Dynamics of a subsurface phytoplankton maximum in the Skagerrak

Abstract

Subsurface maxima in the distribution of autotrophic flagellates and diatoms were found in the nutricline on three successive transects across the Skagerrak, during June 1990. The subsurface phytoplankton maximum increased during the six day investigation period both in intensity and horizontal extension and followed the nutricline, which descended from 15-25 m depth, while the pycnocline remained at 5-10 m depth. The heterotrophic community responded to the subsurface phytoplankton maximum with corresponding maxima of bacterioplankton biomass and production and of biomasses of nano- and microzooplankton, whereas copepod biomass remained higher in the surface layer than in the subsurface phytoplankton maximum. -from Authors