Krill Ocean Acidification Physiology Data

Antarctic krill (Euphausia superba) have a keystone role in the Southern Ocean, as the primary prey of Antarctic predators. Any decreases in krill abundance could result in a major ecological regime shift, but there is currently limited information on how climate change may affect krill. Increasing anthropogenic carbon dioxide (CO2) emissions are causing ocean acidification, as absorption of atmospheric CO2 in seawater alters ocean chemistry. Ocean acidification increases mortality and negatively affects physiological functioning in some marine invertebrates, and is predicted to occur most rapidly at high latitudes. Here we show that, in the laboratory, adult krill are able to survive, grow, store fat, mature, and maintain respiration rates when exposed to near-future ocean acidification (1000 – 2000 μatm pCO2) for one year. Despite differences in seawater pCO2 incubation conditions, adult krill are able to actively maintain the acid-base balance of their body fluids in near-future pCO2, which enhances their resilience to ocean acidification.

南极磷虾（Antarctic krill, Euphausia superba）在南大洋中扮演关键生态种角色，是南极捕食者的主要猎物。磷虾种群丰度的任何下降都可能引发重大生态系统格局转变，但目前关于气候变化如何影响南极磷虾的相关研究仍较为有限。不断增加的人为二氧化碳（CO₂）排放正在引发海洋酸化：大气中的CO₂被海水吸收后会改变海洋化学环境。海洋酸化会提升部分海洋无脊椎动物的死亡率，并损害其生理机能，且据预测，高纬度海域的海洋酸化进程将最为迅猛。本研究通过实验室实验证实，成年南极磷虾在暴露于接近未来水平的海洋酸化环境（1000~2000 μatm pCO₂）中持续饲养一年后，仍能够存活、生长、储存脂肪、完成成熟过程，并维持呼吸速率。尽管不同实验组的海水pCO₂培养条件存在差异，成年南极磷虾仍可在接近未来水平的pCO₂环境中主动维持体液的酸碱平衡，这一能力提升了其应对海洋酸化的韧性。