Energetic Plasticity Underlies a Variable Response to Ocean Acidification in the Pteropod, Limacina Helicina Antarctica
Ocean acidification, caused by elevated seawater carbon dioxide levels, may have a deleterious impact on energetic processes in animals. Here we show that high PCO2 can suppress metabolism, measured as oxygen consumption, in the pteropod, L. helicina forma antarctica, by ∼20%. The rates measured at...
Main Authors: | , , |
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Format: | Article in Journal/Newspaper |
Language: | unknown |
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Digital Commons @ University of South Florida
2012
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Online Access: | https://digitalcommons.usf.edu/msc_facpub/2326 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=3384&context=msc_facpub |
Summary: | Ocean acidification, caused by elevated seawater carbon dioxide levels, may have a deleterious impact on energetic processes in animals. Here we show that high PCO2 can suppress metabolism, measured as oxygen consumption, in the pteropod, L. helicina forma antarctica, by ∼20%. The rates measured at 180–380 µatm (MO2 = 1.25 M−0.25, p = 0.007) were significantly higher (ANCOVA, p = 0.004) than those measured at elevated target CO2 levels in 2007 (789–1000 µatm, = 0.78 M−0.32, p = 0.0008; Fig. 1). However, we further demonstrate metabolic plasticity in response to regional phytoplankton concentration and that the response to CO2 is dependent on the baseline level of metabolism. We hypothesize that reduced regional Chl a levels in 2008 suppressed metabolism and masked the effect of ocean acidification. This effect of food limitation was not, we postulate, merely a result of gut clearance and specific dynamic action, but rather represents a sustained metabolic response to regional conditions. Thus, pteropod populations may be compromised by climate change, both directly via CO2-induced metabolic suppression, and indirectly via quantitative and qualitative changes to the phytoplankton community. Without the context provided by long-term observations (four seasons) and a multi-faceted laboratory analysis of the parameters affecting energetics, the complex response of polar pteropods to ocean acidification may be masked or misinterpreted. |
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