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Yangtze Sturgeon
Dabry's sturgeon (''Acipenser dabryanus''), also known as the Yangtze sturgeon, Chiangjiang sturgeon and river sturgeon, is a species of fish in the sturgeon family, Acipenseridae.Zhuang, P., et al. (1997)Biology and life history of Dabry's sturgeon, ''Acipenser dabryanus'', in the Yangtze River.''Environmental Biology of Fishes'' 48(1-4), 257-64. It is endemic to China and today restricted to the Yangtze River basin, but was also recorded from the Yellow River basin in the past. It was a food fish of commercial importance. Its populations declined drastically, and since 1988, it was designated an endangered species on the Chinese Red List in Category I and commercial harvest was banned. It has been officially declared extinct in the wild by the IUCN as of July 21, 2022. Appearance This sturgeon has been known to reach in length, but it is usually much smaller.Froese, R. and D. Pauly. (Eds.''Acipenser dabryanus''.FishBase. 2011. Its body is blue-gray above and yellowis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FishBase
FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.Marine Fellow: Rainer Froese ''Pew Environment Group''. Over time it has "evolved into a dynamic and versatile ecological tool" that is widely cited in scholarly publications. FishBase provides comprehensive species data, including information on taxonomy, geographical distribution, and morphology, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Extinction
Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a change in the ecology of an area. In recent times, local extinction has sometimes been followed by a replacement of the species taken from other locations; wolf reintroduction is an example of this. The term "local extinction" is highly vernacular. The more proper biological term is ''extirpation''. Discussion Glaciation can lead to local extinction. This was the case during the Pleistocene glaciation event in North America. During this period, most of the native North American species of earthworm were killed in places covered by glaciation. This left them open for colonization by European earthworms brought over in soil from Europe. Species naturally become extirpated from islands over time. The numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Sturgeon
The Chinese sturgeon (''Acipenser sinensis''; ) is a critically endangered member of the family Acipenseridae in the order Acipenseriformes. Historically, this anadromous fish was found in China, Japan, and the Korean Peninsula, but it has been extirpated from most regions due to habitat loss and overfishing. It is strictly protected by the Chinese government, named a "national treasure" much like its mammalian counterpart, the giant panda. China has several conservation programmes, including reserves specifically aimed at this species and restocking through release of juveniles in the Yangtze River. Physical appearance Sturgeon are comparatively basal species of fish, whose earliest fossils date back to the Cretaceous period. They are best-known members of the bony fish taxon Chondrostei, a group of bony fishes that have cartilaginous skeletons superficially similar to the skeletons seen in the unrelated chondrichthyan fishes. In Qing dynasty Chinese cuisine, its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specimen Of A Dabry's Sturgeon, Museum Of Hydrobiological Sciences, Wuhan Institute Of Hydrobiology
Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository for research ** Laboratory specimen, a biological specimen taken by sampling ** Zoological specimen, an animal or part of an animal preserved for scientific use ** Herbarium, a collection of preserved plant specimens for scientific study * Type specimen (mineralogy), a reference sample by which a mineral is defined Printing * Specimen banknote, to aid in the recognition of banknotes * Specimen stamp, used to identify valid stamps Other uses * Specimen (band), a 1980s British band * Specimen Products, a Chicago-based audio equipment manufacturer * Specimen Ridge Specimen Ridge, el. is an approximately ridge along the south rim of the Lamar Valley in Yellowstone National Park. The ridge separates the Lamar Valley from Mirror Plateau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Runoff
Surface runoff (also known as overland flow) is the flow of water occurring on the ground surface when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when the soil is saturated by water to its full capacity, and the rain arrives more quickly than the soil can absorb it. Surface runoff often occurs because impervious areas (such as roofs and pavement) do not allow water to soak into the ground. Furthermore, runoff can occur either through natural or man-made processes. Surface runoff is a major component of the water cycle. It is the primary agent of soil erosion by water. The land area producing runoff that drains to a common point is called a drainage basin. Runoff that occurs on the ground surface before reaching a channel can be a nonpoint source of pollution, as it can carry man-made contaminants or natural forms of pollution (such as rotting leaves). Man-made contaminants in run ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wastewater
Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff / storm water, and any sewer inflow or sewer infiltration". In everyday usage, wastewater is commonly a synonym for sewage (also called sewerage, domestic wastewater, or municipal wastewater), which is wastewater that is produced by a community of people. As a generic term wastewater may also be used to describe water containing contaminants accumulated in other settings, such as: * Industrial wastewater: waterborne waste generated from a variety of industrial processes, such as manufacturing operations, mineral extraction, power generation, or water and wastewater treatment. ** Cooling water, released with potential thermal pollution after use to condense steam or reduce machi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Although environmental pollution can be caused by natural events, the word pollution generally implies that the contaminants have an anthropogenic source – that is, a source created by human activities. Pollution is often classed as point source or nonpoint source pollution. In 2015, pollution killed nine million people worldwide (one in six deaths). This remained unchanged in 2019, with little real progress against pollution being identifiable. Air pollution accounted for of these earlier deaths. Major forms of pollution include air pollution, light pollution, litter, noise pollution, plastic pollution, soil contamination, radioac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, a half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute. The Food and Agriculture Organization of the United Nations defines deforestation as the conversion of forest to other land uses (regardless of whether it is human-induced). "Deforestation" and "forest area net change" are not the same: the latter is the sum of all forest losses (deforestation) and all forest gains (forest expansion) in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Fragmentation
Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes that slowly alter the layout of the physical environment (suspected of being one of the major causes of speciation), and human activity such as land conversion, which can alter the environment much faster and causes the extinction of many species. More specifically, habitat fragmentation is a process by which large and contiguous habitats get divided into smaller, isolated patches of habitats. Definition The term habitat fragmentation includes five discrete phenomena: * Reduction in the total area of the habitat * Decrease of the interior: edge ratio * Isolation of one habitat fragment from other areas of habitat * Breaking up of one patch of habitat into several smaller patches * Decrease in the average size of each patch of hab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three Gorges Dam
The Three Gorges Dam is a hydroelectric gravity dam that spans the Yangtze River by the town of Sandouping, in Yiling District, Yichang, Hubei province, central China, downstream of the Three Gorges. The Three Gorges Dam has been the world's largest power station in terms of installed capacity (22,500 MW) since 2012. The dam generates an average 95±20 TWh of electricity per year, depending on annual amount of precipitation in the river basin. After the extensive monsoon rainfalls of 2020, the dam's annual production nearly reached 112 TWh, breaking the previous world record of ~103 TWh set by Itaipu Dam in 2016. The dam body was completed in 2006. The power plant of the dam project was completed and fully functional as of July 4, 2012, when the last of the main water turbines in the underground plant began production. Each main water turbine has a capacity of 700 MW. Coupling the dam's 32 main turbines with two smaller generators (50 MW each) to power the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gezhouba Dam
The Gezhouba Dam or Gezhouba Water Control Project () on the Yangtze River is located in the western suburbs of Yichang, in central China's Hubei province. One of the largest run-of-the-river dams, it sits several kilometers upstream from downtown Yichang, just downstream of the fall of the Huangbo River into the Yangtze. Construction started on December 30, 1970 and ended on December 10, 1988. The dam has a total installed electrical capacity of . After rushing out of Nanjin Pass (南津关, "South Ford Pass"), the Yangtze River slows down and widens from to about at the dam site. Two small islands, Gezhouba and Xiba, divided the river into three channels. There the Gezhouba Project was built. The facility boasts a generating capacity of along with three ship locks, two power stations that generate of electricity annually. It has 27 gates of spillway, and a non-flowing Dam on both banks. The dam is long with a maximum height of . The reservoir has a total volume of . Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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