North Sea
Overview
 
In the southwest, beyond the Straits of Dover
Strait of Dover
The Strait of Dover or Dover Strait is the strait at the narrowest part of the English Channel. The shortest distance across the strait is from the South Foreland, 6 kilometres northeast of Dover in the county of Kent, England, to Cap Gris Nez, a cape near to Calais in the French of...

, the North Sea becomes the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...

 connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 via the Skagerrak
Skagerrak
The Skagerrak is a strait running between Norway and the southwest coast of Sweden and the Jutland peninsula of Denmark, connecting the North Sea and the Kattegat sea area, which leads to the Baltic Sea.-Name:...

 and Kattegat
Kattegat
The Kattegat , or Kattegatt is a 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 Øresund and the Danish...

, narrow straits that separate Denmark from Norway and Sweden respectively. In the north it is bordered by the Shetland Islands
Shetland Islands
Shetland is a subarctic archipelago of Scotland that lies north and east of mainland Great Britain. The islands lie some to the northeast of Orkney and southeast of the Faroe Islands and form part of the division between the Atlantic Ocean to the west and the North Sea to the east. The total...

, and connects with the Norwegian Sea
Norwegian Sea
The Norwegian Sea is a marginal sea in the North Atlantic Ocean, northwest of Norway. It is located between the North Sea and the Greenland Sea and adjoins the North Atlantic Ocean to the west and the Barents Sea to the northeast. In the southwest, it is separated from the Atlantic Ocean by a...

, which lies in the very north-eastern part of the Atlantic.

It is more than 970 kilometres (602.7 mi) long and 580 kilometres (360.4 mi) wide, with an area of 750000 square kilometres (289,576.6 sq mi) and a volume of 94000 cubic kilometres (22,551.8 cu mi).
Timeline

1362    A storm tide in the North Sea destroys the German city of Rungholt on the island of Strand.

1570    A tidal wave in the North Sea devastates the coast from Holland to Jutland, killing more than 1,000 people.

1980    The Norwegian oil platform Alexander L. Kielland collapses in the North Sea, killing 123 of its crew of 212.

1988    The Piper Alpha drilling platform in the North Sea is destroyed by explosions and fires. 167 oil workers are killed, making it the world's worst offshore oil disaster.

1995    The Draupner wave in the North Sea in Norway is detected, confirming the existence of freak waves.

Encyclopedia
In the southwest, beyond the Straits of Dover
Strait of Dover
The Strait of Dover or Dover Strait is the strait at the narrowest part of the English Channel. The shortest distance across the strait is from the South Foreland, 6 kilometres northeast of Dover in the county of Kent, England, to Cap Gris Nez, a cape near to Calais in the French of...

, the North Sea becomes the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...

 connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 via the Skagerrak
Skagerrak
The Skagerrak is a strait running between Norway and the southwest coast of Sweden and the Jutland peninsula of Denmark, connecting the North Sea and the Kattegat sea area, which leads to the Baltic Sea.-Name:...

 and Kattegat
Kattegat
The Kattegat , or Kattegatt is a 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 Øresund and the Danish...

, narrow straits that separate Denmark from Norway and Sweden respectively. In the north it is bordered by the Shetland Islands
Shetland Islands
Shetland is a subarctic archipelago of Scotland that lies north and east of mainland Great Britain. The islands lie some to the northeast of Orkney and southeast of the Faroe Islands and form part of the division between the Atlantic Ocean to the west and the North Sea to the east. The total...

, and connects with the Norwegian Sea
Norwegian Sea
The Norwegian Sea is a marginal sea in the North Atlantic Ocean, northwest of Norway. It is located between the North Sea and the Greenland Sea and adjoins the North Atlantic Ocean to the west and the Barents Sea to the northeast. In the southwest, it is separated from the Atlantic Ocean by a...

, which lies in the very north-eastern part of the Atlantic.

It is more than 970 kilometres (602.7 mi) long and 580 kilometres (360.4 mi) wide, with an area of 750000 square kilometres (289,576.6 sq mi) and a volume of 94000 cubic kilometres (22,551.8 cu mi). Around the edges of the North Sea are sizeable islands and archipelago
Archipelago
An archipelago , sometimes called an island group, is a chain or cluster of islands. The word archipelago is derived from the Greek ἄρχι- – arkhi- and πέλαγος – pélagos through the Italian arcipelago...

s, including Shetland, Orkney, and the Frisian Islands
Frisian Islands
The Frisian Islands, also known as the Wadden Islands or Wadden Sea Islands, form an archipelago at the eastern edge of the North Sea in northwestern Europe, stretching from the north-west of the Netherlands through Germany to the west of Denmark...

. The North Sea receives freshwater from a number of European continental watersheds, as well as the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...

. A large part of the European drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 empties into the North Sea including water from the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

. The largest and most important affecting the North Sea are the Elbe
Elbe
The Elbe is one of the major rivers of Central Europe. It rises in the Krkonoše Mountains of the northwestern Czech Republic before traversing much of Bohemia , then Germany and flowing into the North Sea at Cuxhaven, 110 km northwest of Hamburg...

 and the Rhine – Meuse watershed. Around 185 million people live in the catchment area
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 of the rivers that flow into the North Sea encompassing some highly industrialized areas.

Major features

For the most part, the sea lies on the European continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...

 with a mean depth of 90 metres (295.3 ft). The only exception is the Norwegian trench
Norwegian trench
The Norwegian trench or Norwegian channel is an elongated depression in the sea floor off the southern coast of Norway....

, which extends parallel to the Norwegian shoreline from Oslo
Oslo
Oslo is a municipality, as well as the capital and most populous city in Norway. As a municipality , it was established on 1 January 1838. Founded around 1048 by King Harald III of Norway, the city was largely destroyed by fire in 1624. The city was moved under the reign of Denmark–Norway's King...

 to an area north of Bergen
Bergen
Bergen is the second largest city in Norway with a population of as of , . Bergen is the administrative centre of Hordaland county. Greater Bergen or Bergen Metropolitan Area as defined by Statistics Norway, has a population of as of , ....

. It is between 20 and 30 km (12.4 and 18.6 mi) wide and has a maximum depth of 725 metres (2,378.6 ft).

The Dogger Bank
Dogger Bank
Dogger Bank is a large sandbank in a shallow area of the North Sea about off the east coast of England. It extends over approximately , with its dimensions being about long and up to broad. The water depth ranges from 15 to 36 metres , about shallower than the surrounding sea. It is a...

, a vast moraine
Moraine
A moraine is any glacially formed accumulation of unconsolidated glacial debris which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past glacial maximum. This debris may have been plucked off a valley floor as a glacier advanced or it may have...

, or accumulation of unconsolidated glacial debris, rises to a mere 15 to 30 metres (50–100 ft) below the surface. This feature has produced the finest fishing location of the North Sea. The Long Forties
Long Forties
200px|rightThe Long Forties is an area of the northern North Sea that is fairly consistently forty fathoms deep . It is located between the northeast coast of Scotland and the southwest coast of Norway, centred about 57°N 0°30′E...

 and the Broad Fourteens
Broad Fourteens
thumb|200px|right|The Broad Fourteens on a map by Delisle The Broad Fourteens is an area of the southern North Sea that is fairly consistently fourteen fathoms deep...

 are large areas with roughly uniform depth in fathom
Fathom
A fathom is a unit of length in the imperial and the U.S. customary systems, used especially for measuring the depth of water.There are 2 yards in an imperial or U.S. fathom...

s, (forty fathoms and fourteen fathoms or 73 and 26 m deep respectively). These great banks and others make the North Sea particularly hazardous to navigate, which has been alleviated by the implementation of satellite navigation systems
Global Navigation Satellite System
A satellite navigation or SAT NAV system is a system of satellites that provide autonomous geo-spatial positioning with global coverage. It allows small electronic receivers to determine their location to within a few metres using time signals transmitted along a line-of-sight by radio from...

. The Devil's Hole
Devil's Hole (North Sea)
Devil's Hole is a group of deep trenches in the North Sea about 200 kilometers east of Dundee, Scotland.The features, which were first charted by HMS Fitzroy, were officially recorded in the Royal Geographical Society's Geographical Journal in 1931...

 lies 200 miles (321.9 km) east of Dundee
Dundee
Dundee is the fourth-largest city in Scotland and the 39th most populous settlement in the United Kingdom. It lies within the eastern central Lowlands on the north bank of the Firth of Tay, which feeds into the North Sea...

, Scotland. The feature is a series of asymmetrical trenches between 20 and 30 km (12.4 and 18.6 mi) long, 1 and 2 km (0.621372736649807 and 1.2 mi) wide and up to 230 metres (754.6 ft) deep.

Extent

The International Hydrographic Organization
International Hydrographic Organization
The International Hydrographic Organization is the inter-governmental organisation representing the hydrographic community. It enjoys observer status at the UN and is the recognised competent authority on hydrographic surveying and nautical charting...

 defines the limits of the North Sea as follows:

On the Southwest. A line joining the Walde Lighthouse (France, 1°55'E) and Leathercoat Point (England, 51°10'N).

On the Northwest. From Dunnet Head

Dunnet Head
Dunnet Head is a peninsula in Caithness, on the north coast of Scotland, that includes the most northerly point of the mainland of Great Britain. The point, known as Easter Head, is at , about westnorthwest of John o' Groats and about from Duncansby Head...

 (3°22'W) in Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

 to Tor Ness (58°47'N) in the Island of Hoy
Hoy
Hoy is an island in Orkney, Scotland. With an area of it is the second largest in the archipelago after the Mainland. It is connected by a causeway called The Ayre to South Walls...

, thence through this island to the Kame of Hoy (58°55'N) on to Breck Ness on Mainland (58°58'N) through this island to Costa Head
Costa Head
Costa Head is a prominent headland on Eynhallow Sound on the northwestern coast of the Orkney Mainland, Scotland. The tidal indraught of Eynhallow Sound is "scarcely felt beyond a line joining Costa Head and the Reef of Quendale". To the east is the Point of Hellia on which is located the Broch...

 (3°14'W) and to Inga Ness (59'17'N) in Westray
Westray
Westray is one of the Orkney Islands in Scotland, with a population of around 550 people. Its main village is Pierowall, with a heritage centre, the ruined Lady Kirk and ferries to Papa Westray.-Geography and geology:...

 through Westray, to Bow Head, across to Mull Head (North point of Papa Westray
Papa Westray
Papa Westray, also known as Papay, is one of the Orkney Islands in Scotland, with a population of 65 at the time of the 2001 Census, now increased to 70 people...

) and on to Seal Skerry (North point of North Ronaldsay
North Ronaldsay
North Ronaldsay is the northernmost of the Orkney Islands, Scotland and with an area of is the fourteenth largest.-Geography:North Ronaldsay lies around north of its nearest neighbour, Sanday at . The island is around long along its length and is defined by two large sandy bays; Linklet Bay on...

) and thence to Horse Island
Horse Holm
The Horse Holm , referred to on maps as Horse Island, known to locals simply as Da Holm, and used as an alignment point by local fishermen for several fishing marks, lies about 2.3 km west of Sumburgh Head at the south tip of the Mainland, Shetland.-Footnotes:This article incorporates text from ...

 (South point of the Shetland Islands).

On the North. From the North point (Fethaland Point) of the Mainland of the Shetland Islands, across to Graveland Ness (60°39'N) in the Island of Yell, through Yell to Gloup Ness (1°04'W) and across to Spoo Ness (60°45'N) in Unst

Unst
Unst is one of the North Isles of the Shetland Islands, Scotland. It is the northernmost of the inhabited British Isles and is the third largest island in Shetland after the Mainland and Yell. It has an area of .Unst is largely grassland, with coastal cliffs...

 island, through Unst to Herma Ness
Hermaness
Hermaness is the northernmost headland of Unst, the northernmost inhabited island of Shetland, Scotland. It consists of sea cliffs and moorland.-Hermaness National Nature Reserve:...

 (60°51'N), on to the SW point of the Rumblings and to Muckle Flugga
Muckle Flugga
Muckle Flugga is a small rocky island north of Unst in the Shetland Islands, Scotland. It is often described as the northernmost point of the British Isles, but the smaller islet of Out Stack is actually farther north...

 (60°51′N 0°53′W) all these being included in the North Sea area; thence up the meridian of 0°53' West to the parallel of 61°00' North
61st parallel north
The 61st parallel north is a circle of latitude that is 61 degrees north of the Earth's equatorial plane. It crosses the Atlantic Ocean, Europe, Asia and North America....

 and eastward along this parallel to the coast of Norway, the whole of Viking Bank being thus included in the North Sea.

On the East. The Western limit of the Skagerrak

Skagerrak
The Skagerrak is a strait running between Norway and the southwest coast of Sweden and the Jutland peninsula of Denmark, connecting the North Sea and the Kattegat sea area, which leads to the Baltic Sea.-Name:...

 [A line joining Hanstholm
Hanstholm
Hanstholm is a small town and a former island, now elevated area in Thisted municipality of Region Nordjylland, located in the northern part of Denmark. Coordinates:...

 (57°07′N 83°6′E) and the Naze (Lindesnes
Lindesnes
Lindesnes is a municipality in the county of Vest-Agder, Norway. Lindesnes was created as a new municipality on 1 January 1964 after the merger of the older municipalities of Spangereid, Sør-Audnedal, and Vigmostad....

, 58°N 7°E)].

Temperature and salinity

The average temperature in summer is 17 °C (62.6 °F) and 6 °C (42.8 °F) in the winter. The average temperatures have been trending higher since 1988, which has been attributed to climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

. Air temperatures in January range on average between 0 to 4 °C (32 to 39.2 F) and in July between 13 to 18 °C (55.4 to 64.4 F). The winter months see frequent gales and storms.

The salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...

 averages between 34 to 35 grams of salt per litre of water. The salinity has the highest variability where there is fresh water
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...

 inflow, such as at the Rhine and Elbe estuaries, the Baltic Sea exit and along the coast of Norway.

Water circulation and tides

The main pattern to the flow of water in the North Sea is an anti-clockwise rotation along the edges.

The North Sea is an arm of the Atlantic Ocean receiving the majority of ocean current
Ocean current
An ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...

 from the northwest opening, and a lesser portion of warm current from the smaller opening at the English Channel. These tidal currents leave along the Norwegian coast. Surface and deep water currents may move in different directions. Low salinity surface coastal waters move offshore, and deeper, denser high salinity waters move in shore.

The North Sea located on the continental shelf has different waves than those in deep ocean water. The wave speeds are diminished and the wave amplitudes are increased. In the North Sea there are two amphidromic
Amphidromic point
An amphidromic point is a point within a tidal system where the tidal range is almost zero. The tidal range is zero at the amphidromic point and increases with distance from this point...

 systems and a third incomplete amphidromic
Amphidromic point
An amphidromic point is a point within a tidal system where the tidal range is almost zero. The tidal range is zero at the amphidromic point and increases with distance from this point...

 system. In the North Sea the average tide difference in wave amplitude is between 0 to 8 m (0 to 26.2 ft).

The Kelvin tide of the Atlantic ocean is a semidiurnal wave that travels northward. Some of the energy from this wave travels through the English Channel into the North Sea. The wave still travels northward in the Atlantic Ocean, and once past the northern tip of Great Britain, the Kelvin wave
Kelvin wave
A Kelvin wave is a wave in the ocean or atmosphere that balances the Earth's Coriolis force against a topographic boundary such as a coastline, or a waveguide such as the equator. A feature of a Kelvin wave is that it is non-dispersive, i.e., the phase speed of the wave crests is equal to the...

 turns east and south and once again enters into the North Sea.

Coasts

The eastern and western coasts of the North Sea are jagged, formed by glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s during the ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...

s. The coastlines along the southernmost part are covered with the remains of deposited glacial sediment. The Norwegian mountains plunge into the sea creating deep fjord
Fjord
Geologically, a fjord is a long, narrow inlet with steep sides or cliffs, created in a valley carved by glacial activity.-Formation:A fjord is formed when a glacier cuts a U-shaped valley by abrasion of the surrounding bedrock. Glacial melting is accompanied by rebound of Earth's crust as the ice...

s and archipelago
Archipelago
An archipelago , sometimes called an island group, is a chain or cluster of islands. The word archipelago is derived from the Greek ἄρχι- – arkhi- and πέλαγος – pélagos through the Italian arcipelago...

s. South of Stavanger, the coast softens, the islands become fewer. The eastern Scottish coast is similar, though less severe than Norway. From north east of England
North East England
North East England is one of the nine official regions of England. It covers Northumberland, County Durham, Tyne and Wear, and Teesside . The only cities in the region are Durham, Newcastle upon Tyne and Sunderland...

, the cliffs become lower and are composed of less resistant moraine
Moraine
A moraine is any glacially formed accumulation of unconsolidated glacial debris which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past glacial maximum. This debris may have been plucked off a valley floor as a glacier advanced or it may have...

, which erodes more easily, so that the coasts have more rounded contours. In Holland, Belgium and in the east of England (East Anglia
East Anglia
East Anglia is a traditional name for a region of eastern England, named after an ancient Anglo-Saxon kingdom, the Kingdom of the East Angles. The Angles took their name from their homeland Angeln, in northern Germany. East Anglia initially consisted of Norfolk and Suffolk, but upon the marriage of...

) the littoral
Littoral
The littoral zone is that part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this intertidal zone and is often used to...

 is low and marshy. The east coast and south-east of the North Sea (Wadden Sea
Wadden Sea
The Wadden Sea is an intertidal zone in the southeastern part of the North Sea. It lies between the coast of northwestern continental Europe and the range of Frisian Islands, forming a shallow body of water with tidal flats and wetlands. It is rich in biological diversity...

) have coastlines that are mainly sandy and straight owing to longshore drift
Longshore drift
Longshore drift consists of the transportation of sediments along a coast at an angle to the shoreline, which is dependent on prevailing wind direction, swash and backwash. This process occurs in the littoral zone, and in or within close proximity to the surf zone...

, particularly along Belgium and Denmark.

Coastal management

The southern coastal areas were originally amphibious flood plains and swampy land. In areas especially vulnerable to storm tides, people settled behind elevated levees and on natural areas of high ground such as spits
Spit (landform)
A spit or sandspit is a deposition landform found off coasts. At one end, spits connect to land, and extend into the sea. A spit is a type of bar or beach that develops where a re-entrant occurs, such as at cove's headlands, by the process of longshore drift...

 and Geestland
Geestland
Geest is a type of slightly raised landscape that occurs in the plains of in Northern Germany, the Northern Netherlands and Denmark. It is a landscape of sandy and gravelly soils, usually mantled by a heathland vegetation, comprising glacial deposits left behind after the last ice age during the...

. As early as 500 BC, people were constructing artificial dwelling hill
Artificial dwelling hill
An artificial dwelling hill is a mound, created to provide safe ground during high tide and river floods....

s higher than the prevailing flood levels. It was only around the beginning of the High Middle Ages
High Middle Ages
The High Middle Ages was the period of European history around the 11th, 12th, and 13th centuries . The High Middle Ages were preceded by the Early Middle Ages and followed by the Late Middle Ages, which by convention end around 1500....

, in 1200 AD, that inhabitants began to connect single ring dikes into a dike line along the entire coast, thereby turning amphibious regions between the land and the sea into permanent solid ground.

The modern form of the dikes supplemented by overflow and lateral diversion channels, began to appear in the 17th and 18th centuries, built in the Netherlands. The North Sea Floods of 1953 and 1962 were impetus for further raising of the dikes as well as the shortening of the coast line so as to present as little surface area as possible to the punishment of the sea and the storms. Currently, 27% of the Netherlands is below sea level protected by dikes, dunes, and beach flats.

Coastal management
Coastal management
In some jurisdictions the terms sea defense and coastal protection are used to mean, respectively, defense against flooding and erosion...

 today consists of several levels. The dike slope reduces the energy of the incoming sea, so that the dike itself does not receive the full impact. Dikes that lie directly on the sea are especially reinforced. The dikes have, over the years, been repeatedly raised, sometimes up to 9 metres (29.5 ft) and have been made flatter to better reduce wave erosion. Where the dunes are sufficient to protect the land behind them from the sea, these dunes are planted with beach grass to protect them from erosion by wind, water, and foot traffic.

Storm tides

Storm tide
Storm tide
A storm tide is a tide with a high flood period caused by a storm. Storm tides can be a severe danger to the coast and the people living along the coast. The water level can rise to more than 5 meters above the normal tide....

s threaten, in particular, the coasts of the Netherlands, Belgium, Germany, and Denmark and low lying areas of eastern England particularly around The Wash
The Wash
The Wash is the square-mouthed bay and estuary on the northwest margin of East Anglia on the east coast of England, where Norfolk meets Lincolnshire. It is among the largest estuaries in the United Kingdom...

 and Fens
The Fens
The Fens, also known as the , are a naturally marshy region in eastern England. Most of the fens were drained several centuries ago, resulting in a flat, damp, low-lying agricultural region....

.
Storm surges are caused by changes in barometric pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...

 combined with strong wind created wave action
Ocean surface wave
In fluid dynamics, wind waves or, more precisely, wind-generated waves are surface waves that occur on the free surface of oceans, seas, lakes, rivers, and canals or even on small puddles and ponds. They usually result from the wind blowing over a vast enough stretch of fluid surface. Waves in the...

.

The first recorded storm tide flood was the Julianenflut, on 17 February 1164. In its wake the Jadebusen
Jadebusen
The Jade Bight, is a bay on the North Sea coast of Germany. It was formerly known simply as Jade or Jahde.About 180 km² in area, the Jade was largely created by storm floods during the 12th and 16th centuries. During this period it was connected in the East to the river Weser...

, (a bay on the coast of Germany), began to form.
A storm tide in 1228 is recorded to have killed more than 100,000 people. In 1362, the Second Marcellus Flood, also known as the Grote Manndränke
Grote Mandrenke
The Grote Mandrenke was the name of a massive southwesterly Atlantic gale which swept across England, the Netherlands, northern Germany, and Schleswig around January 16, 1362, causing at minimum 25,000 deaths. January 16 is the feast day of St...

, hit the entire southern coast of the North Sea. Chronicles of the time again record more than 100,000 deaths as large parts of the coast were lost permanently to the sea, including the now legendary lost city
Lost city
A "Lost City" is a term that is generally considered to refer to a well-populated area which fell into terminal decline, became extensively or completely uninhabited, and whose location has been forgotten. Some lost cities whose locations have been rediscovered have been studied extensively by...

 of Rungholt
Rungholt
Rungholt was a wealthy city in Nordfriesland, northern Germany. It sank beneath the waves when a storm tide in the North Sea tore through the area on January 16, 1362....

.
In the 20th century, the North Sea flood of 1953
North Sea flood of 1953
The 1953 North Sea flood was a major flood caused by a heavy storm, that occurred on the night of Saturday 31 January 1953 and morning of 1 February 1953. The floods struck the Netherlands, Belgium, England and Scotland.A combination of a high spring tide and a severe European windstorm caused a...

 flooded several nations' coasts and cost more than 2,000 lives.
315 citizens of Hamburg died in the North Sea flood of 1962
North Sea flood of 1962
The North Sea flood of 1962 was a natural disaster affecting mainly the coastal regions of Germany and in particular the city of Hamburg in the night from 16 February to 17 February 1962...

.

Tsunamis

Though rare, the North Sea has been the site of a number of historically documented tsunamis. The Storegga Slide
Storegga Slide
The three Storegga Slides are considered to be amongst the largest known landslides. They occurred under water, at the edge of Norway's continental shelf , in the Norwegian Sea, 100 km north-west of the Møre coast, causing a very large tsunami in the North Atlantic Ocean...

s were a series of underwater landslides, in which a piece of the Norwegian continental shelf slid into the Norwegian Sea. The immense landslips occurred between 8150 BC and 6000 BC, and caused a tsunami up to 20 metres (65.6 ft) high that swept through the North Sea, having the greatest effect on Scotland and the Faeroe Islands
Faroe Islands
The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...

.
The Dover Straits earthquake of 1580
Dover Straits earthquake of 1580
Though severe earthquakes in the north of France and Britain are rare, the Dover Straits earthquake of 6 April 1580 appears to have been one of the largest in the recorded history of England, Flanders or northern France...

 is among the first recorded earthquakes in the North Sea measuring between 5.6 and 5.9 on the Richter Scale. This event caused extensive damage in Calais
Calais
Calais is a town in Northern France in the department of Pas-de-Calais, of which it is a sub-prefecture. Although Calais is by far the largest city in Pas-de-Calais, the department's capital is its third-largest city of Arras....

 both through its tremors and possibly triggered a tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...

, though this has never been confirmed. The theory is a vast underwater landslide in the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...

 was triggered by the earthquake, which in turn caused a tsunami. The tsunami triggered by the 1755 Lisbon Earthquake
1755 Lisbon earthquake
The 1755 Lisbon earthquake, also known as the Great Lisbon Earthquake, was a megathrust earthquake that took place on Saturday 1 November 1755, at around 9:40 in the morning. The earthquake was followed by fires and a tsunami, which almost totally destroyed Lisbon in the Kingdom of Portugal, and...

 reached Holland, although the waves had lost their destructive power. The largest earthquake ever recorded in the United Kingdom was the 1931 Dogger Bank earthquake
1931 Dogger Bank earthquake
The Dogger Bank earthquake of 1931 was the strongest earthquake recorded in the United Kingdom since measurements began. It measured 6.1 on the Richter Scale....

, which measured 6.1 on the Richter Scale and caused a small tsunami that flooded parts of the British coast.

Geology

Shallow epicontinental seas like the current North Sea have since long existed on the European continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...

. The rift
Rift
In geology, a rift or chasm is a place where the Earth's crust and lithosphere are being pulled apart and is an example of extensional tectonics....

ing that formed the northern part of the Atlantic Ocean during the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 and Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 periods, from about , caused tectonic uplift
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...

 in the British Isles. Since then, a shallow sea has almost continuously existed between the highs of the Fennoscandian Shield and the British Isles. This precursor of the current North Sea has grown and shrunk with the rise and fall of the eustatic sea level during geologic time. Sometimes it was connected with other shallow seas, such as the sea above the Paris Basin
Seine
The Seine is a -long river and an important commercial waterway within the Paris Basin in the north of France. It rises at Saint-Seine near Dijon in northeastern France in the Langres plateau, flowing through Paris and into the English Channel at Le Havre . It is navigable by ocean-going vessels...

 to the south-west, the Paratethys Sea to the south-east, or the Tethys Ocean
Tethys Ocean
The Tethys Ocean was an ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean.-Modern theory:...

 to the south.

During the Late Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

, about , all of modern mainland Europe except for Scandinavia was a scattering of islands. By the Early Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

, , the emergence of Western and Central Europe had almost completely separated the North Sea from the Tethys Ocean, which gradually shrank to become the Mediterranean as Southern Europe and South West Asia became dry land. The North Sea was cut off from the English Channel by a narrow land bridge
Land bridge
A land bridge, in biogeography, is an isthmus or wider land connection between otherwise separate areas, over which animals and plants are able to cross and colonise new lands...

 until that was breached by at least two catastrophic floods between 450,000 and 180,000 years ago. Since the start of the Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...

 period about , the eustatic sea level has fallen during each glacial period and then risen again. Every time the ice sheet
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...

 reached its greatest extent, the North Sea became almost completely dry. The present-day coastline formed after the Last Glacial Maximum
Last Glacial Maximum
The Last Glacial Maximum refers to a period in the Earth's climate history when ice sheets were at their maximum extension, between 26,500 and 19,000–20,000 years ago, marking the peak of the last glacial period. During this time, vast ice sheets covered much of North America, northern Europe and...

 when the sea began to flood the European continental shelf.

In 2006 a bone fragment was found while drilling for oil in the north sea. Analysis indicated that it was a Plateosaurus
Plateosaurus
Plateosaurus is a genus of plateosaurid dinosaur that lived during the Late Triassic period, around 216 to 199 million years ago, in what is now Central and Northern Europe. Plateosaurus is a basal sauropodomorph dinosaur, a so-called "prosauropod"...

 from 199 to 216 million years ago. This was the deepest dinosaur fossil ever found and the first find for Norway.

Fish and shellfish

Copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...

s and other zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...

 are plentiful in the North Sea. These tiny organisms are crucial elements of the food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...

 supporting many species of fish. Over 230 species of fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

 live in the North Sea. Cod
Cod
Cod is the common name for genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...

, haddock
Haddock
The haddock , also known as the offshore hake, is a marine fish distributed on both sides of the North Atlantic. Haddock is a popular food fish and is widely fished commercially....

, whiting, saithe, plaice
Plaice
Plaice is the common name of four species of flatfishes.Plaice or PLAICE may also refer to:* USS Plaice , a Balao-class submarine* PLAICE, an open source hardware FLASH programmer, memory emulator, and logic analyzer...

, sole
Sole (fish)
Sole is a group of flatfish belonging to several families. Generally speaking, they are members of the family Soleidae, but, outside Europe, the name sole is also applied to various other similar flatfish, especially other members of the sole suborder Soleoidei as well as members of the flounder...

, mackerel
Mackerel
Mackerel is a common name applied to a number of different species of fish, mostly, but not exclusively, from the family Scombridae. They may be found in all tropical and temperate seas. Most live offshore in the oceanic environment but a few, like the Spanish mackerel , enter bays and can be...

, herring
Herring
Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...

, pouting, sprat, and sandeel are all very common and are fished commercially. Due to the various depths of the North Sea trenches and differences in salinity, temperature, and water movement, some fish such as blue-mouth redfish and rabbitfish
Rabbitfish
Rabbitfishes or spinefoots are perciform fishes in the family Siganidae. The 28 species are in a single genus, Siganus. In some now obsolete classifications, the species having prominent face stripes—colloquially called foxfaces–are in the genus Lo. Other species like the Masked...

 reside only in small areas of the North Sea.

Crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s are also commonly found throughout the sea. Norway lobster
Norway lobster
Nephrops norvegicus, known variously as the Norway lobster, Dublin Bay prawn, or scampi, is a slim, orange-pink lobster which grows up to long, and is "the most important commercial crustacean in Europe"...

, deep-water prawn
Prawn
Prawns are decapod crustaceans of the sub-order Dendrobranchiata. There are 540 extant species, in seven families, and a fossil record extending back to the Devonian...

s, and brown shrimp are all commercially fished, but other species of lobster
Lobster
Clawed lobsters comprise a family of large marine crustaceans. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Though several groups of crustaceans are known as lobsters, the clawed lobsters are most...

, shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...

, oyster
Oyster
The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....

, mussel
Mussel
The common name mussel is used for members of several families of clams or bivalvia mollusca, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...

s and clam
Clam
The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...

s all live in the North Sea. Recently non-indigenous species have become established including the Pacific oyster
Pacific oyster
The Pacific oyster, Japanese oyster or Miyagi oyster , is an oyster native to the Pacific coast of Asia. It has become an introduced species in North America, Australia, Europe, and New Zealand.- Etymology :...

 and Atlantic jackknife clam
Atlantic jackknife clam
The Atlantic jackknife , Ensis directus, also known as the bamboo clam, American jackknife clam or razor clam , is a large species of edible marine bivalve mollusc, found on the North American Atlantic coast, from Canada to South Carolina as well as in Europe.This clam lives in sand and mud and is...

.

Birds

The coasts of the North Sea are home to nature reserve
Nature reserve
A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...

s including the Ythan Estuary
Ythan Estuary
The Ythan Estuary is the tidal component of the Ythan River, emptying into the North Sea approximately north of Aberdeen, Scotland. The estuary’s tidal action extends a full inland and has characteristic widths of between and . Besides the tidal channel there are several types of interfaces to...

, Fowlsheugh
Fowlsheugh
Fowlsheugh is a coastal nature reserve in Kincardineshire, northeast Scotland, known for its seventy metre high cliff formations and habitat supporting prolific seabird nesting colonies. Designated as a Site of Special Scientific Interest by Scottish Natural Heritage, the property is owned by the...

 Nature Preserve, and Farne Islands
Farne Islands
The Farne Islands are a group of islands off the coast of Northumberland, England. There are between 15 and 20 or more islands depending on the state of the tide. They are scattered about 2.5–7.5 km distant from the mainland, divided into two groups, the Inner Group and the Outer Group...

 in the UK and The Wadden Sea National Parks
Wadden Sea National Parks
The Wadden Sea National Parks, part of a UNESCO World Heritage Site, are located along the German coast of the North Sea. Named after the Wadden Sea, they consist of three national parks:...

 in Germany. These locations provide breeding habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...

 for dozens of bird species. Tens of millions of birds make use of the North Sea for breeding, feeding, or migratory stopovers every year. Populations of Black legged Kittiwakes, Atlantic Puffins, Northern fulmar
Northern Fulmar
The Northern Fulmar, Fulmarus glacialis, Fulmar, or Arctic Fulmar is a highly abundant sea bird found primarily in subarctic regions of the north Atlantic and north Pacific oceans. Fulmars come in one of two color morphs: a light one which is almost entirely white, and a dark one which is...

s, and species of petrel
Petrel
Petrels are tube-nosed seabirds in the bird order Procellariiformes. The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group...

s, gannet
Gannet
Gannets are seabirds comprising the genus Morus, in the family Sulidae, closely related to the boobies.The gannets are large black and white birds with yellow heads. They have long pointed wings and long bills. Northern gannets are the largest seabirds in the North Atlantic, with a wingspan of up...

s, seaducks, loon
Loon
The loons or divers are a group of aquatic birds found in many parts of North America and northern Eurasia...

s (divers), cormorant
Cormorant
The bird family Phalacrocoracidae is represented by some 40 species of cormorants and shags. Several different classifications of the family have been proposed recently, and the number of genera is disputed.- Names :...

s, gull
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...

s, auk
Auk
An auk is a bird of the family Alcidae in the order Charadriiformes. Auks are superficially similar to penguins due to their black-and-white colours, their upright posture and some of their habits...

s, and tern
Tern
Terns are seabirds in the family Sternidae, previously considered a subfamily of the gull family Laridae . They form a lineage with the gulls and skimmers which in turn is related to skuas and auks...

s, and many other seabirds make these coasts popular for birdwatching
Birdwatching
Birdwatching or birding is the observation of birds as a recreational activity. It can be done with the naked eye, through a visual enhancement device like binoculars and telescopes, or by listening for bird sounds. Birding often involves a significant auditory component, as many bird species are...

.

Marine mammals

The North Sea is also home to marine mammals. Common seals, and Harbour porpoise
Harbour Porpoise
The harbour porpoise is one of six species of porpoise. It is one of the smallest marine mammals. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar porpoise to whale watchers. This porpoise often ventures up rivers, and has been seen...

s can be found along the coasts, at marine installations, and on islands. The very northern North Sea islands such as the Shetland Islands are occasionally home to a larger variety of pinnipeds including bearded
Bearded Seal
The bearded seal , also called the square flipper seal, is a medium-sized pinniped that is found in and near to the Arctic Ocean. It gets its generic name from two Greek words that refer to its heavy jaw...

, harp
Harp Seal
The harp seal or saddleback seal is a species of earless seal native to the northernmost Atlantic Ocean and adjacent parts of the Arctic Ocean. It now belongs to the monotypic genus Pagophilus. Its scientific name, Pagophilus groenlandicus, means "ice-lover from Greenland", and its synonym, Phoca...

, hooded
Hooded Seal
The hooded seal is an arctic pinniped found only in the central and western North Atlantic ranging from Svalbard in the east to the Gulf of St...

 and ringed seal
Ringed Seal
The ringed seal , also known as the jar seal and as netsik or nattiq by the Inuit, is an earless seal inhabiting the Arctic and sub-Arctic regions...

s, and even walrus
Walrus
The walrus is a large flippered marine mammal with a discontinuous circumpolar distribution in the Arctic Ocean and sub-Arctic seas of the Northern Hemisphere. The walrus is the only living species in the Odobenidae family and Odobenus genus. It is subdivided into three subspecies: the Atlantic...

. North Sea cetaceans include various porpoise
Porpoise
Porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. They are distinct from dolphins, although the word "porpoise" has been used to refer to any small dolphin, especially by sailors and fishermen...

, dolphin
Dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...

 and whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...

 species.

Flora

Plant species in the North Sea include species of wrack
Wrack (science)
Wrack is the common name for several species of seaweed in the family Fucaceae. Pelvetia canaliculata Dcne. et Thur., Fucus spiralis L., Fucus vesiculosus L., Ascophyllum nodosum Le Jol. and Fucus serratus L. are the most common examples to be found in the British Isles...

, among them bladder wrack
Bladder wrack
Fucus vesiculosus, known by the common name bladder wrack or bladderwrack, is a seaweed found on the coasts of the North Sea, the western Baltic Sea, and the Atlantic and Pacific Oceans, also known by the common names black tang, rockweed, bladder fucus, sea oak, black tany, cut weed, dyers fucus,...

, knotted wrack
Knotted wrack
Ascophyllum nodosum is a large, common brown alga in the family Fucaceae, being the only species in the genus Ascophyllum. It is seaweed of the northern Atlantic Ocean, also known as rockweed, Norwegian kelp, knotted kelp, knotted wrack or egg wrack...

, and serrated wrack. Algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

, macroalgal, and kelp
Kelp
Kelps are large seaweeds belonging to the brown algae in the order Laminariales. There are about 30 different genera....

, such as oarweed and laminaria hyperboria, and species of maerl
Maerl
Maerl is a collective name for Coralline red algae with a certain growth habit. It accumulates as unattached particles and forms extensive beds in suitable sublittoral sites.-Description:...

 are found as well. Eelgrass
Zostera
Zostera is a small genus of widely distributed seagrass, commonly called marine eelgrass or simply eelgrass . The genus Zostera contains sixteen species.-Ecology:Zostera is found on sandy substrates or in estuaries submerged or partially floating...

, formerly common in the entirety of the Wadden Sea, was nearly wiped out in the 20th century by a disease. Similarly, sea grass
Seagrass
Seagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully saline environments.-Ecology:...

 used to coat huge tracts of ocean floor, but have been damaged by trawling and dredging have diminished its habitat and prevented its return. Invasive Japanese seaweed
Sargassum muticum
Sargassum muticum is a large brown seaweed of the genus Sargassum. It grows attached to rocks by a perennial holdfast up to 5 cm in diameter. From this holdfast the main axis grows to a maximum of 5 cm high. The leaf-like laminae and primary lateral branches grow from this stipe...

 has spread along the shores of the sea clogging harbours and inlets and has become a nuisance.

Biodiversity and conservation

Due to the heavy human populations and high level of industrialization along its shores, the wildlife of the North Sea has suffered from pollution, overhunting, and overfishing. Flamingo
Flamingo
Flamingos or flamingoes are gregarious wading birds in the genus Phoenicopterus , the only genus in the family Phoenicopteridae...

s, pelican
Pelican
A pelican, derived from the Greek word πελεκυς pelekys is a large water bird with a large throat pouch, belonging to the bird family Pelecanidae....

s, and Great Auk
Great Auk
The Great Auk, Pinguinus impennis, formerly of the genus Alca, was a large, flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus Pinguinus, a group of birds that formerly included one other species of flightless giant auk from the Atlantic Ocean...

 were once found along the southern shores of the North Sea, but went extinct over the 2nd millennium. Gray whale
Gray Whale
The gray whale, Eschrichtius robustus, is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of about , a weight of , and lives 50–70 years. The common name of the whale comes from the gray patches and white mottling on its dark skin. Gray whales were...

 also resided in the North Sea but were driven to extinction in the Atlantic in the 17th century Other species have dramatically declined in population, though they are still found. Right whale
Right whale
Right whales are three species of large baleen whales consisting of two genera in the family Balaenidae of order Cetacea. Their bodies are very dark gray or black and rotund....

s, sturgeon
Sturgeon
Sturgeon is the common name used for some 26 species of fish in the family Acipenseridae, including the genera Acipenser, Huso, Scaphirhynchus and Pseudoscaphirhynchus. The term includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common...

, shad
Shad
The shads or river herrings comprise the genus Alosa, fish related to herring in the family Clupeidae. They are distinct from others in that family by having a deeper body and spawning in rivers. The several species frequent different areas on both sides of the Atlantic Ocean, Mediterranean Sea....

, rays
Batoidea
Batoidea is a superorder of cartilaginous fish commonly known as rays and skates, containing more than 500 described species in thirteen families...

, skate
Skate
Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. There are more than 200 described species in 27 genera. There are two subfamilies, Rajinae and Arhynchobatinae ....

s, salmon
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...

, and other species were common in the North Sea until the 20th century, when numbers declined due to overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....

.
Other factors like the introduction of non-indigenous species, industrial and agricultural pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

, trawling
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net that is used for trawling is called a trawl....

 and dredging, human-induced eutrophication
Eutrophication
Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...

, construction on coastal breeding and feeding grounds, sand and gravel extraction, offshore construction
Offshore construction
Offshore construction is the installation of structures and facilities in a marine environment, usually for the production and transmission of electricity, oil, gas and other resources....

, and heavy shipping traffic have also contributed to the decline.
The OSPAR commission manages the OSPAR convention to counteract the harmful effects of human activity on wildlife in the North Sea, preserve endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

, and provide environmental protection. All North Sea border states are signatories of the MARPOL 73/78
MARPOL 73/78
Marpol 73/78 is the International Convention for the Prevention of Pollution From Ships, 1973 as modified by the Protocol of 1978....

 Accords, which preserve the marine environment by preventing pollution from ships.
Germany, Denmark, and the Netherlands also have a trilateral agreement for the protection of the Wadden Sea
Wadden Sea
The Wadden Sea is an intertidal zone in the southeastern part of the North Sea. It lies between the coast of northwestern continental Europe and the range of Frisian Islands, forming a shallow body of water with tidal flats and wetlands. It is rich in biological diversity...

, or mudflat
Mudflat
Mudflats or mud flats, also known as tidal flats, are coastal wetlands that form when mud is deposited by tides or rivers. They are found in sheltered areas such as bays, bayous, lagoons, and estuaries. Mudflats may be viewed geologically as exposed layers of bay mud, resulting from deposition of...

s, which run along the coasts of the three countries on the southern edge of the North Sea.

Name

Through history various names have been used for the North Sea. One of the earliest recorded names was Septentrionalis Oceanus, or "Northern Ocean," which was cited by Pliny. The name "North Sea" probably came into English, however, via the Dutch "Noordzee", who named it thus either in contrast with the Zuiderzee ("South Sea"), located south of Frisia
Frisia
Frisia is a coastal region along the southeastern corner of the North Sea, i.e. the German Bight. Frisia is the traditional homeland of the Frisians, a Germanic people who speak Frisian, a language group closely related to the English language...

, or simply because the sea is generally to the north of the Netherlands. Prior to the adoption of "North Sea," "German Sea" or "German Ocean"--from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 name "Mare Germanicum" and "Oceanus Germanicus"--were the names in English, and they persisted even into the late 19th Century.

Early history

The North Sea has provided waterway access for commerce and conquest. Many areas have access to the North Sea with its long coastline and European rivers that empty into it. The British Isles had been protected from invasion by the North Sea waters until the Roman conquest of Britain
Roman conquest of Britain
The Roman conquest of Britain was a gradual process, beginning effectively in AD 43 under Emperor Claudius, whose general Aulus Plautius served as first governor of Britannia. Great Britain had already frequently been the target of invasions, planned and actual, by forces of the Roman Republic and...

 in 43 AD. The Romans established organised ports, shipping increased and sustained trade began. When the Romans abandoned Britain in 410 the Germanic Angles
Angles
The Angles is a modern English term for a Germanic people who took their name from the ancestral cultural region of Angeln, a district located in Schleswig-Holstein, Germany...

, Saxons
Saxons
The Saxons were a confederation of Germanic tribes originating on the North German plain. The Saxons earliest known area of settlement is Northern Albingia, an area approximately that of modern Holstein...

, and Jutes
Jutes
The Jutes, Iuti, or Iutæ were a Germanic people who, according to Bede, were one of the three most powerful Germanic peoples of their time, the other two being the Saxons and the Angles...

 began the next great migration across the North Sea during the Migration Period
Migration Period
The Migration Period, also called the Barbarian Invasions , was a period of intensified human migration in Europe that occurred from c. 400 to 800 CE. This period marked the transition from Late Antiquity to the Early Middle Ages...

 invading England.

The Viking Age
Viking Age
Viking Age is the term for the period in European history, especially Northern European and Scandinavian history, spanning the late 8th to 11th centuries. Scandinavian Vikings explored Europe by its oceans and rivers through trade and warfare. The Vikings also reached Iceland, Greenland,...

 began in 793 with the attack on Lindisfarne
Lindisfarne
Lindisfarne is a tidal island off the north-east coast of England. It is also known as Holy Island and constitutes a civil parish in Northumberland...

 and for the next quarter-millennium the Vikings ruled the North Sea. In their superior longship
Longship
Longships were sea vessels made and used by the Vikings from the Nordic countries for trade, commerce, exploration, and warfare during the Viking Age. The longship’s design evolved over many years, beginning in the Stone Age with the invention of the umiak and continuing up to the 9th century with...

s, they raided, traded, and established colonies and outposts on the Sea's coasts. From the Middle Ages through the 15th century, the northern Europe
Northern Europe
Northern Europe is the northern part or region of Europe. Northern Europe typically refers to the seven countries in the northern part of the European subcontinent which includes Denmark, Estonia, Latvia, Lithuania, Norway, Finland and Sweden...

an coastal ports exported domestic goods, dyes, linen, salt, metal goods and wine. The Scandinavian and Baltic areas shipped grain, fish, naval necessities, and timber. In turn the North Sea countries imported high grade cloths, spices, and fruits from the Mediterranean region Commerce during this era was mainly undertaken by maritime trade due to underdeveloped roadways.

In the 13th century the Hanseatic League
Hanseatic League
The Hanseatic League was an economic alliance of trading cities and their merchant guilds that dominated trade along the coast of Northern Europe...

, though centred on the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

, started to control most of the trade through important members and outposts on the North Sea. The League lost its dominance in the 16th century, as neighbouring states took control of former Hanseatic cities and outposts and internal conflict prevented effective cooperation and defence. Furthermore, as the League lost control of its maritime cities, new trade route
Trade route
A trade route is a logistical network identified as a series of pathways and stoppages used for the commercial transport of cargo. Allowing goods to reach distant markets, a single trade route contains long distance arteries which may further be connected to several smaller networks of commercial...

s emerged that provided Europe with Asian, American, and African goods.

Age of sail

The 17th century Dutch Golden Age
Dutch Golden Age
The Golden Age was a period in Dutch history, roughly spanning the 17th century, in which Dutch trade, science, military and art were among the most acclaimed in the world. The first half is characterised by the Eighty Years' War till 1648...

 during which Dutch herring
Herring
Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...

, cod
Cod
Cod is the common name for genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...

 and whale fisheries reached an all time high saw Dutch power at its zenith. Important overseas colonies, a vast merchant marine, powerful navy and large profits made the Dutch the main challengers to an ambitious England. This rivalry led to the first three Anglo-Dutch Wars
Anglo-Dutch Wars
The Anglo–Dutch Wars were a series of wars fought between the English and the Dutch in the 17th and 18th centuries for control over the seas and trade routes. The first war took place during the English Interregnum, and was fought between the Commonwealth of England and the Dutch Republic...

 between 1652 and 1673, which ended with Dutch victories. After the Glorious Revolution
Glorious Revolution
The Glorious Revolution, also called the Revolution of 1688, is the overthrow of King James II of England by a union of English Parliamentarians with the Dutch stadtholder William III of Orange-Nassau...

 the Dutch prince William
William III of England
William III & II was a sovereign Prince of Orange of the House of Orange-Nassau by birth. From 1672 he governed as Stadtholder William III of Orange over Holland, Zeeland, Utrecht, Guelders, and Overijssel of the Dutch Republic. From 1689 he reigned as William III over England and Ireland...

 ascended to the English throne. With both countries united, commercial, military, and political power shifted from Amsterdam to London. The Great Northern War
Great Northern War
The Great Northern War was a conflict in which a coalition led by the Tsardom of Russia successfully contested the supremacy of the Swedish Empire in northern Central Europe and Eastern Europe. The initial leaders of the anti-Swedish alliance were Peter I the Great of Russia, Frederick IV of...

 (1700–21) and the War of the Spanish Succession
War of the Spanish Succession
The War of the Spanish Succession was fought among several European powers, including a divided Spain, over the possible unification of the Kingdoms of Spain and France under one Bourbon monarch. As France and Spain were among the most powerful states of Europe, such a unification would have...

 (1701–1714) were fought concurrently.
The British did not face a challenge to their dominance of the North Sea until the 20th century.

Modern era

Tensions in the North Sea were again heightened in 1904 by the Dogger Bank incident
Dogger Bank incident
The Dogger Bank incident occurred when the Russian Baltic Fleet mistook some British trawlers at Dogger Bank for an Imperial Japanese Navy force....

, in which Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n naval vessels mistook British fishing boats for Japanese ships and fired on them, and then upon each other.

During the First World War, Great Britain's Grand Fleet and Germany's Kaiserliche Marine
Kaiserliche Marine
The Imperial German Navy was the German Navy created at the time of the formation of the German Empire. It existed between 1871 and 1919, growing out of the small Prussian Navy and Norddeutsche Bundesmarine, which primarily had the mission of coastal defense. Kaiser Wilhelm II greatly expanded...

 faced each other on the North Sea, which became the main theatre of the war for surface action. Britain's larger fleet was able to establish an effective blockade for most of the war that restricted the Central Powers
Central Powers
The Central Powers were one of the two warring factions in World War I , composed of the German Empire, the Austro-Hungarian Empire, the Ottoman Empire, and the Kingdom of Bulgaria...

' access to many crucial resources. Major battles included the Battle of Heligoland Bight, the Battle of the Dogger Bank
Battle of Dogger Bank (1915)
The Battle of Dogger Bank was a naval battle fought near the Dogger Bank in the North Sea on 24 January 1915, during the First World War, between squadrons of the British Grand Fleet and the German High Seas Fleet....

, and the Battle of Jutland
Battle of Jutland
The Battle of Jutland was a naval battle between the British Royal Navy's Grand Fleet and the Imperial German Navy's High Seas Fleet during the First World War. The battle was fought on 31 May and 1 June 1916 in the North Sea near Jutland, Denmark. It was the largest naval battle and the only...

.
World War I also brought the first extensive use of submarine warfare
Submarine warfare
Naval warfare is divided into three operational areas: surface warfare, air warfare and underwater warfare. The latter may be subdivided into submarine warfare and anti-submarine warfare as well as mine warfare and mine countermeasures...

, and a number of submarine actions occurred in the North Sea.

The Second World War also saw action in the North Sea, though it was restricted more to aircraft reconnaissances, aircraft fighter/bombers, submarines and smaller vessels such as minesweepers
Minesweeper (ship)
A minesweeper is a small naval warship designed to counter the threat posed by naval mines. Minesweepers generally detect then neutralize mines in advance of other naval operations.-History:...

, and torpedo boat
Torpedo boat
A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

s and similar vessels.

In the last years of the war and the first years thereafter, hundreds of thousands of tons of weapons were disposed of by being sunk in the North Sea.

After the war, the North Sea lost much of its military significance because it is bordered only by NATO member-states. However, it gained significant economic importance in the 1960s as the states on the North Sea began full-scale exploitation of its oil and gas resources
North Sea oil
North Sea oil is a mixture of hydrocarbons, comprising liquid oil and natural gas, produced from oil reservoirs beneath the North Sea.In the oil industry, the term "North Sea" often includes areas such as the Norwegian Sea and the area known as "West of Shetland", "the Atlantic Frontier" or "the...

. The North Sea continues to be an active trade route.

Political status

Countries that border the North Sea all claim the 12 nautical miles (22.2 km) of territorial waters
Territorial waters
Territorial waters, or a territorial sea, as defined by the 1982 United Nations Convention on the Law of the Sea, is a belt of coastal waters extending at most from the baseline of a coastal state...

, within which they have exclusive fishing rights. The Common Fisheries Policy
Common Fisheries Policy
The Common Fisheries Policy is the fisheries policy of the European Union . It sets quotas for which member states are allowed to catch what amounts of each type of fish, as well as encouraging the fishing industry by various market interventions...

 of the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...

 (EU) exists to coordinate fishing rights and assist with disputes between EU states and the EU border state of Norway.

After the discovery of mineral resources in the North Sea, the Convention on the Continental Shelf
Convention on the Continental Shelf
The Convention on the Continental Shelf was an international treaty created to codify the rules of international law relating to continental shelves. The treaty, after entering into force 10 June 1964, established the rights of a sovereign state over the continental shelf surrounding it, if there...

 established country rights largely divided along the median line. The median line is defined as the line "every point of which is equidistant from the nearest points of the baselines from which the breadth of the territorial sea of each State is measured."
The ocean floor border between Germany, the Netherlands, and Denmark was only reapportioned after protracted negotiations and a judgement of the International Court of Justice
International Court of Justice
The International Court of Justice is the primary judicial organ of the United Nations. It is based in the Peace Palace in The Hague, Netherlands...

.

Oil and gas

As early as 1859, oil was discovered in onshore areas around the North Sea and natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 as early as 1910.

Test drilling began in 1966 and then, in 1969, Phillips Petroleum Company discovered the Ekofisk oil field
Ekofisk oil field
Ekofisk is an oil field in the Norwegian sector of the North Sea about southwest of Stavanger. Discovered in 1969, it remains one of the most important oil fields in the North Sea. Production began in 1971 after the construction of a series of off-shore platforms by Phillips Petroleum Company...

 distinguished by valuable, low-sulphur oil. Commercial exploitation began in 1971 with tankers and, after 1975, by a pipeline
Pipeline transport
Pipeline transport is the transportation of goods through a pipe. Most commonly, liquids and gases are sent, but pneumatic tubes that transport solid capsules using compressed air are also used....

, first to Teesside
Teesside
Teesside is the name given to the conurbation in the north east of England made up of the towns of Middlesbrough, Stockton-on-Tees, Redcar, Billingham and surrounding settlements near the River Tees. It was also the name of a local government district between 1968 and 1974—the County Borough of...

, England and then, after 1977, also to Emden, Germany.

The exploitation of the North Sea oil reserves
Oil reserves
The total estimated amount of oil in an oil reservoir, including both producible and non-producible oil, is called oil in place. However, because of reservoir characteristics and limitations in petroleum extraction technologies, only a fraction of this oil can be brought to the surface, and it is...

 began just before the 1973 oil crisis
1973 oil crisis
The 1973 oil crisis started in October 1973, when the members of Organization of Arab Petroleum Exporting Countries or the OAPEC proclaimed an oil embargo. This was "in response to the U.S. decision to re-supply the Israeli military" during the Yom Kippur war. It lasted until March 1974. With the...

, and the climb of international oil prices made the large investments needed for extraction much more attractive.

Although the production costs are relatively high, the quality of the oil, the political stability of the region, and the nearness of important markets in western Europe
Western Europe
Western Europe is a loose term for the collection of countries in the western most region of the European continents, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a geographic entity—the region lying in the...

 has made the North Sea an important oil producing region. The largest single humanitarian catastrophe in the North Sea oil industry
Petroleum industry
The petroleum industry includes the global processes of exploration, extraction, refining, transporting , and marketing petroleum products. The largest volume products of the industry are fuel oil and gasoline...

 was the destruction of the offshore oil platform
Oil platform
An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil and natural gas, and to temporarily store product until it can be brought to shore for refining and marketing...

 Piper Alpha
Piper Alpha
Piper Alpha was a North Sea oil production platform operated by Occidental Petroleum Ltd. The platform began production in 1976, first as an oil platform and then later converted to gas production. An explosion and resulting fire destroyed it on 6 July 1988, killing 167 men, with only 61...

 in 1988 in which 167 people lost their lives.

Besides the Ekofisk oil field, the Statfjord oil field
Statfjord oil field
The Statfjord oil field is an enormous oil and gas field in the Norwegian sector of the North Sea operated by Statoil.It is a trans-median field crossing the Norwegian and UK North Sea Boundary with approximately 15% being in the UK Continental Shelf waters. At peak production it produced over of...

 is also notable as it was the cause of the first pipeline to span the Norwegian trench
Norwegian trench
The Norwegian trench or Norwegian channel is an elongated depression in the sea floor off the southern coast of Norway....

. The largest natural gas field
Natural gas field
Oil and natural gas are produced by the same geological process according fossil fuel suggestion: anaerobic decay of organic matter deep under the Earth's surface. As a consequence, oil and natural gas are often found together...

 in the North Sea, Troll gas field, lies in the Norwegian trench dropping over 300 metres (984.3 ft) requiring the construction of the enormous Troll A platform
Troll A platform
The Troll A platform is a condeep offshore natural gas platform in the Troll gas field off the west coast of Norway. It is the tallest construction that has ever been moved to another position, relative to the surface of the Earth, and is among the largest and most complex engineering projects in...

 to access it.

The price of Brent Crude
Brent Crude
Brent Crude is the biggest of the many major classifications of crude oil consisting of Brent Crude, Brent Sweet Light Crude, Oseberg, Ekofisk, and Forties . Brent Crude is sourced from the North Sea. The Brent Crude oil marker is also known as Brent Blend, London Brent and Brent petroleum...

, one of the first types of oil extracted from the North Sea, is used today as a standard price for comparison for crude oil
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 from the rest of the world. The North Sea contains western Europe's largest oil and natural gas reserves and is one of the world's key non-OPEC producing regions.

Fishing


The North Sea is Europe's main fishery accounting for over 5% of international commercial fish caught. Fishing in the North Sea is concentrated in the southern part of the coastal waters. The main method of fishing is trawling
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net that is used for trawling is called a trawl....

.
In 1995, the total volume of fish and shellfish caught in the North Sea was approximately 3.5 million tonnes. Besides fish, it is estimated that one million tonnes of unmarketable by-catch
By-catch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...

 is caught and discarded each year.

In recent decades, overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....

 has left many fisheries unproductive, disturbing marine food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...

 dynamics and costing jobs in the fishing industry
Fishing industry
The fishing industry includes any industry or activity concerned with taking, culturing, processing, preserving, storing, transporting, marketing or selling fish or fish products....

. Herring, cod and plaice fisheries may soon face the same plight as mackerel fishing, which ceased in the 1970s due to overfishing.
The objective of the European Union Common Fisheries Policy
Common Fisheries Policy
The Common Fisheries Policy is the fisheries policy of the European Union . It sets quotas for which member states are allowed to catch what amounts of each type of fish, as well as encouraging the fishing industry by various market interventions...

 is to minimize the environmental impact associated with resource use by reducing fish discards, increasing productivity of fisheries, stabilising markets of fisheries and fish processing, and supplying fish at reasonable prices for the consumer.

Mineral resources

In addition to oil, gas, and fish, the states along the North Sea also take millions of cubic metres per year of sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

 and gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

 from the ocean floor. These are used for beach nourishment
Beach nourishment
Beach nourishment— also referred to as beach replenishment—describes a process by which sediment lost through longshore drift or erosion is replaced from sources outside of the eroding beach...

, land reclamation
Land reclamation
Land reclamation, usually known as reclamation, is the process to create new land from sea or riverbeds. The land reclaimed is known as reclamation ground or landfill.- Habitation :...


and construction.
Rolled pieces of amber
Amber
Amber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...

, may be picked up on the east coast of England.

Renewable energy

Due to the strong prevailing winds
Prevailing winds
Prevailing winds are winds that blow predominantly from a single general direction over a particular point on Earth's surface. The dominant winds are the trends in direction of wind with the highest speed over a particular point on the Earth's surface. A region's prevailing and dominant winds...

, countries on the North Sea, particularly Germany and Denmark, have used the shore for wind power
Wind power
Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships....

 since the 1990s. The North Sea is the home of one of the first large-scale offshore wind farms in the world, Horns Rev 1, completed in 2002. Since then many other wind farm
Wind farm
A wind farm is a group of wind turbines in the same location used to produce electric power. A large wind farm may consist of several hundred individual wind turbines, and cover an extended area of hundreds of square miles, but the land between the turbines may be used for agricultural or other...

s have been commissioned in the North Sea (and elsewhere), including the two largest windfarms in the world as of September 2010; Thanet in the UK and Horns Rev 2 in Denmark.

The expansion of offshore wind farms has met with some resistance. Concerns have include shipping collisions and environmental effects on ocean ecology and wildlife such as fish and migratory birds, however, these concerns were found to be negligible in a long-term study in Denmark released in 2006 and again in a UK government study in 2009.
There are also concerns about reliability, and the rising costs of constructing and maintaining offshore wind farms. Despite these, development of North Sea wind power is continuing, with plans for additional wind farms off the coasts of Germany, the Netherlands, and the UK. There have also been proposals for a transnational power grid in the North Sea to connect new offshore wind farms.

Energy production from tidal power
Tidal power
Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity....

 is still in a pre-commercial stage. The European Marine Energy Centre
European Marine Energy Centre
The European Marine Energy Centre is a research centre focusing on wave and tidal power development based in the Orkney Islands, UK. It claims to provide developers with the opportunity to test full-scale grid-connected prototype devices in unrivalled wave and tidal conditions...

 has installed a wave testing system at Billia Croo on the Orkney mainland and a tidal power testing station on the nearby island of Eday
Eday
Eday is one of the Orkney Islands, which are located to the north of the Scottish mainland in the United Kingdom. Eday is located in the North Isles of Orkney, and is about north of the main island of Orkney Mainland...

. Since 2003, a prototype Wave Dragon
Wave Dragon
Wave Dragon is a floating slack-moored energy converter of the overtopping type, located in the northern Denmark. It was the world's first offshore wave energy converter...

 energy converter has been in operation at Nissum Bredning fjord of northern Denmark.

Tourism

The beaches and coastal waters of the North Sea are popular destinations for tourists. The Belgian, Dutch, German and Danish coasts are especially developed for tourism.
The North Sea Trail
North Sea Trail
The North Sea Trail is a long-distance path linking seven countries and 26 partner areas in Northern Europe around the North Sea.The project's aims are to support sustainable tourism and to explore the heritage of communities along the North Sea coast....

 is a long-distance trail
Long-distance trail
Long-distance trails are the longer recreational trails mainly through rural areas, used for non-motorised recreational travelling ....

 linking seven countries around the North Sea. Windsurfing and sailing are popular sports because of the strong winds. Mudflat hiking, recreational fishing
Fishing
Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....

 and birdwatching are among other popular activities.

The climatic conditions on the North Sea coast are often claimed to be especially healthful. As early as the 19th century, travellers used their stays on the North Sea coast as curative and restorative vacations. The sea air, temperature, wind, water, and sunshine are counted among the beneficial conditions that are said to activate the body's defences, improve circulation, strengthen the immune system, and have healing effects on the skin and the respiratory system.

Marine traffic

The North Sea is important for marine transportation and its shipping lanes are among the busiest in the world. Major ports are located along its coasts: Rotterdam
Rotterdam
Rotterdam is the second-largest city in the Netherlands and one of the largest ports in the world. Starting as a dam on the Rotte river, Rotterdam has grown into a major international commercial centre...

, The busiest port in Europe and the third busiest port in the world by tonnage , Antwerp (16th) and Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

 (27th), Bremen
Bremen
The City Municipality of Bremen is a Hanseatic city in northwestern Germany. A commercial and industrial city with a major port on the river Weser, Bremen is part of the Bremen-Oldenburg metropolitan area . Bremen is the second most populous city in North Germany and tenth in Germany.Bremen is...

/Bremerhaven
Bremerhaven
Bremerhaven is a city at the seaport of the free city-state of Bremen, a state of the Federal Republic of Germany. It forms an enclave in the state of Lower Saxony and is located at the mouth of the River Weser on its eastern bank, opposite the town of Nordenham...

 and Felixstowe
Port of Felixstowe
The Port of Felixstowe, in Felixstowe, Suffolk is the UK's busiest container port, dealing with 35% of the country's container cargo. It was developed following the abandonment of a project for a deep-water harbour at Maplin Sands. In 2005, it was ranked as the 28th busiest container port in the...

, both in the top 30 busiest container seaports, as well as the Port of Bruges-Zeebrugge, Europe's leading RoRo
RORO
Roll-on/roll-off ships are vessels designed to carry wheeled cargo such as automobiles, trucks, semi-trailer trucks, trailers or railroad cars that are driven on and off the ship on their own wheels...

 port.

Fishing boats, service boats for offshore industries, sport and pleasure craft, and merchant ships to and from North Sea ports and Baltic ports
Ports of the Baltic Sea
There are over 200 ports in the Baltic Sea. When only those ports that handle minimum of 50,000 tonnes of cargo annually, and where at least part of this cargo is international, are taken into account the number of ports reaches approximately 190. In 2008, the total amount of cargo handled in the...

 must share routes on the North Sea. The Dover Strait alone sees more than 400 commercial vessels a day. Because of this volume, navigation in the North Sea can be difficult in high traffic zones, so ports have established elaborate vessel traffic service
Vessel Traffic Service
A vessel traffic service is a marine traffic monitoring system established by harbour or port authorities, similar to air traffic control for aircraft...

s to monitor and direct ships into and out of port.

The North Sea coasts are home to numerous canals and canal systems to facilitate traffic between and among rivers, artificial harbours, and the sea. The Kiel Canal
Kiel Canal
The Kiel Canal , known as the Kaiser-Wilhelm-Kanal until 1948, is a long canal in the German state of Schleswig-Holstein.The canal links the North Sea at Brunsbüttel to the Baltic Sea at Kiel-Holtenau. An average of is saved by using the Kiel Canal instead of going around the Jutland Peninsula....

, connecting the North Sea with the Baltic Sea, is the most heavily used artificial seaway in the world reporting an average of 89 ships per day not including sporting boats and other small watercraft in 2009. It saves an average of 250 nautical miles (463 km), instead of the voyage around the Jutland Peninsula
Jutland Peninsula
The Jutland Peninsula or more historically the Cimbrian Peninsula is a peninsula in Europe, divided between Denmark and Germany. The names are derived from the Jutes and the Cimbri....

. The North Sea Canal
North Sea Canal
The North Sea Canal is a Dutch ship canal from Amsterdam to the North Sea at IJmuiden, constructed between 1865 and 1876 to enable seafaring vessels to reach the port of Amsterdam...

 connects Amsterdam
Amsterdam
Amsterdam is the largest city and the capital of the Netherlands. The current position of Amsterdam as capital city of the Kingdom of the Netherlands is governed by the constitution of August 24, 1815 and its successors. Amsterdam has a population of 783,364 within city limits, an urban population...

 with the North Sea.

See also

  • List of the largest islands in the North Sea
  • Doggerland
    Doggerland
    Doggerland is a name given by archaeologists and geologists to a former landmass in the southern North Sea that connected the island of Great Britain to mainland Europe during and after the last Ice Age, surviving until about 6,500 or 6,200 BCE, though gradually being swallowed by rising sea levels...

  • List of languages of the North Sea
  • North Sea Commission
    North Sea Commission
    The North Sea Commission is an international organization founded in 1989. It facilitates partnerships between regions connected with the North Sea and promotes the North Sea Basin as an economic entity within Europe....

  • European atlas of the seas
    European Atlas of the Seas
    The European Atlas of the Seas is an interactive electronic atlas on the coasts and seas within and around Europe. The atlas is freely accessible on the internet and is available in English, French and German...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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