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The Skagerrak (, , ) is a strait running between the
Jutland peninsula Jutland ( da, Jylland ; german: Jütland ; ang, Ēota land ), known anciently as the Cimbric or Cimbrian Peninsula ( la, Cimbricus Chersonesus; da, den Kimbriske Halvø, links=no or ; german: Kimbrische Halbinsel, links=no), is a peninsula of ...
of
Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...
, the southeast coast of
Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the ...
and the west coast of Sweden, connecting the
North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea, epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the ...
and the
Kattegat The Kattegat (; sv, Kattegatt ) is a sea area bounded by the Jutlandic peninsula in the west, the Danish Straits islands of Denmark and the Baltic Sea to the south and the provinces of Bohuslän, Västergötland, Halland and Skåne in Sweden ...
sea area through the
Danish Straits The Danish straits are the straits connecting the Baltic Sea to the North Sea through the Kattegat and Skagerrak. Historically, the Danish straits were internal waterways of Denmark; however, following territorial losses, Øresund and Fehmarn B ...
to the
Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and ...
. The Skagerrak contains some of the busiest
shipping route A sea lane, sea road or shipping lane is a regularly used navigable route for large water vessels (ships) on wide waterways such as oceans and large lakes, and is preferably safe, direct and economic. During the Age of Sail, they were determined ...
s 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 Oslo ( , , or ; sma, Oslove) is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2022, while the city's greater urban area had a population ...
and Gothenburg are the only large cities in the Skagerrak region.


Name

The meaning of ''Skagerrak'' is most likely the Skagen Channel/Strait.
Skagen Skagen () is Denmark's northernmost town, on the east coast of the Skagen Odde peninsula in the far north of Jutland, part of Frederikshavn Municipality in Nordjylland, north of Frederikshavn and northeast of Aalborg. The Port of Skage ...
is a town near the northern cape of Denmark (The Skaw). ''Rak'' means 'straight
waterway A waterway is any navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other languages. A first distinction is necessary b ...
' (compare the
Damrak The Damrak is an avenue and partially filled in canal at the centre of Amsterdam, running between Amsterdam Centraal in the north and Dam Square in the south. It is the main street where people arriving at the station enter the centre of Amsterda ...
in Amsterdam); it is cognate with '' reach''.Nudansk Ordbog (1993), 15th edition, 2nd reprint, Copenhagen: Politikens Forlag, entry ''Skagerrak''. The ultimate source of this syllable is the
Proto-Indo-European Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. Its proposed features have been derived by linguistic reconstruction from documented Indo-European languages. No direct record of Proto-Indo- ...
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). Another possibility is that the Skagerrak was named by Dutch seafarers, in the same way the adjacent Kattegat got its name. It was quite common for the Dutch to call similar stretches of waterways a ''rak'', such as: Langerak, Damrak, Gouderak, and Tuikwerderrak. (See
Kattegat The Kattegat (; sv, Kattegatt ) is a sea area bounded by the Jutlandic peninsula in the west, the Danish Straits islands of Denmark and the Baltic Sea to the south and the provinces of Bohuslän, Västergötland, Halland and Skåne in Sweden ...
for its etymology, in which ''gat'' means "gate" or "hole".)


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 Oslo ( , , or ; sma, Oslove) is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2022, while the city's greater urban area had a population ...
, Larvik and
Kristiansand Kristiansand is a seaside resort city and municipality in Agder county, Norway. The city is the fifth-largest and the municipality the sixth-largest in Norway, with a population of around 112,000 as of January 2020, following the incorporati ...
in
Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the ...
,
Skagen Skagen () is Denmark's northernmost town, on the east coast of the Skagen Odde peninsula in the far north of Jutland, part of Frederikshavn Municipality in Nordjylland, north of Frederikshavn and northeast of Aalborg. The Port of Skage ...
,
Hirtshals Hirtshals is a town and seaport on the coast of Skagerrak on the island of Vendsyssel-Thy at the top of the Jutland peninsula in northern Denmark, Europe. It is located in Hjørring municipality in Region Nordjylland. The town of Hirtshals has a p ...
and
Hanstholm Hanstholm is a small town and a former island, now elevated area in Thisted municipality of Region Nordjylland, located in northern Denmark. The population of the town is 2,104 (1 January 2022).
in
Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...
and
Uddevalla Uddevalla (old no, Oddevold) is a town and the seat of Uddevalla Municipality in Västra Götaland County, Sweden. In 2015, it had a population of 34 781. It is located at a bay of the south-eastern part of Skagerrak. The beaches of Uddevalla ar ...
, Lysekil and
Strömstad Strömstad is a locality and the seat of Strömstad Municipality, Västra Götaland County, Sweden with 6,288 inhabitants in 2010. For historical reasons, Strömstad is called a ''city'' despite its small population. Strömstad became part of S ...
in Sweden. The Skagerrak has an average salinity of 80
practical salinity unit Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...
s, which is very low, close to that of
brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...
, 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
reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock o ...
s in Sweden and Denmark to the depths of the Norwegian trench.


Extent

The
International Hydrographic Organization The International Hydrographic Organization (IHO) is an intergovernmental organisation representing hydrography. , the IHO comprised 98 Member States. A principal aim of the IHO is to ensure that the world's seas, oceans and navigable waters a ...
defines the limits of the Skagerrak as follows:
''On the West.'' A line joining
Hanstholm Hanstholm is a small town and a former island, now elevated area in Thisted municipality of Region Nordjylland, located in northern Denmark. The population of the town is 2,104 (1 January 2022).
() and the Naze (
Lindesnes Lindesnes ( en, the Naze) is a municipality in Agder county, Norway. It is located in the traditional district of Sørlandet. The administrative centre of the municipality is the town of Mandal. Other villages in Lindesnes include Åvik, Hølle ...
, ). ''On the Southeast.'' The Northern limit of the
Kattegat The Kattegat (; sv, Kattegatt ) is a sea area bounded by the Jutlandic peninsula in the west, the Danish Straits islands of Denmark and the Baltic Sea to the south and the provinces of Bohuslän, Västergötland, Halland and Skåne in Sweden ...
Skagen_ Skagen_()_is_Denmark's_northernmost_town,_on_the_east_coast_of_the__Skagen_Odde_peninsula_in_the_far_north_of_Jutland,_part_of__Frederikshavn_Municipality_in__Nordjylland,__north_of__Frederikshavn_and__northeast_of__Aalborg._The__Port_of_Skage_...
_(The_Skaw,_North_Point_of_Denmark)_and_Paternosterskären_()_and_thence_Northeastward_through_the_shoals_to_Tjörn_Municipality.html" ;"title=" line joining
Skagen Skagen () is Denmark's northernmost town, on the east coast of the Skagen Odde peninsula in the far north of Jutland, part of Frederikshavn Municipality in Nordjylland, north of Frederikshavn and northeast of Aalborg. The Port of Skage ...
(The Skaw, North Point of Denmark) and Paternosterskären () and thence Northeastward through the shoals to Tjörn Municipality">Tjörn Island].


History

Older names for the combined Skagerrak and
Kattegat The Kattegat (; sv, Kattegatt ) is a sea area bounded by the Jutlandic peninsula in the west, the Danish Straits islands of Denmark and the Baltic Sea to the south and the provinces of Bohuslän, Västergötland, Halland and Skåne in Sweden ...
were the ''Norwegian Sea'' or ''Jutland Sea''; the latter appears in the
Knýtlinga saga ''Knýtlinga saga'' (''The Saga of Cnut's Descendants'') is an Icelandic kings' saga written in the 1250s, which deals with the kings who ruled Denmark since the early 10th century.Ármann Jakobsson, "Royal biography", p. 397-8 There are good rea ...
. Until the construction of the
Eider Canal The Eider Canal (also called the Schleswig-Holstein Canal) was an artificial waterway in southern Denmark (later northern Germany) which connected the North Sea with the Baltic Sea by way of the rivers Eider and Levensau. Constructed between 1 ...
in 1784 (a predecessor to the
Kiel Canal The Kiel Canal (german: Nord-Ostsee-Kanal, literally "North- oEast alticSea canal", formerly known as the ) is a long freshwater canal in the German state of Schleswig-Holstein. The canal was finished in 1895, but later widened, and links the N ...
), Skagerrak was the only way in and out of the
Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and ...
. For this reason the strait has had a busy international traffic for centuries. After the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
, the traffic increased and today Skagerrak is among the busiest straits in the world. In 1862, a short cut, the Thyborøn Channel at the
Limfjord The Limfjord ( common Danish: ''Limfjorden'' , in north Jutlandish dialect: ''Æ Limfjord'') is a shallow part of the sea, located in Denmark where it has been regarded as a fjord ever since Viking times. However, it now has inlets both from ...
was constructed in Denmark through Skagerrak from the North Sea by going directly to the
Kattegat The Kattegat (; sv, Kattegatt ) is a sea area bounded by the Jutlandic peninsula in the west, the Danish Straits islands of Denmark and the Baltic Sea to the south and the provinces of Bohuslän, Västergötland, Halland and Skåne in Sweden ...
. The Limfjord supports only minor transports though. In both world wars, the Skagerrak was strategically very important for
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
. The biggest sea battle of the
First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
, the Battle of Jutland, also known as the Battle of the Skagerrak, took place here May 31 to June 1, 1916. In the
Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...
, the importance of controlling this waterway, the only sea access to the Baltic, was the motive for the German invasions of
Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...
,
Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the ...
and the construction of the northern parts of the Atlantic Wall. Both of these naval engagements have contributed to the large number of shipwrecks in the Skagerrak.


Traffic and industry

Skagerrak is a heavily trafficated strait, with c. 7,500 individual vessels (excluding fishing vessels) from all over the world visiting in 2013 alone. Cargo ships are by far the most common vessel in Skagerrak at c. 4,000 individual ships in 2013, followed by tankers, which are nearly half as frequent. When viewed in combination with the Baltic Sea area, ships from 122 different nationalities visited in 2013, with most of these carrying cargo or passengers within Europe, regardless of their
flag state The flag state of a merchant vessel is the jurisdiction under whose laws the vessel is registered or licensed, and is deemed the nationality of the vessel. A merchant vessel must be registered and can only be registered in one jurisdiction, but ma ...
. Nearly all commercial vessels in Skagerrak are tracked by the Automatic Identification System (AIS).


Recreation

Skagerrak is popular for recreational activities in all three countries. There are many summer house residences and several marinas along the coasts.


Biology

The Skagerrak is habitat for approximately 2,000 marine species, many of them adapted to its waters. For example, a variety of
Atlantic cod The Atlantic cod (''Gadus morhua'') is a benthopelagic fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling.zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
. Juveniles sink to the bottom where they have a shorter maturity cycle (2 years). They do not migrate but remain local to Norwegian
fjord In physical geography, a fjord or fiord () is a long, narrow inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Alaska, Antarctica, British Columbia, Chile, Denmark, Förden and East Jutland Fjorde, Germany, ...
s. The variety of habitats and the large volume of
plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...
on the surface support prolific marine life. Energy moves from the top to the bottom according to Vinogradov's ladder of migrations; that is, some species are benthic and others
pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...
, but there are graded marine layers within which species move vertically for short distances. In addition, some species are
benthopelagic The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...
, moving between surface and bottom. The benthic species include '' Coryphaenoides rupestris'', '' Argentina silus'', '' Etmopterus spinax'', ''
Chimaera monstrosa ''Chimaera monstrosa'', also known as the rabbit fish or rat fish, is a northeast Atlantic and Mediterranean species of cartilaginous fish in the family Chimaeridae. The rabbit fish is known for its characteristically large head and small, tape ...
'' and ''
Glyptocephalus cynoglossus The witch (''Glyptocephalus cynoglossus''), known in English by a variety of other common names including the witch flounder, pole flounder, craig fluke, Torbay sole and grey sole, is a species of flatfish from the family Pleuronectidae. It occur ...
''. On the top are ''
Clupea harengus Atlantic herring (''Clupea harengus'') is a herring in the family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large schools. They can ...
'', ''
Scomber scombrus The Atlantic mackerel (''Scomber scombrus''), also known as Boston mackerel, Norwegian mackerel, Scottish mackerel or just mackerel, is a species of mackerel found in the temperate waters of the Mediterranean Sea, the Black Sea, and the northern ...
'', ''
Sprattus sprattus The European sprat (''Sprattus sprattus''), also known as bristling, brisling, garvie, garvock, Russian sardine, russlet, skipper or whitebait, is a species of small marine fish in the herring family Clupeidae. Found in European waters, it has si ...
''. Some species that move between are ''
Pandalus borealis ''Pandalus borealis'' is a species of caridean shrimp found in cold parts of the northern Atlantic and northern Pacific Oceans, although the latter population now often is regarded as a separate species, ''P. eous''. The Food and Agriculture Orga ...
'', '' Sabinea sarsi'', '' Etmopterus spinax''.


Reefs

Apart from sandy and stony reefs, extensive cold water
coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. C ...
s, mostly of ''
Lophelia ''Lophelia pertusa'', the only species in the genus ''Lophelia'', is a cold-water coral that grows in the deep waters throughout the North Atlantic ocean, as well as parts of the Caribbean Sea and Alboran Sea. Although ''L. pertusa'' reefs are h ...
'', are growing in Skagerrak. The Säcken Reef in the Swedish marine protection of Koster Fjord is an ancient cold water coral reef and the only known coral reef in the country. The Tisler Reef in the Norwegian marine protection of
Ytre Hvaler National Park Ytre Hvaler National Park ( no, Ytre Hvaler nasjonalpark, literally ''Outer Hvaler National Park'') is a national park located within the municipalities of Hvaler and Fredrikstad in Østfold, Norway. The park was established on 26 June 2009 and w ...
is the largest known coral reef in Europe. Lophelia reefs are also present in the Norwegian trench and they are known from the shallow waters of many Norwegian fjords. Skagerrak also holds a number of rare bubble reefs; biological reefs formed around cold seeps of geological carbohydrate outgassings, usually
methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...
. These rare habitats are mostly known from the Danish waters of Skagerrak west of
Hirtshals Hirtshals is a town and seaport on the coast of Skagerrak on the island of Vendsyssel-Thy at the top of the Jutland peninsula in northern Denmark, Europe. It is located in Hjørring municipality in Region Nordjylland. The town of Hirtshals has a p ...
, but more might be discovered in future surveys. Bubbly reefs are very rare in Europe and supports a very varied ecosystem. With the centuries long heavy international seatraffic of Skagerrak, the seabed also holds an abundance of shipwrecks. Wrecks on shallow waters, provides a firm anchoring for several corals and polyps and explored wrecks have been revealed to support Dead Man's Fingers corals,
Brittle star Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomot ...
s and large
wolffish Anarhichadidae, the wolffishes, sea wolves or wolf eels, is a family of marine ray finned fishes belonging to the order Scorpaeniformes. These are predatory, eel shaped fishes which are native to the cold waters of the Arctic, North Pacific and ...
. A 2020 seafloor mapping project around Jammerbugten in Skaggerak, ran by danish explorer Klaus Thymann, found evidence of much greater biodiversity in a range seafloor habitats previously thought to be sandy with a low density of wildlife. Dead Man’s Fingers corals were again among the species documented for the first time in these coastal habitats.


Environmental concerns

Scientists and environmental institutions have expressed concern about the increasing pressure on the
ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...
in Skagerrak. The pressure has already had negative impacts and is caused by cumulative environmental effects, of which direct human activities are only one piece of the puzzle.
Climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
and
ocean acidification Ocean acidification is the reduction in the pH value of the Earth’s ocean. Between 1751 and 2021, the average pH value of the ocean surface has decreased from approximately 8.25 to 8.14. The root cause of ocean acidification is carbon dioxid ...
are expected to have increasing impacts on the Skagerrak ecosystem in the future. Skagerrak and the North Sea receives considerable inputs of hazardous material and radioactive substances. Most is ascribed to long-range transport from other countries, but not all.
Marine litter Marine debris, also known as marine litter, is human-created waste that has deliberately or accidentally been released in a sea or ocean. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing ...
is also a growing problem. Until recently, waste water and sewage pouring into Skagerrak from settlements and industries was not treated at all. In combination with wash out of excessive nutrients from
conventional farming Intensive agriculture, also known as intensive farming (as opposed to extensive farming), conventional, or industrial agriculture, is a type of agriculture, both of crop plants and of animals, with higher levels of input and output per unit of ag ...
, this has often led to large
algae bloom An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompasse ...
s.


Protections

There are several marine protections in Skagerrak, including: ;Norway *
Ytre Hvaler National Park Ytre Hvaler National Park ( no, Ytre Hvaler nasjonalpark, literally ''Outer Hvaler National Park'') is a national park located within the municipalities of Hvaler and Fredrikstad in Østfold, Norway. The park was established on 26 June 2009 and w ...
, established on 26 June 2009 * Raet National Park, established on 16 December 2016 ;Sweden *
Kosterhavet National Park Kosterhavet National Park ( sv, Kosterhavets nationalpark, literally ''The Koster Sea National Park'') is the first national marine park in Sweden, inaugurated in September 2009. It is part of the Skagerrak sea and is located in Strömstad and ...
* Bratten, a newly designated Natura 2000 sea area beyond Kosterhavet. Pockmarks and biogenic reefs at depths of . * Gullmarsfjorden, Sweden's first marine conservation area from 1983. ;Denmark *
Grenen Grenen is a long sandbar spit at Skagen Odde (the headland of Jutland), north of the town of Skagen. Overview ''Grenen'' (The Branch) was named for its shape like a tree-branch, reaching out from the mainland. The beach of Grenen appears in m ...
and a sea area immediately north.


See also

*
Danish Straits The Danish straits are the straits connecting the Baltic Sea to the North Sea through the Kattegat and Skagerrak. Historically, the Danish straits were internal waterways of Denmark; however, following territorial losses, Øresund and Fehmarn B ...


Notes and references


External links


The Baltic Sea, Kattegat and Skagerrak
Swedish Meteorological and Hydrological Institute (SMHI).
Skagerrak Deep-water Fish Assemblage


Marine vessel Traffic {{Authority control Denmark–Sweden border International straits Landforms of Västra Götaland County Norway–Sweden border Straits of Denmark Straits of Norway Straits of Sweden