Fig. 3.

(A) Conversion of ¹³C methane, ethane, propane, and benzene to [¹³C]DIC during SIP incubations of seawater at 6 °C. (B) Relative abundances in 16S rRNA gene clone libraries from heavy (i.e., ¹³C-labeled) and light (i.e., unlabeled) DNA from SIP incubations with ¹³C methane, ethane, propane, and benzene, and the initial seawater (sample P222). n = 75 (initial), n = 25 (heavy methane), n = 69 (light methane), n = 44 (heavy methane), n = 81 (light methane), n = 43 (heavy methane), n = 78 (light methane), n = 84 (heavy methane), and n = 76 (light benzene).