The highest NOD concentrations recorded were close to the provisional guideline level for recreational waters (2–4 μg dm− 3; first alert level) ( Falconer et al. 1999). Such situations may pose a serious health threat to humans, and an effective early warning system should therefore be developed. Also, economic losses incurred as a result of

the diminished recreational value of affected bathing sites see more as well as the poorer quality and smaller quantity of fish catches should be treated as important negative consequences of cyanobacterial blooms. The seawater samples containing nodularin proved to be non-toxic to the test crustacean Artemia franciscana; nevertheless, the toxin released into the surrounding water during the lysis of cyanobacterial cells can

persist in the aquatic environment for quite some time after the bloom, as it is a relatively stable chemical compound ( Mazur-Marzec Epigenetic inhibitor & Pliński 2009). The metabolites can take part in allelopathic interactions affecting the structure and dynamics of the phytoplankton community ( Suikanen et al. 2004) and, via filter-feeding mussels, they can be passed on to vertebrates, which are thought to be more sensitive to the toxin. With regard to SST, the overestimation and underestimation of temperature from satellite data in individual cases resulted, respectively, from the insufficient masking of hot-spots and thin clouds. Teicoplanin However, the underestimation of Ferry Box temperature by satellite data seems to be due not only to the insufficient masking of clouds, as the statistical error is higher by more than 1 °C in comparison to that calculated on the basis of BOOS data. The differences between satellite and in situ data indicated that the temperature measured by the Ferry Box was usually about 1.0 °C higher than that derived from AVHRR data. Analysis of the location of frontal zones,

their extent and strength between different water masses made it possible to interpret the rapid changes in the Ferry Box values along the ferry route. Ultimately, the project envisages that the current satellite information, analysed by in situ Ferry Box-acquired data, will be processed and presented operationally in the form of maps of environmental parameters. This information, accompanied by quantitative information on the presence of toxic phytoplankton species, will enable the potential threat of HAB occurrence in the area of interest to be assessed. These products should be made available on the internet to various administrative bodies and scientific institutions as well as the general public. Additionally, discrete sampling should make it possible to track and investigate the changes in the phytoplankton community structure, both at a seasonal time scale (natural species succession) and over the years (as changes following eutrophication or the appearance of invasive species).