Abstract
The Baltic Sea is one of the largest brackish water bodies in the world ocean, with only a few but highly productive commercially important fish stocks. The semi-enclosed sea has only a narrow connection to the North Sea and the net surplus of freshwater input results in strong spatial hydrographic gradients. Deep water conditions can only be improved with respect to salinity and oxygen by lateral advection of North Sea water, a process driven by atmospheric forcing. In contrast to “true” marine areas the Baltic is thus affected by climate change and variability both through temperature and salinity changes. The climatic conditions since the late 1980s have resulted on average in higher temperatures and lower salinities which caused pronounced changes in ecosystem structure.
The talk gives an introduction into the special bio-physical features of the Central Baltic ecosystem, and reviews ecosystem changes (incl. Regime shifts and Trophic cascades) during the last 3 decades caused by climate forcing, but also overfishing. Finally, I review the implications of the changes in the ecosystem for the recruitment of the major fish stocks cod (Gadus morhua) and sprat (Sprattus sprattus).
The talk gives an introduction into the special bio-physical features of the Central Baltic ecosystem, and reviews ecosystem changes (incl. Regime shifts and Trophic cascades) during the last 3 decades caused by climate forcing, but also overfishing. Finally, I review the implications of the changes in the ecosystem for the recruitment of the major fish stocks cod (Gadus morhua) and sprat (Sprattus sprattus).
Other information
The CEES seminar room has a coffee-machine – it is therefore recommended that you come a bit earlier and get yourself a good cup of coffee (for the price of 3 NOK).