Salinity, temperature, light transmission, oxygen saturation, pH, pCO2, chlorophyll a fluorescence, and the concentrations of nitrate, nitrite, dissolved silica, orthophosphate, and ammonia are continuously measured with a system designed primarily for estuarine studies. Near-surface water (2-m depth) is sampled continuously while the vessel is underway; on station, water to depths of 100 m is sampled with a submersible pump. The system is comprised of commercially available instruments, equipment, and components, and of specialized items designed and fabricated by the authors. Data are read from digital displays, analog strip-chart recorders, and a teletype printout, and can be logged in disc storage for subsequent plotting.
Data records made in San Francisco Bay illustrate physical, biological, and chemical estuarine processes, such as mixing and phytoplankton net production. The system resolves large- and small-scale events, which contributes to its reliability and usefulness.
Additional publication details
USGS Numbered Series
Continuous water sampling and water analysis in estuaries