{{Short description|Whales or dolphins getting stuck on a beach}} {{Redirect distinguish|Beached whale|Beaked whale}} [[File:Blackfish.jpg|thumb|right|upright=1.6|A mass stranding of pilot whales on the shore of Cape Cod, 1902|alt=Photo of dozens of whales]] '''Cetacean stranding''', commonly known as '''beaching''', is a phenomenon in which whales, dolphins and porpoises strand themselves on land, usually on a beach. Beached whales often die due to dehydration, collapsing under their own weight, or drowning when high tide covers the blowhole.<ref>{{cite web |title=Why do beached whales die so often? |url=https://www.sciencefocus.com/nature/why-do-beached-whales-die-so-often |website=BBC Science Focus Magazine |access-date=28 September 2025 |language=en |date=3 March 2016}}</ref><ref>{{cite web |last1=Ballard |first1=Ryan |title=How Do Whales Die [2022] The 7 Most Frequent Causes |url=https://centerforsurfresearch.org/how-do-whales-die/ |website=Surf Researcher |access-date=28 September 2025 |language=en |date=7 December 2021}}</ref> Cetacean stranding has occurred since before recorded history.<ref name="Álvarez-FernándezCarriol2014" />
Several explanations for why cetaceans strand themselves have been proposed, including changes in water temperatures,<ref name="abc-climate">{{cite web|author1=R. Gales|author2=K. Evans|author3=M. Hindell|url=http://www.abc.net.au/7.30/content/2004/s1255082.htm|publisher=Australian Broadcasting Corporation|format=TV transcript|title=Whale strandings no surprise to climatologists|work=7:30 report|date=2004-11-30|access-date=2006-12-02|archive-url=https://web.archive.org/web/20071215052022/http://www.abc.net.au/7.30/content/2004/s1255082.htm|archive-date=2007-12-15|url-status=dead}}</ref> peculiarities of whales' echolocation in certain surroundings,<ref name="uwa-acoustics"/> and geomagnetic disturbances,<ref name="McGrath2017"/> but none have so far been universally accepted as a definitive reason for the behavior. However, a link between the mass beaching of beaked whales and use of mid-frequency active sonar has been found.<ref name=Commerce2000/>
Whales that die due to stranding can subsequently decay and bloat to the point where they can explode, causing gas and their internal organs to fly out.
==Species== {{See also|List of sperm whale strandings}} [[File:1986 beached whales in Flinders Bay (2).JPG|thumb|Beached false killer whales at Flinders Bay, Western Australia, 1986]] Every year, up to 2,000 animals beach themselves.<ref name="Martin"> {{cite book| last=Martin| first=Anthony R. | title=Whales and Dolphins| year=1991| publisher=Salamander Books Ltd. |location=London| isbn=0-8160-3922-4}}</ref> Although the majority of strandings result in death, they pose no threat to any species as a whole. Only about ten cetacean species frequently display mass beachings, with ten more rarely doing so.{{Citation needed|date=April 2023}}
All frequently involved species are toothed whales (Odontoceti), rather than baleen whales (Mysticeti). These species share some characteristics which may explain why they beach.
Body size does not normally affect the frequency, but both the animals' normal habitat and social organization do appear to influence their chances of coming ashore in large numbers. Odontocetes that normally inhabit deep waters and live in large, tightly knit groups are the most susceptible. This includes the sperm whale, oceanic dolphins, pilot whales and orcas, and a few beaked whale species. The most common species to strand in the United Kingdom is the harbour porpoise; the common dolphin (''Delphinus delphis'') is second-most common, and after that long-finned pilot whales (''Globicephala melas'').<ref>{{Cite journal|last1=Coombs|first1=Ellen J.|last2=Deaville|first2=Rob|last3=Sabin|first3=Richard C.|last4=Allan|first4=Louise|last5=O'Connell|first5=Mick|last6=Berrow|first6=Simon|last7=Smith|first7=Brian|last8=Brownlow|first8=Andrew|last9=Doeschate|first9=Mariel Ten|last10=Penrose|first10=Rod|last11=Williams|first11=Ruth|date=2019|title=What can cetacean stranding records tell us? A study of UK and Irish cetacean diversity over the past 100 years|journal=Marine Mammal Science|language=en|volume=35|issue=4|pages=1527–1555|doi=10.1111/mms.12610|bibcode=2019MMamS..35.1527C |issn=0824-0469|hdl=10141/622700|s2cid=198236986|hdl-access=free}}</ref>
Solitary species naturally do not strand en masse. Cetaceans that spend most of their time in shallow, coastal waters almost never mass strand.
==Causes== Strandings can be grouped into several types. The most obvious distinction is between single and multiple strandings. Many theories, some of them controversial, have been proposed to explain beaching, but the question remains unresolved.
;Natural deaths at sea: The carcasses of deceased cetaceans are likely to float to the surface at some point; during this time, currents or winds may carry them to a coastline. Since thousands of cetaceans die every year, many become stranded posthumously. Offshore deaths of multiple whales are unlikely to lead to multiple strandings, since winds and currents are variable and will scatter a group of corpses. Most carcasses never reach the coast, and are scavenged, or decompose enough to sink to the ocean bottom, where the carcass forms the basis of a unique local ecosystem called a ''whale fall''.
;Individual strandings: Single live strandings are often the result of individual illness or injury; in the absence of human intervention these almost inevitably end in death.
;Multiple strandings: Multiple strandings in one place are rare, and often attract media coverage as well as rescue efforts. The strong social cohesion of toothed whale pods appears to be a key factor in many cases of multiple stranding: If one gets into trouble, its distress calls may prompt the rest of the pod to follow and beach themselves alongside.<ref name="abc-mystery">{{cite AV media |first=Anton |last=van Helden |title=Mass whale beaching mystery solved |date=2003-11-26 |series=The Word Today |publisher=Australian Broadcast Corporation |medium=radio transcript |url=http://www.abc.net.au/worldtoday/content/2003/s997632.htm |access-date=2006-12-01 }}</ref>
===Environmental=== [[File:Three Beached Whales, 1577.jpg|thumb|right|''Three Beached Whales'', a 1577 engraving by the Flemish artist Jan Wierix, depicts stranded sperm whales. Note the incorrectly recorded "nostril" and death erection.]] [[File:The-whale-beached-1617.jpg|thumb|"The Whale beached between Scheveningen and Katwijk, with elegant sightseers", by Esaias van de Velde, {{circa|1617}}]] Whales have beached throughout human history, with evidence of humans salvaging from stranded sperm whales in southern Spain during the Upper Magdalenian era some 14,000 years before the present.<ref name="Álvarez-FernándezCarriol2014" /> Some strandings can be attributed to natural and environmental factors, such as rough weather, weakness due to old age or infection, difficulty giving birth,<ref name="abc-mystery"/> hunting too close to shore, or navigation errors.
In 2004, scientists at the University of Tasmania linked whale strandings and weather, hypothesizing that when cool Antarctic waters rich in squid and fish flow north, whales follow their prey closer towards land.<ref name="abc-climate"/> In some cases predators (such as killer whales) have been known to panic other whales, herding them towards the shoreline.<ref name="abc-climate"/>
Their echolocation system can have difficulty picking up very gently-sloping coastlines.<ref name="fatal shore">{{cite magazine |first=B. |last=Montgomery |date=1998-05-02 |title=The fatal shore |magazine=The Weekend Australian Magazine |via=University of Western Australia, Biophysics Dept. |url=http://www.biophysics.uwa.edu.au/Bioacoustics/waustralian.html |url-status=dead |access-date=2006-12-03 |archive-url=https://web.archive.org/web/20061004062237/http://www.biophysics.uwa.edu.au/Bioacoustics/waustralian.html |archive-date=2006-10-04 }}</ref> This theory accounts for mass beaching hot spots such as Ocean Beach, Tasmania and Geographe Bay, Western Australia, where the slope is about half a degree (approximately {{cvt|8|m|disp=sqbr}} deep {{cvt|1|km|spell=in|disp=sqbr}} out to sea). The University of Western Australia Bioacoustics group proposes that repeated reflections between the surface and ocean bottom in gently sloping shallow water may attenuate sound so much that the echo is inaudible to the whales.<ref name="uwa-acoustics"> {{cite conference |last1=Chambers |first1=S. |last2=James |first2=R.N. |date=9 November 2005 |title=Sonar termination as a cause of mass cetacean strandings in Geographe Bay, south-western Australia |book-title=Acoustics 2005, Acoustics in a Changing Environment |conference=Annual Conference of the Australian Acoustical Society |place=Busselton, Western Australia |url=http://www.biophysics.uwa.edu.au/Bioacoustics/articles/ChambersJames2005.pdf |url-status=dead |access-date=2 December 2006 |archive-url=https://web.archive.org/web/20061004062509/http://www.biophysics.uwa.edu.au/Bioacoustics/articles/ChambersJames2005.pdf |archive-date=4 October 2006 }}</ref> Stirred up sand as well as long-lived microbubbles formed by rain may further exacerbate the effect.
A 2017 study by scientists from Germany's University of Kiel suggests that large geomagnetic disruptions of the Earth's magnetic field, brought on through solar storms, could be another cause for whale beachings.<ref name="McGrath2017"> {{cite news |title=Northern lights linked to North Sea whale strandings |last=McGrath |first=Matt |date=2017-09-05 |work=BBC News |url=https://www.bbc.com/news/science-environment-41110082 |access-date=2017-09-05 }}</ref> The authors hypothesize that whales navigate using the Earth's magnetic field by detecting differences in the field's strength to find their way. The solar storms cause anomalies in the field, which may disturb the whales' ability to navigate, sending them into shallow waters where they get trapped.<ref name="McGrath2017"/> The study is based on the mass beachings of 29 sperm whales along the coasts of Germany, the Netherlands, the UK and France in 2016.<ref name="McGrath2017"/>
=== "Follow-me" strandings === thumb|Mass stranding of dolphins, Nova Scotia (1918) Some strandings may be caused by larger cetaceans following dolphins and porpoises into shallow coastal waters.{{citation needed|date=March 2008}} The larger animals may habituate to following faster-moving dolphins. If they encounter an adverse combination of tidal flow and seabed topography, the larger species may become trapped.
Sometimes following a dolphin can help lead a whale out of danger: In 2008, a local dolphin was followed out to open water by two pygmy sperm whales that had become lost behind a sandbar at Mahia Beach, New Zealand.<ref> {{cite news |date=2008-03-12 |title=Dolphin rescues stranded whales |website=CNN |agency=The Associated Press |url=http://edition.cnn.com/2008/WORLD/asiapcf/03/12/nz.whales.ap/index.html |url-status=dead |access-date=2008-03-15 |archive-url=https://web.archive.org/web/20080313191401/http://edition.cnn.com/2008/WORLD/asiapcf/03/12/nz.whales.ap/index.html |archive-date=2008-03-13 }}</ref>
===Orcas' intentional, temporary strandings=== Pods of killer whales – predators of dolphins and porpoises – very rarely strand. It might be that killer whales have learned to stay away from shallow waters, and that heading to the shallows offers the smaller animals some protection from predators. However, killer whales in Península Valdés, Argentina, and the Crozet Islands in the Indian Ocean ''have'' learned how to operate in shallow waters, particularly in their pursuit of seals. The killer whales regularly demonstrate their competence by chasing seals up shelving gravel beaches, up to the edge of the water. The pursuing whales are occasionally partially thrust out of the sea by a combination of their own impetus and retreating water, and have to wait for the next wave to re-float them and carry them back to sea.<ref name=Baird-2002-p24> {{cite book |last=Baird |first=Robin W. |year=2002 |title=Killer Whales of the World |page=24 |publisher=Voyageur Press |place=Stillwater, MN }}</ref>
[[File:Orcas in Punta Norte Valdes Peninsula - panoramio.jpg|thumb|A killer whale hunting sea lions at Valdes Peninsula, Argentina, deliberately stranding itself in the process]] In Argentina, killer whales are known to hunt on the shore by intentionally beaching themselves and then lunging at nearby seals before riding the next wave safely back into deeper waters. This was first observed in the early 1970s, then hundreds times more since within this pod. This behavior seems to be taught from one generation to the next, evidenced by older individuals nudging juveniles towards the shore, and can sometimes also be a play activity.<ref name=Baird-2002-p24/><ref> {{cite journal |first=C. |last=Guinet |year=1991 |title=Intentional stranding apprenticeship and social play in killer whales (''Orcinus orca'') |journal=Canadian Journal of Zoology |volume=69 |issue=1 |pages=2712–2716 |doi=10.1139/z91-383 |bibcode=1991CaJZ...69.2712G }}</ref><ref> {{cite news |first=Matt |last=Kaplan |year=2007 |title=Unique orca hunting-technique documented |series=News |journal=Nature |doi=10.1038/news.2007.380 |url=https://www.nature.com/news/2007/071214/full/news.2007.380.html }}</ref>
===Sonar=== {{see also|Noise pollution|Marine mammals and sonar}} There is evidence that active sonar leads to beaching. On some occasions cetaceans have stranded shortly after military sonar was active in the area, suggesting a link.<ref name=Commerce2000> {{cite report |collaboration=U.S. Department of Commerce & Secretary of the Navy |title=Bahamas Marine Mammal Stranding Event of 15–16 March 2000 |date=December 2001 |series=Joint Interim Report |url=http://www.nmfs.noaa.gov/pr/pdfs/acoustics/bahamas_stranding.pdf |access-date=13 March 2010 |archive-url=https://web.archive.org/web/20051023064543/http://www.nmfs.noaa.gov/pr/pdfs/acoustics/bahamas_stranding.pdf |archive-date=23 October 2005 |url-status=dead }}</ref> Theories describing how sonar may cause whale deaths have also been advanced after necropsies found internal injuries in stranded cetaceans. In contrast, some who strand themselves due to seemingly natural causes are usually healthy prior to beaching: {{blockquote|The low frequency active sonar (LFA sonar) used by the military to detect submarines is the loudest sound ever put into the seas. Yet the U.S. Navy is planning to deploy LFA sonar across 80 percent of the world ocean. At an amplitude of two hundred forty decibels, it is loud enough to kill whales and dolphins and has already caused mass strandings and deaths in areas where U.S. and/or NATO forces have conducted exercises. |source={{harvnb|Whitty |2007|p=50}} }}
====Direct injury==== The large and rapid pressure changes made by loud sonar can cause hemorrhaging. Evidence emerged after 17 cetaceans were hauled out in the Bahamas in March 2000 following a United States Navy sonar exercise. The Navy accepted blame agreeing that the dead whales experienced acoustically induced hemorrhages around the ears.<ref name=Commerce2000/> The resulting disorientation probably led to the stranding. Ken Balcomb, a cetologist, specializes in the killer whale populations that inhabit the Strait of Juan de Fuca between Washington and Vancouver Island.<ref> {{cite news |last=Balcomb |first=Ken |date=2003-05-12 |title=U.S. Navy sonar blasts Pacific Northwest killer whales |newspaper=San Juan Islander |url=http://www.sanjuanislander.com/groups/center_for_whale_research/sonar.shtml |url-status=dead |access-date=2006-04-30 |archive-url=https://web.archive.org/web/20060523192154/http://www.sanjuanislander.com/groups/center_for_whale_research/sonar.shtml |archive-date=23 May 2006 }}</ref> He investigated these beachings and argues that the powerful sonar pulses resonated with airspaces in the dolphins, tearing tissue around the ears and brain.<ref> {{cite web |last=Balcomb |first=Ken |date=2001-02-23 |title=Letter |publisher=Ocean Mammal Institute |url=http://www.oceanmammalinst.org/kenbalcombletter.htm |url-status=live |access-date=2006-04-30 |archive-url=https://web.archive.org/web/20060525010831/http://www.oceanmammalinst.org/kenbalcombletter.htm |archive-date=25 May 2006 }}</ref> Apparently not all species are affected by sonar.<ref> {{cite magazine |last=Borrell |first=Brendan |date=1 June 2009 |title=Why do whales beach themselves? |magazine=Scientific American |url=https://www.scientificamerican.com/article/why-do-whales-beach-themselves |access-date=September 22, 2020 }}</ref>
====Injury at a vulnerable moment==== Another means by which sonar could be hurting cetaceans is a form of decompression sickness. This was first raised by necrological examinations of 14 beaked whales stranded in the Canary Islands. The stranding happened on 24 September 2002, close to the operating area of Neo Tapon, an international naval exercise, about four hours after the activation of mid-frequency sonar.<ref name="jepson-2003"> {{cite journal |first1=P.D. |last1=Jepson |first2=M. |last2=Arbelo |first3=R. |last3=Deaville |first4=I.A.P. |last4=Patterson |first5=P. |last5=Castro |first6=J.R. |last6=Baker |first7=E. |last7=Degollada |first8=H.M. |last8=Ross |first9=P. |last9=Herráez |first10=A.M. |last10=Pocknell |first11=F. |last11=Rodríguez |first12=F.E. |last12=Howie |first13=A. |last13=Espinosa |first14=R.J. |last14=Reid |first15=J.R. |last15=Jaber |first16=V. |last16=Martin |first17=A.A. |last17=Cunningham |first18=A. |last18=Fernández |display-authors=6 |date=9 October 2003 |title=Gas-bubble lesions in stranded cetaceans |journal=Nature |volume=425 |issue=6958 |pages=575–576 |doi=10.1038/425575a |pmid=14534575 |bibcode=2003Natur.425..575J |s2cid=26717950 }}</ref> The team of scientists found acute tissue damage from gas-bubble lesions, which are indicative of decompression sickness.<ref name="jepson-2003"/>
The precise mechanism of how sonar causes bubble formation is not known. It could be due to cetaceans panicking and surfacing too rapidly in an attempt to escape the sonar pulses. There is also a theoretical basis by which sonar vibrations can cause supersaturated gas to nucleate, forming bubbles, which are responsible for decompression sickness.<ref> {{cite journal |first1=D.S. |last1=Houser |first2=R. |last2=Howards |first3=S. |last3=Ridgway |date=21 November 2001 |title=Can diving-induced tissue nitrogen supersaturation increase the chance of acoustically driven bubble growth in marine mammals? |journal=Journal of Theoretical Biology |volume=213 |issue=2 |pages=183–195 |pmid=11894990 |doi=10.1006/jtbi.2001.2415 |bibcode=2001JThBi.213..183H |s2cid=19130432 |url=https://zenodo.org/record/1229940 }}</ref>
====Diving patterns of Cuvier's beaked whales==== The overwhelming majority of the cetaceans involved in sonar-associated beachings are Cuvier's beaked whales (''Ziphius cavirostrus''). Individuals of this species strand frequently, but mass strandings are rare.
Cuvier's beaked whales are an open-ocean species that rarely approach the shore, making them difficult to study in the wild. Prior to the interest raised by the sonar controversy, most of the information about them came from stranded animals. The first to publish research linking beachings with naval activity were Simmonds and Lopez-Jurado in 1991. They noted that over the past decade there had been a number of mass strandings of beaked whales in the Canary Islands, and each time the Spanish Navy was conducting exercises. Conversely, there were no mass strandings at other times. They did not propose a theory for the strandings. Fernández ''et al.'' in a 2013 letter to ''Nature'' reported that there had been no further mass strandings in that area, following a 2004 ban by the Spanish government on military exercises in that region.<ref> {{cite journal |last1=Fernández |first1=A. |last2=Arbelo |first2=M. |last3=Martín |first3=V. |year=2013 |title=Whales: No mass strandings since sonar ban |journal=Nature |volume=497 |issue=7449 |page=317 |pmid=23676745 |doi=10.1038/497317d |bibcode=2013Natur.497..317F |doi-access=free }}</ref>
In May 1996, there was another mass stranding in West Peloponnese, Greece. At the time, it was noted as "atypical" both because mass strandings of beaked whales are rare, and also because the stranded whales were spread over such a long stretch of coast, with each individual whale spatially separated from the next stranding. At the time of the incident, there was no connection made with active sonar; A. Frantzis, the marine biologist investigating the incident, made the connection to sonar because he discovered a notice to mariners concerning the test. His report was published in March 1998.<ref> {{cite journal |last=Frantzis |first=A. |date=1988-03-05 |title=Does acoustic testing strand whales? |journal=Nature |volume=392 |issue=6671 |page=29 |doi=10.1038/32068 |pmid=9510243 |s2cid=205001662 |doi-access=free }}</ref>
Peter Tyack, of Woods Hole Oceanographic Institute, has been researching noise's effects on marine mammals since the 1970s. He has led much of the recent research on beaked whales (Cuvier's beaked whales in particular). Data tags have shown that Cuvier's dive considerably deeper than previously thought, and are in fact the deepest-diving species of marine mammal yet known.
At shallow depths Cuvier's stop vocalizing, either because of fear of predators, or because they don't need vocalization to track each other at shallow depths, where they have light adequate to see each other.
Their surfacing behavior is highly unusual, because they exert considerable physical effort to surface by a controlled ascent, rather than passively floating to the surface as sperm whales do. Every deep dive is followed by three or four shallow dives. The elaborate dive patterns are assumed to be necessary to control the diffusion of gases in the bloodstream. No data show a beaked whale making an uncontrolled ascent, or failing to do successive shallow dives.{{citation needed|date=September 2020}} This behavior suggests that the Cuvier's are in a vulnerable state after a deep dive – presumably on the verge of decompression sickness – and require time and perhaps the shallower dives to recover.
====Summary review==== De Quirós ''et al.'' (2019)<ref name=de-Quirós-etal-2019-01-30/> published a review of evidence on the mass strandings of beaked whale linked to naval exercises where sonar was used. 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 no more mass strandings had occurred in the Canary Islands once naval exercises where sonar was used were banned, and recommended that the ban be extended to other areas where mass strandings continue to occur.<ref name=de-Quirós-etal-2019-01-30> {{cite journal |last1=Bernaldo de Quirós |first1=Y. |last2=Fernandez |first2=A. |last3=Baird |first3=R.W. |last4=Brownell, Jr. |first4=R.L. |last5=Aguilar de Soto |first5=N. |last6=Allen |first6=D. |last7=Arbelo |first7=M. |last8=Arregui |first8=M. |last9=Costidis |first9=A. |last10=Fahlman |first10=A. |last11=Frantzis |first11=A. |last12=Gulland |first12=F.M.D. |last13=Iñíguez |first13=M. |last14=Johnson |first14=M. |last15=Komnenou |first15=A. |last16=Koopman |first16=H. |last17=Pabst |first17=D.A. |last18=Roe |first18=W.D. |last19=Sierra |first19=E. |last20=Tejedor |first20=M. |last21=Schorr |first21=G. |date=30 January 2019 |title=Advances in research on the impacts of anti-submarine sonar on beaked whales |journal=Proceedings of the Royal Society B |volume=286 |issue=1895 |page= |pmid=30963955 |pmc=6364578 |doi=10.1098/rspb.2018.2533 }}</ref><ref> {{cite news |first=Tom |last=Batchelor |date=30 January 2019 |title=Scientists demand military sonar ban to end mass whale strandings |newspaper=The Independent |url=https://www.independent.co.uk/environment/whales-sonar-ban-military-navy-stranding-beached-canary-islands-a8752611.html }}</ref>
==Ecology== {{Section expand|date=March 2025}} The first detailed ecological study of the decomposition of a stranded whale was carried out with a minke whale (''Balaenoptera acutorostrata'') beached on the Dutch island of Rottumerplaat on 25 November 2020. The carcass was examined at regular intervals over the following two years, recording the scavengers and other species that used it.<ref>{{cite journal | last1=Baptist | first1=Martin J. | last2=Leopold | first2=Mardik F. | last3=van Puijenbroek | first3=Marinka E. B. | last4=Verdaat | first4=Hans | last5=Janinhoff-Verdaat | first5=Nicole | last6=Lammertsma | first6=Dennis R. | last7=Dimmers | first7=Wim J. | last8=Römkens | first8=Paul F. A. M. | last9=Burgers | first9=Jan | title=Decomposition of a minke whale carcass in a temperate dune ecosystem | journal=Frontiers in Marine Science | volume=12 | date=2025-03-05 | issn=2296-7745 | doi=10.3389/fmars.2025.1474460 | doi-access=free | page=| bibcode=2025FrMaS..1274460B }}</ref>
==Rescue== [[File:Whales on beach, Farewell Split, South Island, New Zealand.JPG|thumb|right|Beached whales being kept wet, New Zealand]] Many stranded whales have been rescued; methods include pouring water onto the whale to keep it cool and its skin wet while waiting for a high tide.<ref>{{cite web |title=How Scientists Rescue Stranded Whales Like Those in the Everglades |url=https://www.nationalgeographic.com/adventure/article/131205-rescue-stranded-whales-everglades-marine-mammals-science |website=National Geographic |access-date=4 April 2026}}</ref> Whales are large, making rescue difficult without training; wildlife charities like British Divers Marine Life Rescue have run training courses for local volunteers in some areas where beaching is common.<ref>{{cite news |title=Volunteers take part in training exercise to help beached whales |url=https://www.bbc.co.uk/newsround/66777694 |access-date=4 April 2026 |publisher=BBC}}</ref><ref>{{cite news |title=Volunteers needed as more whales and dolphins strand alive |url=https://www.bbc.com/news/articles/cqlg4vl61kro|work=BBC News |access-date=4 April 2026}}</ref>
==Disposal== {{See also|Exploding whale|Whale fall}} [[File:A beachcomber is looking at the marks of great white sharks bites.jpg|thumb|right|A beachcomber inspects the carcass of a whale. The bite marks on the whale were made by a great white shark.]] [[File:Beached Whale Memorial, Florence, Oregon.jpg|thumb|Memorial to beached whales outside Florence, Oregon]]
If a whale is beached near an inhabited locality, the rotting carcass can pose a nuisance as well as a health risk. Such very large carcasses are difficult to move. The whales are often towed back out to sea away from shipping lanes, allowing them to decompose naturally, or they are towed out to sea and blown up with explosives. Government-sanctioned explosions have occurred in South Africa, Iceland, Australia and United States.<ref>{{cite web|url=https://www.youtube.com/watch?v=y6lTSxJvR4w| archive-url=https://ghostarchive.org/varchive/youtube/20211118/y6lTSxJvR4w| archive-date=2021-11-18 | url-status=live|title=Exploding Whale - Whale Of A Tale|date=29 April 2011|via=YouTube}}{{cbignore}}</ref><ref name="mbl">{{cite news | title=Hvalhræ dregið út á haf og síðan aftur upp í fjöru |trans-title=Whale pulled out to sea and then back up the beach | work=mbl.is | language=is | url=http://www.mbl.is/mm/frettir/frett.html?nid=1142126 | date=June 5, 2005 | access-date=July 17, 2013}}</ref><ref name="ABC1">{{cite news | url=https://www.abc.net.au/news/2010-09-02/explosive-end-for-sick-whale/2246266 | title=Explosive end for sick whale | work=ABC News | date=September 2, 2010 | access-date=September 22, 2020}}</ref> If the carcass is older, it is buried.
In New Zealand, which is the site of many whale strandings, treaties with the indigenous Māori people allow the tribal gathering and customary (that is, traditional) use of whalebone from any animal which has died as a result of stranding. Whales are regarded as ''taonga'' (spiritual treasure), descendants of the ocean god, Tangaroa, and are as such held in very high respect. Sites of whale strandings and any whale carcasses from strandings are treated as ''tapu'' sites, that is, they are regarded as sacred ground.<ref>Te Karaka, "[http://ngaitahu.iwi.nz/our_stories/science-strandings/ The science of strandings]', Te Rūnanga o Ngāi Tahu, 21 December 2014. Retrieved 12 February 2017.</ref>
== Health risks == A beached whale carcass should not be consumed. In 2002, fourteen Alaskans ate ''muktuk'' (whale blubber) from a beached whale, resulting in eight of them developing botulism, with two of the affected requiring mechanical ventilation.<ref> {{cite journal |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5202a2.htm |title=Outbreak of Botulism Type E Associated with Eating a Beached Whale --- Western Alaska, July 2002 |last=Middaugh |first=J |author2=Funk, B |author3=Jilly, B |author4=Maslanka, S |author5=McLaughlin J |journal=Morbidity and Mortality Weekly Report |date=2003-01-17 |volume=52 |issue=2 |pages=24–26 |pmid=12608715}}</ref> This is a possibility for any meat taken from an unpreserved carcass.
==Large strandings== {{incomplete list|date=October 2022}}
This is a list of large cetacean strandings (200 or more).
{| class="wikitable sortable" |- ! Total ! Deaths ! Survived ! Date ! style="width:300px;"|Incident ! Location |- |±1,000 |±1,000 |0 |1918 |Largest reported pilot whale stranding, with up to or over 1000 pilot whales dying in a single stranding.<ref>{{Cite web|url=https://www.doc.govt.nz/news/media-releases/2022-media-releases/stranded-pilot-whales/|title=Stranded pilot whales euthanised on Chatham Island|date=February 14, 2022|website=www.doc.govt.nz}}</ref><ref>{{Cite web|url=https://www.doc.govt.nz/news/media-releases/2020-media-releases/pilot-whales-strand-on-chatham-islands/|title=Pilot whales strand on Chatham Islands|date=November 25, 2020|website=www.doc.govt.nz}}</ref><ref>{{Cite web|url=https://teara.govt.nz/en/whales/page-8/|title=Strandings: whales and dolphins|date=March 2, 2009|website=teara.govt.nz}}</ref> Although commonly reported, details or evidence for the event are minimal.<ref>{{Cite web|url=https://www.nzgeo.com/stories/the-puzzle-of-pilot-whales/|title=The puzzle of pilot whales|date=November 2016|website=www.nzgeo.com}}</ref> |{{Flagicon|New Zealand}} Chatham Islands, New Zealand |- |656 |335 |321 |2017 |About 650 pilot whales beached themselves at the top of South Island, killing 335 of them. The others were able to swim away at high tide or were refloated by volunteers.<ref>{{cite web|url=https://www.npr.org/sections/thetwo-way/2017/02/11/514677975/as-200-more-whales-are-stranded-in-new-zealand-heroics-turn-to-heartbreak|title=As 200 More Whales Are Stranded In New Zealand, Heroics Turn To Heartbreak|website=NPR|date=11 February 2017|last1=Dwyer|first1=Colin}}</ref><ref name="Guardian feb 2017">{{cite news|url=https://www.theguardian.com/world/2017/feb/12/more-than-330-pilot-whales-die-in-new-zealand-mass-stranding|title=Hope for end to New Zealand whale strandings after 350 die|first1=Melissa|last1=Davey|date=12 February 2017|newspaper=The Guardian}}</ref><ref>{{cite web|url=https://www.bbc.co.uk/news/world-asia-38942763|title=New Zealand whales: Hundreds refloat on high tide at Farewell Spit|date=12 February 2017|website=BBC News}}</ref> |{{Flagicon|New Zealand}} South Island, New Zealand |- |500+ |500+ |0 |1897 |More than 500 pilot whales died at Teal Inlet.<ref>[https://trove.nla.gov.au/newspaper/article/39644138?searchTerm=whales Stranding of whales at the Falkland Islands] trove.nla.gov.au accessed 28 September 2025</ref> |{{Flagicon|Falkland Islands}} Teal Inlet, Falkland Islands |- |470 |362 |108 |2020 |About 270 pilot whales were found at Macquarie Heads on September 21, followed by the discovery of 200 dead whales two days later about 10 kilometers south, raising the total to 470. Only 108 were rescued.<ref>{{Cite web |url=https://www.sbs.com.au/news/article/hope-saved-pilot-whales-in-tasmania-can-reunite-at-sea/x6bgkr2oi |title=Hope saved pilot whales in Tasmania can reunite at sea |website=SBS News |access-date=28 September 2025}}</ref><ref>{{Cite web |url=https://www.wwf.org.au/news/blogs/update-on-the-tragic-pilot-whale-stranding-in-tasmania |title=Update on the tragic pilot whale stranding in Tasmania |website=www.wwf.org.au}}{{dead link|date=September 2025}}</ref> |{{Flagicon|Australia}} Tasmania, Australia |- |±300 |±75 |±225 |1985 |Nearly 300 pilot whales ran aground on Great Barrier Island, killing about one-quarter of them. Local residents, who had received rescue lectures after a similar incident the previous year, helped rescue more than 200 whales at high tide.<ref>{{cite web |title=Stranded Whales Driven Back Into Sea |date=1985-08-08 |website=Los Angeles Times |archive-url=https://web.archive.org/web/20221013073758/https://www.latimes.com/archives/la-xpm-1985-08-08-mn-3335-story.html |archive-date=2022-10-13 |url-status=live |url=https://www.latimes.com/archives/la-xpm-1985-08-08-mn-3335-story.html}}</ref> |{{Flagicon|New Zealand}} Great Barrier Island, New Zealand |- |294 |245 |49+ |1935 |Around 300 pilot whales were stranded at Stanley, Tasmania.<ref>{{cite news |url=http://nla.gov.au/nla.news-article51958988 |title=Beach at Stanley Strewn With Whales |newspaper=The Examiner (Tasmania) |volume=XCIV |issue=184 |date=15 October 1935 |access-date=23 September 2020 |page=7 (DAILY) |via=National Library of Australia}}</ref><ref>{{cite news |url=http://nla.gov.au/nla.news-article30059063 |title=300 Whales Stranded |newspaper=The Mercury |volume=CXLIII |issue=20,272 |date=15 October 1935 |access-date=23 September 2020 |page=7 |via=National Library of Australia}}</ref><ref>{{cite news |url=http://nla.gov.au/nla.news-article51959195 |title=The Whales at Stanley will be buried |newspaper=The Examiner (Tasmania) |volume=XCIV |issue=187 |date=16 October 1935 |access-date=23 September 2020 |page=7 (DAILY) |via=National Library of Australia}}</ref> The exact number of deaths or whales involved is unclear, with one newspaper reporting at least 245 confirmed deaths,<ref>{{cite news |url=http://nla.gov.au/nla.news-article30060017 |title=Burying Whales |newspaper=The Mercury |volume=CXLIII |issue=20,277 |date=21 October 1935 |access-date=23 September 2020 |page=11 |via=National Library of Australia}}</ref> while another newspaper reported in 1936 that 70 whales escaped during high tide the day after the stranding.<ref>[https://trove.nla.gov.au/newspaper/article/37770530?searchTerm=whales%20Stanley%201935 A Whale of a Query] Western Mail (Perth, WA : 1885 - 1954) via trove.nla.gov.au accessed 28 September 2025</ref> |{{Flagicon|Australia}} Tasmania, Australia |- |253 |253 |0 |1978 |More than 250 false killer whales stranded and died near Pukekohe.<ref>[https://paperspast.natlib.govt.nz/newspapers/CHP19780405.2.177?items_per_page=10&page=3&query=whales&snippet=true Theory on dead whales] Press, via paperspast.natlib.govt.nz accessed 28 September 2025</ref> |{{Flagicon|New Zealand}} North Island, New Zealand |- |240 |240 |0 |2022 |About 240 pilot whales beached themselves at Walhere Bay on Pitt Island, just 3 days after 240 pilot whales beached themselves at nearby Chatham Island.<ref name="NZ2022">{{Cite web |date=October 10, 2022 |title=Nearly 500 pilot whales die in New Zealand beachings |url=https://bnonews.com/index.php/2022/10/nearly-500-pilot-whales-die-in-new-zealand-beachings/ |access-date=October 10, 2022 |website=BNO News}}</ref> |{{Flagicon|New Zealand}} Pitt Island, New Zealand |- |240 |240 |0 |2022 |About 240 pilot whales beached themselves in the northwest of Chatham Island, just 3 days before 240 whales beached themselves at nearby Pitt Island.<ref name="NZ2022"/> |{{Flagicon|New Zealand}} Chatham Island, New Zealand |- |230 |195 |35 |2022 |About 230 pilot whales beached themselves on the west coast of Tasmania, exactly two years to the day of another mass stranding in the same area.<ref>{{Cite web |url=https://www.9news.com.au/national/pilot-whales-tasmania-rescue-mission-to-save-stranded-pod-continues/ca821991-b4b5-4179-a2ac-cb681713805f |title=Mission to save stranded Tasmanian pod ends with 35 successfully returned to the ocean |date=September 22, 2022 |website=www.9news.com.au}}</ref> |{{Flagicon|Australia}} Tasmania, Australia |- |}
===Others=== On June 23, 2015, 337 dead whales were discovered in a remote fjord in Patagonia, southern Chile, the largest stranding of baleen whales to date.<ref>{{Cite web|title=Apocalypse video: more than 300 whales found dead in Patagonia! Politicians must take Now strict measures to protect more our Oceans!|url=http://www.arctic05.org/en/2015/12/apocalypse-video-more-than-300-whales-found-dead-in-patagonia-politicians-must-take-now-strict-measures-to-protect-more-our-oceans/|access-date=2021-10-11|website=Arctic05|language=en-US}}</ref> Three hundred and five bodies and 32 skeletons were identified by aerial and satellite photography between the Gulf of Penas and Puerto Natales, near the southern tip of South America. They may have been sei whales.<ref>{{Cite web|title = 337 Whales Beached in Largest Stranding Ever|url = http://news.nationalgeographic.com/2015/11/151120-worlds-largest-whale-stranding-sei-chile-animals/|archive-url = https://web.archive.org/web/20151121164219/http://news.nationalgeographic.com/2015/11/151120-worlds-largest-whale-stranding-sei-chile-animals/|url-status = dead|archive-date = November 21, 2015|website = National Geographic News|access-date = 2015-11-21|first1 = Brian Clark|last1 = Howard|last2 = National Geographic|date = 20 November 2015}}</ref> This is one of only two or three such baleen mass stranding events in the last hundred years. It is highly unusual for baleen whales to strand other than singly, and these Patagonia strandings are tentatively attributed to an unusual cause such as ingestion of poisonous algae.
In November 2018, over 140 whales were witnessed stranded on a remote beach in New Zealand and had to be euthanised because of their declining health condition.<ref>{{Cite news|url=https://www.abc.net.au/news/2018-11-26/more-than-140-whales-wash-up-on-remote-new-zealand-beach/10554534|title=More than 140 whales die after mass stranding on remote New Zealand beach|date=26 November 2018|work=ABC News (Australia)|access-date=22 September 2020}}</ref> In July 2019, nearly 50 long-finned pilot whales were found stranded on Snaefellsnes Peninsula in Iceland. However, they were already dead when spotted.<ref>{{Cite news|url=https://www.abc.net.au/news/2019-07-20/dozens-of-pilot-whales-die-on-iceland-beach-in-mass-stranding/11328262|title=Dozens of pilot whales found dead after mass stranding on remote Iceland beach|date=20 July 2019|work=ABC News}}</ref>
On the evening of November 2, 2020, over 100 short-finned pilot whales were stranded on the Panadura Beach in western coast of Sri Lanka.<ref>{{Cite news|date=3 November 2020|title=Largest whale stranding in Sri Lanka draws epic volunteer rescue effort|language=en-GB|work=News First|url=https://www.newsfirst.lk/2020/11/03/video-largest-whale-stranding-in-sri-lanka-draws-epic-volunteer-rescue-effort/|access-date=3 November 2020}}</ref> Four deaths were reported, and all other whales were rescued.<ref>{{Cite news|last=Karunatilake|first=Waruna|date=3 November 2020|title=Sri Lankan navy, villagers rescue more than 100 stranded whales|language=en-GB|agency=Reuters|url=https://news.trust.org/item/20201103054912-nh6ru/|access-date=3 November 2020}}</ref>
==See also== {{portal|Cetaceans}} *Cetacean strandings in Ghana *Cetacean strandings in Tasmania *Dolphin drive hunting, a technique which herds small cetaceans towards the shore for slaughter *Drift whale *Marine Mammal Stranding Center – New Jersey, United States *Saint-Clément-des-Baleines – A coastal area on French island Île de Ré named after mass strandings of whales *Golden Bay, New Zealand – A renowned area for pilot whale mass strandings on Farewell Spit in Cook Strait *Whaling
==References==<!-- http://www.nrdc.org/wildlife/marine/sound/sound.pdf --> {{reflist|2|refs= <ref name="Álvarez-FernándezCarriol2014">{{cite journal|last1=Álvarez-Fernández|first1=Esteban|last2=Carriol|first2=René-Pierre|last3=Jordá|first3=Jesús F.|last4=Aura|first4=J. Emili|last5=Avezuela|first5=Bárbara|last6=Badal|first6=Ernestina|last7=Carrión|first7=Yolanda|last8=García-Guinea|first8=Javier|last9=Maestro|first9=Adolfo|last10=Morales|first10=Juan V.|last11=Perez|first11=Guillém|last12=Perez-Ripoll|first12=Manuel|last13=Rodrigo|first13=María J.|last14=Scarff|first14=James E.|last15=Villalba|first15=M. Paz|last16=Wood|first16=Rachel|title=Occurrence of whale barnacles in Nerja Cave (Málaga, southern Spain): Indirect evidence of whale consumption by humans in the Upper Magdalenian|journal=Quaternary International|volume=337|year=2014|pages=163–169|issn=1040-6182|doi=10.1016/j.quaint.2013.01.014|bibcode=2014QuInt.337..163A|hdl=10550/36217|hdl-access=free}}</ref>
}} {{refbegin}} *{{cite book |first=Julia |last=Whitty |year=2007 |title=The Fragile Edge: Diving and other adventures in the South Pacific |publisher=Houghton Mifflin Harcourt |asin=B002V1GZN2 }}
{{refend}}
==External links== {{commons category|Beached whales}} *[https://www.nrdc.org/issues/protect-marine-mammals-ocean-noise Protect Marine Mammals from Ocean Noise] (Natural Resources Defense Council)
{{hydroacoustics}}
Category:Whales Category:Animal death Category:Cetaceans