Isfjorden is the largest fjord system in Svalbard, located in the dynamic transition zone between warm Atlantic and colder Arctic climate regimes. We will expand the existing time series on seasonal hydrography and plankton dynamics in ice-free Adventfjorden (since 2009) and seasonal ice covered Billefjorden (since 2001) with an observatory located in the mouth of Isfjorden close to Barentsburg and an observatory in the deep Karlskronadjupet, close to Longyearbyen. We will also secure regular monitoring of the seasonal ice-covered Billefjorden by setting up laboratory facilities in Pyramiden. Metadata and results will be secured in online databases, and will be the start of an important database not only for scientists and students, but also for environmental managers and stakeholders. 

Our main objective is to initiate a high-Arctic time series which not only cover annual variation, but also capture seasonal dynamics. Such a long-term data series from the high-Arctic is currently not existing due to logistical constrains. In Isfjorden at 78°N, however, with Barentsburg l cated close to the mouth of Isfjorden, Longyearbyen in the middle and Pyramiden in the innermost part of the fjord system in Billefjorden, we have the ability to sample regularly. Permanent settlements with marine infrastructure such as boats, sample equipment and laboratories are important factors for this proposed marine observatory to be established and successfully continued for decades.