Long-term effects of elevated CO_2 and temperature on the Arctic calanoid copepods Calanus glacialis and C.hyperboreus

摘要

The sensitivity of copepods to ocean acidification (OA) and warming may increase with time, however, studies ＞10 days and on synergistic effects are rare. We therefore incubated late copepodites and females of two dominant Arctic species, Calanus glacialis and Calanus hyperboreus, at 0 ℃ at 390 and 3000 u.atm pCO_2 for several months in fall/winter 2010. Respiration rates, body mass and mortality in both species and life stages did not change with pCC＞2. To detect synergistic effects, in 2011 C hyperboreus females were kept at different pCO_2 and temperatures (0, 5,10 ℃). Incubation at 10 ℃ induced sublethal stress, which might have overruled effects of pCO_2. At 5 ℃ and 3000 μatm, body carbon was significantly lowest indicating a synergistic effect. The copepods, thus, can tolerate pCO_2 predicted for a future ocean, but in combination with increasing temperatures thev could be sensitive to OA.