Longterm variation in phytoplankton productivity

Authors: Gudmundsson Kristinn

Publish Date: 1998/08/01

Volume: 55, Issue: 4, Pages: 635-643

PDF Link

Abstract

Annual variations in primary productivity uptake of 14C measurements in Icelandic waters during spring since 1958 are analysed for four geographically defined regions which correspond to major hydrographical features The overall means by region range from 43 to 92 mg C m−3 h−1 Annual variation in the shelf region northeast of Iceland reflects the major changes observed in environmental conditions especially during the 1970s The seasonal development of phytoplankton productivity depends on surface salinity conditions and its effects on the stability of the water column Given favourable conditions the spring bloom may start to develop in late March/early April and usually has its peak in May In the Arctic Water northeast of Iceland there is a single welldefined peak whereas a sequence of peaks is frequently observed in the Atlantic Water of the southwestern shelf The differences between the regions show the importance of the physical factors affecting phytoplankton dynamics

Keywords: