Ozone hole shrinks atmospheric CO2 uptake in Southern Ocean

Researchers in Europe have discovered that the ozone affects the ocean’s role as a carbon sink, a reservoir that absorbs and stores carbon from another part of the carbon cycle. The four sinks are the atmosphere, terrestrial biosphere, oceans and sediments. The findings, published in the journal Geophysical Research Letters, will help improve future models developed by the Intergovernmental Panel on Climate Change (IPCC), which assesses the scientific, technical and socioeconomic information needed for the understanding of the risk of human-induced climate change.

The results are part of the CARBOOCEAN (’Marine carbon sources and sinks assessment’) project, backed with EUR 14.5 million in funding, CARBOOCEAN falls under the EU’s ‘Sustainable development’ thematic area of the Sixth Framework Programme (FP6). This Integrated Project is targeting the reduction of existing uncertainties in the quantification of net annual air-sea CO2 fluxes by a factor of 2 for the world ocean and by a factor of 4 for the Atlantic Ocean.

In this latest study, the researchers from three laboratories in France used original simulations to show that the ozone layer hole shrinks atmospheric carbon uptake in the Southern Ocean and helps raise ocean acidity.

Ocean acidification affects iron speciation in seawater

Rising atmospheric CO2 is acidifying the surface ocean, a process which is expected to greatly influence the chemistry and biology of the future ocean. Following the development of iron-replete phytoplankton blooms in a coastal mesocosm experiment at 350, 700, and 1050 μatm pCO2, we observed significant increases in dissolved iron concentrations, Fe(II) concentrations, and Fe(II) half-life times during and after the peak of blooms in response to CO2 enrichment, suggesting increased iron bioavailability. If applicable to the open ocean this may provide a negative feedback mechanism to the rising atmospheric CO2 by stimulating marine primary production.

Ocean acidification: Summary for Policymakers

The sponsors of the second symposium on the Ocean in a High-CO2 World publish today an eight-page summary for policymakers on ocean acidification including key recommendations.

The Arctic Ocean marine carbon cycle: evaluation of air-sea CO2 exchanges, ocean acidification impacts and potential feedbacks

At present, although seasonal sea-ice cover mitigates atmosphere-ocean gas exchange, the Arctic Ocean takes up carbon dioxide (CO2) on the order of −65 to −175 Tg C year−1, contributing 5–14% to the global balance of CO2 sinks and sources. Because of this, the Arctic Ocean is an important influence on the global carbon cycle, with the marine carbon cycle and atmosphere-ocean CO2 exchanges sensitive to Arctic Ocean and global climate change feedbacks. In the near-term, further sea-ice loss and increases in phytoplankton growth rates are expected to increase the uptake of CO2 by Arctic surface waters, although mitigated somewhat by surface warming in the Arctic. Thus, the capacity of the Arctic Ocean to uptake CO2 is expected to alter in response to environmental changes driven largely by climate. These changes are likely to continue to modify the physics, biogeochemistry, and ecology of the Arctic Ocean in ways that are not yet fully understood. In surface waters, sea-ice melt, river runoff, cooling and uptake of CO2 through air-sea gas exchange combine to decrease the calcium carbonate (CaCO3) mineral saturation states (Ω) of seawater that is counteracted by seasonal phytoplankton primary production (PP). Biological processes drive divergent trajectories for Ω in surface and subsurface waters of Arctic shelves with subsurface water experiencing undersaturation with respect to aragonite and calcite. Thus, in response to increased sea-ice loss, warming and enhanced phytoplankton PP, the benthic ecosystem of the Arctic shelves are expected to be negatively impacted by the biological amplification of ocean acidification. This in turn reduces the ability of many species to produce CaCO3 shells or tests with profound implications for Arctic marine ecosystems.

New videoconferences from marine center

Canada’s premier coastal and marine facility for teaching and research, Bamfield Marine Sciences Centre, recently listed three videoconferences on www.cilc.org, including one on pH chemistry and biology behind our world’s changing oceans. The programs are all available by request, and open for grade(s): 7, 8, 9, 10, 11, and 12.

Tolerance of allogromiid Foraminifera to severely elevated carbon dioxide concentrations: Implications to future ecosystem functioning and paleoceanographic interpretations

Increases in the partial pressure of carbon dioxide (pCO2) in the atmosphere will significantly affect a wide variety of terrestrial fauna and flora. Because of tight atmospheric–oceanic coupling, shallow-water marine species are also expected to be affected by increases in atmospheric carbon dioxide concentrations. One proposed way to slow increases in atmospheric pCO2 is to sequester CO2 in the deep sea. Thus, over the next few centuries marine species will be exposed to changing seawater chemistry caused by ocean–atmospheric exchange and/or deep-ocean sequestration. This initial case study on one allogromiid foraminiferal species (Allogromia laticollaris) was conducted to begin to ascertain the effect of elevated pCO2 on benthic Foraminifera, which are a major meiofaunal constituent of shallow- and deep-water marine communities. Cultures of this thecate foraminiferan protist were used for 10–14-day experiments. Experimental treatments were executed in an incubator that controlled CO2 (15 000; 30 000; 60 000; 90 000; 200 000 ppm), temperature and humidity; atmospheric controls (i.e., ~ 375 ppm CO2) were executed simultaneously. Although the experimental elevated pCO2 values are far above foreseeable surface water pCO2, they were selected to represent the spectrum of conditions expected for the benthos if deep-sea CO2 sequestration becomes a reality. Survival was assessed in two independent ways: pseudopodial presence/absence and measurement of adenosine triphosphate (ATP), which is an indicator of cellular energy. Substantial proportions of A. laticollaris populations survived 200 000 ppm CO2 although the mean of the median [ATP] of survivors was statistically lower for this treatment than for that of atmospheric control specimens. After individuals that had been incubated in 200 000 ppm CO2 for 12 days were transferred to atmospheric conditions for ~ 24 h, the [ATP] of live specimens (survivors) approximated those of the comparable atmospheric control treatment. Incubation in 200 000 ppm CO2 also resulted in reproduction by some individuals. Results suggest that certain Foraminifera are able to tolerate deep-sea CO2 sequestration and perhaps thrive as a result of elevated pCO2 that is predicted for the next few centuries, in a high-pCO2 world. Thus, allogromiid foraminiferal “blooms” may result from climate change. Furthermore, because allogromiids consume a variety of prey, it is likely that they will be major players in ecosystem dynamics of future coastal sedimentary environments.

Several PhD-student positions , 1 Post-Doc, 1 Technical assistant (aquaculture), within the forthcoming BMBF joint project “Biological Impacts of Ocean Acidification (BIOACID)“

Within the forthcoming BMBF joint project “Biological Impacts of Ocean Acidification (BIOACID)“, starting by September 15th, 2009 – funding provided, the Departments of Bio-, Geo- and Climate sciences seek applications for several PhD-student positions (TVöD-Bund 13/2), 1 Post-Doc (TV-L 13), 1 Technical assistant (aquaculture), TVöD-VKA.

The world oceans take up one third of the anthropogenic carbon dioxide (CO2), causing pH and the carbonate saturation to decline. A reliable prediction of the response of marine organisms (phyto- and zooplankton, invertebrates, fishes and their life stages) and systems to such changes requires a detailed understanding of the underlying mechanisms as well as long-term studies under controlled conditions. BIOACID intends to carry out interdisciplinary studies of development, growth and activity performance, and of the mechanisms of acid-base and ion regulation incl. calcification. The scope of the work is complemented by molecular analyses, by modelling and the study of synergistic effects of ocean acidification and other environmental factors, with the goal to reach predictability of future responses of marine organisms and ecosystems.

Detailed descriptions of each position and of the specific requirements are available on the AWI homepage under Open Positions  (http://www.awi.de/en/news/open_positions/bremerhaven_helgoland_sylt).

Coral reefs in danger of dying out in next 20 years

The world’s coral reefs are in danger of dying in the next 20 years unless the world drastically cuts carbon emissions, a coalition of scientists led by Sir David Attenborough has warned.

The delicate eco systems, known as the “rainforests of the sea”, support huge amounts of marine life.

But as oceans absorb carbon dioxide, they become more acidic, making it impossible for coral reefs like the Great Barrier Reef in Australia to survive. Reefs are also at greater danger of bleaching as sea temperatures warm.

Scientists gathered at the Royal Society in London yesterday to call for tougher targets for the world to cut emissions.

Sir David Attenborough, who co-chaired the meeting, said that the collapse of coral reefs meant the death of marine ecosystems.

“We must do all that is necessary to protect the key components of the life of our planet as the consequences of decisions made now will likely be forever as far as humanity is concerned,” he said.

Experts warn of reef extinction by end of century

Wildlife experts warn that the world’s coral reefs may be extinct by the end of this century unless the amount of carbon dioxide (CO2) in the atmosphere is cut down.

At a meeting in London on Monday, leading wildlife experts claimed that the predicted pace of emissions means a level of 450 parts per million of CO2 in the atmosphere will be reached by 2050.

The emissions will lead to increasingly acidic oceans and warming water temperatures, which will kill off the coral reefs in the following decades.

“The kitchen is on fire and it’s spreading around the house,” said Alex Rogers of the Zoological Society of London and the International Program on the State of the Ocean.

Great Barrier Reef facing destruction ‘within 20 years’ say experts

Children born today could be the last generation to enjoy swimming among stunning coral reefs, marine scientists have said.

A meeting of leading wildlife experts – led by Sir David Attenborough – today warned that tropical reefs face ‘imminent destruction’ unless the world cuts the amount of carbon dioxide in the atmosphere.

They say concentrations of CO2 have already gone beyond the tipping point for reefs – and need to return to the levels of the 1970s.

And Charlie Veron, former chief scientist of the Australian Institute of Marine Science, has claimed that the Great Barrier Reef will be gone within 20 years.

‘There is no way out, no loopholes,’ he said. ‘The Great Barrier Reef will be over within 20 years or so.’