The high cost of building and operating open-flow experimental systems for studies of biological response to ocean acidification (OA) has led to extensive use of short-term incubations in closed-flow systems that do not simulate natural conditions. An inexpensive, highly reliable, open-system that tracks natural diurnal and seasonal changes in water chemistry is described. This approach is based on a gravity-feed seawater supply system that uses a peristaltic pump to regulate CO2 injection rate and a power head that cavitates the injected CO2 into microscopic bubbles that are dissolved immediately. This report describes low-cost methods applicable to small or very large experimental systems. This methodology permits long-term experiments under full sunlight with rapid seawater turnover rate that assures realistic environmental conditions in the experimental chambers.
Jokiel P. L., Bahr K. D. & Rodgers K. S., 2014. Low-cost, high-flow mesocosm system for simulating ocean acidification with CO2 gas. Limnology & Oceanography Methods 12:313-322. Article (subscription required).