Editing Yangtze (section)

===Fish===
[[File:Acipenser sinensis.JPG|thumb|The two [[sturgeon]] species in the Yangtze (here [[Chinese sturgeon]]) are both seriously threatened.]]
{{As of|2011}}, 416 fish species are known from the Yangtze [[Drainage basin|basin]], including 362 that strictly are freshwater species. The remaining are also known from salt or [[brackish]] waters, such as the river's [[estuary]] or the [[East China Sea]]. This makes it one of the most species-rich rivers in Asia and by far the most species-rich in China (in comparison, the [[Pearl River (China)|Pearl River]] has almost 300 fish species and the [[Yellow River]] 160).<ref name=FishDiversity/> 178 fish species are endemic to the Yangtze River Basin.<ref name=FishDiversity/> Many are only found in some section of the river basin and especially the upper reach (above [[Yichang]], but below the headwaters in the [[Qinghai-Tibet Plateau]]) is rich with 279 species, including 147 Yangtze endemics and 97 strict endemics (found only in this part of the basin). In contrast, the headwaters, where the average altitude is above {{convert|4500|m|ft|abbr=on}}, are only home to 14 highly specialized species, but 8 of these are endemic to the river.<ref name=FishDiversity/> The largest orders in the Yangtze are [[Cypriniformes]] (280 species, including 150 endemics), [[Siluriformes]] (40 species, including 20 endemics), [[Perciformes]] (50 species, including 4 endemics), [[Tetraodontiformes]] (12 species, including 1 endemic) and [[Osmeriformes]] (8 species, including 1 endemic). No other order has more than four species in the river and one endemic.<ref name=FishDiversity/>

Many Yangtze fish species have declined drastically and 65 were recognized as [[Threatened species|threatened]] in the 2009 Chinese [[Regional Red List|red list]].<ref name=ThreatenedFish>Wang, S.; and Xie, Y. (2009). ''China species red list''. Vol. II Vertebrates – Part 1. High Education Press, Beijing, China.</ref> Among these are three that are considered entirely [[extinct]] ([[Chinese paddlefish]], ''[[Anabarilius liui liui]]'' and ''[[Atrilinea macrolepis]]''), two that are [[extinct in the wild]] (''[[Anabarilius polylepis]]'', ''[[Schizothorax parvus]]''), four that are [[critically endangered]]  ''[[Euchiloglanis kishinouyei]]'', ''[[Megalobrama elongata]]'', ''[[Schizothorax longibarbus]]'' and ''[[Leiocassis]] longibarbus'').<ref name=ThreatenedFish/><ref name="Animals 2020">{{cite web |date=January 8, 2020 |title=Chinese paddlefish, one of world's largest fish, declared extinct |url=https://www.nationalgeographic.com/animals/2020/01/chinese-paddlefish-one-of-largest-fish-extinct/ |url-status=dead |archive-url=https://web.archive.org/web/20200108130420/https://www.nationalgeographic.com/animals/2020/01/chinese-paddlefish-one-of-largest-fish-extinct/ |archive-date=January 8, 2020 |access-date=January 8, 2020 |website=Animals}}</ref> Additionally, both the [[Yangtze sturgeon]] and [[Chinese sturgeon]] are considered critically endangered by the [[IUCN]]. The survival of these two sturgeon may rely on the continued release of captive bred specimens.<ref name=IUCNAcipenserdabryanus>{{cite iucn |author=Qiwei, W. |date=2010 |title=''Acipenser dabryanus'' |volume=2010 |page=e.T231A174775412 |doi=10.2305/IUCN.UK.2010-1.RLTS.T231A174775412.en |access-date=12 November 2021}}</ref><ref name=IUCNAcipensersinensis>{{cite iucn |author=Qiwei, W. |date=2010 |title=''Acipenser sinensis'' |volume=2010 |page=e.T236A13044272 |doi=10.2305/IUCN.UK.2010-1.RLTS.T236A13044272.en |access-date=12 November 2021}}</ref> Although still listed as critically endangered rather than extinct by both the Chinese red list and IUCN, recent reviews have found that the Chinese paddlefish is extinct.<ref name="Yirka 2020">{{cite web | last=Yirka | first=Bob | title=Chinese paddlefish declared extinct | website=Phys.org | date=January 8, 2020 | url=https://phys.org/news/2020-01-chinese-paddlefish-declared-extinct.html | access-date=January 9, 2020 | archive-url=https://web.archive.org/web/20200108181752/https://phys.org/news/2020-01-chinese-paddlefish-declared-extinct.html | archive-date=January 8, 2020 | url-status=live }}</ref><ref name="Cheung 2020">{{cite web | last=Cheung | first=Eric | title=Up to 23 feet long, the Chinese paddlefish was the giant of the Yangtze. And we killed it | work=CNN | date=January 7, 2020 | url=https://www.cnn.com/2020/01/07/asia/chinese-paddlefish-extinct-study-intl-hnk-scli/index.html | access-date=January 9, 2020 | archive-url=https://web.archive.org/web/20200109010819/https://www.cnn.com/2020/01/07/asia/chinese-paddlefish-extinct-study-intl-hnk-scli/index.html | archive-date=January 9, 2020 | url-status=live }}</ref> Surveys conducted between 2006 and 2008 by [[ichthyologists]] failed to catch any, but two probable specimens were recorded with [[Hydroacoustics|hydroacoustic]] signals.<ref>{{cite journal | year = 2009 | title = Is there evidence that the Chinese paddlefish (Psephurus gladius) still survives in the upper Yangtze River? Concerns inferred from hydroacoustic and capture surveys, 2006–2008. | journal = Journal of Applied Ichthyology | volume = 25 | pages = 95–99 | doi = 10.1111/j.1439-0426.2009.01268.x  | last1 = Zhang | first1 = H. | last2 = Wei | first2 = Q. W. | last3 = Du | first3 = H. | last4 = Shen | first4 = L. | last5 = Li | first5 = Y. H. | last6 = Zhao | first6 = Y.| doi-access = free | bibcode = 2009JApIc..25...95Z }}</ref> The last definite record was an individual that was accidentally captured near Yibin in 2003 and released after having been [[Wildlife radio telemetry|radio tagged]].<ref name="Animals 2020"/> The Chinese sturgeon is the largest fish in the river and among the largest freshwater fish in the world, reaching a length of {{convert|5|m|ft|abbr=on}}; the extinct Chinese paddlefish reputedly reached as much as {{convert|7|m|ft|abbr=on}}, but its maximum size is labeled with considerable uncertainty.<ref>Meadows, D.; and Coll, H. (2013). ''[http://www.nmfs.noaa.gov/pr/pdfs/statusreviews/sturgeon_5foreign.pdf Status Review Report of Five Foreign Sturgeon.] {{Webarchive|url=https://web.archive.org/web/20141219084715/http://www.nmfs.noaa.gov/pr/pdfs/statusreviews/sturgeon_5foreign.pdf |date=December 19, 2014 }}'' National Marine Fisheries Service, Report to Office of Protected Resources.</ref><ref name=IUCNPsephurusgladius>{{cite iucn |author=Qiwei, W. |date=2010 |title=''Psephurus gladius'' |volume=2010 |page=e.T18428A8264989 |doi=10.2305/IUCN.UK.2010-1.RLTS.T18428A8264989.en |access-date=12 November 2021}}</ref><ref>{{FishBase |genus=Psephurus|species=gladius|month=January|year=2020}}</ref>

[[File:Hypophthalmichthys molitrix Hungary.jpg|thumb|The [[silver carp]] is native to the river, but has (like other [[Asian carp]]) been spread through large parts of the world with [[aquaculture]].]]
The largest threats to the Yangtze native fish are [[overfishing]] and habitat loss (such as building of dams and [[land reclamation]]), but pollution, [[destructive fishing practices]] (such as [[Blast fishing|fishing with dynamite]] or poison) and [[introduced species]] also cause problems.<ref name=FishDiversity/> About {{frac|2|3}} of the total freshwater fisheries in China are in the Yangtze Basin,<ref>Liu, J.; and Cao, W. (1992). ''Fish resources in the Yangtze basin and the strategy for their conservation''. Resources and environment in the Yangtze Valley, 1: 17–23.</ref> but a drastic decline in size of several important species has been recorded, as highlighted by data from lakes in the river basin.<ref name=FishDiversity/> In 2015, some experts recommend a 10-year fishing moratorium to allow the remaining populations to recover,<ref name=FishingMoratorium>Yiman, L.; and Zhouyang, D. (January 4, 2013). ''[https://www.chinadialogue.net/article/show/single/en/5572-Expert-calls-for-1-year-fishing-moratorium-on-Yangtze-River Expert calls for 10-year fishing moratorium on Yangtze River.] {{Webarchive|url=https://web.archive.org/web/20160304100207/https://www.chinadialogue.net/article/show/single/en/5572-Expert-calls-for-1-year-fishing-moratorium-on-Yangtze-River |date=March 4, 2016 }}'' ChinaDialogue. Retrieved November 12, 2015.</ref> and in January 2020 China imposed a 10-year fishing moratorium on 332 sites along the Yangtze.<ref>{{cite news |title=China imposes a 10-year fishing ban for Yangtze River to protect marine biodiversity  |work=[[South China Morning Post]] |date=January 7, 2020 |url=https://finance.yahoo.com/video/china-imposes-10-fishing-ban-050107819.html |access-date=January 7, 2020 }}</ref> Dams present another serious problem, as several species in the river perform breeding [[Fish migration|migrations]] and most of these are non-jumpers, meaning that normal [[fish ladder]]s designed for [[salmon]] are ineffective.<ref name=FishDiversity/> For example, the [[Gezhouba Dam]] blocked the migration of the paddlerfish and two sturgeon,<ref name=IUCNAcipenserdabryanus/><ref name=IUCNAcipensersinensis/><ref name=IUCNPsephurusgladius/> while also effectively splitting the [[Chinese high fin banded shark]] population into two<ref>Zhang, C.-G.; and Zhao, Y.-H. (2001). ''Migration of the Chinese sucker (Myxocyprinus asiaticus) in the Yangtze River Basin with discussion on the potential effect of dams on fish''. Current Zoology, 47(5): 518–521.</ref> and causing the [[Local extinction|extirpation]] of the Yangtze population of the [[Japanese eel]].<ref>Xie, P.; and Chen, Y. (1999). ''Threats to biodiversity in Chinese inland waters''. Ambio, 28: 674–681.</ref> In an attempt of minimizing the effect of the dams, the [[Three Gorges Dam]] has released water to mimic the (pre-dam) natural flooding and trigger the breeding of carp species downstream.<ref name=NatureConservancy>{{cite web | title=Protecting the Yangtze River in China | website=nature.org | date=2015-09-10 | url=http://www.nature.org/ourinitiatives/regions/asiaandthepacific/china/placesweprotect/china-yangtze-river.xml | archive-url=https://web.archive.org/web/20151114185049/http://www.nature.org/ourinitiatives/regions/asiaandthepacific/china/placesweprotect/china-yangtze-river.xml | archive-date=2015-11-14 | url-status=unfit }}</ref> In addition to dams already built in the Yangtze basin, several large dams are planned and these may present further problems for the native fauna.<ref name=NatureConservancy/>

While many fish species native to the Yangtze are seriously threatened, others have become important in [[fish farming]] and introduced widely outside their native range. A total of 26 native fish species of the Yangtze basin are farmed.<ref name=FishingMoratorium/> Among the most important are four [[Asian carp]]: [[grass carp]], [[black carp]], [[silver carp]] and [[bighead carp]]. Other species that support important fisheries include [[northern snakehead]], [[Chinese perch]], ''[[Takifugu]]'' pufferfish (mainly in the lowermost sections) and [[predatory carp]].<ref name=FishDiversity/>