The Bermuda Atlantic Time-series Study (BATS) is a long-term oceanographic study by the Bermuda Institute of Ocean Sciences (BIOS). Based on regular (monthly or better) research cruises, it samples an area of the western Atlantic Ocean nominally at the coordinates (31°40′N64°10′W). The cruise programme routinely samples physical properties such as ocean temperature and salinity, but focuses on variables of biological or biogeochemical interest including: nutrients (nitrate, nitrite, phosphate and silicic acid), dissolved inorganic carbon, oxygen, HPLC of pigments, primary production and sediment trap flux.