Editing Holocene extinction (section)

===Overexploitation===
{{See also|Species affected by poaching|Overfishing}}
[[File:Vaquita4 Olson NOAA.jpg|thumb|upright=1.15|The [[vaquita]], the world's most endangered marine mammal, was reduced to 30 individuals as of February 2017. They are often killed by commercial fishing nets.<ref>{{cite news|first=Virginia|last=Morell|title=World's most endangered marine mammal down to 30 individuals|url=https://www.science.org/content/article/world-s-most-endangered-marine-mammal-down-30-individuals|work=[[Science (magazine)|Science]]|date=February 1, 2017|access-date=February 3, 2017}}</ref> As of March 2019, only 10 remain, according to The International Committee for the Recovery of the Vaquita.<ref>{{cite news|date= March 15, 2019|title=World's most endangered marine mammal is now down to 10 animals|url=https://www.newscientist.com/article/2196694-worlds-most-endangered-marine-mammal-is-now-down-to-10-animals/|work=New Scientist|access-date=March 16, 2019}}</ref>]]
[[File:Northwest Atlantic cod biomass.svg|thumb|upright=1.15|left|The [[collapse of the Atlantic northwest cod fishery]] as a result of [[overfishing]], and subsequent recovery.]]
Overhunting can reduce the local population of [[game (hunting)|game animals]] by more than half, as well as reducing population density, and may lead to extinction for some species.<ref>{{cite journal|last=Redford|first=K. H.|year=1992|title=The empty forest|journal=BioScience|volume=42|issue=6|pages=412–422|url=http://www.dse.ufpb.br/alexandre/Redford%201992%20-The%20empty%20forest.pdf|doi=10.2307/1311860|jstor=1311860|access-date=2017-01-10|archive-date=2021-02-28|archive-url=https://web.archive.org/web/20210228092214/http://www.dse.ufpb.br/alexandre/Redford%201992%20-The%20empty%20forest.pdf|url-status=live}}</ref> Populations located nearer to villages are significantly more at risk of depletion.<ref name=peres2006>{{cite book|last1=Peres|first1=Carlos A.|first2=Hilton S.|last2=Nascimento|title=Human Exploitation and Biodiversity Conservation |chapter=Impact of Game Hunting by the Kayapo´ of South-eastern Amazonia: Implications for Wildlife Conservation in Tropical Forest Indigenous Reserves|series=Topics in Biodiversity and Conservation|volume=3|issue=8|year=2006 |pages=287–313|isbn=978-1-4020-5283-5}}</ref><ref>{{cite journal|last1=Altrichter|first1=M. |last2=Boaglio|first2=G.|title=Distribution and Relative Abundance of Peccaries in the Argentine Chaco: Associations with Human Factors|journal=Biological Conservation|volume=116|issue=2|year=2004|pages=217–225|doi=10.1016/S0006-3207(03)00192-7|bibcode=2004BCons.116..217A }}</ref> Several conservationist organizations, among them [[IFAW]] and [[HSUS]], assert that [[Trophy hunting|trophy hunters]], particularly from the United States, are playing a significant role in the decline of giraffes, which they refer to as a "silent extinction".<ref>{{cite news|last=Milman|first=Oliver|date=April 19, 2017|title=Giraffes must be listed as endangered, conservationists formally tell US|url=https://www.theguardian.com/environment/2017/apr/19/giraffes-endangered-species-conservation-hunting|work=The Guardian|access-date=April 29, 2018|archive-date=April 30, 2018|archive-url=https://web.archive.org/web/20180430050100/https://www.theguardian.com/environment/2017/apr/19/giraffes-endangered-species-conservation-hunting|url-status=live}}</ref>

The surge in the mass killings by [[poachers]] involved in the illegal ivory trade along with habitat loss is threatening [[African elephant]] populations.<ref>{{cite report |author1=UNEP |author2=CITES |author3=IUCN |author4=TRAFFIC |year=2013 |url=http://www.unep.org/pdf/RRAivory_draft7.pdf |title=Elephants in the Dust – The African Elephant Crisis |type=A Rapid Response Assessment |isbn=978-82-7701-111-0 |publisher=United Nations Environment Programme. Printed by Birkeland Trykkeri AS, Norway |archive-url=https://web.archive.org/web/20160810061656/http://www.unep.org/pdf/RRAivory_draft7.pdf |archive-date=2016-08-10|url-status=dead}}</ref><ref name="sevenyears">{{cite news |title=African Elephant Population Dropped 30 Percent in 7 Years |work=The New York Times |date=September 1, 2016 |url=https://www.nytimes.com/2016/09/02/world/africa/african-elephant-population-dropped-30-percent-in-7-years.html?_r=1 |url-access=subscription |access-date=February 22, 2017 |archive-date=March 8, 2021 |archive-url=https://web.archive.org/web/20210308134535/https://www.nytimes.com/2016/09/02/world/africa/african-elephant-population-dropped-30-percent-in-7-years.html?_r=1 |url-status=live }}</ref> In 1979, their populations stood at 1.7&nbsp;million; at present there are fewer than 400,000 remaining.<ref>{{cite web |last=Marche |first=Stephen |url=https://www.esquire.com/entertainment/movies/a50431/the-ivory-game-review-netflix/ |title=This Is the Most Important Issue That's Not Being Talked About in This Election |work=[[Esquire (magazine)|Esquire]] |date=November 7, 2016 |access-date=March 14, 2022 |archive-date=March 14, 2022 |archive-url=https://web.archive.org/web/20220314145407/https://www.esquire.com/entertainment/movies/a50431/the-ivory-game-review-netflix/ |url-status=live }}</ref> Prior to European colonization, scientists believe Africa was home to roughly 20 million elephants.<ref>{{cite web |last1=McKenzie |first1=David |last2=Formanek |first2=Ingrid |url=http://www.cnn.com/2016/08/31/africa/great-elephant-census/ |title=Our living dinosaurs |publisher=[[CNN]] |date=September 1, 2016 |access-date=2022-11-10 |archive-date=2021-02-13 |archive-url=https://web.archive.org/web/20210213183959/http://www.cnn.com/2016/08/31/africa/great-elephant-census/ |url-status=live }}</ref> According to the [[Great Elephant Census]], 30% of African elephants (or 144,000 individuals) disappeared over a seven-year period, 2007 to 2014.<ref name="sevenyears"/><ref>{{cite news |last=McKenzie |first=David |date=December 31, 2016 |title=We are failing the elephants |publisher=CNN |url=http://www.cnn.com/2016/12/11/world/vanishing-mckenzie-botswana-elephants/index.html |access-date=2022-11-10 |archive-date=2021-02-06 |archive-url=https://web.archive.org/web/20210206012402/http://www.cnn.com/2016/12/11/world/vanishing-mckenzie-botswana-elephants/index.html |url-status=live }}</ref> African elephants could become extinct by 2035 if poaching rates continue.<ref name="suttergiraffe"/>

[[File:Number of African elephants.svg|thumb|Decline in the number of African elephants since 1500 AD]]

Fishing has had a devastating effect on marine organism populations for several centuries even before the explosion of destructive and highly effective fishing practices like [[trawling]].<ref>{{Cite book|title=The Unnatural History of the Sea|last=Roberts|first=Callum|year=2007}}</ref> Humans are unique among predators in that they regularly prey on other adult [[apex predator]]s, particularly in marine environments;<ref name="Darimont-2015" /> [[bluefin tuna]], [[blue whale]]s, [[North Atlantic right whale]]s,<ref>{{cite news|author=Claudia Geib|date=July 16, 2020|title=North Atlantic right whales now officially 'one step from extinction'|url=https://www.theguardian.com/environment/2020/jul/16/north-atlantic-right-whales-critically-endangered-one-step-from-extinction|work=The Guardian|access-date=July 17, 2020|archive-date=April 8, 2021|archive-url=https://web.archive.org/web/20210408110539/https://www.theguardian.com/environment/2020/jul/16/north-atlantic-right-whales-critically-endangered-one-step-from-extinction|url-status=live}}</ref> and over fifty species of sharks and [[Batoidea|ray]]s are vulnerable to predation pressure from human fishing, in particular commercial fishing.<ref>{{cite news|last=Briggs|first=Helen|date=December 4, 2018|title=World's strangest sharks and rays 'on brink of extinction'|url=https://www.bbc.com/news/science-environment-46420736|work=BBC|access-date=December 10, 2018|archive-date=February 7, 2021|archive-url=https://web.archive.org/web/20210207124715/https://www.bbc.com/news/science-environment-46420736|url-status=live}}</ref> A 2016 study published in ''Science'' concludes that humans tend to hunt larger species, and this could disrupt ocean ecosystems for millions of years.<ref>{{cite journal|last1=Payne|first1=Jonathan L. |last2=Bush|first2=Andrew M.|last3= Heim|first3= Noel A.|last4=Knope| first4=Matthew L.|last5=McCauley |first5=Douglas J. |year=2016|title =Ecological selectivity of the emerging mass extinction in the oceans|journal=Science|volume=353|issue=6305|pages =1284–1286|doi =10.1126/science.aaf2416|pmid= 27629258|bibcode=2016Sci...353.1284P|doi-access=free}}</ref> A 2020 study published in ''[[Science Advances]]'' found that around 18% of marine megafauna, including iconic species such as the [[Great white shark]], are at risk of extinction from human pressures over the next century. In a worst-case scenario, 40% could go extinct over the same time period.<ref>{{cite news|last=Osborne|first=Hannah|date=April 17, 2020|title=Great White Sharks Among Marine Megafauna That Could Go Extinct in Next 100 Years, Study Warns|url=https://www.newsweek.com/great-white-shark-extinction-megafauna-1498592|work=[[Newsweek]]|access-date=April 28, 2020|archive-date=February 22, 2021|archive-url=https://web.archive.org/web/20210222113455/https://www.newsweek.com/great-white-shark-extinction-megafauna-1498592|url-status=live}}</ref> According to a 2021 study published in ''Nature'', 71% of oceanic shark and ray populations have been destroyed by [[overfishing]] (the primary driver of ocean [[defaunation]]) from 1970 to 2018, and are nearing the "point of no return" as 24 of the 31 species are now threatened with extinction, with several being classified as critically endangered.<ref>{{cite news|last=Yeung|first=Jessie|date=January 28, 2021|title=Shark and ray populations have dropped 70% and are nearing 'point of no return,' study warns|url=https://www.cnn.com/2021/01/28/world/sharks-rays-decline-study-intl-hnk-scli-scn/index.html|work=CNN|location=|access-date=January 28, 2021|archive-date=March 7, 2021|archive-url=https://web.archive.org/web/20210307120210/https://www.cnn.com/2021/01/28/world/sharks-rays-decline-study-intl-hnk-scli-scn/index.html|url-status=live}}</ref><ref>{{cite journal|last1= Pacoureau|first1=Nathan|last2= Rigby |first2=Cassandra L.|display-authors=etal.|date=2021|title=Half a century of global decline in oceanic sharks and rays|url=|journal=[[Nature (journal)|Nature]]|volume=589|issue= 7843|pages=567–571|doi=10.1038/s41586-020-03173-9|pmid=33505035|bibcode=2021Natur.589..567P|hdl=10871/124531|s2cid=231723355|hdl-access=free}}</ref><ref>{{cite news|last=Einhorn|first=Catrin|date=January 27, 2021|title=Shark Populations Are Crashing, With a 'Very Small Window' to Avert Disaster|url=https://www.nytimes.com/2021/01/27/climate/sharks-population-study.html|work=[[The New York Times]]|location=|access-date=February 2, 2021|archive-date=January 31, 2021|archive-url=https://web.archive.org/web/20210131005226/https://www.nytimes.com/2021/01/27/climate/sharks-population-study.html|url-status=live}}</ref> Almost two-thirds of sharks and rays around coral reefs are threatened with extinction from overfishing, with 14 of 134 species being critically endangered.<ref>{{cite journal |last1= Sherman|first1=C. Samantha|last2= Simpfendorfer|first2=Colin A.|display-authors=et al|date=2023 |title=Half a century of rising extinction risk of coral reef sharks and rays|url= |journal=[[Nature Communications]] |volume=14 |issue=15 |page=15 |doi=10.1038/s41467-022-35091-x|pmid=36650137 |pmc=9845228 |bibcode=2023NatCo..14...15S |access-date=}}</ref>

{{blockquote|text=If this pattern goes unchecked, the future oceans would lack many of the largest species in today's oceans. Many large species play critical roles in ecosystems and so their extinctions could lead to ecological cascades that would influence the structure and function of future ecosystems beyond the simple fact of losing those species.|source=Jonathan Payne, associate professor and chair of geological sciences at Stanford University<ref>{{cite news |last=Vaughan |first=Adam |date=September 14, 2016 |url=https://www.theguardian.com/environment/2016/sep/14/humanity-driving-unprecedented-marine-extinction |title=Humanity driving 'unprecedented' marine extinction |work=The Guardian |access-date=September 20, 2016 |archive-date=May 6, 2021 |archive-url=https://web.archive.org/web/20210506001024/https://www.theguardian.com/environment/2016/sep/14/humanity-driving-unprecedented-marine-extinction |url-status=live }}</ref>}}
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