J.M. Holding, C.M. Duarte, M. Sanz-Martín, E. Mesa, J.M. Arrieta, M. Chierici, I.E. Hendriks, L.S. García-Corral, A. Regaudie-de-Gioux, A. Delgado, M. Reigstad, P. Wassmann, S. Agusti
Nature Climate Change, (2015)
The Arctic Ocean is warming at two to three times the global rate1 and is perceived to be a bellwether for ocean acidification2, 3. Increased CO2 concentrations are expected to have a fertilization effect on marine autotrophs4, and higher temperatures should lead to increased rates of planktonic primary production5. Yet, simultaneous assessment of warming and increased CO2 on primary production in the Arctic has not been conducted. Here we test the expectation that CO2-enhanced
gross primary production (GPP) may be temperature dependent, using data
from several oceanographic cruises and experiments from both spring and
summer in the European sector of the Arctic Ocean. Results confirm that
CO2 enhances GPP (by a factor of up to ten) over a range of 145–2,099 μatm;
however, the greatest effects are observed only at lower temperatures
and are constrained by nutrient and light availability to the spring
period. The temperature dependence of CO2-enhanced primary production has significant implications for metabolic balance in a warmer, CO2-enriched
Arctic Ocean in the future. In particular, it indicates that a twofold
increase in primary production during the spring is likely in the
Arctic.