A fast and sensitive method for the continuous in situ determination of dissolved methane and its δ13C‐isotope ratio in surface waters. - Hartmann, Jan F.; Gentz, Torben; Schiller, Amanda; Greule, Markus; Grossart, Hans‐Peter; Ionescu, Danny; Keppler, Frank; Martinez‐Cruz, Karla; Sepulveda‐Jauregui, Armando; Isenbeck‐Schröter, Margot (Limnology & Oceanography, Methods, 2018)