Technical Note: Controlled experimental aquarium system for multi-stressor investigation of carbonate chemistry, oxygen saturation, and temperature

[摘要] As the field of ocean acidification has grown, researchers have increasinglyturned to laboratory experiments to understand the impacts of increasedCO₂ on marine organisms. However, other changes such as ocean warmingand deoxygenation are occurring concurrently with the increasing CO₂concentrations, complicating the understanding of the impacts ofanthropogenic changes on organisms. This experimental aquarium design allowsfor independent regulation of CO₂ concentration, O₂ levels, andtemperature in a controlled environment to study the impacts of multiplestressors. The system has the flexibility for a wide range of treatmentchemistry, seawater volumes, and study organisms. Control of the seawaterchemistry is achieved by equilibration of a chosen gas mixture with seawaterusing a Liqui-Cel^® membrane contactor.Included as examples, two experiments performed using the system have showncontrol of CO₂ at values between approximately 500 and 1400 μatmand O₂ at values from 80 to 240 μmol kg⁻¹. Temperature hasbeen maintained to 0.5 °C or better in the range of10–17 °C. On a weeklong timescale, the system has achievedvariability in pH of less than 0.007 pH units and in oxygen concentration ofless than 3.5 μmol kg⁻¹. Longer experiments, over a month induration, have been completed with control to better than 0.08 pH units and13 μmol kg⁻¹ O₂. The ability to study the impacts ofmultiple stressors in the laboratory simultaneously, as well asindependently, will be an important part of understanding the response ofmarine organisms to a high-CO₂ world.

[学科分类] 地球化学与岩石