151-589: The Skagit River ( / ˈ s k æ dʒ ɪ t / SKAJ -it ) is a river in southwestern British Columbia in Canada and northwestern Washington in the United States, approximately 150 mi (240 km) long. The river and its tributaries drain an area of 1.7 million acres (690,000 hectares) of the Cascade Range along the northern end of Puget Sound and flows into the sound. The Skagit watershed
302-582: 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
453-536: 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
604-715: 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
755-545: A branch of Puget Sound . The Skagit provides spawning habitat for salmon . It is the only large river system in Washington that contains healthy populations of all five native salmon species – chinook , coho , chum , pink , and sockeye – and two species of trout : steelhead and coastal cutthroat . The river supports one of the largest wintering bald eagle populations in the contiguous United States. The eagles feed on Chum and Coho salmon that have returned to spawn in
906-515: 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
1057-413: A common outlet. Rivers have a great effect on the landscape around them. They may regularly overflow their banks and flood 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
1208-503: A conservation advocacy group, are currently petitioning for an ESA listing on Chinook in several river basins in Washington state, including the Chehalis , Quinault, Queets, Hoh and Quillayute. The petition, filed in 2023, focuses on spring-run Chinook, the region's most vulnerable salmon population. In April 2008, commercial fisheries in both Oregon and California were closed in response to
1359-408: 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
1510-564: 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
1661-495: 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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#17330846799791812-589: A month. The years 1909, 1917, and 1921 are the other annual peak discharges of record for the gauging station at Concrete which is at the confluence of the Baker and Skagit Rivers. November 2017 brought significant flooding to the lower river at Mt. Vernon and Lyman . In 1978, the United States Congress established the Skagit Wild and Scenic River System . The system includes 158.5 miles (255.1 km) of
1963-548: 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
2114-427: A pronounced curve or hook called a " kype ." Studies have shown that larger and more dominant male salmon have a reproductive advantage as female Chinook are often more aggressive toward smaller males. Chinook spawn in larger and deeper waters than other salmon species and can be found on the spawning redds (nests) from September to December. The female salmon may lay her eggs in four to five nesting pockets within
2265-730: A redd. After laying eggs, females guard the redd from four to 25 days before dying, while males seek additional mates. Chinook eggs hatch 90 to 150 days after deposition, depending upon water temperature. Egg deposits are timed to ensure the young salmon fry emerge during an appropriate season for survival and growth. Fry and parr (young fish) usually stay in fresh water for 12 to 18 months before traveling downstream to estuaries , where they remain as smolts for several months. Some Chinook return to fresh water one or two years earlier than their counterparts and are referred to as "jack" salmon. "Jack" salmon are typically less than 60 cm (24 in) long but are sexually mature. The Yukon River has
2416-622: A result, progress is slowly being made to help restore the salmon habitats along the river. Many tribes, including the Hoopa Valley Tribe, Karuk Tribe , Yurok Tribe , and the Shasta Indian Nation, voiced support for the removal of dams on the Klamath River. Representatives of the Shasta Indian Nation claimed that the construction of Copco No 1 Dam caused the submerging of sites significant to them, including burial grounds. Un-Dam
2567-866: 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
2718-425: 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
2869-1026: 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 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
3020-460: 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
3171-525: A short period until they are strong enough to journey out to the ocean and acquire more food. Chinook juveniles divide into two types: ocean-type and stream-type. Ocean-type Chinook migrate to salt water in their first year. Stream-type salmon spend one full year in fresh water before migrating to the ocean. After a few years in the ocean, adult salmon, then large enough to escape most predators, return to their natal streambeds to mate. Chinook can have extended lifespans, in which some fish spend one to five years in
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#17330846799793322-634: A similar legend that has illustrated the importance of not messing up the Chinook salmon migration. The legend described three Skookums which can be related to the three dams on the Klamath river in California. It has been known that the creation of dams has negatively impacted the lives of many Native American Indians by disrupting their food supply and the flow of water. The impact on the salmon migration has been seen by not only tribal members but others as well, and as
3473-532: A single stocking of juveniles in the lower river around 1930. Sporadic efforts to introduce the fish to New Zealand waters in the late 19th century were largely failures and led to no evident establishments. Initially ova were imported from the Baird hatchery of the McCloud River in California. Further efforts in the early 20th century were more successful and subsequently led to the establishment of spawning runs in
3624-503: A sustainable manner. The planning and approval process for new salmon farms in New Zealand considers the farm's potential environmental effects, its effects on fishing activities (if it is a marine farm), and any possible cultural and social effects. In the interest of fish welfare, a number of New Zealand salmon farming operations anaesthetise salmon before slaughter using Aqui-S™, an organically based anaesthetic developed in New Zealand that
3775-491: A trip to catch Chinook salmon, $ 90 for lake trout , and $ 180 for walleye . Should the Chinook salmon fishery collapse and be replaced with a native lake trout fishery, the economic value would decrease by 80%. Since the later 1970s, the size and age range of Chinook salmon have been declining according to studies along the northwest Pacific coast from Alaska to California for the years of 1977 to 2015 which examined about 1.5 million Chinook salmon. Ocean-5 Chinook (which means
3926-463: A value of NZ$ 61 million in export earnings. For the year ended March 2011, this amount had increased to NZ$ 85 million. New Zealand accounts for about half of the global production of Chinook salmon, and about half of New Zealand's production is exported. Japan is New Zealand's largest export market, with stock also being supplied to other countries of the Pacific Rim , including Australia. Farming of
4077-406: A village at the tip of the delta which they called Skagit City . The massive logjam was found about 10 miles (16 km) upstream from the mouth of the river. Attempts to remove it began in 1874 by a team of loggers, who salvaged the logs. After three years of work, a 5-acre (20,000 m) section of the jam broke free and scattered downriver. Soon thereafter the river became navigable. Mount Vernon
4228-438: 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
4379-563: 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. Chinook salmon The Chinook salmon / ʃ ɪ ˈ n ʊ k / ( Oncorhynchus tshawytscha )
4530-445: 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
4681-462: Is a prized and sought-after catch for a sporting angler. The flesh of the salmon is also highly valued for its dietary nutritional content, which includes high levels of important omega-3 fatty acids . Some populations are endangered; however, many are healthy. The Chinook salmon has not been assessed for the IUCN Red List . According to NOAA , the Chinook salmon population along the California coast
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4832-877: Is also conducting efforts to revegetate certain areas in the watershed with trees and native grasses. The Oregon Department of Fish and Wildlife (ODFW), in cooperation with members of the Klamath and Yurok tribes, also finalized a two-phase plan to re-establish wild Chinook and other anadromous fishes in the Upper Klamath Basin. As of December 2022, the plan is in its monitoring phase, in which ODFW are studying 10,000 hatchery-born spring-run Chinook released in certain tributaries of Upper Klamath Lake . Introduced Chinook salmon in Lake Michigan are sought after by tourists enjoying chartered fishing trips . A 2016 survey of Wisconsin anglers found they would, on average, pay $ 140 for
4983-496: 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
5134-552: 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
5285-448: 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
5436-405: 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
5587-509: Is characterized by a temperate, mid-latitude, maritime climate. Temperatures range widely throughout the watershed. Recorded temperatures at Newhalem range from a low of −6 °F (−21 °C) to a high of 109 °F (43 °C), with greater extremes likely in the mountains. The highest temperatures are commonly recorded in July; the lowest are in January. The Skagit River rises at Allison Pass in
5738-656: Is compromised, affected stock can decline. One Seattle Times article states, "Pacific salmon have disappeared from 40 percent of their historic range outside Alaska," and concludes it is imperative for people to realize the needs of salmon and try not to contribute to destructive practices that harm salmon runs. In the Pacific Northwest, the summer runs of especially large Chinook once common (before dams and overfishing led to declines) were known as June hogs . A Chinook's birthplace and later evolution can be tracked by looking at its otolith (ear) bone. The bone can record
5889-453: 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
6040-527: Is crossed by Interstate 5 , a major national highway, between Burlington and Mount Vernon; the four-lane bridge over the Skagit River collapsed in May 2013 and was reopened a month later. At the former site of Skagit City , the Skagit River diverges into two forks, a north and south fork. Fir Island lies between the forks in the 90,000-acre (36,000 ha) floodplain. These two forks both empty into Skagit Bay ,
6191-574: Is declining from factors such as overfishing, loss of freshwater and estuarine habitat, hydropower development, poor ocean conditions, and hatchery practices. Historically, the native distribution of Chinook salmon in North America ranged from the Ventura River in California in the south to Kotzebue Sound in Alaska in the north. Recent studies have shown that Chinook salmon are historically native to
Skagit River - Misplaced Pages Continue
6342-485: Is essential for algae and other water-filtering agents not to be destroyed in the oceans because they contribute to the well-being of the food chain . With some populations endangered, precautions are necessary to prevent overfishing and habitat destruction , including appropriate management of hydroelectric and irrigation projects. If too few fish remain because of fishing and land management practices, salmon have more difficulty reproducing. When one of these factors
6493-497: 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
6644-555: Is in the Middle Fork and Upper Salmon River in Idaho. These fish travel over 2,100 m (7,000 ft) in elevation, and over 1,400 km (900 mi), in their migration through eight dams and reservoirs on the Columbia and Lower Snake Rivers. Chinook eat amphipods and other crustaceans and insects while young, and primarily other fish when older. Young salmon feed in streambeds for
6795-560: Is known locally in New Zealand) have established sizeable pelagic runs. The Chinook is blue-green, red, or purple on the back and on the top of the head, with silvery sides and white ventral surfaces. It has black spots on its tail and the upper half of its body. Although spots are seen on the tail in pink salmon and silver on the tail in coho and chum salmon , Chinook are unique among the Pacific salmon in combining black spots and silver on
6946-570: Is made up of high peaks and low valleys. The highest points in the basin are two volcanoes : Mount Baker , elevation 10,781 feet (3,286 m), and Glacier Peak, elevation 10,541 feet (3,213 m). Most of the basin lies above 2,000 feet (610 m). The river completes its course at sea level where it meets the Puget Sound. The river takes its name from the Skagit tribe, a name used by Europeans and Americans for two distinct Native American peoples,
7097-459: Is managed by the U.S. Forest Service as part of the Mt. Baker-Snoqualmie National Forest . The Skagit River Hydroelectric Project is a group of three major dams, constructed in the 1920s and 1930s, which are a primary source of hydroelectric power for Seattle and other area communities. The Skagit River Railway was constructed by the city of Seattle to transport workers and construction materials for
7248-402: 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
7399-560: 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
7550-765: Is safe for use in food and that has been favourably reported on by the British Humane Slaughter Association . In recognition of the sustainable, environmentally conscious practices, the New Zealand salmon farming industry has been acknowledged as the world's greenest by the Global Aquaculture Performance Index. Chile is the only country other than New Zealand currently producing significant quantities of farmed Chinook salmon. The United States has not produced farmed Chinook in commercial quantities since 1994. In Canada, most commercial Chinook salmon farming ceased by 2009. Fisheries in
7701-527: Is similar to how other tribes relied more on buffalo for food, and have many legends and spiritual ties to them. Chinook salmon were described and enthusiastically eaten by the Lewis and Clark Expedition . Lewis wrote that, when fresh, they tasted better than any other fish he had ever eaten. They did not particularly like dried or "pounded" salmon. Lewis and Clark knew about Pacific salmon but had never seen one. The Western world had known about Pacific salmon since
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#17330846799797852-671: 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
8003-549: Is that the upper Skagit once drained northward into Canada and the growth and retreat of successive Cordilleran ice flows brought about the reversal. Each advance blocked the river, forcing it to find new routes to the south, in the process carving deep gorges. Eventually, the Skagit gorge was so deep that even after the Cordilleran ice retreated for good, the river continued flowing south instead of north into Canada. The Skagit watershed
8154-539: 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
8305-503: Is the largest and most valuable species of Pacific salmon . Its common name is derived from the Chinookan peoples . Other vernacular names for the species include king salmon , Quinnat salmon , Tsumen , spring salmon , chrome hog , Blackmouth , and Tyee salmon . The scientific species name is based on the Russian common name chavycha (чавыча). Chinook are anadromous fish native to
8456-573: Is vitally important for the fish to reach the oceans to grow into healthy adult fish to sustain the species without being impeded by man-made structures such as dams. The bodies of water for salmon habitat must be clean and oxygenated. One sign of high productivity and growth rate in the oceans is the level of algae . Increased algal levels lead to higher levels of carbon dioxide in the water, which transfers into living organisms, fostering underwater plants and small organisms, which salmon eat. Algae can filter high levels of toxins and pollutants. Thus, it
8607-808: 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
8758-587: 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,
8909-479: 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
9060-515: The California drought made them even more vulnerable. A study was done specifically on the California Delta over three years, and it was discovered that the Chinook salmon had a low survival rate for different reasons, and as a result, the Chinook salmon population here has been on a decline. Some of the factors affecting the populations include the route used during migration, drought conditions,
9211-475: The Canada–United States border and into Washington state. Ross Lake is formed by Ross Dam and is approximately 24 miles (39 km) long, winding south through Ross Lake National Recreation Area . Here the river receives Beaver Creek from the right and Ruby Creek from the left. Spilling out of the dam the river enters Diablo Lake, formed by Diablo Dam , and receives Thunder and Colonial creeks from
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#17330846799799362-688: The Canadian Cascades of British Columbia . From there it flows northwest along the Crowsnest Highway , which follows the river into Manning Provincial Park . It turns abruptly south, where it receives Snass Creek from the right, then enters Skagit Valley Provincial Park at the point where it receives the Sumallo River from the right. It receives the Klesilkwa River from the right, and turns southeast to flow into Ross Lake , where it crosses
9513-634: The Guadalupe River watershed in California, the southernmost major metropolitan area hosting salmon runs in the United States. Populations have disappeared from large areas where they once flourished, however, or shrunk by as much as 40 percent. In some regions, their inland range has been cut off, mainly by dams and habitat alterations: in Southern California , in some areas east of the Coast Ranges of California and Oregon , and in large areas in
9664-492: 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
9815-492: The Klamath River , four dams on the Klamath ( Iron Gate Dam , Copco No 2 Dam , Copco No 1 Dam , and John C. Boyle Dam ) will be removed by the end of 2024. Klamath River Renewal Corporation (KRRC), who is in charge of the operation, cited the adverse effects of the dams on fish survivability and the blockage of fish habitat as major reasons for removal. In June 2023, Copco 2 Dam was torn down. In addition to dam removal, KRRC
9966-522: The Klamath tribes and the Yurok Tribe , have lived along the Klamath river , and the Chinook salmon have been an important part of their lives, spiritually and physically. An Indian legend of a tribe on the Klamath river describes how the construction of the dam has hurt the fish population and that the impact on them has gone unnoticed, and the destruction of the dam is what has brought back their food supply and made them happy again. The Klamath tribe had
10117-755: 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
10268-472: The Lushootseed language, a branch of the Salishan family. The Upper Skagit tribe occupied the land along the Skagit from what is now Newhalem to the mouth of the river at Puget Sound. The Lower Skagit tribe lived on northern Whidbey Island and have come to be known also as the Whidbey Island Skagit. Archaeological evidence reveals that these peoples collected their food from the natural resources, through fishing, hunting, and gathering. The upper Skagit area
10419-423: 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
10570-423: The North Pacific Ocean and the river systems of western North America, ranging from California to Alaska , as well as Asian rivers ranging from northern Japan to the Palyavaam River in Arctic northeast Siberia. They have been introduced to other parts of the world, including New Zealand and Patagonia . Introduced Chinook salmon are thriving in Lake Michigan and Michigan 's western rivers. A large Chinook
10721-493: 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
10872-608: 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
11023-637: The Snake River and upper Columbia River drainage basins . In certain areas such as California's Sacramento–San Joaquin River Delta , it was revealed that extremely low numbers of juvenile Chinook salmon (less than 1%) were surviving. In the western Pacific, the distribution ranges from northern Japan ( Hokkaido ) in the south to the Arctic Ocean as far as the East Siberian Sea and Palyavaam River in
11174-753: 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
11325-535: The Upper Skagit and Lower Skagit . Native people have lived along the Skagit for thousands of years. Archaeological evidence indicates that ancestors of the Upper Skagit tribe lived in the area now called Ross Lake National Recreation Area at least 8,000 years ago. They quarried chert from Hozomeen Mountain to make blades, which were used across a wide trading area. Both tribes traditionally spoke dialects of
11476-461: The alewife , an invasive species of nuisance fish from the Atlantic Ocean. In the 1960s, alewives constituted 90% of the biota in these lakes. Coho salmon had been introduced the year before, and the program was successful. Chinook and Coho salmon thrived on the alewives and spawned in the lakes' tributaries. After this success, Chinook were introduced into the other Great Lakes , where sport fishermen prize them for their aggressive behaviour on
11627-485: 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
11778-665: 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
11929-478: 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
12080-465: 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
12231-436: 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
12382-471: The water cycle , the processes by which water moves around the Earth. Water first enters rivers through precipitation , whether from rainfall, 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
12533-521: 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
12684-617: The 1860s, they have had a reserve there.) Custer documented this encounter and the accuracy of the chief's map in his Report of Henry Custer, Assistant of Reconnaissances, Made in 1859 over the routes in the Cascades Mountains in the vicinity of the 49th parallel , now in the collection of the National Park Service . Settlement along the river by European Americans in the late 1800s was inhibited by two ancient logjams that blocked navigation upriver. The settlers first established
12835-403: The 2008 estimate was 66,000 fish. Scientists from universities and federal, state, and tribal agencies concluded the 2004 and 2005 broods were harmed by poor ocean conditions in 2005 and 2006, in addition to "a long-term, steady degradation of the freshwater and estuarine environment." Such conditions included weak upwelling, warm sea surface temperatures , and low densities of food. In Oregon,
12986-679: The 2010 spring Chinook run was forecast to increase by up to 150% over 2009 populations, growing from 200,000 to over 500,000, making this the largest run in recorded history. Lower temperatures in 2008 North Pacific waters brought in fatter plankton, which, along with greater outflows of Columbia River water, fed the resurgent populations. The Oregon Department of Fish and Wildlife estimated 80% were hatchery-born. Chinook runs in other habitats have not recovered proportionately. In April 2016, Coleman National Fish Hatchery outside of Red Bluff, California , released 12 million juvenile Chinook salmon, with many salmon being tagged for monitoring. The release
13137-649: The Chinook are in highly impacts their survival rates, as some, like the Chinook in the Fraser River, only have a 30% survival rate. More studies and actions are needed for there to be an impact on the survival rates of the Chinook. Due to many of these reasons, the National Wildlife Federation has listed Chinook populations as endangered or threatened. The Chinook salmon is spiritually and culturally prized among certain First Nations peoples. For tribes on
13288-458: The Northwest coast, salmon were an important part of their culture for spiritual reasons and food. Many celebrate the first spring Chinook caught each year with "first-salmon ceremonies." While salmon fishing in general remains important economically for many tribal communities, it is especially the Chinook harvest that is typically the most valuable. The relation to salmon for the tribes in this area
13439-669: The Skagit River Basin . The Skagit River was highly influenced by the repeated advance and retreat of the Puget Lobe of the Cordilleran Ice Sheet . Ice and gravel moraines repeatedly blocked the Skagit, causing it to pool into lakes and forcing it to drain south into the future North Fork Stillaguamish River . After the ice retreated the Skagit breached the moraine dam near Concrete, Washington, finding its present course. The Sauk River and Suiattle River continued to drain into
13590-501: The Skagit and its tributaries — the Sauk, Suiattle, and Cascade rivers. This Wild and Scenic designation is meant to protect and enhance the values that caused it to be listed: The Skagit Wild and Scenic River System flows through both public and private lands. Fifty percent of the system is in private ownership, 44 percent is National Forest System land, and 6 percent is owned by the state and other agencies. The Skagit Wild and Scenic River
13741-545: The Skagit and its tributaries. The eagles arrive in late October or early November and stay into February. The highest number of eagles is usually seen in January. These eagles come from inland Canada and as far away as Alaska and Montana . When the salmon run is plentiful, as many as 600 to 800 eagles are attracted to the river. Thousands of snow geese winter in the Skagit River estuary . These geese feed on intertidal marsh plants such as bulrush and they are drawn to nearby farmlands where they find leftover potatoes in
13892-702: The Skagit from the right as it meanders slowly through an agricultural valley, past Marblemount , where the Cascade River joins from the left, and Rockport , where it receives its major tributary, the Sauk River , from the left. After receiving the Sauk River, the Skagit turns west, flowing past Concrete and receiving the Baker River , its second-largest tributary, from the right. The river continues to flow west, past Sedro-Woolley , Burlington and then Mount Vernon . It
14043-566: The U.S. and Canada are limited by impacts to weak and endangered salmon runs. Nine populations of Chinook salmon are listed under the U.S. Endangered Species Act (ESA) as either threatened or endangered. In the Snake River , Spring/Summer Chinook and Fall Chinook are ESA listed as Threatened. The fall and late-fall runs in the Central Valley population in California is a U.S. National Marine Fisheries Service (NMFS) species of concern . The Center for Biological Diversity and Pacific Rivers,
14194-448: The amount of snowmelt, and infrastructure that affects the flow of water (such as dams and levees). Each of these factors has significantly impacted Chinook survival rates, as most have made it more challenging for Chinook to travel from their spawning grounds to the ocean and back. The fluctuation of water depth as well as temperature have made this more challenging, and as a result, Chinook populations are declining. Which rivers or streams
14345-578: The baby salmon are typically grown to the smolt stage (around six months of age) before they are transferred to the sea cages or ponds. Most sea cage farming occurs in the Marlborough Sounds , Stewart Island, and Akaroa Harbour, while freshwater operations in Canterbury , Otago , and Tasman use ponds, raceways, and hydro canals for grow-out operations. Low stocking densities, ranging between less than 1 kg/m and around 25 kg/m (depending on
14496-695: 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
14647-445: The chemical composition of the water the fish had lived in, just as a tree's growth rings provide hints about dry and wet years. The bone is built with the chemical signature of the environment that hosted the fish. Researchers were able to tell where different individuals of Chinook were born and lived in the first year of their lives. Testing was done by measuring the strontium in the bones. Strontium can accurately show researchers
14798-405: 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
14949-606: The dams. The river today is a popular destination for whitewater rafting and fly fishing . Tributaries in Canada Tributaries in the US River A river 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
15100-436: 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
15251-545: The energy for migration. Later, they change physiologically to live in salt water. They rely on eelgrass and seaweeds for camouflage (protection from predators), shelter, and foraging habitat as they make their way to the open ocean. Adult fish need a rich, open ocean habitat to acquire the strength needed to travel back upstream, escape predators, and reproduce before dying. In his book King of Fish , David Montgomery writes, "The reserves of fish at sea are important to restocking rivers disturbed by natural catastrophes." Thus, it
15402-428: The exact location and time of a fish swimming in a river. The total North Pacific fisheries harvest of the Chinook salmon in 2010 was some 1.4 million fish, corresponding to 7,000 tonnes ; 1.1 million of the fish were captured in the United States, and others were divided by Canada and Russia. The share of Chinook salmon from the total commercial Pacific salmon harvest was less than 1% by weight and only about 0.3% of
15553-464: The fields. Trumpeter swans are drawn to the estuary habitat as well. There can be several hundred swans in the Skagit valley from October to February. Historically, the Skagit tidal estuary had beaver dams in the myrtle zone. These were overtopped at high tide, but at low tide their ponds nurtured juvenile salmon. The Skagit River basin provides habitat for a diverse set of animals. For more information about these animals, see List of Wildlife of
15704-484: The fish has spent five years in the ocean) have declined from being up to 3–5% of the population to being almost none. Ocean-4 chinook are also seeing a rapid decline in their population. This means that Chinook are not living as long as they used to. This trend has mostly been seen in Alaska, but also Oregon and Washington. New trends have also been seen regarding the size of Ocean-1, 2, 3, 4, and 5 from 1975 to 2015. The size of Chinook who have spent one and two years in
15855-451: 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
16006-665: 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,
16157-412: 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
16308-399: 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
16459-650: 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
16610-428: The future North Fork Stillaguamish River until eruptions of Glacier Peak choked the rivers with debris, causing the formation of an alluvial fan near present-day Darrington, Washington . The debris forced the two rivers north to join the Skagit. Above Newhalem, Washington, the Skagit flows through a deep gorge, contrasting strongly with the glacial valley below Newhalem. One of the several theories about this anomaly
16761-502: 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
16912-402: The harvestable size of 3–4 kilograms (7–9 pounds). The broodstock for the farms is usually selected from existing farm stock or sometimes sourced from wild populations. Eggs and milt are stripped manually from sexually mature salmon and incubated under conditions replicating the streams and rivers where the salmon would spawn naturally (at around 10–12 °C or 50–54 °F). After hatching,
17063-574: The hook. The species has also established itself in Patagonian waters in South America, where both introduced and escaped hatchery fish have colonized rivers and established stable spawning runs . Chinook salmon have been found spawning in headwater reaches of the Rio Santa Cruz , apparently having migrated over 1,000 km (620 mi) from the ocean. The population is thought to be derived from
17214-428: 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
17365-704: The largest of the Pacific salmon. In the Kenai River of Alaska, mature Chinook averaged 16.8 kg (37 lb 1 oz). The current sport-caught world record, 44.1 kg ( 97 + 1 ⁄ 4 lb), was caught on May 17, 1985, in the Kenai River. The commercial catch world record is 57 kg (126 lb) caught near Rivers Inlet , British Columbia, in the late 1970s. Chinook, like many other species of salmon, are considered euryhaline , and thus live in both saltwater and freshwater environments throughout their life. Once hatching, salmon spend one to eight years in
17516-420: The late 18th century. Maritime fur traders and explorers, such as George Vancouver , frequently acquired salmon by trade with the indigenous people of the Northwest coast. Lewis and Clark first encountered Chinook salmon as a gift from Chief Cameahwait , on August 13, 1805, near Lemhi Pass . Tasting it convinced Lewis they had crossed the continental divide. In Oregon, many Native American tribes, including
17667-434: 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
17818-529: The left, before it enters the third and final reservoir, Gorge Lake, formed by Gorge Dam . All three dams are part of the Skagit River Hydroelectric Project . Past Gorge Dam, the river is often dry, as its waters have been diverted to generate hydroelectricity . Water is returned to the river as it passes Newhalem , a company town for Seattle City Light . Copper and Bacon creeks, both flowing from North Cascades National Park , merge into
17969-469: 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
18120-494: The life stage of the salmon), and the absence of disease in the fish mean New Zealand farmers do not need to use antibiotics or vaccines to maintain the health of their salmon stocks. The salmon are fed food pellets of fish meal specially formulated for Chinook salmon (typical proportions of the feed are: 45% protein, 22% fat, and 14% carbohydrate plus ash and water) that contain no steroids or other growth enhancers. Regulations and monitoring programmes ensure salmon are farmed in
18271-561: 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
18422-555: The longest freshwater migration route of any salmon, over 3,000 km (1,900 mi) from its mouth in the Bering Sea to spawning grounds upstream of Whitehorse, Yukon . Since Chinook rely on fat reserves for energy upon re-entering fresh water, commercial fish caught here are highly prized for their unusually high levels of heart-healthy omega-3 fatty acids . However, the high costs of harvest and transport from this rural area limits its affordability. The highest elevation Chinook spawn
18573-480: The low count of Chinook salmon present because of the collapse of the Sacramento River run, one of the biggest south of the Columbia. In April 2009, California again canceled the season. The Pacific Fishery Management Council's goal for the Sacramento River run is an escapement total (fish that return to freshwater spawn areas and hatcheries) of 122,000–180,000 fish. The 2007 escapement was estimated at 88,000, and
18724-407: 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
18875-400: 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
19026-399: 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
19177-429: 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
19328-793: The north. Nevertheless, they are consistently present and the distribution is well known only in Kamchatka . Elsewhere, information is scarce, but they have a patchy presence in the Anadyr River basin and parts of the Chukchi Peninsula . Also, in parts of the northern Magadan Oblast near the Shelikhov Gulf and Penzhina Bay , stocks might persist but remain poorly studied. In 1967, the Michigan Department of Natural Resources introduced Chinook into Lake Michigan and Lake Huron to control
19479-447: The number of fish. The trend has been down in the captures compared to the period before 1990, when the total harvest had been around 25,000 tonnes. Global production has, however, remained at a stable level because of increased aquaculture. The world's largest producer and market supplier of Chinook salmon is New Zealand. In 2009, New Zealand exported 5,088 tonnes (5,609 short tons) of Chinook salmon, marketed as king salmon, equating to
19630-413: The ocean (averaging from three to four years) before returning to their home rivers to spawn. The salmon undergo radical morphological changes as they prepare for the spawning event ahead. Salmon lose the silvery blue they had as ocean fish, and their color darkens, sometimes with a radical change in hue. Salmon are sexually dimorphic , and the male salmon develop canine-like teeth, and their jaws develop
19781-431: The ocean has been rising, while the size of Chinook of three to five years has been declining. The size increase was seen mainly in hatchery fish, not wild, and hatchery fish were often larger than wild, but the decrease was seen in both types of populations. Factors have been discovered that have influenced the size of the Chinook. They include, but are not limited to, the years they spent in fresh water before migrating to
19932-530: The ocean, reaching age eight. More northerly populations tend to have longer lives. Salmon need suitable spawning habitat. Clean, cool, oxygenated, sediment-free fresh water is essential for egg development. Chinook use larger sediment (gravel) sizes for spawning than other Pacific salmon. Riparian vegetation and woody debris help juvenile salmon by providing cover and maintaining low water temperatures. Chinook also need healthy ocean habitats. Juvenile salmon grow in clean, productive estuarine environments and gain
20083-423: The ocean, the time of year they were caught, which season run they participated in, and where they were caught. However, what is causing these negative trends is still not fully known or researched. Some possibilities can be climate change, pollution, and fishing practices. In California specifically, Chinook populations in the rivers have been declining. Chinook that are migratory are already more vulnerable, and
20234-425: 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
20385-448: 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
20536-530: 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
20687-461: 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
20838-552: 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
20989-620: 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
21140-837: The rivers of Canterbury and North Otago: Rangitata River , the Opihi River , the Ashburton River , the Rakaia River , the Waimakariri River , the Hurunui River , and the Waiau Uwha River . The success of the latter introductions is thought to be partly attributable to the use of ova from autumn-run populations as opposed to ova from spring-run populations used in the first attempts. Whilst other salmon have also been introduced into New Zealand, only Chinook salmon (or king salmon as it
21291-457: 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
21442-412: 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
21593-409: 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
21744-414: 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
21895-601: The species in New Zealand began in the 1970s when hatcheries were initially set up to enhance and support wild fish stocks, with the first commercial operations starting in 1976. After some opposition against their establishment by societal groups, including anglers, the first sea cage farm was established in 1983 at Big Glory Bay in Stewart Island by British Petroleum NZ Ltd. Today, the salmon are hatched in land-based hatcheries (several of which exist) and transferred to sea cages or freshwater farms, where they are grown out to
22046-519: 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
22197-437: The tail. Another distinctive feature is a black gum line that is present in both salt and fresh water. Adult fish typically range in size from 60 to 90 cm (24 to 36 in), but may be up to 150 cm (58 in) in length; they average 4.5 to 22.7 kg (10 to 50 lb), but may reach 59 kg (130 lb). The meat can be either pink or white, depending on what the salmon have been feeding on. Chinook salmon are
22348-484: The time. Custer later talked about the area with an elder Samona chief named Chinsoloc who had lived there at one time; he drew a detailed map from memory, which the topographer found to be accurate. (Note: It is unclear what tribe this refers to; there is no local tribe called Samona. The Skeetchestn Indian Band , of the Secwepemc (Shuswap) Nation, were located in the area of present-day Savona, British Columbia . Since
22499-564: Was done in hopes of helping restore the salmon population of Battle Creek . In June 2021, the California State Water Resources Control Board approved a plan by the United States Bureau of Reclamation to release water from Lake Shasta for irrigation use, which "significantly" increased the risk of extinction of winter-run Chinook in the Sacramento River. In an effort to restore the fish habitat of
22650-570: Was first described in writing in 1859 by Henry Custer , the American topographer for the US Boundary Commission. With two other American government men and ten locals from the Nooksack and Chilliwack bands, he canoed and portaged from the Canada–United States border down to Ruby Creek, a tributary of the upper Skagit River. The party found no native people inhabiting the Upper Skagit area at
22801-402: Was founded at the approximate site of this logjam. In November 1897, the Skagit River flooded severely; in the aftermath as the floodwaters receded, two new logjams formed and blocked navigation. The largest was near the mouth, and filled the river from bank to bank for about 800 yards (730 m). Using a recently built logjam removal boat named Skagit , teams finally cleared this jam in about
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