The North Sea
The North Sea is a marginal sea of the Atlantic Ocean located between Great Britain, Scandinavia, Germany, the Netherlands, Belgium, and France. An epeiric (or "shelf") sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north. It is more than 970 kilometres long and 580 kilometres wide, with an area of around 750,000 square kilometres.
The North Sea has long been the site of important European shipping lanes as well as a major fishery. The sea is a popular destination for recreation and tourism in bordering countries and more recently has developed into a rich source of energy resources including fossil fuels, wind, and early efforts in wave power.
Historically, the North Sea has featured prominently in geopolitical and military affairs, particularly in Northern Europe but also globally through the power northern Europeans projected worldwide during much of the Middle Ages and into the modern era. The North Sea was the centre of the Vikings´ rise. Subsequently, the Hanseatic League, the Netherlands, and the British each sought to dominate the North Sea and thus the access to the markets and resources of the world. As Germany´s only outlet to the ocean, the North Sea continued to be strategically important through both World Wars.
The coast of the North Sea presents a diversity of geological and geographical features. In the north, deep fjords and sheer cliffs mark the Norwegian and Scottish coastlines, whereas in the south it consists primarily of sandy beaches and wide mudflats. Due to the dense population, heavy industrialization, and intense use of the sea and area surrounding it, there have been a number of environmental issues affecting the sea´s ecosystems. Environmental concerns - commonly including overfishing, industrial and agricultural runoff, dredging, and dumping among others - have led to a number of efforts to prevent degradation of the sea while still making use of its economic potential.
For the most part, the sea lies on the European continental shelf with a mean depth of 90 metres. The only exception is the Norwegian trench, which extends parallel to the Norwegian shoreline from Oslo to an area north of Bergen. It is between 20 and 30 kilometres wide and has a maximum depth of 725 metres. The Norwegian mountains plunge into the sea creating deep fjords and archipelagos. South of Stavanger, the coast softens, the islands become fewer.
Copepods and other zooplankton are plentiful in the North Sea. These tiny organisms are crucial elements of the food chain supporting many species of fish. Over 230 species of fish live in the North Sea. Cod, haddock, saithe, mackerel, whiting, plaice, sole, herring, 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 reside only in small areas of the North Sea.
Crustaceans are also commonly found throughout the sea. Norway lobster, deep-water prawns, and brown shrimp are all commercially fished, but other species of lobster, prawn, oyster, mussels and clams all live in the North Sea. Recently non-indigenous species have become established including the Pacific oyster and Atlantic jackknife clam.
As early as 1859, oil was discovered in onshore areas around the North Sea and natural gas as early as 1910. Test drilling began in 1966 and then, in 1969, Phillips Petroleum Company discovered the Ekofisk oil field distinguished by valuable, low-sulphur oil. Commercial exploitation began in 1971 with tankers and, after 1975, by a pipeline, first to Teesside, England and then, after 1977, also to Emden, Germany.
The exploitation of the North Sea oil reserves began just before the 1973 oil crisis, 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 has made the North Sea an important oil producing region. Besides the Ekofisk oil field, the Statfjord oil field is also notable as it was the cause of the first pipeline to span the Norwegian trench.
The largest natural gas field in the North Sea, Troll gas field, lies in the Norwegian trench dropping over 300 metres requiring the construction of the enormous Troll A platform to access it.
The price of Brent Crude, one of the first types of oil extracted from the North Sea, is used today as a standard price for comparison for crude oil 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.