Oostzee

Oostzee is the Dutch name for the Baltic Sea, a marginal sea of the North Atlantic located between Scandinavia, the Baltic states, and northern Central Europe. It covers about 377,000 square kilometers and reaches depths of up to around 459 meters at the Landsort Deep. Its western boundary lies along Denmark and Sweden, and it connects to the North Sea through the Øresund, the Great Belt, and the Little Belt.

Etymology and usage: Oostzee literally means East Sea in Dutch and is the equivalent of the German Ostsee. In modern Dutch, the Baltic Sea is often referred to simply as de Baltische Zee or de Oostzee in historical or geographic contexts. The term Oostzee appears in older maps and writings as part of traditional Dutch usage.

Geography and hydrology: The Baltic is bounded by Denmark, Sweden, Finland, Estonia, Latvia, Lithuania, Poland, and Russia’s Kaliningrad Oblast. It is a semi‑enclosed sea with substantial freshwater input from large rivers, producing a brackish water column. Notable subregions include the Gulf of Bothnia to the north, the Gulf of Finland to the east, and the Gulf of Riga between Latvia and Estonia.

Ecology and economy: The Baltic hosts a range of species adapted to low salinity and varying oxygen levels. It is particularly sensitive to nutrient pollution and invasive species, which have affected ecological balance and fisheries. Major ports along its coast include Gdansk, Gdynia, Stockholm, Helsinki, Tallinn, Riga, Copenhagen, and the Saint Petersburg region. Shipping, fishing, and maritime trade are central to the region’s economy.

History and current issues: The Baltic has long been a key trade corridor, notably during the era of the Hanseatic League. Today it faces environmental challenges such as eutrophication, climate change impacts, and habitat disruption, prompting regional cooperation through organizations that address marine protection and safe navigation.