Complex sentence: The delta is a complex of smaller muddy islands, separated from each other by canals, seasonally flooded, especially when waters of the Baltic, pushed by northern winds, enter Zalew Szczecinski (Szczecin Bay).
Split into simpler sentences: The delta is a complex of smaller muddy islands, separated from each other by canals. They are seasonally flooded, especially when waters of the Baltic, pushed by northern winds, enter Zalew Szczecinski (Szczecin Bay).