Research article2020Peer reviewedOpen access
Basin-specific changes in filamentous cyanobacteria community composition across four decades in the Baltic Sea
Olofsson, Malin; Suikkanen, Sanna; Kobos, Justyna; Wasmund, Norbert; Karlson, Bengt
Abstract
Almost every summer, dense blooms of filamentous cyanobacteria are formed in the Baltic Sea. These blooms may cause problems for tourism and ecosystem services, where surface accumulations and beach fouling are commonly occurring. Future changes in environmental drivers, including climate change and other anthropogenic disturbances, may further enhance these problems. By compiling monitoring data from countries adjacent to the Baltic Sea, we present spatial and temporal genus-specific distribution of diazotrophic filamentous cyanobacteria (Nostocales) during four decades (1979-2017). While the summer surface salinity decreased with a half up to one unit, the surface temperature in July-August increased with 2-3 degrees C in most sub-basins of the Baltic Sea, during the time period. The biovolumes of the toxic Nodularia spumigena did not change in any of the sub-basins during the period. On the other hand, the biovolume of the non-toxic Aphanizomenon sp. and the potentially toxic Dolichospermum spp. increased in the northern parts of the Baltic Sea, along with the decreased salinity and elevated temperatures, but Aphanizomenon sp. decreased in the southern parts despite decreased salinity and increased temperatures. These contradictory changes in biovolume of Aphanizomenon sp. between the northern and southern parts of the Baltic Sea may be due to basin-specific effects of the changed environmental conditions, or can be related to local adaptation by sub-populations of the genera. Overall, this comprehensive dataset presents insights to genus-specific bloom dynamics by potentially harmful diazotrophic filamentous cyanobacteria in the Baltic Sea.
Keywords
Filamentous cyanobacteria; Climate change; Salinity; Temperature; Long-term monitoring
Published in
Harmful Algae
2020, Volume: 91, article number: 101685Publisher: ELSEVIER
Sustainable Development Goals
SDG14 Life below water
UKÄ Subject classification
Oceanography, Hydrology, Water Resources
Publication identifier
DOI: https://doi.org/10.1016/j.hal.2019.101685
Permanent link to this page (URI)
https://res.slu.se/id/publ/104948