Hydrochemistry is the chemical analysis of seawater and is primarily focussed on salinity, dissolved oxygen, and nutrients.
The determination and monitoring of these properties provide scientists with insights into ocean circulation, biological activity, effects of changing climate, and the impacts and sustainability of aquaculture.
Water samples are collected on board oceanic research vessels and analysed in shipboard laboratories. Analysis at the source greatly improves the data quality.
Salinity is determined be measuring the conductivity of seawater using a Salinometer, dissolved oxygen is measured using automated titration of reacted seawater against sodium thiosulfate, and nutrient levels in seawater are quantified using segmented flow analysis and colorimetry.
The key benefit of Hydrochemistry is its ability to produce data that are more accurate and precise than those produced by sensors and as a result these sensor readings can be adjusted and calibrated.
The CSIRO Hydrochemistry group performs these analyses to an international standard and contributes to the global understanding of the oceans.