Phytoplankton community structure on the Faroe Shelf

Abstract

The phytoplankton distribution, biomass and species composition were investigated in relation to the hydrographical and chemical environment for the algae on the Faroe Shelf during 1995. The water on the Faroe Shelf is relatively well isolated from the surrounding waters by a tidal front, which surrounds the islands at about 100-130 m bottom depth. It has its own planktonecosystem, which is separated and is quite different from that in the surrounding oceanic environment. The phytoplankton spring bloom developed in late Aprilearly May in the shelf water which was about one month earlier than outside the tidal front. The spring bloom started in the central and the northern part of the shelf. The limited water mass on the shelf - and, hence, also the limited amount of nutrients - affected the potential new primary production and around mid July 1995, allthe nitrate on the central and northern shelf had been assimilated. From mid July and throughout the rest of the summer, the potential new production was low and was dependent on advection of nutrients from outside the tidal front.