Aspero is a well-studied Late Preceramic site archaeological complex located near the mouth of the Supe River, south of Supe Puerto, on the central coast of Peru. It forms part of the ancient Caral-Supe civilization and was occupied during the Late Archaic period, from before 3000 BCE to around 1800 BCE. It is connected culturally to the ancient city of Caral , located 25 km up-valley, for which it presumably served as a major fishery. The site covers an area of approximately 14 hectares (35 acres) and features numerous temples or huacas, of which the most prominent are the Huaca Alta, the Huaca de los ídolos and the Huaca de los Sacrificios. Remains of human sacrifice have been found in the latter, dated to about 4500 years ago.
120-571: Aspero is located on the right bank of the Supe River, 2 km south of the port of the same name, about 500 m from the Pacific Ocean, in the midst of sandy hills, wetlands and cultivated fields. It belongs to the jurisdiction of the district of Supe Puerto in the province of Barranca in the department of Lima. To access the site, visitors have to walk 2 km southwest from the Plazuela Grau, along
240-580: A hunter-gatherer lifestyle and were, of necessity, constantly on the move. However, early examples of permanent settlements (though not necessarily permanently occupied), such as those at Lepenski Vir , were almost always associated with fishing as a major source of food. The ancient river Nile was full of fish; fresh and dried fish were a staple food for much of the population. The Egyptians had implements and methods for fishing and these are illustrated in tomb scenes, drawings, and papyrus documents. Some representations hint at fishing being pursued as
360-582: 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
480-518: A time temperature indicator on certain fresh chilled seafood products. Because fresh fish is highly perishable, it must be eaten promptly or discarded; it can be kept for only a short time. In many countries, fresh fish are filleted and displayed for sale on a bed of crushed ice or refrigerated . Fresh fish is most commonly found near bodies of water, but the advent of refrigerated train and truck transportation has made fresh fish more widely available inland. Long term preservation of fish
600-536: 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
720-537: A 2014 study published in PLOS One found that 15% of MSC certified Patagonian toothfish originated from uncertified and mercury polluted fisheries. These fishery-stock substitutions had 100% more mercury than their genuine counterparts, "vastly exceeding" limits in Canada, New Zealand, and Australia. Research into population trends of various species of seafood is pointing to a global collapse of seafood species by 2048. Such
840-715: 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
960-515: 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
1080-591: A collapse would occur due to pollution and overfishing , threatening oceanic ecosystems, according to some researchers. A major international scientific study released in November 2006 in the journal Science found that about one-third of all fishing stocks worldwide have collapsed (with a collapse being defined as a decline to less than 10% of their maximum observed abundance), and that if current trends continue all fish stocks worldwide will collapse within fifty years. In July 2009, Boris Worm of Dalhousie University ,
1200-408: 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
1320-433: A distinct smell. It also exists in freshwater species, but becomes more numerous in the cells of an animal the deeper it lives, so fish from the deeper parts of the ocean have a stronger taste than species that live in shallow water. Eggs from seaweed contain sex pheromones called dictyopterenes, which are meant to attract the sperm. These pheromones are also found in edible seaweeds, which contributes to their aroma. There
SECTION 10
#17328527258631440-456: A few selected fish species, among women of childbearing age. Avoidance of modest fish consumption due to confusion regarding risks and benefits could result in thousands of excess CHD [congenital heart disease] deaths annually and suboptimal neurodevelopment in children." Due to the wide array of options in the seafood marketplace, seafood is far more susceptible to mislabeling than terrestrial food. There are more than 1,700 species of seafood in
1560-564: 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
1680-481: A healthy and balanced diet. The UK National Health Service gives similar advice, recommending at least 2 portions (about 10 oz) of fish weekly. The Chinese National Health Commission recommends slightly more, advising 10–20 oz of fish weekly. There are numerous factors to consider when evaluating health hazards in seafood. These concerns include marine toxins, microbes, foodborne illness , radionuclide contamination , and man-made pollutants. Shellfish are among
1800-410: A highly toxic organic compound of mercury, polychlorinated biphenyls (PCBs), and microplastics. Species of fish that are high on the food chain , such as shark , swordfish , king mackerel , albacore tuna , and tilefish contain higher concentrations of these bioaccumulates. This is because bioaccumulates are stored in the muscle tissues of fish, and when a predatory fish eats another fish, it assumes
1920-495: 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
2040-425: A list of fish prices. The cheapest was skaren (probably parrotfish ) whereas Atlantic bluefin tuna was three times as expensive. Common salt water fish were yellowfin tuna , red mullet , ray , swordfish , or sturgeon , a delicacy that was eaten salted. Lake Copais itself was famous in all of Greece for its eels , celebrated by the hero of The Acharnians . Other freshwater fish were pike fish , carp , and
2160-456: A pastime. Fishing scenes are rarely represented in ancient Greek culture, a reflection of the low social status of fishing. However, Oppian of Corycus , a Greek author wrote a major treatise on sea fishing, the Halieulica or Halieutika , composed between 177 and 180. This is the earliest such work to have survived to the modern day. The consumption of fish varied by the wealth and location of
2280-548: 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
2400-519: A post-resurrection scene, Jesus tells his disciples where they can catch fish, before cooking breakfast for them to eat. Pescatarianism was widespread in the early Christian Church , among both the clergy and laity. In ancient and medieval times, the Catholic Church forbade the practice of eating meat, eggs and dairy products during Lent . Thomas Aquinas argued that these "afford greater pleasure as food [than fish], and greater nourishment to
2520-866: 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
SECTION 20
#17328527258632640-425: 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
2760-460: 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
2880-590: A trade advocacy group representing the United States seafood industry, disagree. They claim that currently observed declines in fish populations are due to natural fluctuations and that enhanced technologies will eventually alleviate whatever impact humanity is having on oceanic life. For the most part Islamic dietary laws allow the eating of seafood, though the Hanbali forbid eels, the Shafi forbid frogs and crocodiles, and
3000-438: 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
3120-445: 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
3240-502: Is accomplished in a variety of ways. The oldest and still most widely used techniques are drying and salting . Desiccation (complete drying) is commonly used to preserve fish such as cod . Partial drying and salting are popular for the preservation of fish like herring and mackerel . Fish such as salmon , tuna , and herring are cooked and canned . Most fish are filleted before canning, but some small fish (e.g. sardines ) are only decapitated and gutted before canning. Seafood
3360-496: 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
3480-552: 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
3600-448: 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
3720-405: 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
Aspero - Misplaced Pages Continue
3840-466: Is believed to have been primarily maritime because of its proximity to the Pacific Ocean. Fish hooks and nets have also been found in trash middens and domestic contexts to support this idea. Research at the site led to the controversial "Maritime Foundations of Andean culture" theory, which suggests that the initial development of ancient Peruvian culture was based on fishing, shellfish collecting, and hunting sea mammals, rather than agriculture . The idea
3960-412: Is broad scientific consensus that docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) found in seafood are beneficial to neurodevelopment and cognition, especially at young ages. The United Nations Food and Agriculture Organization has described fish as "nature's super food." Seafood consumption is associated with improved neurologic development during pregnancy and early childhood and
4080-697: Is consumed all over the world; it provides the world's prime source of high-quality protein : 14–16% of the animal protein consumed worldwide; over one billion people rely on seafood as their primary source of animal protein. Fish is among the most common food allergens . Since 1960, annual global seafood consumption has more than doubled to over 20 kg per capita. Among the top consumers are Korea (78.5 kg per head), Norway (66.6 kg) and Portugal (61.5 kg). The UK Food Standards Agency recommends that at least two portions of seafood should be consumed each week, one of which should be oil-rich. There are over 100 different types of seafood available around
4200-506: Is cooked. Delivery of live fish without water is also being explored. While some seafood restaurants keep live fish in aquaria for display purposes or cultural beliefs, the majority of live fish are kept for dining customers. The live food fish trade in Hong Kong , for example, is estimated to have driven imports of live food fish to more than 15,000 tonnes in 2000. Worldwide sales that year were estimated at US$ 400 million, according to
4320-453: 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
4440-423: Is essential for healthy skin and muscles as well as fertility. Casanova reputedly ate 50 oysters a day. Over 33,000 species of fish and many more marine invertebrate species have been identified. Bromophenols, which are produced by marine algae, give marine animals an odor and taste that is absent from freshwater fish and invertebrates. Also, a chemical substance called dimethylsulfoniopropionate (DMSP) that
4560-450: Is found in red and green algae is transferred into animals in the marine food chain. When broken down, dimethyl sulfide (DMS) is produced, and is often released during food preparation when fresh fish and shellfish are heated. In small quantities it creates a specific smell one associates with the ocean, but in larger quantities gives the impression of rotten seaweed and old fish. Another molecule known as TMAO occurs in fishes and gives them
4680-497: 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
4800-677: Is more tenuously linked to reduced mortality from coronary heart disease . Fish consumption has been associated with a decreased risk of dementia , lung cancer and stroke . A 2020 umbrella review concluded that fish consumption reduces all-cause mortality, cancer, cardiovascular disease, stroke and other outcomes. The review suggested that two to four servings per week is generally safe. However, two other recent umbrella reviews have found no statistically significant associations between fish consumption and cancer risks and have cautioned researchers when it comes to interpreting reported associations between fish consumption and cancer risks because
4920-520: Is often inaccurate or unavailable. While ciguatera is relatively widespread compared to other seafood-related health hazards (up to 50,000 people suffer from ciguatera every year), mortality is very low. Scombroid food poisoning , is also a seafood illness. It is typically caused by eating fish high in histamine from being stored or processed improperly. Fish and shellfish have a natural tendency to concentrate inorganic and organic toxins and pollutants in their bodies, including methylmercury ,
Aspero - Misplaced Pages Continue
5040-402: 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
5160-560: 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
5280-671: 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
5400-539: 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
5520-653: Is the culinary name for food that comes from any form of sea life , prominently including fish and shellfish . Shellfish include various species of molluscs (e.g., bivalve molluscs such as clams , oysters , and mussels ). The harvesting, processing, and consuming of seafoods are ancient practices with archaeological evidence dating back well into the Paleolithic . Findings in a sea cave at Pinnacle Point in South Africa indicate Homo sapiens (modern humans) harvested marine life as early as 165,000 years ago, while
5640-808: 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
5760-407: Is widely disputed by other scholars who claim there is evidence of earlier, inland sites where irrigation agriculture was widespread. New technology has led to the discoveries that changed our views of Aspero. Carbon dating has given a more exact date, while also connecting Aspero to other more agriculturally based inland sites. Carbon dating of the communal structures of the local sites surrounding
5880-587: 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,
6000-479: 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
6120-642: The FAO to collect and compile fishery statistics. The production figures have been extracted from the FAO FishStat database, and include both capture from wild fisheries and aquaculture production. [REDACTED] [REDACTED] Fish is a highly perishable product: the "fishy" smell of dead fish is due to the breakdown of amino acids into biogenic amines and ammonia . Live food fish are often transported in tanks at high expense for an international market that prefers its seafood killed immediately before it
SECTION 50
#17328527258636240-727: The Hanafi forbid bottom feeders such as shellfish and carp . The Jewish laws of Kashrut forbid the eating of shellfish and eels. In the Old Testament, the Mosaic Covenant allowed the Israelites to eat Finfish , but shellfish and eels were an abomination and not allowed. In the New Testament , Luke's gospel reports Jesus' eating of a fish after his resurrection , and in John 21 , also
6360-492: 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
6480-755: 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
6600-701: The Neanderthals , an extinct human species contemporary with early Homo sapiens , appear to have been eating seafood at sites along the Mediterranean coast beginning around the same time. Isotopic analysis of the skeletal remains of Tianyuan man , a 40,000-year-old anatomically modern human from eastern Asia, has shown that he regularly consumed freshwater fish. Archaeology features such as shell middens , discarded fish bones, and cave paintings show that sea foods were important for survival and consumed in significant quantities. During this period, most people lived
6720-517: 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
6840-558: 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
6960-608: 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
7080-753: 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
7200-485: 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
7320-665: 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
SECTION 60
#17328527258637440-478: 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
7560-465: 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
7680-436: 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
7800-521: 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
7920-453: The 1950s in Minamata , Japan . Wastewater from a nearby chemical factory released methylmercury that accumulated in fish which were consumed by humans. Severe mercury poisoning is now known as Minamata disease . The 2011 Fukushima Daiichi Nuclear Power Plant disaster and 1947 - 1991 Marshall Islands nuclear bomb testing led to dangerous radionuclide contamination of local sea life which, in
8040-455: 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 a common outlet. Rivers have a great effect on
8160-449: The Pérez de Cuellar housing estate. After excavations archaeologists have found that each mound was built in stages, having two or three tiers rising about 10m about the surface. They have found ceremonial buildings, plazas, terraces, and large middens. Caches were found in these structures including clay figurines, wooden bowls, feathers, cotton, and string and cane objects. The diet of Aspero
8280-477: The Supe Valley places Aspero within 3700~2500 cal. B.C. or the middle to late Archaic Period. These connections have led archaeologists to believe that Aspero wasn't mainly a maritime culture, but an agriculture-based community with more local maritime traits. In other words, Aspero exploited the trade and knowledge of agriculture from the inland sites, such as Caral and Lurihuasi. This does not completely disprove
8400-577: The United States' consumer marketplace, 80 - 90% of which are imported and less than 1% of which are tested for fraud. However, more recent research into seafood imports and consumption patterns among consumers in the United States suggests that 35%-38% of seafood products are of domestic origin. consumption suggests Estimates of mislabelled seafood in the United States range from 33% in general up to 86% for particular species. Byzantine supply chains , frequent bycatch, brand naming, species substitution, and inaccurate ecolabels all contribute to confusion for
8520-520: The World Resources Institute. If the cool chain has not been adhered to correctly, food products generally decay and become harmful before the validity date printed on the package. As the potential harm for a consumer when eating rotten fish is much larger than for example with dairy products, the U.S. Food and Drug Administration (FDA) has introduced regulation in the USA requiring the use of
8640-821: The author of the November 2006 study in Science , co-authored an update on the state of the world's fisheries with one of the original study's critics, Ray Hilborn of the University of Washington at Seattle. The new study found that through good fisheries management techniques even depleted fish stocks can be revived and made commercially viable again. An analysis published in August 2020 indicates that seafood could theoretically increase sustainably by 36–74% by 2050 compared to current yields and that whether or not these production potentials are realised sustainably depends on several factors "such as policy reforms, technological innovation, and
8760-536: The beginning of the Imperial era, however, this custom suddenly came to an end, which is why mullus in the feast of Trimalchio (see the Satyricon ) could be shown as a characteristic of the parvenu , who bores his guests with an unfashionable display of dying fish. In medieval times, seafood was less prestigious than other animal meats, and was often seen as merely an alternative to meat on fast days. Still, seafood
8880-695: 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
9000-679: The coast of the UK. Oil-rich fish such as mackerel or herring are rich in long chain Omega-3 oils. These oils are found in every cell of the human body, and are required for human biological functions such as brain functionality. Whitefish such as haddock and cod are very low in fat and calories which, combined with oily fish rich in Omega-3 such as mackerel , sardines , fresh tuna , salmon and trout , can help to protect against coronary heart disease , as well as helping to develop strong bones and teeth. Shellfish are particularly rich in zinc , which
9120-405: 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
9240-401: The consumer. A 2013 study by Oceana found that one third of seafood sampled from the United States was incorrectly labeled. Snapper and tuna were particularly susceptible to mislabelling, and seafood substitution was the most common type of fraud. Another type of mislabelling is short-weighting, where practices such as overglasing or soaking can misleadingly increase the apparent weight of
9360-493: The dried fish with a mallet before soaking it in water. A wide range of mollusks (including oysters , mussels and scallops ) were eaten by coastal and river-dwelling populations, and freshwater crayfish were seen as a desirable alternative to meat during fish days. Compared to meat, fish was much more expensive for inland populations, especially in Central Europe, and therefore not an option for most. Modern knowledge of
9480-436: 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
9600-445: The entire body burden of bioaccumulates in the consumed fish. Thus species that are high on the food chain amass body burdens of bioaccumulates that can be ten times higher than the species they consume. This process is called biomagnification . Man-made disasters can cause localized hazards in seafood which may spread widely via piscine food chains. The first occurrence of widespread mercury poisoning in humans occurred this way in
9720-404: The extent of future shifts in demand". The FAO State of World Fisheries and Aquaculture 2004 report estimates that in 2003, of the main fish stocks or groups of resources for which assessment information is available, "approximately one-quarter were overexploited , depleted or recovering from depletion (16%, 7% and 1% respectively) and needed rebuilding." The National Fisheries Institute ,
9840-826: 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
9960-451: 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
10080-696: The fish. For supermarket shoppers, many seafood products are unrecognisable fillets . Without sophisticated DNA testing , there is no foolproof method to identify a fish species without their head, skin, and fins. This creates easy opportunities to substitute cheap products for expensive ones, a form of economic fraud. Beyond financial concerns, significant health risks arise from hidden pollutants and marine toxins in an already fraught marketplace. Seafood fraud has led to widespread keriorrhea due to mislabeled escolar, mercury poisoning from products marketed as safe for pregnant women, and hospitalisation and neurological damage due to mislabeled pufferfish . For example,
10200-665: 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,
10320-412: 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
10440-399: 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
10560-650: 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
10680-502: 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
10800-485: The household. In the Greek islands and on the coast, fresh fish and seafood ( squid , octopus , and shellfish ) were common. They were eaten locally but more often transported inland. Sardines and anchovies were regular fare for the citizens of Athens. They were sometimes sold fresh, but more frequently salted. A stele of the late 3rd century BCE from the small Boeotian city of Akraiphia , on Lake Copais , provides us with
10920-570: The human body, so that from their consumption there results in a greater surplus available for seminal matter, which when abundant becomes a great incentive to lust". In the United States, the Catholic practice of abstaining from meat on Fridays during Lent has popularised the Friday fish fry , and parishes often sponsor a fish fry during Lent. In predominantly Roman Catholic areas, restaurants may adjust their menus during Lent by adding seafood items to
11040-428: 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
11160-566: 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 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
11280-434: 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
11400-474: The latter case, remained as of 2008. A widely cited study in JAMA which synthesized government and MEDLINE reports, and meta-analyses to evaluate risks from methylmercury, dioxins, and polychlorinated biphenyls to cardiovascular health and links between fish consumption and neurologic outcomes concluded that: "The benefits of modest fish consumption (1-2 servings/wk) outweigh the risks among adults and, excepting
11520-461: The less appreciated catfish . Pictorial evidence of Roman fishing comes from mosaics . At a certain time, the goatfish was considered the epitome of luxury, above all because its scales exhibit a bright red colour when it dies out of water. For this reason, these fish were occasionally allowed to die slowly at the table. There even was a recipe where this would take place in Garo , in the sauce . At
11640-469: 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
11760-413: The liver, roe, head, and intestines of reef fish . It is the most common disease associated with seafood consumption and poses the greatest risk to consumers. The population of plankton that produces these toxins varies significantly over time and location, as seen in red tides. Evaluating the risk of ciguatera in any given fish requires specific knowledge of its origin and life history, information that
11880-561: 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
12000-571: The maritime theory because Aspero was taking advantage of its proximity to the Pacific Ocean for maritime resources. These new dates not only provide an insight into how Aspero developed, but also show the cultural connection that Aspero had with its neighboring sites. Researchers have established a general timeline which links Aspero and its adjacent sites to a much larger cultural system that spread across several valleys. 10°48′56″S 77°44′28″W / 10.8156°S 77.741°W / -10.8156; -77.741 Seafood Seafood
12120-407: 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
12240-423: The menu. 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 the water cycle , the processes by which water moves around
12360-400: 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
12480-489: The more common food allergens . Most of these dangers can be mitigated or avoided with accurate knowledge of when and where seafood is caught. However, consumers have limited access to relevant and actionable information in this regard and the seafood industry's systemic problems with mislabelling make decisions about what is safe even more fraught. Ciguatera fish poisoning (CFP) is an illness resulting from consuming toxins produced by dinoflagellates which bioaccumulate in
12600-399: 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
12720-429: 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
12840-425: 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
12960-582: The quality of evidence is very low. The parts of fish containing essential fats and micronutrients, often cited as primary health benefits of eating seafood, are frequently discarded in the developed world . Micronutrients including calcium, potassium, selenium, zinc, and iodine are found in their highest concentrations in the head, intestines, bones, and scales. Government recommendations promote moderate consumption of fish. The US Food and Drug Administration recommends moderate (4 oz for children and 8–12 oz for adults, weekly) consumption of fish as part of
13080-448: 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
13200-493: The reproductive cycles of aquatic species has led to the development of hatcheries and improved techniques of fish farming and aquaculture . A better understanding of the hazards of eating raw and undercooked fish and shellfish has led to improved preservation methods and processing. The following table is based on the ISSCAAP classification (International Standard Statistical Classification of Aquatic Animals and Plants) used by
13320-530: 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
13440-461: 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
13560-552: 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
13680-620: 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
13800-457: 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
13920-412: 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
14040-409: 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
14160-414: 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
14280-519: 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
14400-488: Was the mainstay of many coastal populations. Kippers made from herring caught in the North Sea could be found in markets as far away as Constantinople . While large quantities of fish were eaten fresh, a large proportion was salted, dried, and, to a lesser extent, smoked. Stockfish - cod that was split down the middle, fixed to a pole, and dried - was very common, though preparation could be time-consuming, and meant beating
#862137