CTD or Conductivity Temperature Depth stations measure the sea temperature and salinity of the marine water column water column at various depths from the surface to within 10m of the bottom of the water column. A CTD is the oceanography instrument used to determine the conductivity, temperature, and depth of the ocean. The CTD may be incorporated into an array of Niskin bottles referred to as a carousel or rosette. The sampling bottles close at predefined depths, triggered either manually or by a computer, and the water samples may subsequently be analysed further for biological and chemical parameters. Standard oceanographic research data collection to ascertain the condition of the ocean. MSFD characteristics. MSP scientific research. ICES CTD reporting.