WILL KRILL FARE WELL UNDER SOUTHERN OCEAN ACIDIFICATION?

Antarctic krill embryos and larvae were experimentally exposed to 380 (control), 1000 and 2000 μatm pCO2 in order to assess the possible impact of ocean acidification on early development of krill. No significant effects were detected on embryonic development or larval behaviour at 1000 μatm pCO2; however, at 2000 μatm pCO2 development was disrupted before gastrulation in 90 per cent of embryos, and no larvae hatched successfully. Our model projections demonstrated that Southern Ocean sea water pCO2 could rise up to 1400 μatm in krill’s depth range under the IPCC IS92a scenario by the year 2100 (atmospheric pCO2 788 matm). These results point out the urgent need for understanding the pCO2-response relationship for krill developmental and later stages, in order to predict the possible fate of this key species in the Southern Ocean.