You are here:
Calcification in Caribbean reef-building corals at high pCO2 levels in a recirculating ocean acidification exposure system
Enzor, L., C. Hankins, D. Vivian, W. Fisher, AND M. Barron. Calcification in Caribbean reef-building corals at high pCO2 levels in a recirculating ocean acidification exposure system. JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY. Elsevier Science Ltd, New York, NY, 499:9-16, (2018).
This paper summarizes the development of a novel ocean acidification exposure system based on recirculating flow conditions. The work is important because the system will have utility for other laboratories that do not have access to flow through sea water.
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.