mess with ocean animals‘ minds.

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Postdoc in phytoplankton and ocean acidification

Bigelow Laboratory for Ocean Sciences, USA
Application deadline: 15 Oct 2012

Bigelow Laboratory for Ocean Sciences invites applications for a three-year Postdoctoral Research Scientist in the area of phytoplankton physiology and ocean acidification. The work is associated with a recently-funded NSF project on the effects of ocean acidification (OA) on coccolithophores and their associated grazers, as well as impacts of OA on the oceanic alkalinity and biological carbon pumps.

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Ocean acidification: a Q&A with NOAA scientist Shallin Busch

Scientists have been studying the effects of carbon dioxide on climate for decades. More recently, however, an additional carbon dioxide problem has come to light. The oceans have absorbed about a third of the carbon dioxide emitted into the atmosphere. Carbon dioxide alters ocean chemistry, making seawater more acidic. The term researchers use for this phenomenon is ‘Ocean Acidification’ and it threatens not only the ecological health of the oceans, but also the economic well-being of the people and industries that depend on a healthy and productive marine environment.

Dr. Shallin Busch co-leads a team of scientists at NOAA’s Northwest Fisheries Science Center studying ocean acidification, and she is in Washington, DC, this week to brief Congress on its ecological and economic impacts. She stopped in to NOAA headquarters while in town, and we had a chance to ask Dr. Busch a few questions.

Continue reading ‘Ocean acidification: a Q&A with NOAA scientist Shallin Busch’

Natural labs help scientists study ocean acidification

Scientists are using “natural laboratories” — seafloor vents that release millions of streams of small bubbles of carbon dioxide – to study how ocean acidification may affect the future of coral reefs and other marine ecosystems as global carbon dioxide emissions rise.
These techniques and others were discussed Tuesday during the second press briefing at the Third International Symposium on The Ocean in a High-CO2 World in Monterey, Calif.

When Dr. Katharina Fabricius of the Australian Institute of Marine Science in Australia discovered the carbon dioxide vents in Papua New Guinea “ocean acidification wasn’t an issue.” Her recent work at the sites would show that “seagrasses do amazingly well, but coral reefs cannot survive when conditions get too corrosive.”

Continue reading ‘Natural labs help scientists study ocean acidification’


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