Vistula Lagoon Vistula Lagoon The Vistula Lagoon (; or "Kaliningradskiy Zaliv"; ; ) is a brackish water lagoon on the Baltic Sea roughly 56 miles (90 km) long, 6 to 15 miles (10 to 19 km) wide, and up to 17 feet (5 m) deep, separated from Gdańsk Bay by the Vistula Spit. It is now known as the Vistula Bay or Vistula Gulf. The modern German name, "Frisches Haff", is derived from an earlier form, "Friesisches Haff". The lagoon is a mouth of a few branches of the Vistula River, notably the Nogat, and the Pregolya River. It is connected to
Washdyke Lagoon as the lagoon and the surrounding 250 hectares are classified as a wildlife refuge and it demonstrates the role human structures have on coastline evolution. Washdyke Lagoon is a coastal lake, ‘choked’ type lagoon as it is separated from the sea by a built-up bar, and has only minimal tidal input (<5% of total tidal impact to coast within the lagoon). Lagoons of this type usually form along high energy, microtidal coastlines, have high ratio of fresh to salt water and rarely open to the ocean. This type of lagoon differs from more ‘open’ lagoons which are open to the