How does rising atmospheric CO2 affect marine organisms?

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The Role of Intertidal Macro-Algae in a Future High-CO2 World

Paper Reviewed
Marba, N., Kause-Jensen, D., Olesen, B., Christensen, P.B., Merzouk, A., Rodrigues, J., Wegeberg, S. and Wilce, R.T. 2017. Climate change stimulates the growth of the intertidal macroalgae Ascophyllum nodosum near the northern distribution limit. Ambio 46 (Suppl. 1): S119-S131.

Working with Ascophyllum nodosum -- a foundation macro-algae of the oceanic intertidal zone that distributes itself across latitudes 41.3-69.7°N -- Marba et al. (2017) tested their hypothesis that the growth of A. nodosum near the northern distribution edge of its population increases with warming. And what did they learn by so doing?

Working with eight populations of A. nodosum at West Greenland and Northern Norway (from 64°N to 69°N), the eight scientists determined that "individuals at northern populations elongated between 2.0 and 9.1 cm per year," with the greatest growth extensions occurring in the warmest waters. As for the significance of these findings, they say "they demonstrate that arctic climate change [CO2-induced warming] enhances the growth of A. nodosum populations;" while further noting that the increase in their productivity may increase the growth rates of aquatic animals that feed on them.

In light of these several findings, Marba et al. conclude that "given the role of A. nodosum as a key foundation species, climate change [warming] is expected to increase food and habitat provisions to intertidal communities."

Posted 14 June 2017