Development and Application of Chemical Sensors for Nutrients, Iron and Manganese in Coastal Waters

Eric P Achterberg, Felix Geissler and Mario Esposito, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
We need chemical and biological measurements of the ocean to better understand and manage biogeochemical cycles and the sustainable exploitation of ocean resources including fisheries and aquaculture, but also deep sea minerals and subseabed storage of carbon dioxide.

Traditional methods, using ships and laboratory analysis of samples are unable to make enough measurements to deliver sufficiently for these applications. In the oceans, scale is the challenge. Not only the spatial vastness, but also its depth and the variation in time and space scales at which processes occur and hence we need data.

However, technology is enabling us to address this undersampling ever more efficiently. As part of the international efforts we work to provide chemical sensors for these existing platforms.

In this presentation we will address priority sensors that provide data to validate ocean biogeochemical models. Here the priority inorganic chemicals are for nutrients, iron and manganese, for which reagent based assays are available and Lab on Chip sensors have been developed. In addition, we will present novel algorithm developments for the TRiOS OPUS UV nitrate sensor. The metrology performance of the sensors can be assured by using high sensitivity assays, with well characterised and limited interferences which can be calibrated in the laboratory and in situ using standards or CRMs.

Application of the sensors in coastal waters of the North Sea and Baltic Sea will be presented.