How does rising atmospheric CO2 affect marine organisms?

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Responses of Two Coral Species to Elevated CO2 and Temperature

Paper Reviewed
Maor-Landaw, K., Ben-Asher, H.W., Karako-Lampert, S., Salmon-Divon, M., Prada, F., Caroselli, E., Goffredo, S., Falini, G., Dubinsky, Z. and Levy, O. 2017. Mediterranean versus Red Sea Corals facing climate change, a transcriptome analysis. Scientific Reports 7: 42405.

Introducing their work, Maor-Landaw et al. (2017) describe how they used transcriptome analysis to study the effect of long-term gradual temperature increase (annual rate), combined with lowered pH values, on a sub-tropical Red Sea coral (Stylophora pistillata), as well as on a temperate Mediterranean symbiotic coral (Balanophyllia europaea). And what did they learn by so doing?

The ten researchers -- five from Israel and five from Italy -- report that "gene expression profiles revealed a strong effect of both temperature increase and pH decrease," which they say implies a "synergism response." And another significant finding of theirs was the fact that the temperate coral, which was exposed to a twice-as-high range of seasonal temperature fluctuations than that experienced by the Red Sea species, "faced stress more effectively."

In commenting further on their findings, Maor-Landaw et al. say that the corals' compensatory strategies for coping apparently involves shifting cellular resources into a massive up-regulation of genes in general, but more specifically "those involved in the generation of metabolic energy," noting that their results suggest that "sub-lethal, prolonged exposure to stress can stimulate evolutionary increase in stress resilience."

Consequently, the ten researchers conclude their report by suggesting that the corals they studied would appear to be capable of successfully meeting, and subsequently prevailing against, the challenges of (1) global warming, (2) atmospheric CO2 enrichment, and by (3) doing so at one and the same time.

Posted 10 May 2017