Learn how plants respond to higher atmospheric CO2 concentrations

How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic


Calcifying Coccolithophores off the California Coast
Reference
Grelaud, M., Schimmelmann, A. and Beaufort, L. 2009. Coccolithophore response to climate and surface hydrography in Santa Barbara Basin, California, AD 1917-2004. Biogeosciences 6: 2025-2039.

Background
The authors write that "coccolithophores are unicellular pelagic algae that represent a large part of the world ocean's nannophytoplankton and play a significant role in the carbon cycle as major producers of biogenic calcium carbonate," stating that "the inorganic fossil remains of coccolithophores consist of <20Ám calcareous plates called coccoliths," the small size and large abundance of which "make it possible to sample marine sediment cores at mm to sub-mm intervals with ultra-high resolution."

What was done
Grelaud et al. say that "in the context of modern global warming and ocean acidification due to anthropogenic CO2 release," they "investigated the morphometry (size, weight) of selected species of the order Isochrysidales (i.e., E. huxleyi, G. muellerae and G. oceanica) to understand how coccolithophores' carbonate mass is influenced by recent oceanographic global changes." This they did for sediment cores taken from "the deep center of the Santa Barbara Basin (SBB) on the North American Pacific margin in the interval from AD 1917 to 2004."

What was learned
The three researchers report that "morphometric parameters measured on E. Huxleyi, G. muellerae and G. oceanica indicate increasing coccolithophore shell carbonate mass from ~1917 until 2004 concomitant with rising pCO2 and sea surface temperature in the region of the SBB." More specifically, they say that "a >33% increase in mean coccolith weight was determined for the order Isochrysidales over 87 years from ~1917 until 2004."

What it means
Grelaud et al. write that "the last century has witnessed an increasing net influx of atmospheric carbon dioxide into the world's oceans, a rising of pCO2 of surface waters, and under-saturation with respect to aragonite, especially along the North American Pacific margin," which was the site of their study. These conditions, as they describe it, have been predicted by climate alarmists "to result in reduced coccolithophore carbonate mass and a concomitant decrease in size and weight of coccoliths [italics added]." As indicated by Grelaud et al.'s study, however, just the opposite appears to be the case in the real world, even in places where the predicted calcification reductions are expected to be greatest, as has also been demonstrated to be the case by the work of Iglesias-Rodriguez et al. (2008), who observed -- in the words of Grelaud et al. -- "a 40% increase in average coccolith weight across the last 220 years, as recorded in a box core from the subpoloar North Atlantic," and as has been further confirmed by the complimentary work of Halloran et al. (2008).

Clearly, the world's climate alarmists are totally out of touch with reality on this important issue, as indicated by the recent report of Veron et al. (2009), who continue to proclaim as factual that which is not only demonstrably fictitious, but which is one hundred and eighty degrees out of phase with what has been observed in nature on a multiplicity of occasions.

References
Halloran, P.R., Hall, I.R., Colmenero-Hidalgo, E. and Rickaby, R.E.M. 2008. Evidence for a multi-species coccolith volume change over the past two centuries: understanding a potential ocean acidification response. Biogeosciences 5: 1651-1655.

Iglesias-Rodriguez, M.D., Halloran, P.R., Rickaby, R.E.M., Hall, I.R., Colmenero-Hidalgo, E., Gittins, J.R., Green, D.R.H., Tyrrell, T., Gibbs, S.J., von Dassow, P., Rehm, E., Armbrust, E.V. and Boessenkool, K.P. 2008. Phytoplankton calcification in a high-CO2 world. Science 320: 336-340.

Veron, J.E.N., Hoegh-Guldberg, O., Lenton, T.M., Lough, J.M., Obura, D.O., Pearce-Kelly, P., Sheppard, C.R.C., Spalding, M., Stafford-Smith, M.G. and Rogers, A.D. 2009. The coral reef crisis: The critical importance of <350 ppm CO2. Marine Pollution Bulletin 58: 1438-1436.

Reviewed 6 January 2010