Archive for December, 2011



Polycentric systems and interacting planetary boundaries – emerging governance of climate change–ocean acidification–marine biodiversity

Planetary boundaries and their interactions pose severe challenges for global environmental governance due to their inherent uncertainties and complex multi-scale dynamics. Here we explore the global governance challenge posed by planetary boundaries interactions by focusing on the role of polycentric systems and order, a theoretical field that has gained much interest in the aftermath of claims of a stagnant UN-process. In the first part we work toward a clarification of polycentric order in an international context, and develop three propositions. We then present a case study of the emergence of international polycentricity to address interacting planetary boundaries, namely the climate change, ocean acidification and loss of marine biodiversity complex. This is done through a study of the Global Partnership on Climate, Fisheries and Aquaculture (PaCFA) initiative. As the case study indicates, a range of mechanisms of polycentric order (ranging from information sharing to coordinated action and conflict resolution) operates at the international level through the interplay between individuals, international organizations and their collaboration patterns. While polycentric coordination of this type certainly holds potential, it is also vulnerable to internal tensions, unreliable external flows of funding, and negative institutional interactions.

Continue reading ‘Polycentric systems and interacting planetary boundaries – emerging governance of climate change–ocean acidification–marine biodiversity’

Decreasing pH trend estimated from 35-yr time series of carbonate parameters in the Pacific sector of the Southern Ocean in summer

The Southern Ocean is an important region for investigation because it has a major effect on global air-to-sea CO2 fluxes and because of the ocean acidification resulting from the uptake of anthropogenic carbon, leading to serious consequences for marine ecosystems in the near future. We estimated long-term trends of ocean acidification in surface waters of the Pacific sector of the Southern Ocean, based on the summer observational records of oceanic CO2 partial pressure and related surface properties during 1969–2003. The computed pH time series exhibited substantial decreasing trends in the extensive region from the subtropical to polar zones. The mean rates of pH decrease over the 35-year period were 0.0011 to 0.0013 yr–1 in the zones north of the Polar Front and were larger in the polar zone (0.0020 yr–1). The contribution of trends in sea surface temperature to the trends of pH decrease was small in all zones. The high rate of pH decrease in the polar zone was attributed to the supply of dissolved inorganic carbon from lower layers, enhanced by intensified wind stress and superimposed onto the accumulation of anthropogenic CO2. A preliminary evaluation of thermodynamic changes in the upper carbonate system, using observational results, projected that the polar zone south of the Polar Front would be undersaturated with respect to aragonite in summer after 80 years.

Continue reading ‘Decreasing pH trend estimated from 35-yr time series of carbonate parameters in the Pacific sector of the Southern Ocean in summer’

Ocean acidification project

Rising levels of atmospheric carbon dioxide (CO2), a major “greenhouse” gas and driven primarily through increased fossil fuel emissions and changes in land use, produce changes in ocean chemistry that may affect marine life globally. Since the Industrial Revolution (IR), the atmospheric CO2 concentration has increased by about 35%. When CO2 from the atmosphere dissolves in seawater, it reacts with water to produce carbonic acid that acidifies seawater. Carbonic acid decreases the ocean pH, hence the term “acidification”. In response, ocean pH has decreased from about 8.2 to 8.1 since IR. Ocean pH is expected to continue to decline additional 0.2 – 0.3 units by the next century.

In January 2009 PMEL, AOML, and NOAA’s Coral Health and Monitoring Program deployed the MapCO2 buoy in order to establish an Atlantic Ocean Acidification Test-bed (AOAT) in coastal coral reef environments. This mooring is located along the fore-reef of the Cayo Enrique shelf reef at La Parguera, Puerto Rico. This buoy complement the Integrated Coral Observing Network (ICON) located at Media Luna shelf reef. Local support for the mooring was initially provided by the Caribbean Coral Reef Institute; subsequently by CariCOOS and throughout the deployment by the University of Puerto Rico, Department of Marine Sciences. A suite of chemical, physical, and meteorological measurements monitored within the La Parguera Marine Reserve are used to track the dynamics and controls on local carbon chemistry at the site. These autonomous observations are validated and supplemented on a weekly basis through a discrete sampling campaign conducted by CariCOOS. For more information visit: http://www.pmel.noaa.gov/co2/story/La+Parguera

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Combined effects of inorganic carbon and light on Phaeocystis globosa Scherffel (Prymnesiophyceae)

Phaeocystis globosa (Prymnesiophyceae) is a globally dominating phytoplankton species. It plays an important role in both the global sulfur and carbon cycles, by the production of dimethylsulfide (DMS) and the drawdown of inorganic carbon. Phaeocystis globosa has a polymorphic life cycle and is considered to be a harmful algal bloom (HAB) forming species. All these aspects make this an interesting species to study the effects of increasing carbon dioxide (CO2) concentrations, due to anthropogenic carbon emissions. Here, the combined effects of three different dissolved carbon dioxide concentrations (CO2(aq)) (low: 4 μmol kg−1, intermediate: 6–10 μmol kg−1 and high CO2(aq): 21–24 μmol kg−1) and two different light intensities (low light, suboptimal: 80 μmol photons m−2s–1 and high light, light saturated: 240 μmol photons m−2s−1) are reported. The experiments demonstrated that the specific growth rate of P. globosa in the high light cultures decreased with increasing CO2(aq) from 1.4 to 1.1 d−1 in the low and high CO2 cultures respectively. Concurrently, the photosynthetic efficiency increased with increasing CO2(aq) from 0.56 to 0.66. The different light conditions affected photosynthetic efficiency and chlorophyll-a concentrations, both of which were lower in the high light cultures as compared to the low light cultures. These results suggest that in the future, inorganic carbon enriched oceans, P. globosa will become less competitive and feedback mechanisms to global change may decrease in strength.

Continue reading ‘Combined effects of inorganic carbon and light on Phaeocystis globosa Scherffel (Prymnesiophyceae)’

Impacts of anthropogenic SOx, NOx and NH3 on acidification of coastal waters and shipping lanes

The acidification of the ocean by anthropogenic CO2 absorbed from the atmosphere is now well-recognized and is considered to have lowered surface ocean pH by 0.1 since the mid-18th century. Future acidification may lead to undersaturation of CaCO3 making growth of calcifying organisms difficult. However, other anthropogenic gases also have the potential to alter ocean pH and CO2 chemistry, specifically SOx and NOx and NH3. We demonstrate using a simple chemical model that in coastal water regions with high atmospheric inputs of these gases, their pH reduction is almost completely canceled out by buffering reactions involving seawater HCO3− and CO32− ions. However, a consequence of this buffering is a significant decrease in the uptake of anthropogenic CO2 by the atmosphere in these areas.

Continue reading ‘Impacts of anthropogenic SOx, NOx and NH3 on acidification of coastal waters and shipping lanes’

Burning of fossil fuels causing rise in ocean acidity (audio)

The burning of fossil fuels is causing a rise of acid levels in the ocean, and it may be harming sea life, according to a new study by researchers at Scripps Institution of Oceanography.

Scientists have found ocean water becomes more acidic because about a quarter of the carbon emissions in the air go into the sea.

Jennifer Smith, an assistant professor of Marine Ecology at Scripps Institute of Oceanography, says that affects ocean life.

“As the water becomes more acidic, it becomes more difficult for things that have skeletons and shells, things like mussels and oysters. It makes it more difficult for them to build shells,” she said.

Continue reading ‘Burning of fossil fuels causing rise in ocean acidity (audio)’

L’acidification des océans menace les poissons (in French)

Le changement climatique réduit les chances de survie de certaines espèces commerciales comme le cabillaud

Souvent résumé à la quantité de dioxyde de carbone (CO2) présente dans l’atmosphère, le changement climatique aura aussi un impact majeur sur le maintien de certaines formes de vie présentes dans les océans. Car une partie du CO2 en surplus dans l’air se dissout dans les mers et contribue à les acidifier. L’impact négatif sur les organismes calcaires – coquillages, crustacés, planctons à exosquelette de calcite ou d’aragonite – est connu. Mais deux nouvelles études, à paraître dans la prochaine édition de Nature Climate Change, documentent pour la première fois des effets importants sur certains poissons. La première étude, menée par la biologiste Andrea Frommel (Institut Leibniz des sciences marines de Kiel, Allemagne), a observé sur une espèce de grande importance commerciale – le cabillaud (Gadus morhua) – une détérioration de certains organes lorsque les larves se développaient dans une eau plus acide que le niveau actuel. A mesure que les taux de CO2 dans l’air ambiant grimpent et que l’eau s’acidifie, les chercheurs notent l’apparition d’anomalies sur le pancréas, le foie, les reins des poissons. Ces anomalies peuvent réduire les chances de survie des individus ou être directement létales. Les niveaux d’acidité simulés par les chercheurs sont élevés – 1 800 parties par million (ppm) et 4 200 ppm de CO2 atmosphérique, contre 390 ppm aujourd’hui. Soit des niveaux d’acidité qui, en moyenne, ne seront globalement la norme qu’au XXIIe siècle et au-delà. Si, toutefois, les émissions de CO2 se poursuivent au rythme actuel.

Continue reading ‘L’acidification des océans menace les poissons (in French)’

Comprehensive study makes key findings of ocean pH variations

Some organisms already experiencing ocean acidification levels not predicted to be reached until 2100

Scripps Institution of Oceanography / University of California, San Diego

A group of 19 scientists from five research organizations have conducted the broadest field study of ocean acidification to date using sensors developed at Scripps Institution of Oceanography, UC San Diego.

The study, “High-Frequency Dynamics of Ocean pH: A Multi-Ecosystem Comparison,” is reported in today’s issue of the journal PLoS One. It is an important step toward understanding how specific ecosystems are responding to the change in seawater chemistry that is being caused as the oceans take up extra carbon dioxide produced by human greenhouse gas emissions, said its authors.

Continue reading ‘Comprehensive study makes key findings of ocean pH variations’

High-frequency dynamics of ocean pH: a multi-ecosystem comparison

The effect of Ocean Acidification (OA) on marine biota is quasi-predictable at best. While perturbation studies, in the form of incubations under elevated pCO2, reveal sensitivities and responses of individual species, one missing link in the OA story results from a chronic lack of pH data specific to a given species’ natural habitat. Here, we present a compilation of continuous, high-resolution time series of upper ocean pH, collected using autonomous sensors, over a variety of ecosystems ranging from polar to tropical, open-ocean to coastal, kelp forest to coral reef. These observations reveal a continuum of month-long pH variability with standard deviations from 0.004 to 0.277 and ranges spanning 0.024 to 1.430 pH units. The nature of the observed variability was also highly site-dependent, with characteristic diel, semi-diurnal, and stochastic patterns of varying amplitudes. These biome-specific pH signatures disclose current levels of exposure to both high and low dissolved CO2, often demonstrating that resident organisms are already experiencing pH regimes that are not predicted until 2100. Our data provide a first step toward crystallizing the biophysical link between environmental history of pH exposure and physiological resilience of marine organisms to fluctuations in seawater CO2. Knowledge of this spatial and temporal variation in seawater chemistry allows us to improve the design of OA experiments: we can test organisms with a priori expectations of their tolerance guardrails, based on their natural range of exposure. Such hypothesis-testing will provide a deeper understanding of the effects of OA. Both intuitively simple to understand and powerfully informative, these and similar comparative time series can help guide management efforts to identify areas of marine habitat that can serve as refugia to acidification as well as areas that are particularly vulnerable to future ocean change.

Continue reading ‘High-frequency dynamics of ocean pH: a multi-ecosystem comparison’

Two centuries-long records of skeletal calcification in massive Porites colonies from Meiji Reef in the southern South China Sea and its responses to atmospheric CO2 and seawater temperature

Rising atmospheric CO2 and warming of the global climate that have occurred since the industrial revolution are regarded as fatal threats to coral reefs. We analyzed the skeletal calcification rate of 14 massive Porites corals from the Meiji Reef in the southern South China Sea through X-ray photography of coral skeletons. A general pattern of change in coral skeletal calcification was determined. The change pattern of coral calcification on the Meiji Reef over the past two centuries can be divided into five periods: calcification increase in 1770–1830, 1870–1920, and 1980–2000 and calcification decline in 1830–187 and 1920–1980. Over the past two centuries, the largest increase in calcification was 4.5%, occurring in 1770–1830, whereas the largest decline in calcification was 6.2%, occurring in 1920–1980. Coral calcification slightly increased in the recent 20 years (1980–2000). The response relationship of coral calcification to atmospheric CO2 and sea surface temperature (SST) shows that calcification was not correlated with atmospheric CO2 but responded nonlinearly to SST with maxima at ∼27.2°C in 1900–2000. On the Meiji Reef, increasing atmospheric CO2 had a negligible effect on coral growth in the past century. However, rising SST improved coral growth in the early and middle 20th century, and restricted coral growth in the recent 20 years.

Continue reading ‘Two centuries-long records of skeletal calcification in massive Porites colonies from Meiji Reef in the southern South China Sea and its responses to atmospheric CO2 and seawater temperature’


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Ocean acidification in the IPCC AR5 WG II

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