Editing Great Barrier Reef (section)

===Climate change===
The Great Barrier Reef Marine Park Authority considers the greatest threat to the Great Barrier Reef to be climate change, causing [[ocean warming]] which increases [[coral bleaching]].<ref>{{cite news |url=http://www.150.theage.com.au/view_bestofarticle.asp?straction=update&inttype=1&intid=1850 |title=Global climate change, the Great Barrier Reef and our obligations |publisher=The National Forum |access-date=26 September 2007 |date=19 November 2004 |author1=Rothwell, Don |author2=Stephens, Tim |location=Melbourne |url-status=dead |archive-url=https://web.archive.org/web/20071012184305/http://150.theage.com.au/view_bestofarticle.asp?straction=update&inttype=1&intid=1850 |archive-date=12 October 2007 }}</ref><ref>{{cite web |url=http://www.gbrmpa.gov.au/corp_site/info_services/publications/misc_pub/climate_change_vulnerability_assessment/our_changing_climate |title=Our changing climate |access-date=26 September 2007 |author=Great Barrier Reef Marine Park Authority |url-status=dead |archive-url=https://web.archive.org/web/20071029074337/http://www.gbrmpa.gov.au/corp_site/info_services/publications/misc_pub/climate_change_vulnerability_assessment/our_changing_climate |archive-date=29 October 2007 }}</ref> Mass coral bleaching events due to [[marine heatwave]]s occurred in the summers of 1998, 2002, 2006, 2016, 2017 and 2020,<ref>{{cite web |author=Great Barrier Reef Marine Park Authority |title=Coral Bleaching and Mass Bleaching Events |url=http://www.gbrmpa.gov.au/corp_site/info_services/science/climate_change/coral_bleaching.html |access-date=30 May 2006 |archive-url=https://web.archive.org/web/20060420004634/http://www.gbrmpa.gov.au/corp_site/info_services/science/climate_change/coral_bleaching.html |archive-date=20 April 2006 |url-status=dead }}</ref><ref name=":1" /><ref name=":2">{{Cite news |date=14 October 2020 |title=Great Barrier Reef has lost half of its corals since 1995 |language=en-GB |work=BBC News |url=https://www.bbc.com/news/world-australia-54533971 |access-date=10 November 2020 |archive-date=1 November 2020 |archive-url=https://web.archive.org/web/20201101142224/https://www.bbc.com/news/world-australia-54533971 |url-status=live }}</ref> and coral bleaching is expected to become an annual occurrence.<ref name="tele">{{cite news |url=http://www.news.com.au/story/0,10117,21141105-1702,00.html?from=public_rss |title=Online version |newspaper=[[The Daily Telegraph (Sydney)|The Daily Telegraph]] |date=30 January 2007 |url-status=dead |archive-url=https://web.archive.org/web/20090226143455/http://www.news.com.au/story/0%2C10117%2C21141105-1702%2C00.html?from=public_rss |archive-date=26 February 2009 }}</ref> In 2020, a study found that the Great Barrier Reef has lost more than half of its corals since 1995 due to warmer seas driven by climate change.<ref name=":2" /><ref>{{cite journal |last1=Dietzel |first1=Andreas |last2=Bode |first2=Michael |last3=Connolly |first3=Sean R. |last4=Hughes |first4=Terry P. |title=Long-term shifts in the colony size structure of coral populations along the Great Barrier Reef |journal=Proceedings of the Royal Society B: Biological Sciences |date=14 October 2020 |volume=287 |issue=1936 |pages=20201432 |doi=10.1098/rspb.2020.1432 |pmid=33049171 |pmc=7657849 }}</ref> As global warming continues, corals will not be able to keep up with increasing ocean temperatures. Coral bleaching events lead to increased disease susceptibility, which causes detrimental ecological effects for reef communities.<ref name="Littman">{{cite journal |last1=Littman |first1=Raechel |last2=Willis |first2=Bette L. |last3=Bourne |first3=David G. |year=2011 |title=Metagenomic analysis of the coral holobiont during a natural bleaching event on the Great Barrier Reef |journal=Environmental Microbiology Reports |volume=3 |issue=6 |pages=651–660 |doi=10.1111/j.1758-2229.2010.00234.x |pmid=23761353 |bibcode=2011EnvMR...3..651L }}</ref>

In July 2017 [[UNESCO]] published in a draft decision, expressing serious concern about the impact of coral bleaching on the Great Barrier Reef.  The draft decision also warned Australia that it will not meet the targets of the Reef 2050 report without considerable work to improve water quality.<ref name=":0">[https://www.theguardian.com/environment/2017/jun/03/great-barrier-reef-australia-must-act-urgently-on-water-quality-says-unesco#img-1 Great Barrier Reef: Australia must act urgently on water quality, says Unesco] {{webarchive |url=https://web.archive.org/web/20170603075819/https://www.theguardian.com/environment/2017/jun/03/great-barrier-reef-australia-must-act-urgently-on-water-quality-says-unesco |date=3 June 2017 }} The Guardian. Retrieved 3 June 2017</ref>

Climate change has implications for other forms of reef life{{snd}}some fish's preferred temperature range leads them to seek new habitat, thus increasing chick mortality in predatory seabirds. Climate change will also affect the sea turtle's population and available habitat.<ref name="GBRMPAclimatechange">{{cite web |author=Great Barrier Reef Marine Park Authority |url=http://www.gbrmpa.gov.au/corp_site/info_services/science/climate_change |title=Climate change and the Great Barrier Reef |access-date=16 March 2007 |url-status=dead |archive-url=https://web.archive.org/web/20061208045117/http://www.gbrmpa.gov.au/corp_site/info_services/science/climate_change |archive-date=8 December 2006 }}</ref>

Bleaching events in benthic coral communities (deeper than {{convert|20|m|ft|disp=or}}) in the Great Barrier reef are not as well documented as those at shallower depths, but recent research has shown that benthic communities are just as negatively impacted in the face of rising ocean temperatures. Five Great Barrier Reef species of large benthic corals were found bleached under elevated temperatures, affirming that benthic corals are vulnerable to thermal stress.<ref name="Schmidt">{{cite journal |last1=Schmidt |first1=C. |last2=Heinz |first2=P. |last3=Kucera |first3=M. |first4=Sven |last4=Uthicke |year=2011 |title=Temperature-induced stress leads to bleaching in larger benthic foraminifera hosting endosymbiotic diatoms |journal=Limnology and Oceanography |volume=56 |issue=5 |pages=1587–1602 |url=http://wap.aslo.org/lo/toc/vol_56/issue_5/1587.pdf |doi=10.4319/lo.2011.56.5.1587 |url-status=dead |archive-url=https://web.archive.org/web/20160304034652/http://wap.aslo.org/lo/toc/vol_56/issue_5/1587.pdf |archive-date=4 March 2016 |bibcode=2011LimOc..56.1587S |s2cid=85648669 }}</ref>