The North Sea is a marginal sea of the Atlantic Ocean located between the United Kingdom, Norway, Germany, the Netherlands and France. An epeiric 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 570,000 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 has developed into a rich source of energy resources including fossil fuels and early efforts in wave power. The North Sea has featured prominently in geopolitical and military affairs in Northern Europe, it was important 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, the British each sought to dominate the North Sea and thus access to the world's markets and resources.
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 geographical features. In the north, deep fjords and sheer cliffs mark the Norwegian and Scottish coastlines, whereas in the south, the coast consists of sandy beaches and wide mudflats. Due to the dense population, heavy industrialization, intense use of the sea and area surrounding it, there have been various environmental issues affecting the sea's ecosystems. Adverse environmental issues – including overfishing and agricultural runoff 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; the North Sea is bounded by the Orkney Islands and east coast of Great Britain to the west and the northern and central European mainland to the east and south, including Norway, Germany, the Netherlands and France. In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean.
In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively. In the north it is bordered by the Shetland Islands, connects with the Norwegian Sea, which lies in the north-eastern part of the Atlantic; the North Sea is more than 970 kilometres long and 580 kilometres wide, with an area of 570,000 square kilometres and a volume of 54,000 cubic kilometres. Around the edges of the North Sea are sizeable islands and archipelagos, including Shetland and the Frisian Islands; the North Sea receives freshwater from a number of European continental watersheds, as well as the British Isles. A large part of the European drainage basin empties into the North Sea, including water from the Baltic Sea; the largest and most important rivers flowing into the North Sea are the Elbe and the Rhine – Meuse watershed. Around 185 million people live in the catchment area of the rivers discharging into the North Sea encompassing some industrialized areas.
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 has a maximum depth of 725 metres. The Dogger Bank, a vast moraine, or accumulation of unconsolidated glacial debris, rises to a mere 15 to 30 m below the surface; this feature has produced the finest fishing location of the North Sea. The Long Forties and the Broad Fourteens are large areas with uniform depth in fathoms; these great banks and others make the North Sea hazardous to navigate, alleviated by the implementation of satellite navigation systems. The Devil's Hole lies 200 miles east of Scotland; the feature is a series of asymmetrical trenches between 20 and 30 kilometres long and two kilometres wide and up to 230 metres deep. Other areas which are less deep are Fisher Bank and Noordhinder Bank; the International Hydrographic Organization defines the limits of the North Sea as follows: On the Southwest.
A line joining the Walde Lighthouse and Leathercoat Point. On the Northwest. From Dunnet Head in Scotland to Tor Ness in the Island of Hoy, thence through this island to the Kame of Hoy on to Breck Ness on Mainland through this island to Costa Head and to Inga Ness in Westray through Westray, to Bow Head, across to Mull Head and on to Seal Skerry and thence to Horse Island. On the North. From the North point of the Mainland of the Shetland Islands, across to Graveland Ness in the Island of Yell, through Yell to Gloup Ness and across to Spoo Ness in Unst island, through Unst to Herma Ness, on to the SW point of the Rumblings and to Muckle Flugga all these being included in the North Sea area.
The Atlantic Ocean is the second largest of the world's oceans, with an area of about 106,460,000 square kilometers. It covers 20 percent of the Earth's surface and about 29 percent of its water surface area, it separates the "Old World" from the "New World". The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Europe and Africa to the east, the Americas to the west; as one component of the interconnected global ocean, it is connected in the north to the Arctic Ocean, to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, the Southern Ocean in the south. The Equatorial Counter Current subdivides it into the North Atlantic Ocean and the South Atlantic Ocean at about 8°N. Scientific explorations of the Atlantic include the Challenger expedition, the German Meteor expedition, Columbia University's Lamont-Doherty Earth Observatory and the United States Navy Hydrographic Office; the oldest known mentions of an "Atlantic" sea come from Stesichorus around mid-sixth century BC: Atlantikoi pelágei and in The Histories of Herodotus around 450 BC: Atlantis thalassa where the name refers to "the sea beyond the pillars of Heracles", said to be part of the sea that surrounds all land.
Thus, on one hand, the name refers to Atlas, the Titan in Greek mythology, who supported the heavens and who appeared as a frontispiece in Medieval maps and lent his name to modern atlases. On the other hand, to early Greek sailors and in Ancient Greek mythological literature such as the Iliad and the Odyssey, this all-encompassing ocean was instead known as Oceanus, the gigantic river that encircled the world. In contrast, the term "Atlantic" referred to the Atlas Mountains in Morocco and the sea off the Strait of Gibraltar and the North African coast; the Greek word thalassa has been reused by scientists for the huge Panthalassa ocean that surrounded the supercontinent Pangaea hundreds of millions of years ago. The term "Aethiopian Ocean", derived from Ancient Ethiopia, was applied to the Southern Atlantic as late as the mid-19th century. During the Age of Discovery, the Atlantic was known to English cartographers as the Great Western Ocean; the term The Pond is used by British and American speakers in context to the Atlantic Ocean, as a form of meiosis, or sarcastic understatement.
The term dates to as early as 1640, first appearing in print in pamphlet released during the reign of Charles I, reproduced in 1869 in Nehemiah Wallington's Historical Notices of Events Occurring Chiefly in The Reign of Charles I, where "great Pond" is used in reference to the Atlantic Ocean by Francis Windebank, Charles I's Secretary of State. The International Hydrographic Organization defined the limits of the oceans and seas in 1953, but some of these definitions have been revised since and some are not used by various authorities and countries, see for example the CIA World Factbook. Correspondingly, the extent and number of oceans and seas varies; the Atlantic Ocean is bounded on the west by South America. It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea and Barents Sea. To the east, the boundaries of the ocean proper are Europe: the Strait of Africa. In the southeast, the Atlantic merges into the Indian Ocean; the 20° East meridian, running south from Cape Agulhas to Antarctica defines its border.
In the 1953 definition it extends south to Antarctica, while in maps it is bounded at the 60° parallel by the Southern Ocean. The Atlantic has irregular coasts indented by numerous bays and seas; these include the Baltic Sea, Black Sea, Caribbean Sea, Davis Strait, Denmark Strait, part of the Drake Passage, Gulf of Mexico, Labrador Sea, Mediterranean Sea, North Sea, Norwegian Sea all of the Scotia Sea, other tributary water bodies. Including these marginal seas the coast line of the Atlantic measures 111,866 km compared to 135,663 km for the Pacific. Including its marginal seas, the Atlantic covers an area of 106,460,000 km2 or 23.5% of the global ocean and has a volume of 310,410,900 km3 or 23.3% of the total volume of the earth's oceans. Excluding its marginal seas, the Atlantic covers 81,760,000 km2 and has a volume of 305,811,900 km3; the North Atlantic covers 41,490,000 km2 and the South Atlantic 40,270,000 km2. The average depth is 3,646 m and the maximum depth, the Milwaukee Deep in the Puerto Rico Trench, is 8,486 m.
The bathymetry of the Atlantic is dominated by a submarine mountain range called the Mid-Atlantic Ridge. It runs from 87°N or 300 km south of the North Pole to the subantarctic Bouvet Island at 42°S; the MAR divides the Atlantic longitudinally into two halves, in each of which a series of basins are delimited by secondary, transverse ridges. The MAR reaches above 2,000 m along most of its length, but is interrupted by larger transform faults at two places: the Romanche Trench near the Equator and the Gibbs Fracture Zone at 53°N; the MAR is a barrier for bottom water, but at these two transform faults deep water currents can pass from one side to the othe
The Baltic Sea is a marginal sea of the Atlantic Ocean, enclosed by Denmark, Finland, Lithuania, northeast Germany, Poland and the North and Central European Plain. The sea stretches from 53 ° N from 10 ° E to 30 ° E longitude. A mediterranean sea of the Atlantic, with limited water exchange between the two bodies, the Baltic Sea drains through the Danish islands into the Kattegat by way of the straits of Øresund, the Great Belt, the Little Belt, it includes the Gulf of Bothnia, the Bay of Bothnia, the Gulf of Finland, the Gulf of Riga, the Bay of Gdańsk. The Baltic Proper is bordered on its northern edge, at the latitude 60°N, by the Åland islands and the Gulf of Bothnia, on its northeastern edge by the Gulf of Finland, on its eastern edge by the Gulf of Riga, in the west by the Swedish part of the southern Scandinavian Peninsula; the Baltic Sea is connected by artificial waterways to the White Sea via the White Sea Canal and to the German Bight of the North Sea via the Kiel Canal. Administration The Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea Area includes the Baltic Sea and the Kattegat, without calling Kattegat a part of the Baltic Sea, "For the purposes of this Convention the'Baltic Sea Area' shall be the Baltic Sea and the Entrance to the Baltic Sea, bounded by the parallel of the Skaw in the Skagerrak at 57°44.43'N."Traffic history Historically, the Kingdom of Denmark collected Sound Dues from ships at the border between the ocean and the land-locked Baltic Sea, in tandem: in the Øresund at Kronborg castle near Helsingør.
The narrowest part of Little Belt is the "Middelfart Sund" near Middelfart. Oceanography Geographers agree that the preferred physical border of the Baltic is a line drawn through the southern Danish islands, Drogden-Sill and Langeland; the Drogden Sill is situated north of Køge Bugt and connects Dragør in the south of Copenhagen to Malmö. By this definition, the Danish Straits are part of the entrance, but the Bay of Mecklenburg and the Bay of Kiel are parts of the Baltic Sea. Another usual border is the line between Falsterbo and Stevns Klint, Denmark, as this is the southern border of Øresund. It's the border between the shallow southern Øresund and notably deeper water. Hydrography and biology Drogden Sill sets a limit to Øresund and Darss Sill, a limit to the Belt Sea; the shallow sills are obstacles to the flow of heavy salt water from the Kattegat into the basins around Bornholm and Gotland. The Kattegat and the southwestern Baltic Sea have a rich biology; the remainder of the Sea is poor in oxygen and in species.
Thus, the more of the entrance, included in its definition, the healthier the Baltic appears. Tacitus called it Mare Suebicum after the Germanic people of the Suebi, Ptolemy Sarmatian Ocean after the Sarmatians, but the first to name it the Baltic Sea was the eleventh-century German chronicler Adam of Bremen; the origin of the latter name is speculative and it was adopted into Slavic and Finnic languages spoken around the sea likely due to the role of Medieval Latin in cartography. It might be connected to the Germanic word belt, a name used for two of the Danish straits, the Belts, while others claim it to be directly derived from the source of the Germanic word, Latin balteus "belt". Adam of Bremen himself compared the sea with a belt, stating that it is so named because it stretches through the land as a belt, he might have been influenced by the name of a legendary island mentioned in the Natural History of Pliny the Elder. Pliny mentions an island named Baltia with reference to accounts of Xenophon.
It is possible. Baltia might be derived from belt and mean "near belt of sea, strait." Meanwhile, others have suggested that the name of the island originates from the Proto-Indo-European root *bhel meaning "white, fair". This root and its basic meaning were retained in both Latvian. On this basis, a related hypothesis holds that the name originated from this Indo-European root via a Baltic language such as Lithuanian. Another explanation is that, while derived from the aforementioned root, the name of the sea is related to names for various forms of water and related substances in several European languages, that might have been associated with colors found in swamps, yet another explanation is that the name meant "enclosed sea, bay" as opposed to open sea. Some Swedish historians believe. In the Middle Ages the sea was known by a variety of names; the name Baltic Sea became dominant only after 1600. Usage of Baltic and similar terms to denote the region east of the sea started only in 19th century.
The Baltic Sea was known in ancient Latin language sources as Mare Suebicum or Mare Germanicum. Older native names in languages that used to be spoken on the shores of the sea or near it indicate the geographical location of the sea, or its size in relation to smaller gulfs, or tribes associated with it. In modern lang
Sweden the Kingdom of Sweden, is a Scandinavian Nordic country in Northern Europe. It borders Norway to the west and north and Finland to the east, is connected to Denmark in the southwest by a bridge-tunnel across the Öresund, a strait at the Swedish-Danish border. At 450,295 square kilometres, Sweden is the largest country in Northern Europe, the third-largest country in the European Union and the fifth largest country in Europe by area. Sweden has a total population of 10.2 million. It has a low population density of 22 inhabitants per square kilometre; the highest concentration is in the southern half of the country. Germanic peoples have inhabited Sweden since prehistoric times, emerging into history as the Geats and Swedes and constituting the sea peoples known as the Norsemen. Southern Sweden is predominantly agricultural, while the north is forested. Sweden is part of the geographical area of Fennoscandia; the climate is in general mild for its northerly latitude due to significant maritime influence, that in spite of this still retains warm continental summers.
Today, the sovereign state of Sweden is a constitutional monarchy and parliamentary democracy, with a monarch as head of state, like its neighbour Norway. The capital city is Stockholm, the most populous city in the country. Legislative power is vested in the 349-member unicameral Riksdag. Executive power is exercised by the government chaired by the prime minister. Sweden is a unitary state divided into 21 counties and 290 municipalities. An independent Swedish state emerged during the early 12th century. After the Black Death in the middle of the 14th century killed about a third of the Scandinavian population, the Hanseatic League threatened Scandinavia's culture and languages; this led to the forming of the Scandinavian Kalmar Union in 1397, which Sweden left in 1523. When Sweden became involved in the Thirty Years War on the Reformist side, an expansion of its territories began and the Swedish Empire was formed; this became one of the great powers of Europe until the early 18th century. Swedish territories outside the Scandinavian Peninsula were lost during the 18th and 19th centuries, ending with the annexation of present-day Finland by Russia in 1809.
The last war in which Sweden was directly involved was in 1814, when Norway was militarily forced into personal union. Since Sweden has been at peace, maintaining an official policy of neutrality in foreign affairs; the union with Norway was peacefully dissolved in 1905. Sweden was formally neutral through both world wars and the Cold War, albeit Sweden has since 2009 moved towards cooperation with NATO. After the end of the Cold War, Sweden joined the European Union on 1 January 1995, but declined NATO membership, as well as Eurozone membership following a referendum, it is a member of the United Nations, the Nordic Council, the Council of Europe, the World Trade Organization and the Organisation for Economic Co-operation and Development. Sweden maintains a Nordic social welfare system that provides universal health care and tertiary education for its citizens, it has the world's eleventh-highest per capita income and ranks in numerous metrics of national performance, including quality of life, education, protection of civil liberties, economic competitiveness, equality and human development.
The name Sweden was loaned from Dutch in the 17th century to refer to Sweden as an emerging great power. Before Sweden's imperial expansion, Early Modern English used Swedeland. Sweden is derived through back-formation from Old English Swēoþēod, which meant "people of the Swedes"; this word is derived from Sweon/Sweonas. The Swedish name Sverige means "realm of the Swedes", excluding the Geats in Götaland. Variations of the name Sweden are used in most languages, with the exception of Danish and Norwegian using Sverige, Faroese Svøríki, Icelandic Svíþjóð, the more notable exception of some Finnic languages where Ruotsi and Rootsi are used, names considered as referring to the people from the coastal areas of Roslagen, who were known as the Rus', through them etymologically related to the English name for Russia; the etymology of Swedes, thus Sweden, is not agreed upon but may derive from Proto-Germanic Swihoniz meaning "one's own", referring to one's own Germanic tribe. Sweden's prehistory begins in the Allerød oscillation, a warm period around 12,000 BC, with Late Palaeolithic reindeer-hunting camps of the Bromme culture at the edge of the ice in what is now the country's southernmost province, Scania.
This period was characterised by small bands of hunter-gatherer-fishers using flint technology. Sweden is first described in a written source in Germania by Tacitus in 98 AD. In Germania 44 and 45 he mentions the Swedes as a powerful tribe with ships that had a prow at each end. Which kings ruled these Suiones is unknown, but Norse mythology presents a long line of legendary and semi-legendary kings going back to the last centuries BC; as for literacy in Sweden itself, the runic script was in use among the south Scandinavian elite by at least the 2nd century AD, but all that has come down to the present from the Roman Period is curt inscriptions on artefacts of male names, demonstrating th
Uddevalla is a town and the seat of Uddevalla Municipality in Västra Götaland County, Sweden. In 2010, it had a population of 31,212, it is located at a bay of the south-eastern part of Skagerrak. The beaches of Uddevalla are filled with seashells and Uddevalla has one of the largest shell-banks in the world. Uddevalla has a port and it once had a large shipyard, the Uddevallavarvet, the largest employer in Bohuslän during the 1960s; the 1970s recession, that affected the Swedish shipyard industry led to the closing of the wharf in 1985. Uddevalla received its town privileges in 1498, but it was a place for trade long before that. Uddevalla belonged to Norway, its name today comes from the original Norwegian Oddevald. Due to its close location to Sweden and Denmark, it was besieged. In 1612, it was burnt down by Swedish troops led by Jesper Mattson Krus and in 1644, it was once again burnt down, this time by Swedish commander Harald Stake. In 1658, it was ceded to Sweden at the treaty of Roskilde.
The Norwegians recaptured the town a year and in 1660, it was once again ceded to Sweden at the peace treaty of Copenhagen. Norway annexed Uddevalla and the nearby fortress on the Galleberg the last time in 1788. In the 18th and 19th century, Uddevalla's main source of income was herring fishing; the town was noted for the great fires that damaged the city on several occasions. The most devastating fire was in 1806. Only four houses were left untouched and 4,000 people became homeless. During the 19th century, Uddevalla had trouble getting out of its own recession and alcoholism were widespread among the population; the reasons were the aftermath of the fire in 1806, the decrease in herring fishing and the opening of the Trollhätte Canal. In 1870–80, Uddevalla began to attract new industries. Much of that development can be attributed to the Scottish businessman William Thorburn, said to have been amazed by the town's beauty and therefore settled down in Uddevalla with his wife Jessy Macfie in 1822.
He founded a number of industries, starting with textile companies. The building of a new railroad, the Bohus Line contributed to the town's recovering economy. A prominent person in Uddevalla's history was Ture Malmgren, newspaper publisher and progressive liberal politician. During the 1958 FIFA World Cup, Uddevalla was one of twelve Swedish towns to host matches, which were played at the Rimnersvallen stadium. After the Swedish shipyard crisis during the 1980s, resulting in the closing of the Uddevallavarvet, Uddevalla suffered an economic setback. Over the thirty years following that, the town has recovered and the population is once again increasing but steadily. All the high schools in Uddevalla are administered as one school, the Uddevalla Gymnasieskola, now the largest high school in Sweden; the school has 4,000 students attending the following branches of the high school: Agneberg – Social studies Sinclair – The arts and Media studies Östrabo 1 – Science studies Östrabo Y – Heavy industry schooling Margretegärde – Social studies and Science studiesThere are many primary schools in Uddevalla, some of them are: Äsperödskolan Västerskolan Fridaskolan Ramnerödsskolan Norgårdenskolan Norrskolan Sommarhemsskolan Agnebergshallen is an indoor sports arena for various sports including handball.
The home ground for the IK Oddevold is the outdoor arena Rimnersvallen. A large indoor arena, the Rimnershallen, is next to the Rimnersvallen, it is used for floorball as well as other sports. The following sports clubs are located in Uddevalla: IK Oddevold IFK Uddevalla IFK Lane Herrestad AIF Ik Rösso Uddevalla HC GF Kroppskultur Uddevalla HK Walkesborg 99 Herrestad AIF IFK Uddevalla Futsal Swedish Championship gold season 2016/2017. IK Oddevold Futsal Uddevalla is twinned with: Thisted, Denmark Skien, Norway Loimaa, Finland Mosfellsbær, Iceland Okazaki, Japan Irvine, United Kingdom Jõhvi, Estonia Fjällhyddan Tureborg Castle Ture Valleys Jeanna Oterdahl Eastern Cemetery Uddevalla Suffrage Association Bibliography This article contains content from the Owl Edition of Nordisk familjebok, a Swedish encyclopedia published between 1904 and 1926, now in the public domain. Nationalencyklopedin Article Uddevalla, from NF Uddevalla Gymnasieskola Official site for Uddevalla Gymnasieskola Official website of Uddevalla
Brackish water is water having more salinity than freshwater, but not as much as seawater. It may result from mixing seawater with fresh water together, as in estuaries, or it may occur in brackish fossil aquifers; the word comes from the Middle Dutch root "brak". Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is the primary waste product of the salinity gradient power process; because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment. Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more expressed as 0.5 to 30 parts per thousand, a specific gravity of between 1.005 and 1.010. Thus, brackish covers a range of salinity regimes and is not considered a defined condition, it is characteristic of many brackish surface waters that their salinity can vary over space or time.
Brackish water condition occurs when fresh water meets seawater. In fact, the most extensive brackish water habitats worldwide are estuaries, where a river meets the sea; the River Thames flowing through London is a classic river estuary. The town of Teddington a few miles west of London marks the boundary between the tidal and non-tidal parts of the Thames, although it is still considered a freshwater river about as far east as Battersea insofar as the average salinity is low and the fish fauna consists predominantly of freshwater species such as roach, carp and pike; the Thames Estuary becomes brackish between Battersea and Gravesend, the diversity of freshwater fish species present is smaller roach and dace. Further east, the salinity increases and the freshwater fish species are replaced by euryhaline marine ones, until the river reaches Gravesend, at which point conditions become marine and the fish fauna resembles that of the adjacent North Sea and includes both euryhaline and stenohaline marine species.
A similar pattern of replacement can be observed with the aquatic plants and invertebrates living in the river. This type of ecological succession from a freshwater to marine ecosystem is typical of river estuaries. River estuaries form important staging points during the migration of anadromous and catadromous fish species, such as salmon and eels, giving them time to form social groups and to adjust to the changes in salinity. Salmon are anadromous, meaning they ascend rivers to spawn. Besides the species that migrate through estuaries, there are many other fish that use them as "nursery grounds" for spawning or as places young fish can feed and grow before moving elsewhere. Herring and plaice are two commercially important species that use the Thames Estuary for this purpose. Estuaries are commonly used as fishing grounds, as places for fish farming or ranching. For example, Atlantic salmon farms are located in estuaries, although this has caused controversy, because in doing so, fish farmers expose migrating wild fish to large numbers of external parasites such as sea lice that escape from the pens the farmed fish are kept in.
Another important brackish water habitat is the mangrove mangal. Many, though not all, mangrove swamps fringe estuaries and lagoons where the salinity changes with each tide. Among the most specialised residents of mangrove forests are mudskippers, fish that forage for food on land, archer fish, perch-like fish that "spit" at insects and other small animals living in the trees, knocking them into the water where they can be eaten. Like estuaries, mangrove swamps are important breeding grounds for many fish, with species such as snappers and tarpon spawning or maturing among them. Besides fish, numerous other animals use mangroves, including such species as the saltwater crocodile, American crocodile, proboscis monkey, diamondback terrapin, the crab-eating frog, Fejervarya cancrivora. Mangroves represent important nesting site for numerous birds groups such as herons, spoonbills, kingfishers and seabirds. Although plagued with mosquitoes and other insects that make them unpleasant for humans, mangrove swamps are important buffer zones between land and sea, are a natural defense against hurricane and tsunami damage in particular.
The Sundarbans and Bhitarkanika Mangroves are two of the large mangrove forests in the world, both on the coast of the Bay of Bengal. Some seas and lakes are brackish; the Baltic Sea is a brackish sea adjoining the North Sea. The confluence of two major river systems prior to the Pleistocene, since it has been flooded by the North Sea but still receives so much freshwater from the adjacent lands that the water is brackish; because the salt water coming in from the sea is denser than freshwater, the water in the Baltic is stratified, with salt water at the bottom and freshwater at the top. Limited mixing occurs because of the lack of tides and storms, with the result that the fish fauna at the surface is freshwater in composition while that lower down is more marine. Cod are an example of a species only found in deep water in the Baltic, while pike are confined to the less saline surface waters; the Caspian Sea is the world's largest lake and contains brackish water with a salinity about one-third that of normal seawater.
The Caspian is famous for its peculiar animal fauna, including one of