Subarctic fjord systems are facing a continuous temperature increase as well as more frequent and more intense marine heatwaves (MHWs). MHWs are periods of exceptionally high temperatures above the long-term average. In the Porsangerfjord (Northern Norway), the average water temperature ranges from 2.5°C in March to 10°C in August.

Kelps (Laminariales, Phaeophyceae) are foundation species along Arctic rocky shores, providing the basis for complex ecosystems and supporting a high secondary production. Due to ongoing climate change glacial and terrestrial run-off are currently accelerating, drastically changing physical and chemical water column parameters, e.g., water transparency for photosynthetically active radiation or dissolved concentrations of (harmful) elements.

EU-PolarNet co-coordinates the EU Polar Cluster and, hence, is connecting all EU-funded polar projects. Furthermore, EU-PolarNet developed polar research priorities in close cooperation with stake- and rightsholders over the past years.

30. November 2024: Vortrag von Prof. Dr. Kai Bischof [in German]

The Arctic is seasonally exposed to long periods of low temperatures and complete darkness. Consequently, perennial primary producers have to apply strategies to maximize energy efficiency. Global warming is occurring in the Arctic faster than the rest of the globe. The highest amplitude of temperature rise occurs during Polar Night.

The Arctic is projected to warm by 2 to 5 °C by the end of the century. Warming causes melting of glaciers, shrinking of the areas covered by sea ice, and increased terrestrial runoff from snowfields and permafrost thawing. Warming, decreasing coastal underwater irradiance, and lower salinity are potentially threatening polar marine organisms, including kelps, that are key species of hard-bottom shallow communities.

Fjord systems in the Norwegian Arctic are experiencing an increasing frequency and magnitude of marine heatwaves. These episodic heat stress events can have varying degrees of acute impacts on primary production and nutrient uptake of mixed kelp communities, as well as modifying the biogeochemical cycling in nearshore systems where vast areas of kelp create structural habitat.

On 20 September 2024, Sarina Niedzwiedz successfully defended her PhD thesis, entitled "The Dark Side of Polar Day - The influence of coastal run-off on Arctic kelp communities". Sarina is working within the FACE-IT project at the department of Marine Botany at the University of Bremen, Germany.

Conference from 16 to 20 September 2024