Volcanic carbon dioxide vents show ecosystem effects of ocean acidification

In the paper

“and may lead to a drop in seawater pH of up to 0.5 units by 2100 (refs 2, 3).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [2] Intergovernmental Panel on Climate Change. Summary for Policymakers. In Climate Change 2007: The Physical Sciences Basis. Working Group I Contribution to the Fourth Assessment Report of the IPCC (eds Solomon, S. et al.) (Cambridge Univ. Press, Cambridge, 2007)
• Supported

  Section 3.1.1 reports that the highest-emission SRES pathway produces a global surface-ocean pH reduction approaching 0.5 units by 2100. The Discussion and Conclusions likewise gives a range of about 0.3–0.5 units by 2100 for the SRES pathways. (LLM, conf=0.94)

  cites [3] Caldeira, K. & Wickett, M. E. Ocean model predictions of chemistry changes from carbon dioxide emissions to the atmosphere and ocean. J. Geophys. Res. 110 C09S04 doi: 10.1029/2004JC002671 (2005) source

In the paper

“The oceans are a principal sink for anthropogenic CO 2 where it is estimated to have caused a 30% increase in the concentration of Hfoot_0 in ocean surface waters since the early 1900s”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [2] Intergovernmental Panel on Climate Change. Summary for Policymakers. In Climate Change 2007: The Physical Sciences Basis. Working Group I Contribution to the Fourth Assessment Report of the IPCC (eds Solomon, S. et al.) (Cambridge Univ. Press, Cambridge, 2007)
• Partly supported

  The Introduction (§1) says added CO₂ lowers ocean pH, and Table 1 in Discussion and Conclusions (§5) gives a mean surface-ocean pH decrease of 0.09 from preindustrial conditions to 2000. That corresponds to roughly a 23% increase in H⁺ concentration, not the claimed 30%; the table also uses a preindustrial baseline rather than the early 1900s. (LLM, conf=0.86)

  cites [3] Caldeira, K. & Wickett, M. E. Ocean model predictions of chemistry changes from carbon dioxide emissions to the atmosphere and ocean. J. Geophys. Res. 110 C09S04 doi: 10.1029/2004JC002671 (2005) sourceExperimental — accuracy not yet measured

In the paper

“given that high-latitude pteropods and coral reefs may be unable to make their skeletons by the year 2100 (refs 7, 13).”

What the sources say

• Partly supported

  The Biological impacts section (p. 5) reports shell dissolution in live pteropods under conditions projected for 2100 and suggests that some high-latitude pteropods may be unable to maintain their shells. For reef-building corals, the paper reports declining calcification rates (p. 1), not that coral reefs may be unable to make skeletons by 2100. (LLM, conf=0.87)

  cites [7] Orr, J. C. et al. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681–686 (2005) sourceExperimental — accuracy not yet measured
• Partly supported

  Section 2.1 (page unavailable) says organisms with calcium-carbonate skeletons face hindered growth in undersaturated water and projects that about 70% of known cold-water coral locations could become undersaturated by 2099. It does not say that coral reefs generally will be unable to make skeletons, and the searched passages do not address high-latitude pteropods. (LLM, conf=0.85)

  cites [13] Davies, A. J., Roberts, J. M. & Hall-Spencer, J. Preserving deep-sea natural heritage: emerging issues in offshore conservation and management. Biol. Conserv. 138, 299–312 (2007) sourceExperimental — accuracy not yet measured

In the paper

“Short-term laboratory experiments show that many calcareous organisms may be unable to build their skeletons as oceans acidify over the next 100 years 6,7 .”

What the sources say

• ?Not checked — no full text of the sourcecites [6] Feely, R. A. et al. Impact of anthropogenic CO2 on the CaCO3 system in the oceans. Science 305, 362–366 (2004) source
• Partly supported

  The opening section (p. 1) says experimental evidence suggests corals and some plankton will have difficulty maintaining calcium-carbonate skeletons as ocean chemistry changes this century. Biological impacts (p. 5) reports shell dissolution in a 48-hour pteropod experiment and reduced calcification in other organisms. These passages support a risk to skeleton formation, but they do not show that many kinds of organisms may be unable to build skeletons altogether. (LLM, conf=0.86)

  cites [7] Orr, J. C. et al. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681–686 (2005) sourceExperimental — accuracy not yet measured

In the paper

“This may combine with other stresses, such as global warming, to drive tropical coral reefs towards functional collapse 8 .”

What the sources say

• Supported

  The paper’s opening summary says global warming and ocean acidification will compromise reef growth and drive reefs toward a tipping point for functional collapse. The ‘Thermal Stress, Synergies, and Ecological Feedback Loops’ section also says acidification and bleaching together enhance harmful feedbacks in coral ecosystems. Page numbers are not provided in our copy. (LLM, conf=0.93)

  cites [8] Hoegh-Guldberg, O. et al. Coral reefs under rapid climate change and ocean acidification. Science 318, 1737–1742 (2007) source

In the paper

“The pH and saturation states (V) of calcite and aragonite varied with sea state, being lowest on calm days, and showed large decreases as p CO 2 amounts increased from approximately 300 to more than 2,000 matm through the venting gas fields (Fig. 2 and Supplementary Table 2).”

In the paper

“Sea urchins (Paracentrotus lividus, Arbacia lixula), which have high magnesium calcite skeletons, were the most common large invertebrates on sublittoral rock outside the vents but their abundance was significantly reduced where pH reached minima of 7.4-7.5 (Table 1 and Fig. 2).”

In the paper

“Sea-grass leaves at P 1 (pH 8.2) had 75% cover of calcified epiphytes but only 2% cover at P 4 (mean pH 7.6) with a significant reduction in epiphytic calcium carbonate per leaf (Table 1 and Figs 3 and 4).”

In the paper

“Sea-grass production was highest in an area at mean pH 7.6 (1,827 matm p CO 2 ) where coralline algal biomass was significantly reduced and gastropod shells were dissolving due to periods of”

In the paper

“Organisms with aragonite skeletons were common outside the vents (for example, Halimeda algae and the corals Caryophyllia, Cladocora and Balanophyllia) but were absent at mean V arag # 2.5 (minimum V arag 0.8-1.2),providing in situ support for predictions of global coral reef dissolution at these concentrations 8 .”

In the paper

“As coralline algal cover fell from .60% outside the vent area to zero within it, non-calcareous algal cover increased significantly from near zero to .60% (Fig. 2 and Table 1).”

In the paper

“where shoot density was significantly higher (Table 1 and Fig. 3) and approximately 30% higher than that known anywhere else around Ischia 12 .”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [12] Ambiente. Marino Costiero e Territorio Delle Isole Flegree (eds Gambi, M. C., Lauro, M. & Jannuzzi, F.) (Accademia di Scienze Fische e Matematiche, Italy, 2003)

In the paper

“Other calcitic organisms, such as the barnacle Chthamalus stellatus, for example, may survive pH minima by closing their rostral plates as their abundance was not significantly reduced until extremely low mean pH 6.6 (Table 1 and Fig. 2).”

In the paper

“When heavily epiphytised leaves were transplanted from station P 1 to P 4 they showed complete dissolution of Corallinaceae in 2 weeks, whereas transplants moved within P 1 were unaffected.”

In the paper

“Along gradients of normal pH (8.1-8.2) to lowered pH (mean 7.8-7.9,minimum 7.4-7.5),typical rocky shore communities with abundant calcareous organisms shifted to communities lacking scleractinian corals with significant reductions in sea urchin and coralline algal abundance.”

In the paper

“The atmospheric partial pressure of carbon dioxide (p CO 2 ) will almost certainly be double that of pre-industrial levels by 2100 and will be considerably higher than at any time during the past few million years 1 .”

What the sources say

• ?Not checked — no full text of the sourcecites [1] Pearson, P. N. & Palmer, M. R. Atmospheric carbon dioxide concentrations over the past 60 million years. Nature 406, 695–699 (2000) source

In the paper

“Some marine CO 2 vents are at ambient seawater temperature and lack toxic sulphur compounds; such vents can prevail for years to millenia 12 and may be used as natural experiments to advance our understanding of ocean acidification at the ecosystem level.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [12] Ambiente. Marino Costiero e Territorio Delle Isole Flegree (eds Gambi, M. C., Lauro, M. & Jannuzzi, F.) (Accademia di Scienze Fische e Matematiche, Italy, 2003)

In the paper

“Mesocosm experiments have led to predictions that Corallinaceae, which help to protect against coral reef erosion in the tropics, are vulnerable to ocean acidification due to the solubility of their high magnesium calcite skeletons 15,16 .”

What the sources say

• Not checked yetcites [15] Kleypas, J. A. et al. Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers: A Guide for Future Research. Report of a workshop held 18–20 April 2005, St. Petersburg, FL, sponsored by NSF, NOAA, and the US Geological Survey. (2006)
• ?Not checked — no full text of the sourcecites [16] Kuffner, I. B. et al. Decreased abundance of crustose coralline algae due to ocean acidification. Nature Geosci 1, 114–117 (2008) source

In the paper

“The only Cnidaria in waters undersaturated with aragonite were anemones such as Anemonia viridis, which may benefit from increased p CO 2 for photosynthesis of its endosymbiotic dinoflagellates.”

In the paper

“Some marine CO 2 vents are at ambient seawater temperature and lack toxic sulphur compounds; such vents can prevail for years to millenia 12 and may be used as natural experiments to advance our understanding of ocean acidification at the ecosystem level.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [12] Ambiente. Marino Costiero e Territorio Delle Isole Flegree (eds Gambi, M. C., Lauro, M. & Jannuzzi, F.) (Accademia di Scienze Fische e Matematiche, Italy, 2003)

In the paper

“A suite of algal genera proved to be resilient to naturally high amounts of p CO 2 (for example, Caulerpa, Cladophora, Asparagopsis, Dictyota and Sargassum), some of which include invasive alien species that have begun to alter shallow marine ecosystems worldwide 17 .”

What the sources say

• ?Not checked — no full text of the sourcecites [17] Boudouresque, C. F. & Verlaque, M. Biological pollution in the Meditterranean Sea: invasive versus introduced macrophytes. Mar. Pollut. Bull. 44, 32–38 (2002) source

In the paper

“Marine CO 2 vents are abundant in the Mediterranean, especially around Italy and Greece where they typically eject volcanic fluids containing up to 1-2% hydrogen sulphide 10,11 .”

What the sources say

• ?Not checked — no full text of the sourcecites [10] Williams, S. N., Schaefer, S. J., Calvache v, M. L & Lopez, D. Global carbon dioxide emission to the atmosphere by volcanoes. Geochim. Cosmochim. Acta 56, 1765–1770 (1992) source
• ?Not checked — no full text of the sourcecites [11] Dando, P. R., Stuben, D. & Varnavas, S. P. Hydrothermalism in the Mediterranean Sea. Prog. Oceanogr. 44, 333–367 (1999) source

In the paper

“Mesocosm experiments have shown that sea-grass production can be enhanced at high p CO 2 (ref.19).”

What the sources say

• ?Not checked — no full text of the sourcecites [19] Palacios, S. L. & Zimmerman, R. C. Response of eelgrass Zostera marina to CO2 enrichment: possible impacts of climate change and potential for remediation of coastal habitats. Mar. Ecol. Prog. Ser. 344, 1–13 (2007) source

In the paper

“Although scleractinians can survive skeletal dissolution as polyps in the laboratory 14 , reduced calcification due to low V arag may result in increased risk to predation or competition in open ecosystems.”

What the sources say

• ?Not checked — no full text of the sourcecites [14] Fine, M. & Tchernov, D. Scleractinian coral species survive and recover from decalcification. Science 315, 1811 (2007) source

In the paper

“Natural CO 2 flux from volcanic vents and high heat flow areas amounts to less than 0.5% of anthropogenic emissions to the global carbon budget, but can alter local ocean chemistry 9,10 .”

What the sources say

• ?Not checked — no full text of the sourcecites [9] Kerrick, D. M., McKibben, M. A., Seward, T. M. & Caldeira, K. Convective hydrothermal CO2 emission from high heat-flow regions. Chem. Geol. 121, 285–293 (1995) source
• ?Not checked — no full text of the sourcecites [10] Williams, S. N., Schaefer, S. J., Calvache v, M. L & Lopez, D. Global carbon dioxide emission to the atmosphere by volcanoes. Geochim. Cosmochim. Acta 56, 1765–1770 (1992) source

In the paper

“Although atmospheric diffusion of CO 2 is not predicted to result in aragonite undersaturation in shallow waters of the Mediterranean, observations of such areas are relevant to the localized effects caused by deliberate CO 2 sequestration and to the widespread effects predicted for areas that at present have low V arag , given that high-latitude pteropods and coral reefs may be unable to make”

In the paper

“The analysed Posidonia oceanica shoots were .10yr old at the subtidal study sites and will have integrated the effects of lowered pH over this time.”

In the paper

“Salinity (38%) and total alkalinity (2.5 mequiv.kg 21 ) were homogeneous between survey stations and temperature-matched ambient seasonal fluctuations (13-25 uC).”

In the paper

“as ocean acidification will probably bring about reductions in biodiversity and radically alter ecosystems.”

In the paper

“This opportunity to observe the tipping points at which principal groups of marine organisms are affected by lowered pH proves that, even without global warming, the projected rise in atmospheric CO 2 concentration is hazardous, as ocean acidification will probably”