Scientific work: DMS, Organic Matter and Nutrients

Scientific work aboard the CCGS Amundsen

Working group categories for sampling and research interests: DMS, Organic Matter and Nutrients

This is the chemistry part of the oceanographic misson. Water samples are taken from the rosette. Dissolved and particulate organic and inorganic material are quantified and identified. We focus primarily on Carbon, Nitrogen and Phosphorus, as these elements are the main fuel (together with light) of primary production. They also play a crucial role in bacterial and nutrient cycles

We also measure Silicia (various forms) and micronutrients. Sulphur (DMS) is also important, as it is a product of  phytoplankton activity and could contribute to a reduction of the greenhouse effect. DMS is “the perfume of the ocean”, it is the molecule we smell when we say “it smells like the ocean” while walking on the beach. DMS is measured using Gas Chromatography. Nitrogen, Phosphorus and Silicia content are measured in their dissolved inorganic form using an Autoanalyzer .

Particles in the ocean can be organic or inorganic. Whatever they are made of, scientists must filter the seawater in order to retrieve them. This also insures sufficient quantities of material as concentrations of particulate material can be below the detection limit of the various methods used for their identification and quantification.

During a research cruise like Green Edge, scientists altogether will filter more than 50 000 liters of seawater onto filters of all sizes and porosities. Filtration is also a great way to separate particles according to their size.

How are variables measured? 

Flavienne Bruyant


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