Systematics, Biodiversity and Evolution of Plants

Language Selection

Breadcrumb Navigation


Thursday December 2, 2021, 4 pm GMT+1


Bengt KARLSON1, Agneta ANDERSSON2, Anders F. ANDERSSON3, Sonia BRUGEL2, Krzysztof JURDZINSKI3, Mikael HEDBLOM4, Meike LATZ3, Markus LINDH4, Jenny LYCKEN4 and Anders TORSTENSSON

Diversity and distribution of pelagic dinoflagellates along a salinity gradient from the Baltic Sea to the Skagerrak based on a combination of metabarcoding and microscopy 

1 Oceanographic Research, Swedish Meteorological and Hydrological Institute, Gothenburg, Sweden
2 Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
3 Department of Gene Technology, SciLifeLab, School of Biotechnology, KTH Royal Institute of Technology, Stockholm, Sweden
4 Oceanographic Services, Swedish Meteorological and Hydrological Institute, Gothenburg, Sweden


The Baltic Sea area is located in Northern Europe. The area is strongly affected by anthropogenic eutrophication. In addition, long term changes in salinity and temperature are observed, likely due to climate change. The surface waters form a salinity gradient from c. 3-30 from the northernmost part, the Bothnian Bay, to the Skagerrak, which is part of the Greater North Sea. Dinoflagellates are important primary producers in the area. Some phycotoxin producing dinoflagellates cause problems for the mussel and oyster industry, mainly in the Skagerrak. High biomass blooms of Karenia mikimotoi and Karlodinium veneficum have caused fish mortalities. Other high biomass dinoflagellate blooms include Tripos spp., Lepidodinium sp. and Noctiluca scintillans. Plankton diversity and distribution have been investigated since the 1800s. In the beginning silk nets were used for sampling and light microscopy for analysis. During the last ~30 years tube sampling and concentration of samples using the sedimentation chamber method and analysis using inverted light microscopes (Utermöhl 1958) have been the dominating monitoring method. In a study aiming to investigate the usefulness of adding metabarcoding and high throughput sequencing as a monitoring tool, the diversity and distribution of Dinophyceae was investigated during year 2019 and part of 2020 based on the V4 region of 18S rDNA (primers according to Piredda et al. 2017). The PR2 database was used for annotating ASV’s (Guillou et al 2013). Preliminary results show that 10 different orders of Dinophyceae were observed using a combination of metabarcoding and the Utermöhl method. However, each method only resulted in observations of representatives of nine orders each. Microscopy resulted in observations of 35 genera while 18S metabarcoding revealed 79 annotated genera. At the species level the preliminary data show 73 species based on microscopy and 142 annotated species based on 18S metabarcoding. Additional aspects will be discussed.


Guillou, L. et al. 2013. The Protist Ribosomal Reference database (PR(2)): a catalog of unicellular eukaryote Small Sub-Unit rRNA sequences with curated taxonomy. Nucleic Acids Res. 41(Database issue), D597-D604. Version 4.14.0 25 June 2021

Piredda, R. et al. 2017. Diversity and temporal patterns of planktonic protist assemblages at a Mediterranean Long Term Ecological Research site. FEMS microbiology ecology 93(1), fiw200.

Utermöhl, H., 1958. Zur Vervollkomnung der quantitativen Phytoplankton-Methodik. Mitt. int. Ver. ther. angew. Limnol. 9, 1-38.