Eutrophication and effects of algal bloom in the south–western part of the Curonian Lagoon alongside the Curonian Spit

Intensive algal blooms, particularly Cyanobacteria hyperblooms, are a persistent issue in the south-western part of the Curonian Lagoon, driven by high mineral nitrogen and phosphorus ratios. These blooms, occurring from July to October, lead to significant environmental impacts such as increased ammonia nitrogen levels, pH, and BOD5, exceeding thresholds for fishery waters. Over six years (2008–2016), chlorophyll a concentrations consistently reached hyperbloom states (>100 μg/l), causing localized oxygen deficits and fish mortality due to algal accumulation and decomposition. Water temperature emerged as a key factor influencing seasonal and long-term variability in phytoplankton abundance, thereby shaping eutrophication levels in the lagoon. The study analyzed data from four sampling points near the Curonian Spit, providing critical insights into the ecological consequences of eutrophication in this UNESCO-listed coastal lagoon.

Aleksandrov, S., Krek, A., Bubnova, E., & Danchenkov, A. (2018). Eutrophication and effects of algal bloom in the south–western part of the Curonian Lagoon alongside the Curonian Spit. Baltica, 31(1), 1–12. https://doi.org/10.5200/baltica.2018.31.01