The concentration of dissolved methane was measured using a PP1 methane and non-methane hydrocarbons analyzer (Peak Laboratories). Concentrations of methane in surface water (5 m) and in the marine boundary layer were continuously monitored at time intervals of up to several hours along the entire cruise track. Surface water samples were collected from the ship's pumping system located in the engine room or using a high-density polyethylene bucket. Vertical profiles of methane were collected at selected stations (mainly basic, full, and nutrient stations). Vertical profiling samples were taken with 16-L Niskin bottles attached to a CTD rosette.