Proportion of copepod biomass declines with decreasing salinity in the Baltic Sea

: Hänninen Jari, Vuorinen Ilppo, Viitasalo Markku, Helminen Ulla, Kuosa Harri

Publisher: ACADEMIC PRESS LTD

: 1998

: ICES Journal of Marine Science

: ICES JOURNAL OF MARINE SCIENCE

: ICES J MAR SCI

: 55

: 4

: 767

: 774

: 8

: 1054-3139

DOI: https://doi.org/10.1006/jmsc.1998.0398

The biomass ratio of copepoda/cladocera decreased in the Northern Baltic Archipelago Sea (SW Finland) in concert with a decrease in the seawater salinity during the 1980s. There also was an increase in freshwater run-off from the watershed of the Baltic Proper. Seawater salinity correlated negatively with freshwater run-off with a time lag of several years. The abundance percentages of most dominant zooplankton species correlated significantly with salinity, either positively (large neritic copepods), or negatively (freshwater cladocerans). All data sets together indicate a close connection between the functioning of the pelagic Baltic Sea ecosystem and large-scale weather patterns over the run-off area. (C) 1998 International Council for the Exploration of the Sea.