The investigations of the nutrient dynamics in the polar oceans are closely related to biological and hydrographical studies. These basic data are important to study phytoplankton development and succession and to characterise water masses due to different nutrient concentrations in the oceans.

An example is the relationship between nitrate and phosphate which is appropriate to distinguish between water of Pacific and Atlantic origin in the Arctic. Nutrient data from 1984 to 1997 in Fram Strait showed that a surface layer of about 50 m of pure Pacific Water is present above the slope. Sometime after 1997 an almost complete disappearance of Pacific Water in Fram Strait occurred which was detected first during our 2004 survey. It is now important to monitor how long it takes before Pacific Water again exits Fram Strait and to compare the Pacific Water outflow through Fram Strait and the Canadian Archipelago.