Are there concerns regarding cHAB in coastal bathing waters affected by freshwater-brackish continuum?

Abstract

Toxic cyanobacterial blooms, their prevalence in freshwaters, and their impact on water quality are well documented. In contrast, the impact on the recreational value of bathing sites of the cyanotoxin-contaminated inland waters, transported to estuarine and coastal marine waters, has been less frequently studied. The aim of this work was to assess water quality at bathing sites located in the southern Baltic Sea and the Curonian Lagoon, using cyanotoxins concentrations as an indicator. Our results showed that higher diversity and concentrations of cyanotoxins in some areas of the coastal zone are related to the transport of waters from the Curonian Lagoon. The studied bathing sites had a relatively low probability of adverse health effects, with a potential higher risk in the southern part of the Curonian Lagoon (Lithuania). Due to the observed changes in the cyanobacteria community, the determination of cyanotoxins concentrations, irrespective of the analysis of cyanobacteria, is recommended.