127-751: The River Greet is a small river in Nottinghamshire , England . Rising close to the village of Kirklington , the Greet flows in a southeasterly direction past Southwell and Rolleston to meet the River Trent at Fiskerton . The river has a catchment of 17.85 square miles (46.2 km) and an average flow of 6.08 million gallons (27.65 Megalitres) per day, measured at the gauging station in Southwell. The catchment receives 25.47 inches (647 mm) of rainfall in an average year. Above Southwell,
254-582: A lake , an ocean , or another river. A stream refers to water that flows in a natural channel , a geographic feature that can contain flowing water. A stream may also be referred to as a watercourse. The study of the movement of water as it occurs on Earth is called hydrology , and their effect on the landscape is covered by geomorphology . Rivers are part of the water cycle , the continuous processes by which water moves about Earth. This means that all water that flows in rivers must ultimately come from precipitation . The sides of rivers have land that
381-502: A riverine ecotype called river trout or Salmo trutta morpha fario ; a lacustrine ecotype or S. trutta morpha lacustris , also called the lake trout (not to be confused with the lake trout in North America ); and anadromous populations known as the sea trout or S. trutta morpha trutta , which upon adulthood migrate downstream to the oceans for much of its life and only returns to fresh water to spawn in
508-547: A trip hammer , and grind grains with a millstone . In the Middle Ages , water mills began to automate many aspects of manual labor , and spread rapidly. By 1300, there were at least 10,000 mills in England alone. A medieval watermill could do the work of 30–60 human workers. Water mills were often used in conjunction with dams to focus and increase the speed of the water. Water wheels continued to be used up to and through
635-740: A boat along certain stretches. In these religions, such as that of the Altai in Russia , the river is considered a living being that must be afforded respect. Rivers are some of the most sacred places in Hinduism. There is archeological evidence that mass ritual bathing in rivers at least 5,000 years ago in the Indus river valley . While most rivers in India are revered, the Ganges is most sacred. The river has
762-515: A central role in various Hindu myths, and its water is said to have properties of healing as well as absolution from sins. Hindus believe that when the cremated remains of a person is released into the Ganges, their soul is released from the mortal world. Freshwater fish make up 40% of the world's fish species, but 20% of these species are known to have gone extinct in recent years. Human uses of rivers make these species especially vulnerable. Dams and other engineered changes to rivers can block
889-408: A continuous flow of water throughout the year. This may be because an arid climate is too dry depending on the season to support a stream, or because a river is seasonally frozen in the winter (such as in an area with substantial permafrost ), or in the headwaters of rivers in mountains, where snowmelt is required to fuel the river. These rivers can appear in a variety of climates, and still provide
1016-525: A favoured target for fly fishing . Sea trout are fished for especially at night using wet flies . Brown trout can be caught with lures such as spoons, spinners, jigs, plugs, plastic worm imitations, and live or dead baitfish . Brown trout rarely form hybrids with other species; if they do, they are almost invariably infertile. One such example is the tiger trout , a hybrid with the brook trout . Field studies have demonstrated that brown trout fed on several animal prey species, aquatic invertebrates being
1143-520: A fleet of barges in the 1580s, and delivered coal to Southwell, which Caffyn has taken to mean that the river was navigable for the first 4 miles (6.4 km) to enable this to happen. Those who lived beside the river had a responsibility to keep it scoured, and on 13 July 1642 the residents of Rolleston, Southwell and Upton were indicted for not carrying out this duty. The upper reaches of the river contain fish such as brown trout ( Salmo trutta ), but although coarse fish species can be found lower down,
1270-564: A habitat for aquatic life and perform other ecological functions. Subterranean rivers may flow underground through flooded caves. This can happen in karst systems, where rock dissolves to form caves. These rivers provide a habitat for diverse microorganisms and have become an important target of study by microbiologists . Other rivers and streams have been covered over or converted to run in tunnels due to human development. These rivers do not typically host any life, and are often used only for stormwater or flood control. One such example
1397-495: A large scale. This has been attributed to unusually large floods destroying infrastructure; however, there is evidence that permanent changes to climate causing higher aridity and lower river flow may have been the determining factor in what river civilizations succeeded or dissolved. Water wheels began to be used at least 2,000 years ago to harness the energy of rivers. Water wheels turn an axle that can supply rotational energy to move water into aqueducts , work metal using
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#17327939012121524-501: A lighter golden cast with some red spotting and fewer dark spots. Notably, both strains can show considerable individual variation from this general description. Early stocking efforts in the United States used fish taken from Scotland and Germany . The brown trout is a medium-sized fish, growing to 20 kg (44 lb) or more and a length of about 100 cm (39 in) in some localities, although in many smaller rivers,
1651-652: A marked reduction in intraspecific competition in the fish population, facilitating the partitioning of resources. First feeding of newly emerged fry is very important for brown trout survival in this phase of the lifecycle, and first feeding can occur even prior to emergence. Fry start to feed before complete yolk absorption and the diet composition of newly emerged brown trout is composed of small prey such as chironomid larvae or baetid nymphs. The species has been widely introduced for sport fishing into North America , South America , Australia , New Zealand , and many other countries, including Bhutan , where they are
1778-526: A mature weight of 1.0 kg (2.2 lb) or less is common. S. t. lacustris reaches an average length of 40–80 cm (16–31 in) with a maximum length of 140 cm (55 in) and about 60 pounds (27 kg). On September 11, 2009, a 41.45-lb (18.80-kg) brown trout was caught by Tom Healy in the Manistee River system in Michigan, setting a new state record. As of late December 2009,
1905-556: A peak in the 1970s, when between two or three dams were completed every day, and has since begun to decline. New dam projects are primarily focused in China , India , and other areas in Asia . The first civilizations of Earth were born on floodplains between 5,500 and 3,500 years ago. The freshwater, fertile soil, and transportation provided by rivers helped create the conditions for complex societies to emerge. Three such civilizations were
2032-580: A popular game fish of European anglers for centuries. It was first mentioned in angling literature as "fish with speckled skins" by Roman author Aelian ( circa 200 AD) in On the Nature of Animals . This work is credited with describing the first instance of fly fishing for trout, the trout being the brown trout found in Macedonia. The Treatyse of Fysshynge with an Angle (1496) by Dame Juliana Berners , O.S.B
2159-421: A reduction in dissolved oxygen levels which can cause "summer kills" of local populations if temperatures remain high for sufficient duration and deeper/cooler or fast, turbulent more oxygenated water is not accessible to the fish. This phenomenon can be further exacerbated by eutrophication of rivers due to pollution —often from the use of agricultural fertilizers within the drainage basin . Overfishing
2286-891: A ritualistic sense has been compared to the Christian ritual of baptism , famously the Baptism of Jesus in the Jordan River . Floods also appear in Norse mythology , where the world is said to emerge from a void that eleven rivers flowed into. Aboriginal Australian religion and Mesoamerican mythology also have stories of floods, some of which contain no survivors, unlike the Abrahamic flood. Along with mythological rivers, religions have also cared for specific rivers as sacred rivers. The Ancient Celtic religion saw rivers as goddesses. The Nile had many gods attached to it. The tears of
2413-425: A river can take several forms. Tidal rivers (often part of an estuary ) have their levels rise and fall with the tide . Since the levels of these rivers are often already at or near sea level, the flow of alluvium and the brackish water that flows in these rivers may be either upriver or downriver depending on the time of day. Rivers that are not tidal may form deltas that continuously deposit alluvium into
2540-460: A section of the river behind them into a lake or reservoir. This can provide nearby cities with a predictable supply of drinking water. Hydroelectricity is desirable as a form of renewable energy that does not require any inputs beyond the river itself. Dams are very common worldwide, with at least 75,000 higher than 6 feet (1.8 m) in the U.S. Globally, reservoirs created by dams cover 193,500 square miles (501,000 km ). Dam-building reached
2667-564: A slender body with a long, narrow head. The mouth is large, and on its roof, vomerine teeth are developed in a zig-zag pattern. The caudal fin is deltaform without forking, unlike that of the related Atlantic salmon ( Salmo salar ). Dark and red spots are often present on the sides, but do not extend to the tail. Parr trout (juvenile) often have a red margin on their adipose fin , with dark blotches along their sides that also become inconspicuous with age. Freshwater brown trout range in colour from largely silver with relatively few spots and
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#17327939012122794-438: A water body is that body's riparian zone . Plants in the riparian zone of a river help stabilize its banks to prevent erosion and filter alluvium deposited by the river on the shore, including processing the nitrogen and other nutrients it contains. Forests in a riparian zone also provide important animal habitats . River ecosystems have also been categorized based on the variety of aquatic life they can sustain, also known as
2921-625: A water cycle that involved precipitation. The term flumen , in planetary geology , refers to channels on Saturn 's moon Titan that may carry liquid. Titan's rivers flow with liquid methane and ethane . There are river valleys that exhibit wave erosion , seas, and oceans. Scientists hope to study these systems to see how coasts erode without the influence of human activity, something that isn't possible when studying terrestrial rivers. Brown trout Salmo trutta morpha trutta Salmo trutta morpha fario Salmo trutta morpha lacustris The brown trout ( Salmo trutta )
3048-413: A white belly, to the more well-known brassy reddish-brown cast fading to creamy white on the fish's belly, with medium-sized spots surrounded by lighter halos. The more silver forms can be mistaken for rainbow trout. Regional variants include the so-called "Loch Leven" trout, distinguished by larger fins, a slimmer body, and heavy black spotting, but lacking red spots. The continental European strain features
3175-555: Is a grade II listed structure. The river continues under the Nottingham to Lincoln Line close to Rolleston railway station , to reach Fiskerton Mill, built on the site of a medieval mill owned by the monks of Thurgaton Priory. Just beyond the mill, it passes under a minor road and into the River Trent . There was some sort of dispute in 1598, when the millers from Fiskerton, Rolleston and Upton went to Newark to collect corn for milling. They were detained, with their horses taken to
3302-445: Is a tributary , and the place they meet is a confluence . Rivers must flow to lower altitudes due to gravity . The bed of a river is typically within a river valley between hills or mountains . Rivers flowing through an impermeable section of land such as rocks will erode the slopes on the sides of the river. When a river carves a plateau or a similar high-elevation area, a canyon can form, with cliffs on either side of
3429-713: Is a 97-centimetre (38 in) fish caught in Milwaukee Harbor, Wisconsin on 16 December 2011. The spawning behaviour of brown trout is similar to that of the closely related Atlantic salmon . A typical female produces about 2,000 eggs per kg (900 eggs per lb) of body weight at spawning. Brown trout can live 20 years, but as with the Atlantic salmon, a high proportion of males die after spawning, and probably fewer than 20% of anadromous female kelts recover from spawning . The migratory forms grow to significantly larger sizes for their age due to abundant forage fish in
3556-590: Is a fish that feeds clean and purely, in the swiftest streams, and on the hardest gravel; and that he may justly contend with all fresh water fish, as the Mullet may with all sea fish, for precedency and daintiness of taste; and that being in right season, the most dainty palates have allowed precedency to him. Throughout the 17th, 18th, and 19th centuries, angling authors, mostly British, some French, and later American, writing about trout fishing were writing about fishing for brown trout. Once brown trout were introduced into
3683-519: Is a natural freshwater stream that flows on land or inside caves towards another body of water at a lower elevation , such as an ocean , lake , or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle , the processes by which water moves around the Earth. Water first enters rivers through precipitation , whether from rainfall,
3810-427: Is a problem where anglers fail to identify and return mature female fish into the lake or stream. Each large female removed can result in thousands fewer eggs released back into the system when the remaining fish spawn. In small streams, brown trout are important predators of macroinvertebrates , and declining brown trout populations in these specific areas affect the entire aquatic food web . Global climate change
3937-452: Is a species of salmonid ray-finned fish and the most widely distributed species of the genus Salmo , endemic to most of Europe , West Asia and parts of North Africa , and has been widely introduced globally as a game fish , even becoming one of the world's worst invasive species outside of its native range . Brown trout are highly adaptable and have evolved numerous ecotypes / subspecies . These include three main ecotypes:
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4064-504: Is also important for the lumber industry , as logs can be shipped via river. Countries with dense forests and networks of rivers like Sweden have historically benefited the most from this method of trade. The rise of highways and the automobile has made this practice less common. One of the first large canals was the Canal du Midi , connecting rivers within France to create a path from
4191-487: Is also of concern. S. trutta morpha fario prefers well-oxygenated water in the temperature range of 60 to 65 °F (16 to 18 °C). S. trutta bones from an archaeological site in Italy, and ancient DNA extracted from some of these bones, indicate that both abundance and genetic diversity increased markedly during the colder Younger Dryas period, and fell during the warmer Bølling-Allerød event. Cover or structure
4318-564: Is an ancient dam built on the Nile 4,500 years ago. The Ancient Roman civilization used aqueducts to transport water to urban areas . Spanish Muslims used mills and water wheels beginning in the seventh century. Between 130 and 1492, larger dams were built in Japan, Afghanistan, and India, including 20 dams higher than 15 metres (49 ft). Canals began to be cut in Egypt as early as 3000 BC, and
4445-448: Is at a higher elevation than the river itself, and in these areas, water flows downhill into the river. The headwaters of a river are the smaller streams that feed a river, and make up the river's source. These streams may be small and flow rapidly down the sides of mountains . All of the land uphill of a river that feeds it with water in this way is in that river's drainage basin or watershed. A ridge of higher elevation land
4572-405: Is because any natural impediment to the flow of the river may cause the current to deflect in a different direction. When this happens, the alluvium carried by the river can build up against this impediment, redirecting the course of the river. The flow is then directed against the opposite bank of the river, which will erode into a more concave shape to accommodate the flow. The bank will still block
4699-456: Is considered a foundational work in the history of recreational fishing , especially fly fishing. One of the most prominent fish described in the work is the brown trout of English rivers and streams: The trout, because he is a right dainty fish and also a right fervent biter, we shall speak of next. He is in season from March until Michaelmas. He is on clean gravel bottom and in a stream. The renowned The Compleat Angler (1653) by Izaak Walton
4826-453: Is correlated with and thus can be used to predict certain data points related to rivers, such as the size of the drainage basin (drainage area), and the length of the channel. The ecosystem of a river includes the life that lives in its water, on its banks, and in the surrounding land. The width of the channel of a river, its velocity, and how shaded it is by nearby trees. Creatures in a river ecosystem may be divided into many roles based on
4953-454: Is important to trout, and they are more likely to be found near submerged rocks and logs, undercut banks, and overhanging vegetation. Structure provides protection from predators, bright sunlight, and higher water temperatures. Access to deep water for protection in winter freezes, or fast water for protection from low oxygen levels in summer are also ideal. Trout are more often found in heavy and strong currents. Defining characteristics include
5080-497: Is in part because of a projected loss of snowpack in mountains, meaning that melting snow can't replenish rivers during warm summer months, leading to lower water levels. Lower-level rivers also have warmer temperatures, threatening species like salmon that prefer colder upstream temperatures. Attempts have been made to regulate the exploitation of rivers to preserve their ecological functions. Many wetland areas have become protected from development. Water restrictions can prevent
5207-402: Is part of permafrost ice caps, or trace amounts of water vapor in the atmosphere. However, there is evidence that rivers flowed on Mars for at least 100,000 years. The Hellas Planitia is a crater left behind by an impact from an asteroid. It has sedimentary rock that was formed 3.7 billion years ago, and lava fields that are 3.3 billion years old. High resolution images of the surface of
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5334-570: Is rarely static, the exact location of a river border may be called into question by countries. The Rio Grande between the United States and Mexico is regulated by the International Boundary and Water Commission to manage the right to fresh water from the river, as well as mark the exact location of the border. Up to 60% of fresh water used by countries comes from rivers that cross international borders. This can cause disputes between countries that live upstream and downstream of
5461-425: Is replete with advice on "the trout": The Trout is a fish highly valued, both in this and foreign nations. He may be justly said, as the old poet said of wine, and we English say of venison, to be a generous fish: a fish that is so like the buck, that he also has his seasons; for it is observed, that he comes in and goes out of season with the stag and buck. Gesner says, his name is of a German offspring; and says he
5588-701: Is that of the Mississippi River , whose drainage basin covers 40% of the contiguous United States . The river was then used for shipping crops from the American Midwest and cotton from the American South to other states as well as the Atlantic Ocean. The role of urban rivers has evolved from when they were a center of trade, food, and transportation to modern times when these uses are less necessary. Rivers remain central to
5715-553: Is the Sunswick Creek in New York City, which was covered in the 1800s and now exists only as a sewer-like pipe. While rivers may flow into lakes or man-made features such as reservoirs , the water they contain will always tend to flow down toward the ocean . However, if human activity siphons too much water away from a river for other uses, the riverbed may run dry before reaching the sea. The outlets mouth of
5842-842: Is what typically separates drainage basins; water on one side of a ridge will flow into one set of rivers, and water on the other side will flow into another. One example of this is the Continental Divide of the Americas in the Rocky Mountains . Water on the western side of the divide flows into the Pacific Ocean , whereas water on the other side flows into the Atlantic Ocean . Not all precipitation flows directly into rivers; some water seeps into underground aquifers . These, in turn, can still feed rivers via
5969-599: The 2024 Summer Olympics . Another example is the restoration of the Isar in Munich from being a fully canalized channel with hard embankments to being wider with naturally sloped banks and vegetation. This has improved wildlife habitat in the Isar, and provided more opportunities for recreation in the river. As a natural barrier , rivers are often used as a border between countries , cities, and other territories . For example,
6096-941: The Arctic Ocean to the Atlas Mountains in North Africa. The western limit of their native range is Iceland in the north Atlantic, while the eastern limit is in Aral Sea tributaries in Afghanistan and Pakistan . Brown trout have been widely introduced into suitable environments around the world, including North and South America, Australasia, Asia, and South and East Africa. Introduced brown trout have established self-sustaining, wild populations in many introduced countries. The first introductions were in Australia in 1864 when 300 of 1500 brown trout eggs from
6223-487: The Atlantic Ocean to the Mediterranean Sea . The nineteenth century saw canal-building become more common, with the U.S. building 4,400 miles (7,100 km) of canals by 1830. Rivers began to be used by cargo ships at a larger scale, and these canals were used in conjunction with river engineering projects like dredging and straightening to ensure the efficient flow of goods. One of the largest such projects
6350-842: The Cold Spring Hatchery operated by Mather, one in Caledonia, New York , operated by pisciculturalist Seth Green , and other hatchery in Northville, Michigan . Additional shipments of "von Behr" brown trout eggs arrived in 1884. In 1885, brown trout eggs from Loch Leven, Scotland , arrived in New York. These "Loch Leven" brown trout were distributed to the same hatcheries. Over the next few years, additional eggs from Scotland, England, and Germany were shipped to U.S. hatcheries. Behnke (2007) believed all life forms of brown trout—anadromous, riverine, and lacustrine—were imported into
6477-501: The Industrial Revolution as a source of power for textile mills and other factories, but were eventually supplanted by steam power . Rivers became more industrialized with the growth of technology and the human population . As fish and water could be brought from elsewhere, and goods and people could be transported via railways , pre-industrial river uses diminished in favor of more complex uses. This meant that
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#17327939012126604-791: The Lamari River in New Guinea separates the Angu and the Fore people in New Guinea. The two cultures speak different languages and rarely mix. 23% of international borders are large rivers (defined as those over 30 meters wide). The traditional northern border of the Roman Empire was the Danube , a river that today forms the border of Hungary and Slovakia . Since the flow of a river
6731-574: The Natal and Cape Provinces of South Africa took place in 1890 and 1892, respectively. By 1909, brown trout were established in the mountains of Kenya . The first introductions into the Himalayas in northern India took place in 1868, and by 1900, brown trout were established in Kashmir and Madras . In the 1950s and 1960s, Edgar Albert de la Rue [ fr ] , a French geologist, began
6858-525: The Nile and the Ganges . The Quran describes these four rivers as flowing with water, milk, wine, and honey, respectively. The book of Genesis also contains a story of a great flood . Similar myths are present in the Epic of Gilgamesh , Sumerian mythology, and in other cultures. In Genesis, the flood's role was to cleanse Earth of the wrongdoing of humanity. The act of water working to cleanse humans in
6985-636: The Northwest Territories . Introductions into South America began in 1904 in Argentina . Brown trout are now established in Chile , Peru and the Falklands . Sea-run forms of brown trout exceeding 20 lb (9.1 kg) are caught by local anglers on a regular basis. The first introductions into the U.S. started in 1883 when Fred Mather , a New York pisciculturist and angler , under
7112-568: The River Continuum Concept . "Shredders" are organisms that consume this organic material. The role of a "grazer" or "scraper" organism is to feed on the algae that collects on rocks and plants. "Collectors" consume the detritus of dead organisms. Lastly, predators feed on living things to survive. The river can then be modeled by the availability of resources for each creature's role. A shady area with deciduous trees might experience frequent deposits of organic matter in
7239-762: The River Itchen survived a four-month voyage from Falmouth, Cornwall to Melbourne on the sailing ship Norfolk . By 1866, 171 young brown trout were surviving in a Plenty River hatchery in Tasmania . Thirty-eight young trout were released in the river, a tributary of the River Derwent in 1866. By 1868, the Plenty River hosted a self-sustaining population of brown trout which became a brood source for continued introduction of brown trout into Australian and New Zealand rivers. Successful introductions into
7366-627: The River Lethe to forget their previous life. Rivers also appear in descriptions of paradise in Abrahamic religions , beginning with the story of Genesis . A river beginning in the Garden of Eden waters the garden and then splits into four rivers that flow to provide water to the world. These rivers include the Tigris and Euphrates , and two rivers that are possibly apocryphal but may refer to
7493-787: The Sumerians in the Tigris–Euphrates river system , the Ancient Egyptian civilization in the Nile, and the Indus Valley Civilization on the Indus River . The desert climates of the surrounding areas made these societies especially reliant on rivers for survival, leading to people clustering in these areas to form the first cities . It is also thought that these civilizations were the first to organize
7620-485: The climate . The alluvium carried by rivers, laden with minerals, is deposited into the floodplain when the banks spill over, providing new nutrients to the soil, allowing them to support human activity like farming as well as a host of plant and animal life. Deposited sediment from rivers can form temporary or long-lasting fluvial islands . These islands exist in almost every river. About half of all waterways on Earth are intermittent rivers , which do not always have
7747-685: The cultural identity of cities and nations. Famous examples include the River Thames 's relationship to London , the Seine to Paris , and the Hudson River to New York City . The restoration of water quality and recreation to urban rivers has been a goal of modern administrations. For example, swimming was banned in the Seine for over 100 years due to concerns about pollution and the spread of E. coli , until cleanup efforts to allow its use in
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#17327939012127874-484: The discharge of a river, the amount of water passing through it at a particular time. The flow of a river can act as a means of transportation for plant and animal species, as well as a barrier. For example, the Amazon River is so wide in parts that the variety of species on either side of its basin are distinct. Some fish may swim upstream to spawn as part of a seasonal migration . Species that travel from
8001-465: The extinction of some species, and lowered the amount of alluvium flowing through rivers. Decreased snowfall from climate change has resulted in less water available for rivers during the summer. Regulation of pollution, dam removal , and sewage treatment have helped to improve water quality and restore river habitats. A river is a natural flow of freshwater that flows on or through land towards another body of water downhill. This flow can be into
8128-719: The gravel beds of headstreams . Sea trout in Ireland and Great Britain have many regional names: sewin in Wales , finnock in Scotland , peal in the West Country , mort in North West England , and white trout in Ireland. The lacustrine and riverine morphs of brown trout are both potamodromous , meaning they are also migratory, though only between freshwater bodies. Lacustrine trout mainly inhabit large lakes with calm and stratified deep water, while riverine trout forms fluvial populations typically in large rivers but sometimes in shallower creeks and alpine streams , both still migrating upstream during reproductive seasons. Anadromous and potamodromous morphs coexisting in
8255-402: The runoff of water down a slope, the melting of glaciers or snow , or seepage from aquifers beneath the surface of the Earth. Rivers flow in channeled watercourses and merge in confluences to form drainage basins , areas where surface water eventually flows to a common outlet. Rivers have a great effect on the landscape around them. They may regularly overflow their banks and flood
8382-436: The sea . The sediment yield of a river is the quantity of sand per unit area within a watershed that is removed over a period of time. The monitoring of the sediment yield of a river is important for ecologists to understand the health of its ecosystems, the rate of erosion of the river's environment, and the effects of human activity. Rivers rarely run in a straight direction, instead preferring to bend or meander . This
8509-521: The water table , the groundwater beneath the surface of the land stored in the soil . Water flows into rivers in places where the river's elevation is lower than that of the water table. This phenomenon is why rivers can still flow even during times of drought . Rivers are also fed by the melting of snow glaciers present in higher elevation regions. In summer months, higher temperatures melt snow and ice, causing additional water to flow into rivers. Glacier melt can supplement snow melt in times like
8636-498: The U.S. By 1900, 38 states and two territories had received stocks of brown trout. Their adaptability resulted in most of these introductions establishing wild, self-sustaining populations. The fish is not considered to be endangered , although some individual stocks are under various degrees of stress mainly through habitat degradation, overfishing , and artificial propagation leading to introgression . Increased frequency of excessively warm water temperatures in high summer causes
8763-468: The U.S. and intermingled genetically to create what he calls the American generic brown trout and a single subspecies the North European brown trout ( S. t. trutta ). In April 1884, the U.S. Fish Commission released 4900 brown trout fry into the Baldwin River , a tributary of the Pere Marquette River in Michigan. This was the first release of brown trout into U.S. waters. Between 1884 and 1890, brown trout were introduced into suitable habitats throughout
8890-458: The U.S. in the 1880s, they became a major subject of American angling literature. In 1889, Frederic M. Halford , a British angler, author published Dry-Fly Fishing in Theory and Practice , a seminal work codifying a half century of evolution of fly fishing with floating flies for brown trout. In the late 19th century, American angler and writer Theodore Gordon , often called the "Father of American Dry Fly Fishing", perfected dry-fly techniques for
9017-418: The authority of the U.S. Fish Commissioner, Spencer Baird , obtained brown trout eggs from a Baron Lucius von Behr, president of the German Fishing Society [ de ] . The von Behr brown trout came from both mountain streams and large lakes in the Black Forest region of Baden-Württemberg . The original shipment of "von Behr" brown trout eggs were handled by three hatcheries, one on Long Island ,
9144-695: The bodies of humans and animals worldwide, as well as in the soil, with potentially negative health effects. Research into how to remove it from the environment, and how harmful exposure is, is ongoing. Fertilizer from farms can lead to a proliferation of algae on the surface of rivers and oceans, which prevents oxygen and light from dissolving into water, making it impossible for underwater life to survive in these so-called dead zones . Urban rivers are typically surrounded by impermeable surfaces like stone, asphalt , and concrete. Cities often have storm drains that direct this water to rivers. This can cause flooding risk as large amounts of water are directed into
9271-470: The castle, and the corn was taken to "her majesty's mills", where it was ground and tolls were paid. Eventually the millers were set free. On another occasion, Rolleston's miller was detained by Edward Earl of Rutland, but was released when he promised not to collect any more corn from Newark. There seems to have been less of an issue when the inhabitants of Newark took their corn to the mills voluntarily. The Willoughby family , who lived at Wollaton Hall ran
9398-405: The complete draining of rivers. Limits on the construction of dams, as well as dam removal , can restore the natural habitats of river species. Regulators can also ensure regular releases of water from dams to keep animal habitats supplied with water. Limits on pollutants like pesticides can help improve water quality. Today, the surface of Mars does not have liquid water. All water on Mars
9525-585: The early nineteenth century, after which silk and lace thread was produced. A small community was established around the mill, with cottages for some of the workers, of whom there were 70 in 1838, a general store, a public house and a mission hall. Willow for making baskets was grown in osier beds, and hops were also cultivated. The building was used as a billet for soldiers during the Second World War , by which time its industrial function had ceased. It has subsequently been converted into flats, with some of
9652-436: The effect of normalizing the effects of rivers; the greatest floods are smaller and more predictable, and larger sections are open for navigation by boats and other watercraft. A major effect of river engineering has been a reduced sediment output of large rivers. For example, the Mississippi River produced 400 million tons of sediment per year. Due to the construction of reservoirs , sediment buildup in man-made levees , and
9779-542: The environment. The volume of groundwater extracted from the catchment has fallen in recent years, with the result that water levels have risen a little. Catches of Atlantic salmon ( Salmo salar ) have also been reported on the river. The Environment Agency measure the water quality in the river systems of England. Each is given an overall ecological status, which may be one of five levels: high, good, moderate, poor and bad. There are several components that are used to determine this, including biological status, which looks at
9906-399: The family Galaxiidae , which also have affinity for well-oxygenated, cold streams. Brown trout additionally are voracious predators of invertebrates and can carry microbial pathogens like Aeromonas salmonicida . Genetic background is a very important factor when determining the success of trout populations, this information is vital to restore and enhance previous populations. Because of
10033-577: The first comprehensive text, The Book of The Sea Trout , specifically addressing angling techniques for the anadromous forms of brown trout. Introductions of brown trout into the American West created new angling opportunities, none so successful from an angling perspective as was the introduction of browns into the upper Firehole River in Yellowstone National Park in 1890. One of the earliest accounts of trout fishing in
10160-826: The first human civilizations . The organisms that live around or in a river such as fish , aquatic plants , and insects have different roles, including processing organic matter and predation . Rivers have produced abundant resources for humans, including food , transportation , drinking water , and recreation. Humans have engineered rivers to prevent flooding, irrigate crops, perform work with water wheels , and produce hydroelectricity from dams. People associate rivers with life and fertility and have strong religious, political, social, and mythological attachments to them. Rivers and river ecosystems are threatened by water pollution , climate change , and human activity. The construction of dams, canals , levees , and other engineered structures has eliminated habitats, has caused
10287-855: The fish captured by Healy was confirmed by both the International Game Fish Association and the Fresh Water Fishing Hall of Fame as the new all-tackle world record for the species. This fish, which supplanted the former world record from the Little Red River in Arkansas, has in turn been exceeded by a 20.1-kilogram (44 lb) specimen caught in the Ohau Canal in Twizel, New Zealand on 27 October 2020. The all-tackle length IGFA world record
10414-451: The fish zonation concept. Smaller rivers can only sustain smaller fish that can comfortably fit in its waters, whereas larger rivers can contain both small fish and large fish. This means that larger rivers can host a larger variety of species. This is analogous to the species-area relationship , the concept of larger habitats being host to more species. In this case, it is known as the species-discharge relationship, referring specifically to
10541-673: The floating of wood on rivers to transport it, was especially important. Rivers also were an important source of drinking water . For civilizations built around rivers, fish were an important part of the diet of humans. Some rivers supported fishing activities, but were ill-suited to farming, such as those in the Pacific Northwest . Other animals that live in or near rivers like frogs , mussels , and beavers could provide food and valuable goods such as fur . Humans have been building infrastructure to use rivers for thousands of years. The Sadd el-Kafara dam near Cairo , Egypt,
10668-412: The flow of the river beneath its surface. These help rivers flow straighter by increasing the speed of the water at the middle of the channel, helping to control floods. Levees are also used for this purpose. They can be thought of as dams constructed on the sides of rivers, meant to hold back water from flooding the surrounding area during periods of high rainfall. They are often constructed by building up
10795-399: The flow, causing it to reflect in the other direction. Thus, a bend in the river is created. Rivers may run through low, flat regions on their way to the sea. These places may have floodplains that are periodically flooded when there is a high level of water running through the river. These events may be referred to as "wet seasons' and "dry seasons" when the flooding is predictable due to
10922-516: The focus of a specialised fly fishery. The first planting in the United States occurred on April 11, 1884, into the Baldwin River, one mile east of Baldwin, Michigan . Brown trout have had serious negative impacts on upland native fish species in some of the countries where they have been introduced, particularly Australia. In Chile , Australia , New Zealand and other locations in the southern hemisphere, brown trout compete with fish from
11049-650: The form of leaves. In this type of ecosystem, collectors and shredders will be most active. As the river becomes deeper and wider, it may move slower and receive more sunlight . This supports invertebrates and a variety of fish , as well as scrapers feeding on algae. Further downstream, the river may get most of its energy from organic matter that was already processed upstream by collectors and shredders. Predators may be more active here, including fish that feed on plants, plankton , and other fish. The flood pulse concept focuses on habitats that flood seasonally, including lakes and marshes . The land that interfaces with
11176-508: The goddess Isis were said to be the cause of the river's yearly flooding, itself personified by the goddess Hapi . Many African religions regard certain rivers as the originator of life. In Yoruba religion , Yemọja rules over the Ogun River in modern-day Nigeria and is responsible for creating all children and fish. Some sacred rivers have religious prohibitions attached to them, such as not being allowed to drink from them or ride in
11303-522: The introduction of several species of salmonids on the remote Kerguelen Islands in the southern Indian Ocean . Of the seven species introduced, only brook trout , Salvelinus fontinalis , and brown trout survived to establish wild populations. The first introductions in Canada occurred in 1883 in Newfoundland and continued until 1933. The only Canadian regions without brown trout are Yukon and
11430-428: The irrigation of desert environments for growing food. Growing food at scale allowed people to specialize in other roles, form hierarchies, and organize themselves in new ways, leading to the birth of civilization. In pre-industrial society , rivers were a source of transportation and abundant resources. Many civilizations depended on what resources were local to them to survive. Shipping of commodities, especially
11557-434: The late summer, when there may be less snow left to melt, helping to ensure that the rivers downstream of the glaciers have a continuous supply of water. Rivers flow downhill, with their direction determined by gravity . A common misconception holds that all or most rivers flow from North to South, but this is not true. As rivers flow downstream, they eventually merge to form larger rivers. A river that feeds into another
11684-474: The level of river branching in a drainage basin. Several systems of stream order exist, one of which is the Strahler number . In this system, the first tributaries of a river are 1st order rivers. When two 1st order rivers merge, the resulting river is 2nd order. If a river of a higher order and a lower order merge, the order is incremented from whichever of the previous rivers had the higher order. Stream order
11811-561: The local ecosystems of rivers needed less protection as humans became less reliant on them for their continued flourishing. River engineering began to develop projects that enabled industrial hydropower , canals for the more efficient movement of goods, as well as projects for flood prevention . River transportation has historically been significantly cheaper and faster than transportation by land. Rivers helped fuel urbanization as goods such as grain and fuel could be floated downriver to supply cities with resources. River transportation
11938-407: The mechanical shadoof began to be used to raise the elevation of water. Drought years harmed crop yields, and leaders of society were incentivized to ensure regular water and food availability to remain in power. Engineering projects like the shadoof and canals could help prevent these crises. Despite this, there is evidence that floodplain-based civilizations may have been abandoned occasionally at
12065-400: The migration routes of fish and destroy habitats. Rivers that flow freely from headwaters to the sea have better water quality, and also retain their ability to transport nutrient-rich alluvium and other organic material downstream, keeping the ecosystem healthy. The creation of a lake changes the habitat of that portion of water, and blocks the transportation of sediment, as well as preventing
12192-453: The modifications made to the channel to assist its land-drainage function have resulted in the habitat suffering, with a result that fish numbers are low. The Environment Agency , who manage the river, have applied a "Hands-Off Flow" limit to the river, which specifies that if the flow drops below 2650 Megalitres per day (Mld) in the Trent, all abstraction of water must cease, in order to protect
12319-426: The most abundant prey items. However, brown trout also feed on other taxa such as terrestrial invertebrates (e.g. Hymenoptera) or other fish. Moreover, in brown trout, as in many other fish species, a change in the diet composition normally occurs during the life of the fish, and piscivorous behaviour is most frequent in large brown trout. These shifts in the diet during fish lifecycle transitions may be accompanied by
12446-399: The natural meandering of the river. Dams block the migration of fish such as salmon for which fish ladder and other bypass systems have been attempted, but these are not always effective. Pollution from factories and urban areas can also damage water quality. " Per- and polyfluoroalkyl substances (PFAS) is a widely used chemical that breaks down at a slow rate. It has been found in
12573-429: The natural terrain with soil or clay. Some levees are supplemented with floodways, channels used to redirect floodwater away from farms and populated areas. Dams restrict the flow of water through a river. They can be built for navigational purposes, providing a higher level of water upstream for boats to travel in. They may also be used for hydroelectricity , or power generation from rivers. Dams typically transform
12700-595: The newly arrived, but difficult-to-catch brown trout in Catskill rivers such as the Beaverkill and Neversink Rivers . In the early 20th century, British angler and author G. E. M. Skues pioneered nymphing techniques for brown trout on English chalk streams. His Minor Tactics of the Chalk Stream (1910) began a revolution in fly fishing techniques for trout. In 1917, Scottish author Hamish Stuart published
12827-464: The outbuildings used as industrial workshops. There are two mill buildings, the north mill and the south mill, both of which are grade II listed structures. Below Maythorne, the Robin Hood Way, a long distance footpath, follows the banks of the river, which forms the northern boundary of Southwell. There is a wildfowl centre on the north bank, and Caudwell flour Mill is on the south bank. It
12954-572: The park is from Mary Trowbridge Townsend's 1897 article in Outing Magazine "A Woman's Trout Fishing in Yellowstone Park" in which she talks about catching the von Behr trout in the river: Long dashes down stream taxed my unsteady footing; the sharp click and whirr of the reel resounded in desperate efforts to hold him somewhat in check; another headlong dash, then a vicious bulldog shake of the head as he sawed back and forth across
13081-425: The plain show evidence of a river network, and even river deltas. These images reveal channels formed in the rock, recognized by geologists who study rivers on Earth as being formed by rivers, as well as "bench and slope" landforms, outcroppings of rock that show evidence of river erosion. Not only do these formations suggest that rivers once existed, but that they flowed for extensive time periods, and were part of
13208-438: The quantity and varieties of invertebrates , angiosperms and fish. Chemical status, which compares the concentrations of various chemicals against known safe concentrations, is rated good or fail. The water quality of the Greet and its tributaries was as follows in 2019. Reasons for the water quality being less than good include sewage discharge into the river, physical modification of the river channel, drainage of water from
13335-448: The removal of natural banks replaced with revetments , this sediment output has been reduced by 60%. The most basic river projects involve the clearing of obstructions like fallen trees. This can scale up to dredging , the excavation of sediment buildup in a channel, to provide a deeper area for navigation. These activities require regular maintenance as the location of the river banks changes over time, floods bring foreign objects into
13462-536: The reverse, death and destruction, especially through floods . This power has caused rivers to have a central role in religion , ritual , and mythology . In Greek mythology , the underworld is bordered by several rivers. Ancient Greeks believed that the souls of those who perished had to be borne across the River Styx on a boat by Charon in exchange for money. Souls that were judged to be good were admitted to Elysium and permitted to drink water from
13589-468: The river, and natural sediment buildup continues. Artificial channels are often constructed to "cut off" winding sections of a river with a shorter path, or to direct the flow of a river in a straighter direction. This effect, known as channelization, has made the distance required to traverse the Missouri River in 116 kilometres (72 mi) shorter. Dikes are channels built perpendicular to
13716-552: The river. Areas of a river with softer rock weather faster than areas with harder rock, causing a difference in elevation between two points of a river. This can cause the formation of a waterfall as the river's flow falls down a vertical drop. A river in a permeable area does not exhibit this behavior and may even have raised banks due to sediment. Rivers also change their landscape through their transportation of sediment , often known as alluvium when applied specifically to rivers. This debris comes from erosion performed by
13843-625: The river. A country that is downstream of another may object to the upstream country diverting too much water for agricultural uses, pollution, as well as the creation of dams that change the river's flow characteristics. For example, Egypt has an agreement with Sudan requiring a specific minimum volume of water to pass into the Nile yearly over the Aswan Dam , to maintain both countries access to water. The importance of rivers throughout human history has given them an association with life and fertility . They have also become associated with
13970-457: The rivers themselves, debris swept into rivers by rainfall, as well as erosion caused by the slow movement of glaciers. The sand in deserts and the sediment that forms bar islands is from rivers. The particle size of the debris is gradually sorted by the river, with heavier particles like rocks sinking to the bottom, and finer particles like sand or silt carried further downriver . This sediment may be deposited in river valleys or carried to
14097-412: The rivers. Due to these impermeable surfaces, these rivers often have very little alluvium carried in them, causing more erosion once the river exits the impermeable area. It has historically been common for sewage to be directed directly to rivers via sewer systems without being treated, along with pollution from industry. This has resulted in a loss of animal and plant life in urban rivers, as well as
14224-418: The rocks. Every wile inherited from generations of wily ancestors was tried until, in a moment of exhaustion, the net was slipped under him. Wading ashore with my prize, I had barely time to notice his size—a good four-pounder, and unusual markings, large yellow spots encircled by black, with great brilliancy of iridescent color—when back he flopped into the water and was gone. However, I took afterward several of
14351-521: The same river appear genetically identical. What determines whether they migrate to sea or not remains unknown. The scientific name of the brown trout is Salmo trutta . The specific epithet trutta derives from the Latin trutta , meaning, literally, " trout ". Behnke (2007) relates that the brown trout was the first species of trout described in the 1758 edition of Systema Naturae by Swedish zoologist Carl Linnaeus . Systema Naturae established
14478-891: The same variety, known in the Park as the Von Baer [sic] trout, and which I have since found to be the Salmo fario , the veritable trout of Izaak Walton. Within the US, brown trout introductions have created self-sustaining fisheries throughout the country. Many are considered "world-class" such as in the Great Lakes and in several Arkansas tailwaters. Outside the U.S. and outside its native range in Europe, introduced brown trout have created "world-class" fisheries in New Zealand, Patagonia , and
14605-409: The sea from their mouths. Depending on the activity of waves, the strength of the river, and the strength of the tidal current, the sediment can accumulate to form new land. When viewed from above, a delta can appear to take the form of several triangular shapes as the river mouth appears to fan out from the original coastline . In hydrology , a stream order is a positive integer used to describe
14732-414: The sea to breed in freshwater rivers are anadromous. Salmon are an anadromous fish that may die in the river after spawning, contributing nutrients back to the river ecosystem. Modern river engineering involves a large-scale collection of independent river engineering structures that have the goal of flood control , improved navigation, recreation, and ecosystem management. Many of these projects have
14859-519: The spread of waterborne diseases such as cholera . In modern times, sewage treatment and controls on pollution from factories have improved the water quality of urban rivers. Climate change can change the flooding cycles and water supply available to rivers. Floods can be larger and more destructive than expected, causing damage to the surrounding areas. Floods can also wash unhealthy chemicals and sediment into rivers. Droughts can be deeper and longer, causing rivers to run dangerously low. This
14986-485: The surrounding area, spreading nutrients to the surrounding area. Sediment or alluvium carried by rivers shapes the landscape around it, forming deltas and islands where the flow slows down. Rivers rarely run in a straight line, instead, they bend or meander ; the locations of a river's banks can change frequently. Rivers get their alluvium from erosion , which carves rock into canyons and valleys . Rivers have sustained human and animal life for millennia, including
15113-452: The system of binomial nomenclature for animals . Salmo trutta was used to describe anadromous or sea-run forms of brown trout. Linnaeus also described two other brown trout species in 1758. Salmo fario was used for riverine forms. Salmo lacustris was used for lake-dwelling forms. The native range of brown trout extends from northern Norway and White Sea tributaries in Russia in
15240-557: The transport infrastructure, runoff from agricultural land, and the presence of the invasive North American crayfish. Like most rivers in the UK, the chemical status changed from good to fail in 2019, due to the presence of polybrominated diphenyl ethers (PBDE), perfluorooctane sulphonate (PFOS) and mercury compounds, none of which had previously been included in the assessment. Download coordinates as: [REDACTED] Media related to River Greet at Wikimedia Commons River A river
15367-523: The trout's importance as a food and game fish, it has been artificially propagated and stocked in many places in its range, and fully natural populations (uncontaminated by allopatric genomes ) probably exist only in isolated places, for example in Corsica or in high alpine valleys on the European mainland. Farming of brown trout has included the production of infertile triploid fish by increasing
15494-416: The underlying geology is mainly Sherwood and Mercia sandstone , with some Mercia mudstone along the southern edge of the catchment. Below Southwell, the geology is predominantly Mercia mudstone. There is a layer of clay, sand and gravel alluvium overlaying this in the river channel. The river is greatly affected by rainfall, raising levels and muddying the water. The river rises as a series of springs to
15621-670: The water temperature just after fertilisation of eggs, or more reliably, by a process known as pressure shocking. Triploids are favoured by anglers because they grow faster and larger than diploid trout. Proponents of stocking triploids argue, because they are infertile, they can be introduced into an environment that contains wild brown trout without the negative effects of cross-breeding. However, stocking triploids may damage wild stocks in other ways. Triploids certainly compete with diploid fish for food, space, and other resources. They could also be more aggressive than diploid fish and they may disturb spawning behaviour. The brown trout has been
15748-456: The waters where they spend most of their lives. Sea trout are more commonly female in less nutrient-rich rivers. Brown trout are active both by day and by night and are opportunistic feeders. While in freshwater, their diets frequently include invertebrates from the streambed , other fish, frogs, mice, birds, and insects flying near the water's surface. The high dietary reliance upon insect larvae , pupae , nymphs , and adults allows trout to be
15875-432: The west of Kirklington, close to the 160-foot (49 m) contour. It is joined by Cotton Mill Dyke and Edingley Beck, and to the east of Kirklington, turns to flow in a south-easterly direction. Halam Beck joins from the south, and there is a disused mill at Maythorne . It was built as a cotton mill in 1795 by a hop merchant, to supply yarn to the framework knitting industry. The firm of Messrs. Bean and Johnson altered it in
16002-400: Was built over the site of Burgage mill, a medieval building, and was bought by Charles Caudwell in 1851. He increased the capacity of the mill, which was subsequently damaged by fires in 1867, 1893 and 1917. Each time the mill was rebuilt, the equipment was upgraded. The Caudwell family were millers for four generations, after which Associated British Foods bought the mill. It closed in 1977, and
16129-475: Was turned into flats in 1989. After leaving the mill, the river crosses under the A612 road and flows through open countryside, to reach Upton Mill. It passes to the north of Southwell Racecourse, and then turns to the south, where Rolleston Mill is built over its course. This is a late eighteenth-century brick structure, with a basement, two storeys and a garret, which still contains some of the milling equipment. It
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