IMPACT OF INCREASED RIVER DISCHARGE ON THE PHYTOPLANKTON COMMUNITY INTHE OUTER OSLOFJORD, NORWAY

Authors
Citation
S. Kristiansen, IMPACT OF INCREASED RIVER DISCHARGE ON THE PHYTOPLANKTON COMMUNITY INTHE OUTER OSLOFJORD, NORWAY, Hydrobiologia, 363, 1998, pp. 169-177
Citations number
32
Categorie Soggetti
Marine & Freshwater Biology
Journal title
ISSN journal
00188158
Volume
363
Year of publication
1998
Pages
169 - 177
Database
ISI
SICI code
0018-8158(1998)363:<169:IOIRDO>2.0.ZU;2-A
Abstract
An extraordinary flood event occurred in Southern Norway in May-June 1 995. The impact of fresh water discharge from the river Glomma on phyt oplankton species composition and on primary production during the flo od was studied. The phytoplankton community was dominated by species u sually found in the fjord, the diatom Skeletonema costatum dominated t he community together with cyanobacteria. Potentially harmful species (e.g. Chrysochromulina polylepis) were found in low cell densities. No large increase in nutrient concentrations were found. Primary product ion and uptake rates of nitrate and ammonium were very low in low-sali nity water near the river outlet. Nutrients from the river water were efficiently utilized in the open part of the fjord. The flood trigged a phytoplankton bloom dominated by harmless, species commonly observed in the fjord plankton.