With a salinity of 17, the Black Sea is in the middle between fresh and seawater, but harbors mostly marine phytoplankton species. Although many potentially toxigenic microalgal species have been recorded for the Black Sea, almost nothing is known about phycotoxins produced by these species in this isolated water body. The aim of PHYCOB is to fill this knowledge gap.
The main scientific objectives for the proposed research cruise are:
1) To assess the presence of toxic microalgae in the plankton assemblage of the Western Black Sea.
2) To quantitatively determine the spatial distribution of toxic phytoplankton species and their corresponding toxins in the plankton.
3) To quantitatively describe the spatial distribution of toxic phytoplankton resting stages in surface sediments and determine hotspots of recruitment and bloom initiation.
4) To define correlations among hydrographic and/or meteorological conditions and occurrence of HAB species.
5) To characterize the plankton communities accompanying HAB species together with toxin analysis of size fractionated samples.
6) To identify heterotrophic dinoflagellates, ciliates, or other small zooplankton as possible toxin vectors.
7) To isolate toxic Black Sea microalgal species and establish monoclonal cultures for characterization of Black Sea strains.
8) To perform an interseasonal comparison of toxigenic plankton species by combining the data sets collected during the R/V Akademik cruise that was performed in May/June 2019 with our data from summer.
9) To compare the data set from the Western Black Sea to the Southern (North-) Western North Sea, Baltic Sea and West Greenland obtained during earlier expeditions for site comparisons.