The North and Baltic Seas are habitats that are always changing over the course of time—such changes are also occurring even today. Currents, temperatures and winds change and with them the living conditions for sea animals and plants. To understand how intense this variability is and how it is triggered, researchers from the Institute of Coastal Research at the Helmholtz-Zentrum Geesthacht (HZG) have run a sixty-year computer simulation for the first time for the North and Baltic Seas. The results are, in part, astonishing and not least vital in understanding the consequences of climate change.
Habitats change. This is an entirely natural process. Even without human endeavours, the climate, for example, can change. There are ice and warm ages as well as long or short-term climatic fluctuations. Over the north-eastern Atlantic, for example, every ten years, large-scale changes occur in air pressure conditions that also characterise weather in Europe. These changes crucially influence the North Sea and the Baltic Sea habitat. If changes in wind or ocean currents occur, salinity and water temperatures can also change. On this, in turn, depends how much phytoplankton thrives in the water or how well the fish eggs and larvae develop.