Greifswalder Boddenrandschwelle

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The Greifswalder Boddenrandschwelle is a shoal in the transition area between the Greifswalder Bodden and the open Baltic Sea . The Boddenrandschwelle was registered as a fauna-flora-habitat (FFH) together with parts of the Pomeranian Bay .

The Boddenrandschwelle is the submarine remainder of a terminal moraine ridge . It represents the morphogenetic link between the islands of Rügen and Usedom as well as the Ruden and the Greifswalder Oie . The Oie on the eastern ledge of the Bodden Sill and the Ruden on its southern end are the result of erosion and landfall processes.

The average water depth in this area is 1.5 to 2.5 meters. Towards the lagoon in the west, the water depth increases only gradually, while it reaches more than 10 meters in a relatively short distance to the Pomeranian Bay in the east.

The Boddenrandschwelle occupies a key position for the water exchange between Greifswalder Bodden and the Baltic Sea. It turns the Bodden into a partial body of water that is largely closed off from the Baltic Sea. An unhindered flow of water from the Baltic Sea into the Bodden only takes place during floods, which are essentially caused by the wind conditions.

In the north and south of the Boddenrandschwelle there are shallow gullies. The extending between the Peenemünder hooks off the north end of the island Usedom and Ruden about 5 to 6 meters deep and 2.5 kilometers Osttief ( "Easter low", formerly also "Old depth") is a continuation of Peenestrom channel . Before the Western On the side of the rudder was the “Westtief” (“Westertief”, formerly also “New Deep”), which was rendered unusable by sinking ships in the wars of the early modern period and subsequently silted up. Instead, in the 18th century, to the west of it, the land low south of the Thiessower hook formed directly in front of the Mönchgut , sometimes also referred to as the New Deep . It is about 2.8 kilometers long, 60 meters wide, 5 meters deep and today forms the second northern entrance to the lagoon alongside the eastern low. Both channels silted up several times in the past. To ensure that it can be used as a sea waterway - the land valley had to be temporarily closed to merchant shipping after the Second World War - the channels have to be dredged repeatedly.

The Boddenrandschwelle is characterized by extensive sandbanks with embedded reef structures, which are always weakly washed over by the Baltic Sea . As part of the most important wintering and feeding areas in the Baltic Sea region, it has decisive hydrographic protective functions. Therefore it was registered in 2007 as a marine FFH area "Greifswalder Boddenrandschwelle and parts of the Pomeranian Bay". The animal species found in the area include gray seals , common seals , sea ​​lamprey , river lamprey , feint , salmon and bitterling .

The North European gas pipeline crosses the threshold Bodden southeast of the country lows .

literature

  • Joachim Blüthgen: Greifswalder Oie and Ruden. A comparative study of the island studies of the Baltic Sea . Justus Perthes, Gotha 1952
  • Gottfried Loeck: Selected representations of the new low in printed nautical and maps of the 16th – 19th centuries. Century. In: German Shipping Archive . Vol. 22, Hamburg 2000, pp. 169-188
  • Guido Verse: Sedimentation and paleogeographical development of the Greifswalder Bodden and the sea area of ​​the Greifswalder Oie (southern Baltic Sea) since the Vistula Late Glacial . (Dissertation), University of Greifswald 2001 ( digitized introduction , PDF 345 kB)

Web links

Coordinates: 54 ° 14 '  N , 13 ° 47'  E