Influence of global warming

Sedimentload in Potter Cove, Antarctic peninsula
Sedimentload in Potter Cove, Antarctic peninsula (Photo: Katharina Zacher)
Underwater recruitment experiment,  Antarctica
Underwater recruitment experiment, Antarctica (Photo: Max Schwanitz)
Macroalgae at the Biologische Anstalt Helgoland
Macroalgae at Helgoland (Photo: Cornelia Buchholz)

We study if and how anthropogenic environmental change (especially global warming) influences the production and interaction of species. In Arctic and Antarctic regions global warming has reduced ice coverage in winter, leading to extended periods of photosynthetic activity for marine macroalgae and decreasing mechanical disturbance through ice-scour. Simultaneously, sediment input by melting glaciers is enhanced. Both processes have major impacts on polar macroalgae. Areas which were formerly ice covered, are now colonized and the overall biomass of macroalgae is increasing thereby adding to a food source for consumers of higher trophic levels. Concurrently, increased sedimentation reduces the lower depth limit and has a negative impact on recruitment of local macroalgal species.