Effects of Atmospheric CO2 Enrichment on Cuttlefish Eggs and Embryo Development
Lacoue-Labarthe, T., Martin, S., Oberhansli, F., Teyssie, J.-L., Markich, S., Ross, J. and Bustamante, P. 2009. Effects of increased pCO2 and temperature on trace element (Ag, Cd and Zn) bioaccumulation in the eggs of the common cuttlefish, Sepia officinalis. Biogeosciences 6: 2561-2573.
According to the authors, "decreasing pH resulted in higher egg weight at the end of development at both temperatures (p < 0.05), with maximal values at pH 7.85 (1.60 ± 0.21 g and 1.83 ± 0.12 g at 16°C and 19°C, respectively)." In addition, they found that "hatchlings were smaller when they developed at 16°C than at 19°C (p < 0.05)." They also observed that zinc (Zn) accumulation "was higher at pH 7.85 during the full developmental period," when "high embryonic requirements for Zn are not fully covered by the maternal pool," so that the higher accumulation of Zn "was associated with a greater rate of growth of both egg and embryo." Concurrently, there was also a greater accumulation of potentially detrimental silver in the tissues of the hatchlings; but any deleterious effects of the extra silver were apparently more than overcome by the positive effects of lowered pH on beneficial zinc accumulation, while toxic cadmium accumulation was actually reduced in the lower pH (or higher CO2) treatments.
The seven scientists conclude their paper by writing that "decreasing pH until 7.85," such as could be expected to occur in air enriched with carbon dioxide to a concentration of 900 ppm, "should lead to some possibly beneficial effects, such as a larger egg and presumably hatchling size and a better incorporation of the essential element[s] such as Zn in the embryonic tissue," which phenomena, in their words, "may improve the survival [of] the newly hatched juveniles." What is more, they add that Gutowska et al. (2008) have demonstrated that "calcification was enhanced in sub-adult cuttlefish reared at 6,000 ppm CO2." Hence, it would appear that the ongoing rise in the air's CO2 content may well prove providential for cuttlefish.
Gutowska, M.A., Portner, H.O. and Melzner, F. 2008. Growth and calcification in the cephalopod Sepia officinalis under elevated seawater pCO2. Marine Ecology Progress Series 373: 303-309.