Due to increasing concerns about anthropogenic climate change and global warming, methanotrophs have become increasingly important for the mitigation of methane, a greenhouse gas. Methane oxidation using methanotrophic biofilters has been shown to be effective in treating gases with high methane concentrations. The work was done in collaboration with the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research. Data collection took place on the deep-sea island of Helgoland. For this purpose, water samples were taken from the pond on the neighboring dune and used to grow methanotrophic enrichments. In this work, an existing method for culturing methanotrophic biofilms in medium and freshwater and subsequent effectiveness measurements was improved. Methane, carbon dioxide, and nitrous oxide concentrations were measured to provide information on the effectiveness and usefulness of such biofilms. Questions raised included under which conditions the methanotrophs grow best and oxidize methane, and whether methanotrophic pure cultures are more effective than enrichments from pond water. The evaluations showed that the methanotrophs grew best at 16 °C and with constantly exchanged methane supply and renewal of the medium. The experiments with pond water and additives showed the strongest methane oxidation. Methanotrophic enrichments from pond water are most effective in this series of experiments.