The Kattegat (Danish, from Dutch, commonly used in English), or Kattegatt (Swedish) is a 30.000 km2 sea area bounded by the Jutland peninsula and the Straits islands of Denmark on the west and south, and the provinces of Västergötland, Scania, Halland and Bohuslän in Sweden on the east. The Baltic Sea drains into the Kattegat through the Danish Straits. The Kattegat is a continuation of the Skagerrak and may be seen as either a bay of the Baltic Sea, a bay of the North Sea, or, in traditional Scandinavian usage, neither of these.
It is a rather shallow sea and can be very difficult and dangerous to navigate, due to the many sandy and stony reefs and tricky currents that often shifts. In modern times, artificial seabed canals have been dug, many reefs have been sandpumped or stonefished and a well developed light signaling network have been installed to safeguard the very heavy traffic of this small sea.
According to the definition established in a 1932 convention signed by Denmark, Norway and Sweden (registered in the League of Nations Treaty Series 199 - 1933), the northern boundary between Kattegat and Skagerrak is found at the northernmost point of Skagen on Jutland and the southern boundary towards Øresund is found at the tip of Kullen Peninsula in Scania.
Waterways that drain into the Kattegat are the rivers of Göta älv at Gothenburg, together with the Lagan, Nissan, Ätran and Viskan from the province of Halland on the Swedish side, and the river of Gudenå from Jutland, in Denmark.
A number of noteworthy coastal areas abut the Kattegat, including the Kullaberg Nature Reserve in Scania, Sweden, which contains a number of rare species and a scenic rocky shore, the town of Mölle, which has a picturesque harbour and views into the Kullaberg, and Skagen at the northern tip of Denmark.
Currently, a proposed bridge from Jutland to Zealand across the southern part of Kattegat is under political consideration in Denmark, linking the islands of Zealand and Samsø with continental Denmark.
- On the South. The limits of the Baltic Sea in the Belts and Sound:
- In the Little Belt. A line joining Falshöft ( ) and Vejsnæs Nakke (Ærö: ).
According to Den Store Danske Encyklopædi and Nudansk Ordbog, the name derives from the Dutch words kat (cat) and gat (hole, gate). It refers to late medieval navigation jargon, when captains of the Hanseatic trading fleets would compare the Danish Straits to a hole so narrow that even a cat would have difficulty squeezing its way through on account of the many reefs and shallow waters. At one point, the passable waters were a mere 3.84 kilometers (2.39 mi) wide. The name of the Copenhagen street Kattesundet has the same etymological meaning, namely "narrow passage".
Control of and access to Kattegat, has been of great importance ever since international seafaring took of, as it was up until the completion of the Eider Canal in 1784, the only water route in and out of the Baltic Region.
In the middle ages, The Kingdom of Denmark have prospered greatly over many centuries from the Strait Dues payed for passage in Øresund at Copenhagen and at the same time providing protection, trade and repair opportunities and keeping the sea safe from piracy.
Kattegat was one of the first marine dead zones to be noted in the 1970s, when scientists began studying how intensive industrial activities, affected the natural world. In recent years studies and research have revealed a lot of insight into the process of eutrophication for example and how to deal with it. Denmark and the EU, have initiated costly and far reaching domestic projects in order to repair, stop and prevent these degrading and even more costly processes, since the first Action Plan for the Aquatic Environment in 1985 and are now busy implementing the fourth Action Plan. The action plans sums up a broad range of initiatives and includes the socalled Nitrate Directives. The action plans have been viewed as a success, although the work is not finished and all goals are not completely met yet.
- Convention No 3210. League of Nations Treaty Series 139, 1933. Retrieved 27 December 2012.
- "Limits of Oceans and Seas, 3rd edition". International Hydrographic Organization. 1953. Retrieved 6 February 2010.
- Den Store Danske Encyklopædi (2004), CD-ROM edition, Copenhagen: Gyldendal, entry Kattegat.
- Nudansk Ordbog (1993), 15th edition, 2nd reprint, Copenhagen: Politikens Forlag, entry Kattegat.
- "Cattegat, The". New International Encyclopedia. 1905.
- Implementation of the Nitrates directive in Denmark Danish Ministry of the Environment
- Action Plans for the Aquatic Environment have been a success Politiken (25th of October 2011) (Danish)