Skip to main content
Research article - Peer-reviewed, 2022

Seawater browning alters community composition and reduces nutritional quality of plankton in a subarctic marine ecosystem

Bandara, Tharindu; Brugel, Sonia; Andersson, Agneta; Lau, Danny Chun Pong


Inflows of coloured terrestrial organic matter cause seawater browning and reduced phytoplankton production in subarctic coastal ecosystems, potentially deteriorating the nutritional quality of marine food webs. We analyzed the fatty-add (FA) compositions of seston and the zooplankton taxa Eutytemora affinis and cladocerans at three locations of the northern Baltic Sea. At the coastal and northerly locations, salinity and phosphorus concentrations were low, while concentrations of humic substances (i.e., terrestrial organic matter) were high. The southerly location showed the opposite trend. The ratio between alga-specific omega 3 polyunsaturated FA and terrigenous monounsaturated FA (MUFA) in Fun/femora decreased from south to north, as did the ratio between the alga-specific docosahexaenoic add (DHA) and terrigenous MUFA in cladocerans. With increasing humic substances, the biomass of DHA-rich phytoplankton decreased and the zooplankton MUFA content increased. Our results indicate that coloured terrestrial organic matter alters the phytoplankton composition, consequently affecting the zooplankton nutritional quality.

Published in

Canadian Journal of Fisheries and Aquatic Sciences
2022, volume: 79, number: 8, pages: 1291-1301

Authors' information

Bandara, Tharindu
Umea University
Bandara, Tharindu
Uva Wellassa University
Brugel, Sonia
Umea University
Andersson, Agneta
Umea University
Umeå University
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment

Sustainable Development Goals

SDG14 Life below water

UKÄ Subject classification

Fish and Aquacultural Science

Publication Identifiers


URI (permanent link to this page)