Bottom-up regulation of food webs in shallow Baltic estuaries

Summary

To obtain the basic knowledge needed for the restoration and management of shallow eutrophic estuaries, interdisciplinary mesocosm experiments were performed in the Darss-Zingst area from late spring to midsummer in 1985, 1986 and 1987. The principal results were:

-	The main carbon flux is linked to microbial food webs.
-	Bottom-up regulation by nutrient manipulation is overridden by water temperature fluctuation.
-	Efficient carbon flux and biomass regulation mechanisms permit fast adaptation of the microbial food web to nutrient and temperature induced changes.

Consequently, in shallow estuarine ecosystems, shortterm management is easier to achieve than the induction of long-term changes.