Editing Sonar (section)

=== Effect on marine mammals ===
{{Further|Marine mammals and sonar}}
[[File:Humpback Whale underwater shot.jpg|thumb|A [[humpback whale]]]]
Research has shown that use of active sonar can lead to [[Cetacean stranding|mass strandings]] of [[marine mammals]].<ref name="guardian">{{cite news |url=https://www.theguardian.com/environment/2013/jul/03/whales-flee-military-sonar-strandings |title=Whales flee from military sonar leading to mass strandings, research shows |author=Damian Carrington |work=The Guardian |date=3 July 2013 |url-status=live |archive-url=https://web.archive.org/web/20171001191231/https://www.theguardian.com/environment/2013/jul/03/whales-flee-military-sonar-strandings |archive-date=1 October 2017 }}</ref> [[Beaked whales]], the most common casualty of the strandings, have been shown to be highly sensitive to mid-frequency active sonar.<ref>{{cite journal |title=First direct measurements of behavioural responses by Cuvier's beaked whales to mid-frequency active sonar |author=Stacy L. DeRuiter |author2=Brandon L. Southall |author3=John Calambokidis |author4=Walter M. X. Zimmer |author5=Dinara Sadykova |author6=Erin A. Falcone |author7=Ari S. Friedlaender |author8=John E. Joseph |author9=David Moretti |author10=Gregory S. Schorr |author11=Len Thomas |author12=Peter L. Tyack |journal=Biology Letters |year=2013 |volume=9 |issue=4 |page=20130223 |pmid=23825085 |doi=10.1098/rsbl.2013.0223 |pmc=3730631 }}</ref> Other marine mammals such as the [[blue whale]] also flee from the source of the sonar,<ref>{{cite journal |title=Blue whales respond to simulated mid-frequency military sonar |author1=Goldbogen J. A. |author2=Southall B. L. |author3=Deruiter S. L. |author4=Calambokidis J. |author5=Friedlaender A. S. |author6=Hazen E. L. |author7=Falcone E. A. |author8=Schorr G. S. |author9=Douglas A. |author10=Moretti D. J. |author11=Kyburg C. |author12=McKenna M. F. |author13=Tyack P. L. |journal=[[Proceedings of the Royal Society B]] |date=Jul 3, 2013 |volume=280 |issue=765 |page=20130657 |pmid=23825206 |doi=10.1098/rspb.2013.0657 |pmc=3712439 }}</ref> while naval activity was suggested to be the most probable cause of a mass stranding of dolphins.<ref>{{cite journal |title=What caused the UK's largest common dolphin (Delphinus delphis) mass stranding event? |author1=Jepson P. D. |author2=Deaville R. |author3=Acevedo-Whitehouse K. |author4=Barnett J. |author5=Brownlow A. |author6=Brownell R. L. Jr. |author7=Clare F. C. |author8=Davison N. |author9=Law R. J. |author10=Loveridge J. |author11=Macgregor S. K. |author12=Morris S. |author13=Murphy S. |author14=Penrose R. |author15=Perkins M. W. |author16=Pinn E. |author17=Seibel H. |author18=Siebert U. |author19=Sierra E. |author20=Simpson V. |author21=Tasker M. L. |author22=Tregenza N. |author23=Cunningham A. A. |author24=Fernández A. |display-authors=3 |journal=PLOS ONE |date=Apr 30, 2013 |volume=8 |issue=4 |page=e60953 |doi=10.1371/journal.pone.0060953 |pmid=23646103 |bibcode=2013PLoSO...860953J |pmc=3640001 |doi-access=free }}</ref> The US Navy, which part-funded some of the studies, said that the findings only showed behavioural responses to sonar, not actual harm, but they "will evaluate the effectiveness of [their] marine mammal protective measures in light of new research findings".<ref name="guardian"/> A 2008 US Supreme Court ruling on the use of sonar by the US Navy noted that there had been no cases where sonar had been conclusively shown to have harmed or killed a marine mammal.<ref>[https://www.supremecourt.gov/opinions/08pdf/07-1239.pdf Winter vs. National Resources Defense Council] {{webarchive|url=https://web.archive.org/web/20171209044148/https://www.supremecourt.gov/opinions/08pdf/07-1239.pdf |date=2017-12-09 }} No. 07–1239., October term, 2008</ref>

Some marine animals, such as [[whale]]s and [[dolphin]]s, use [[Animal echolocation|echolocation]] systems, sometimes called ''biosonar'' to locate predators and prey. Research on the effects of sonar on [[blue whale]]s in the [[Southern California Bight]] shows that mid-frequency sonar use disrupts the whales' feeding behavior. This indicates that sonar-induced disruption of feeding and displacement from high-quality prey patches could have significant and previously undocumented impacts on [[baleen whale]] foraging ecology, individual [[fitness (biology)|fitness]] and population health.<ref>{{cite journal |title=Blue whales respond to simulated mid-frequency military sonar |author1=Goldbogen J. A. |author2=Southall B. L. |author3=Deruiter S. L. |author4=Calambokidis J. |author5=Friedlaender A. S. |author6=Hazen E. L. |author7=Falcone E. A. |author8=Schorr G. S. |author9=Douglas A. |author10=Moretti D. J. |author11=Kyburg C. |author12=McKenna M. F. |author13=Tyack P. L. |journal=[[Proceedings of the Royal Society B]] |date=Jul 3, 2013 |volume=280 |issue=765 |pmid=23825206 |doi=10.1098/rspb.2013.0657 |page=20130657 |pmc=3712439 }}</ref>

A review of evidence on the mass strandings of beaked whale linked to naval exercises where sonar was used was published in 2019. It concluded that the effects of mid-frequency active sonar are strongest on Cuvier's beaked whales but vary among individuals or populations. The review suggested the strength of response of individual animals may depend on whether they had prior exposure to sonar, and that symptoms of [[decompression sickness]] have been found in stranded whales that may be a result of such response to sonar.  It noted that in the Canary Islands where multiple strandings had been previously reported, no more mass strandings had occurred once naval exercises during which sonar was used were banned in the area, and recommended that the ban be extended to other areas where mass strandings continue to occur.<ref>{{cite journal |title=Advances in research on the impacts of anti-submarine sonar on beaked whales |author1=Bernaldo de Quirós Y |author2=Fernandez A |author3=Baird RW |author4=Brownell RL Jr |author5=Aguilar de Soto N |author6=Allen D, Arbelo M |author7=Arregui M |author8=Costidis A |author9=Fahlman A |author10=Frantzis A |author11=Gulland FMD |author12=Iñíguez M |author13=Johnson M |author14=Komnenou A |author15=Koopman H |author16=Pabst DA |author17=Roe WD |author18=Sierra E |author19=Tejedor M |author20=Schorr G. |display-authors=3 |journal=Proceedings of the Royal Society B |date= 30 January 2019|volume=286|issue=1895|page=20182533| doi= 10.1098/rspb.2018.2533|pmid=30963955 |pmc=6364578}}</ref><ref>{{cite news |url=https://www.independent.co.uk/environment/whales-sonar-ban-military-navy-stranding-beached-canary-islands-a8752611.html |title=Scientists demand military sonar ban to end mass whale strandings|first=Tom |last=Batchelor|date=30 January 2019 |work=The Independent }}</ref>