Абстракт
Highlights: Emiliania huxleyi blooms in the open Black Sea during late spring-summer and winter. Large interannual variability in late spring-summer bloom frequency and duration. Shallow upper mixed layer promotes E. huxleyi blooms during late spring-summer. Winter bloom frequency has declined from 5 to 28% before 2007 to 1–3% in recent years. Weakened convective mixing and deep location of the nutricline reduce winter blooms.