Projected increases in ocean pCO2 levels are anticipated to affect calcifying organisms more rapidly and to a greater extent than other marine organisms. The effects of ocean acidification (OA) have been documented in numerous species of corals in laboratory studies, largely tested using flow-through exposure systems. We developed a recirculating ocean acidification exposure system that allows precise pCO2 control using a combination of off-gassing measures including aeration, water retention devices, venturi injectors, and CO2 scrubbing. We evaluated the recirculating system performance in off-gassing effectiveness and maintenance of target pCO2 levels over an 84-day experiment. The system was used to identify changes in calcification and tissue growth in response to elevated pCO2 (1000 μatm) in three reef-building corals of the Caribbean: Pseudodiploria clivosa, Montastraea cavernosa, and Orbicella faveolata. All three species displayed an overall increase in net calcification over the 84-day exposure period regardless of pCO2 level (control +0.28- 1.12 g, elevated pCO2 +0.18- 1.16 g), and the system was effective at both off-gassing acidified water to ambient pCO2 levels, and maintaining target elevated pCO2 levels over the 3-month experiment.

中文翻译：

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在循环海洋酸化暴露系统中高 p CO 2 水平下加勒比造礁珊瑚的钙化

与其他海洋生物相比，预计海洋 pCO2 水平的预计增加会更快、更大程度地影响钙化生物。海洋酸化 (OA) 的影响已在实验室研究中的多种珊瑚中得到记录，主要使用流通式暴露系统进行测试。我们开发了一种循环海洋酸化暴露系统，该系统可以结合使用排气措施（包括曝气、保水装置、文丘里喷射器和 CO2 洗涤）来精确控制 pCO2。我们在 84 天的实验中评估了再循环系统在排气有效性和维持目标 pCO2 水平方面的性能。该系统用于识别加勒比地区三个造礁珊瑚中钙化和组织生长的变化，以响应升高的 pCO2 (1000 μatm)：Pseudodiploria clivosa、Montastraeacabernosa 和 Orbicella faveolata。无论 pCO2 水平如何（控制 +0.28- 1.12 g，升高的 pCO2 +0.18- 1.16 g），在 84 天的暴露期内，所有三个物种都显示出净钙化的总体增加，并且该系统对酸化水的排气均有效到环境 pCO2 水平，并在 3 个月的实验中保持目标升高的 pCO2 水平。