Archive for June, 2018

Ocean Acidification International Coordination Centre (OA-ICC) hosts annual expert group meeting

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The Ocean Acidification International Coordination Centre (OA-ICC) hosted their annual expert group meeting at the International Atomic Energy Agency (IAEA) Environmental Laboratories in Monaco on 28 June. The goal of the technical meeting was to report and foster discussion on the coordination of OA-ICC activities within the past year as well as plans for the upcoming year.

Included in the 18 participants of this meeting were focal points for the OA-ICC capacity building initiatives, data management and outreach, collaboration between natural and social sciences, best practices in ocean acidification research, among other efforts. This year marks the 5th year of the OA-ICC, as well as the 10th SOLAS-IMBER OA working group meeting, whose participants are closely involved in OA-ICC activities and who all attended the OA-ICC Expert Group meeting in Monaco.

 

June 26th and 27th 2018 – the Institut de la Mer de Villefranche welcomes the 2018 meeting of the SOLAS-IMBER working group on ocean acidification

On June 26th and 27th, the Institut de la Mer de Villefranche will welcome the 2018 meeting of the SOLAS-IMBER Working Group on Ocean AcidificationThe Ocean Acidification sub-group is appointed jointly by the IMBER and SOLAS. It consists of a Chair and approximately twelve members assembled for their experience and expertise in the area of ocean acidification.
The primary responsibilities of this sub-group are to:
– coordinate international research efforts in ocean acidification
– undertake synthesis activities in ocean acidification at the international level
– develop and maintain an international website on ocean acidification.

Participant list :
Sam DUPONT, University of Gothenburg
James ORR, LSCE/IPSL, Laboratoire des Sciences du Climat et de l’Environnement CEA-CNRS-UVSQ
Alexandre MAGNAN, L’Institut du développement durable et des relations internationales (IDDRI)
Lina HANSSON, IAEA Monaco
John BAXTER, Scottish Natural Heritage
Kristy KROEKER, University of California, Santa Cruz
Shallin BUSH, NOAA
Marine LEBREC, IAEA Monaco
Kim CURRIE, NIWA/University of Otago
Frédéric GAZEAU, LOV

 

Observatoire Oceanologique de Villefranche sur Mer, 27 June 2018. Press release.

‘Electrogeochemistry’ captures carbon, produces fuel, offsets ocean acidification

Credit: © Francesco Scatena / Fotolia

A new study evaluates the potential for recently described methods that capture carbon dioxide from the atmosphere through an “electrogeochemical” process that also generates hydrogen gas for use as fuel and creates by-products that can help counteract ocean acidification.

Limiting global warming to 2 degrees Celsius will require not only reducing emissions of carbon dioxide, but also active removal of carbon dioxide from the atmosphere. This conclusion from the Intergovernmental Panel on Climate Change has prompted heightened interest in “negative emissions technologies.”

A new study published June 25 in Nature Climate Change evaluates the potential for recently described methods that capture carbon dioxide from the atmosphere through an “electrogeochemical” process that also generates hydrogen gas for use as fuel and creates by-products that can help counteract ocean acidification.

First author Greg Rau, a researcher in the Institute of Marine Sciences at UC Santa Cruz and visiting scientist at Lawrence Livermore National Laboratory, said this technology significantly expands the options for negative emissions energy production.

Continue reading ‘‘Electrogeochemistry’ captures carbon, produces fuel, offsets ocean acidification’

Effects of ocean acidification on the levels of primary and secondary metabolites in the brown macroalga Sargassum vulgare at different time scales

Highlights

Sargassum vulgare growing at CO2 vents was compared with those growing at control site.
S. vulgare from control site was transplanted to CO2 vents for 2 weeks.
• In short-term responses, S. vulgare showed increased level of sugars, PUFAs, and EAAs.
• Natural population at vents showed decreased sugars, PUFAs, phenols, and increased EAAs.
• Nutritional values of algae will decrease under acidification in long time scale.

Abstract

Most of the studies regarding the impact of ocean acidification on macroalgae have been carried out for short-term periods, in controlled laboratory conditions, thus hampering the possibility to scale up the effects on long-term. In the present study, the volcanic CO2 vents off Ischia Island were used as a natural laboratory to investigate the metabolic response of the brown alga Sargassum vulgare to acidification at different time scales. For long-term effects, algal populations naturally growing at acidified and control sites were compared. For short-term responses, in situ reciprocal transplants from control to acidified site and vice-versa were performed. Changes in the levels of sugars, fatty acids (FAs), amino acids (AAs), antioxidants, and phenolic compounds were examined. Our main finding includes variable metabolic response of this alga at different time scales to natural acidification. The levels of sugars, FAs, and some secondary metabolites were lower in the natural population at the acidified site, whereas the majority of AAs were higher than those detected in thalli growing at control site. Moreover, in algae transplanted from control to acidified site, soluble sugars (glucose and mannose), majority of AAs, and FAs increased in comparison to control plants transplanted within the same site. The differences in the response of the macroalga suggest that the metabolic changes observed in transplants may be due to acclimation that supports algae to cope with acidification, thus leading to adaptation to lowered pH in long time scale.

Graphical abstract

Unlabelled Image

Continue reading ‘Effects of ocean acidification on the levels of primary and secondary metabolites in the brown macroalga Sargassum vulgare at different time scales’

An acidified San Francisco bay? No one’s studied that yet

This buoy measures seawater chemistry near the Estuary & Ocean Science Center in Tiburon. (Photo by Eric Simons)

Ocean acidification and the effect it will have on the San Francisco Bay hasn’t received the scientific study you might imagine, given how frequently climate change comes up in discussions of the Bay.

To date there has been almost no long-term monitoring of the Bay’s carbon chemistry, for example. Ocean acidification is “expected to impact estuaries on the West Coast,” one scientific report concluded in 2016, but “chemical and biological data on acidification threats and impacts are lacking.”

There are a lot of basic questions. Does ocean upwelling bring acidified—CO2-rich and oxygen-poor—water into the Bay? Does acidification threaten the Bay’s marine life, and which life, and how much? Do restored tidal marshes soak up or burp out carbon? How much carbon, and are all estuaries like that? Could local projects to capture and store CO2 before it’s emitted become part of the carbon offset market?

Continue reading ‘An acidified San Francisco bay? No one’s studied that yet’

Tribes, communities monitor ocean acidification in near-shore waters

Petersburg Indian Association’s Brandon Thynes caps a bottle of ocean water at Sandy Beach. The sample is a part of Sitka Tribe’s efforts to study ocean acidification. (Photo by Alanna Elder/KFSK)

Petersburg Indian Association’s Brandon Thynes caps a bottle of ocean water at Sandy Beach. The sample is a part of Sitka Tribe’s efforts to study ocean acidification. (Photo by Alanna Elder/KFSK)

Southeast tribes are joining in research efforts to monitor ocean acidification in the waters closest to shore.

This coincides with data coming in from a ferry that for the past six months has been taking measurements along its regular route from Bellingham, Washington, to Juneau.

This information may one day give communities a better idea of what to expect from change in the ocean.

Continue reading ‘Tribes, communities monitor ocean acidification in near-shore waters’

Nutrient pollution runoff makes ocean acidification worse for coral reefs

Nutrient pollution runoff from the land may be accelerating the negative impact global ocean acidification is having on coral reefs, according to CSUN biologist Nyssa Silbiger. The coral reef, above, is in Kaneohe Bay, Hawaii, where her research was conducted. Photo credit Nyssa Silbiger.

Nutrient pollution runoff from the land — whether from sewage, farm fertilizer or the aftermath of a rainstorm — may be accelerating the negative impact global ocean acidification is having on coral reefs.

This is according to a new study by a team of researchers, including California State University, Northridge assistant professor of biology Nyssa Silbiger, recently published in the “Proceedings of the Royal Society B: Biological Science.”

Continue reading ‘Nutrient pollution runoff makes ocean acidification worse for coral reefs’

Experts finalize methodology to measure ocean acidification

Highlights
The Global Ocean Acidification Observing Network Executive Council discussed and finalized a methodology for collecting information on global ocean acidification, in support of monitoring SDG target indicator 14.3.1.
The Network is also working to build the capacity of scientists to collect reliable, globally comparable data on the indicator.

Continue reading ‘Experts finalize methodology to measure ocean acidification’

Model constraints on the anthropogenic carbon budget of the Arctic Ocean

The Arctic Ocean is projected to experience not only amplified climate change but also amplified ocean acidification. Modeling future acidification depends on our ability to simulate baseline conditions and changes over the industrial era. Such centennial-scale changes require a global model to account for exchange between the Arctic and surrounding regions. Yet the coarse resolution of typical global models may poorly resolve that exchange as well as critical features of Arctic Ocean circulation. Here we assess how simulations of Arctic Ocean storage of anthropogenic carbon (Cant), the main driver of open- ocean acidification, differ when moving from coarse to eddy admitting resolution in a global ocean circulation-biogeochemistry model (NEMO-PISCES). The Arctic’s regional storage of Cant is enhanced as model resolution increases. While the coarse- resolution model configuration ORCA2 (2°) stores 2.0 Pg C in the Arctic Ocean between 1765 and 2005, the eddy-admitting versions ORCA05 and ORCA025 (1/2° and 1/4°) store 2.4 and 2.6 Pg C. That result from ORCA025 falls within the uncertainty range from a previous data-based Cant storage estimate (2.5 to 3.3 Pg C). Yet those limits may each need to be reduced by about 10 % because data-based Cant concentrations in deep waters remain at ∼ 6 μmol kg−1, while they should be almost negligible by analogy to the near-zero observed CFC-12 concentrations from which they are calculated. Across the three resolutions, there was roughly three times as much anthropogenic carbon that entered the Arctic Ocean through lateral transport than via the flux of CO2 across the air-sea interface. Wider comparison to nine earth system models that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) reveals much larger diversity of stored anthropogenic carbon and lateral transport. Only the CMIP5 models with higher lateral transport obtain Cant inventories that are close to the data-based estimates. Increasing resolution also enhances acidification, e.g., with greater shoaling of the Arctic’s average depth of the aragonite saturation horizon during 1960–2012, from 50 m in ORCA2 to 210 m in ORCA025. To assess the potential to further refine modeled estimates of the Arctic Ocean’s Cant storage and acidification, sensitivity tests that adjust model parameters are needed given that century-scale global ocean biogeochemical simulations still cannot be run routinely at high resolution.

Continue reading ‘Model constraints on the anthropogenic carbon budget of the Arctic Ocean’

Mechanisms to explain the elemental composition of the initial aragonite shell of larval oysters

Abstract

Calcifying organisms face increasing stress from the changing carbonate chemistry of an acidifying ocean, particularly bivalve larvae that live in upwelling regions of the world, such as the coastal and estuarine waters of Oregon (USA). Arguably the first and most significant developmental hurdle faced by larval oysters is formation of their initial prodissoconch I (PDI) shell, upon which further ontological development depends. We measured the minor metal compositions (Sr/Ca, Mg/Ca) of this aragonitic PDI shell and of post‐PDI larval Crassostrea gigas shell, as well as the water they were reared in, over ∼20 days for a May and an August cohort in 2011, during which time there was no period of carbonate under‐saturation. After testing various methods, we successfully isolated the shell from organic tissue using a 5% active chlorine bleach solution. Elemental compositions (Sr, Mg, C, N) of the shells post‐treatment showed that shell Sr/Ca ranged from 1.55 to 1.82 mmol/mol; Mg/Ca from 0.60 to 1.11 mmol/mol, similar to the few comparable published data for larval oyster aragonite compositions. We compare these data in light of possible biomineralization mechanisms: an amorphous calcium carbonate (ACC) path, an intercellular path, and a direct‐from‐seawater path to shell formation via biologically induced inorganic precipitation of aragonite. The last option provides a mechanistic explanation for: (1) the accelerated precipitation rates of biogenic calcification in the absence of a calcifying fluid; (2) consistently elevated precipitation rates at varying ambient‐water saturation states; and (3) the high Ca‐selectivity of the early larval calcification despite rapid precipitation rates.

Plain Language Summary

Larval oysters are particularly susceptible to changes in ocean water chemistry thought to result from the increasing concentration of atmospheric carbon dioxide. Here, we use trace element concentrations measured in larval shells and the water in which the larvae were reared in order to investigate how and why the larvae are so sensitive to these small chemical changes in their environment. We suggest that the way in which larval oysters make their shells is inherently prone to these changes in water chemistry, but once past an initial phase of shell growth, the juvenile oysters may become more resilient.

Continue reading ‘Mechanisms to explain the elemental composition of the initial aragonite shell of larval oysters’


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Ocean acidification in the IPCC AR5 WG II

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