Cryptophyte bloom in a Mediterranean estuary: High abundance of Plagioselmis cf. prolonga in the Krka River estuary (eastern Adriatic Sea)


  • Luka Šupraha Department of Biology, Faculty of Science, University of Zagreb - Department of Earth Sciences, Paleobiology Programme, Uppsala University
  • Sunčica Bosak Department of Biology, Faculty of Science, University of Zagreb
  • Zrinka Ljubešić Department of Biology, Faculty of Science, University of Zagreb
  • Hrvoje Mihanović Hydrographic Institute of the Republic of Croatia
  • Goran Olujić Hydrographic Institute of the Republic of Croatia
  • Iva Mikac Ruđer Bošković Institute
  • Damir Viličić Department of Biology, Faculty of Science, University of Zagreb



estuarine ecosystem, phytoplankton bloom, cryptophytes, chemotaxonomy, Mediterranean Sea, Krka River estuary


During the June 2010 survey of phytoplankton and physicochemical parameters in the Krka River estuary (eastern Adriatic Sea), a cryptophyte bloom was observed. High abundance of cryptophytes (maximum 7.9×106 cells l–1) and high concentrations of the class-specific biomarker pigment alloxanthine (maximum 2312 ng l–1) were detected in the surface layer and at the halocline in the lower reach of the estuary. Taxonomical analysis revealed that the blooming species was Plagioselmis cf. prolonga. Analysis of the environmental parameters in the estuary suggested that the bloom was supported by the slower river flow as well as the increased orthophosphate and ammonium concentrations. The first record of a cryptophyte bloom in the Krka River estuary may indicate that large-scale changes are taking place in the phytoplankton community. Such changes could have a major impact on the natural ecosystem dynamics and the mariculture production in the area.


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How to Cite

Šupraha L, Bosak S, Ljubešić Z, Mihanović H, Olujić G, Mikac I, Viličić D. Cryptophyte bloom in a Mediterranean estuary: High abundance of Plagioselmis cf. prolonga in the Krka River estuary (eastern Adriatic Sea). scimar [Internet]. 2014Sep.30 [cited 2023Dec.11];78(3):329-38. Available from: