How does rising atmospheric CO2 affect marine organisms?

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Not All Australian Marine Fauna Obeying Climate-Alarmist Dogma
Poloczanska, E.S., Smith, S., Fauconnet, L., Healy, J., Tibbetts, I.R., Burrows, M.T. and Richardson, A.J. 2011. Little change in the distribution of rocky shore faunal communities on the Australian east coast after 50 years of rapid warming. Journal of Experimental Marine Biology and Ecology 400: 145-154.

One of the main tenets of global warming orthodoxy is that as temperatures around the world rise, both terrestrial and aquatic plants and animals will be forced to migrate to cooler parts of the planet in order to avoid extinction, which for marine organisms can mean only that they must move poleward in latitude. But is this really so?

What was done
The authors resurveyed a historical census of rocky-shore marine fauna that had been conducted in the 1940s and 1950s, in order to determine if there had been subsequent latitudinal changes in the distribution and abundance of intertidal marine species consistent with global climate change along Australia's east coast, which region, as they demonstrate, "has undergone rapid warming, with increases in temperature of ~1.5°C over the past 60 years." This survey was conducted at 22 rocky-shore sites that were located between 23 and 35°S latitude, which stretched across 1500 km of coastline.

What was learned
Poloczanska et al. report that of the 37 species they encountered that had distributional data available from both time periods, "only six species showed poleward shifts consistent with predictions of global climate change." Four others actually moved in the opposite direction "inconsistent with expectations under climate change," while the rest "showed no significant changes in range edges."

What it means
In discussing the roles of wave exposure, local currents and the presence of large sand islands, the seven scientists state that it is the combination of those factors -- and "not temperature" -- that "is the primary factor influencing biogeographic distributions along the subtropical east coast of Australia." And supporting this conclusion is the contemporaneous study of Seabra et al. (2011), which describes how it is that intertidal marine species can easily withstand significant climatic warming without having to migrate poleward.

Seabra, R., Wethey, D.S., Santos, A.M. and Lima, F.P. 2011. Side matters: Microhabitat influence on intertidal heat stress over a large geographical scale. Journal of Experimental Marine Biology and Ecology 400: 200-208.

Reviewed 24 August 2011