Temperature and pCO2 effect on the bioaccumulation of radionuclides and trace elements in the eggs of the common cuttlefish, Sepia officinalis

The increasing release of CO2 by human activities leads to ocean acidification and global warming. Both those consequences (i.e., increase in seawater pCO2 and temperature) may drastically affect the physiology of marine organisms. The effects of low pH and elevated temperature on the bioaccumulation of radionuclides (241Am, 134Cs) and trace elements (60Co, 54Mn or 75Se) were studied during the embryonic development of the common cuttlefish Sepia officinalis. The lowered accumulation of essential 60Co and 54Mn with decreasing pH was larger at 16 °C than at 19 °C. Se was not detected in the embryo whereas it penetrated through the eggshell, suggesting that an alternative pathway ensures the supply of this essential metal for the embryo. 241Am was totally retained by the eggshell irrespective of pH and temperature. Finally, the amount of Cs found in the peri-vitelline fluid increased with decreasing pH likely because of an enhanced swelling of the cuttlefish egg under elevated CO2.

► We study metal uptake in cuttlefish embryo under relevant pCO2 and T°C values. ► We examine distribution and concentration factors in egg compartments. ► Increasing pCO2 and T°C lower Co and Mn uptake in embryo, 134Cs increase in PVF. ► 241Am and Se do not penetrate through the eggshell. ► Both element chemistry and embryo biology could account for the observed effects.