National Coral Reef Monitoring Program: Shallow water conductivity-temperature-depth (CTD) profiles for selected locations across the Pacific Remote Island Areas

Shallow water CTD surveys provide vertical profiles of temperature, salinity, and turbidity providing indications for water masses and local sea water chemistry changes. These surveys are conducted to characterize the spatial structure of the physical and chemical properties of the ocean environment influencing the living coral reef resources observed during Rapid Ecological Assessments (REA) and towed-diver surveys, both of which are archived separately.

Shallow CTD casts are vertical profiles (max 30 meter depth, downcast only) of water column conductivity, temperature, and pressure (Sea-Bird Electronics, SBE19-plus; accuracy of 0.005 S m-1 in conductivity, 0.0002C in temperature, and 0.1% in pressure). A transmissometer (Wetlabs Inc; provides profiles of beam transmittance, related to turbidity) and a dissolved oxygen sensor (Sea-Bird Electronics, SBE43; accuracy of 2% of saturation) are also attached.