Presence of microcystins in the littoral zone of the Curonian Lagoon by the data of immunochromatographic analysis in 2017

Abstract

The presence of hepatotoxic cyanotoxins of microcystin group has been recorded in the southern part of the Curonian Lagoon annually since 2010. Because of unique natural features and cultural heritage, the Curonian Spit and the Curonian Lagoon are involved into diverse recreational usage. The potential health hazard due to microcystins is, thus, an inherent problem of the area. Rapid immunochromatographic semi-quantitative test (Microcystin Strip Test, Abraxis Ltd) was applied for the detection of microcystins in water samples from littoral zone. Samples were collected twice per month in May – November 2017 at six monitoring sites around the Lagoon. For the first time, the presence of toxic metabolites of cyanobacteria (microcystins) in the whole littoral of the southern part of the Curonian Lagoon during vegetation season was established. As previously noted, microcystins were present in water samples in summer and autumn. During May it were not found. The highest values (5–10 µg per litre) were recorded in the late June and during September at the Curonian Spit. These values were rather low in comparison with those of 2011–2016. From mid-to-late October toxins were recorded twice only, at the Curonian Spit. At the eastern and southern coasts maximal value was 5 µg per litre (once at the end of September). In other samples toxins were not detected or their values did not exceed 2.5 µg per litre.