Wingenter OW, Haase KB, Zeigler M, Blake DR, Rowland SF, Sive BC, Paulino A, Thyrhaug R, Larsen A, Schulz K, Meyerhofer M, Riebesell U
co2, acidification, Dimethylsulfide, DMS, mesocosm, Espegrend, 11 m3, Bergen, Norway
Increasing atmospheric mixing ratios of CO2 havealready lowered surface ocean pH by 0.1 units compared topreindustrial values and pH is expected to decrease anadditional 0.3 units by the end of this century. Pronouncedphysiological changes in some phytoplankton have beenobserved during previous CO2 perturbation experiments.Marine microorganisms are known to consume and produceclimate-relevant organic gases. Concentrations of (CH3)2S(DMS) and CH2ClI were quantified during the Third PelagicEcosystem CO2 Enrichment Study. Positive feedbacks wereobserved between control mesocosms and those simulatingfuture CO2. Dimethyl sulfide was 26% (±10%) greater thanthe controls in the 2x ambient CO2 treatments, and 18%(±10%) higher in the 3xCO2 mesocosms. For CH2ClIthe 2xCO2 treatments were 46% (±4%) greater than thecontrols and the 3xCO2 mesocosms were 131% (±11%)higher. These processes may help contribute to thehomeostasis of the planet.