Skagerrak

The Skagerrak (; , , ) is a strait running between the North Jutlandic Island of Denmark, the east coast of Norway and the west coast of Sweden, connecting the North Sea and the Kattegat sea.

The Skagerrak contains some of the busiest shipping routes in the world, with vessels from every corner of the globe. It also supports an intensive fishing industry. The ecosystem is strained and negatively affected by direct human activities. Oslo and Gothenburg are the only large cities in the Skagerrak region.

The strait is likely named after Skagen, a town near the northern cape of Denmark, with 'Rak' meaning 'straight waterway'. The Skagerrak is 240 km long and 80–140 km wide, deepening towards the Norwegian coast. It has an average salinity comparable to other coastal waters, housing a variety of habitats.

Historically, the Skagerrak was the only access to the Baltic Sea until the construction of the Eider Canal in 1784. During both World Wars, the strait held strategic importance for Germany. Presently, it remains one of the busiest straits worldwide.

The Skagerrak is a habitat for approximately 2,000 marine species, including a unique variety of Atlantic cod. It also contains sandy and stony reefs and cold-water coral reefs. Environmental institutions have expressed concern about increasing pressure on the ecosystem due to human activities and climate change. Protections are in place, with several marine protected areas in Skagerrak, including Ytre Hvaler National Park in Norway and Kosterhavet National Park in Sweden.

Name

The meaning of ''Skagerrak'' is most likely the Skagen Channel/Strait. Skagen is a town near the northern cape of Denmark (The Skaw). In Dutch, means 'straight waterway', as seen in Dutch hydronyms such as Damrak, Gouderak, Langerak, Tuikwerderrak, and Volkerak), cognate with .Nudansk Ordbog (1993), 15th edition, 2nd reprint, Copenhagen: Politikens Forlag, entry ''Skagerrak''. The ultimate source of this syllable is the Proto-Indo-European root *reg-, 'straight'. ''Rak'' means 'straight' as in 'straight ahead' in modern Norwegian and Swedish. ''Råk'' in both modern Norwegian and Swedish refers to a channel or opening of water in an otherwise ice-covered body of water. There is no evidence to suggest a connection with the modern Danish word ''rak'' (meaning rabble or riff-raff). It is therefore likely that the Skagerrak was named by Dutch seafarers, as was the adjacent Kattegat.

Geography

The Skagerrak is long and between wide. It deepens toward the Norwegian coast, reaching over 700 m at the Norwegian Trench. Some ports along the Skagerrak are Oslo, Larvik and Kristiansand in Norway, Skagen, Hirtshals and Hanstholm in Denmark and Uddevalla, Lysekil and Strömstad in Sweden.

The Skagerrak has an average salinity of 80 practical salinity units, which is very low, close to that of brackish water, but comparable to most other coastal waters. The area available to biomass is about and includes a wide variety of habitats, from shallow sandy and stony reefs in Sweden and Denmark to the depths of the Norwegian trench.

Extent

The International Hydrographic Organization defines the limits of the Skagerrak as follows:

''On the West.'' A line joining Hanstholm () and the Naze ( Lindesnes, ).

''On the Southeast.'' The Northern limit of the Kattegat Skagen