Tutorial: Mammals – Strandings
The term stranding refers to an aquatic animal observed in an inappropriate location, for example, an offshore species found inshore. Most often, stranded animals are found on a beach or in shallow water. Observations as far back as Aristotle and illustrations from the Middle Ages show us that marine mammals have been stranding for millennia. There are many causes of strandings, such as disease, ship-strike, injuries, storms, and entanglement. Only very few strandings have been attributed to sound.
In the U.S. alone, about 1,000 cetaceans and 2,500 pinnipeds strand annually. Some animals strand live and are returned to sea. Others die at sea or on shore. Animals may strand singly or in groups. When 3 or more animals strand together in time and place, it is called a mass stranding. Some species, such as pilot whales, mass strand regularly around the world.
Determining the cause of a stranding or death of a stranded animal can be difficult. Dead stranded animals are sometimes necropsied which is a thorough examination of the entire body. Scientists usually have little or no information about the animal’s history or the circumstances that preceded the stranding. A cause of death can be determined in only about half of all stranding cases.
There is consensus that military sonar exercises have contributed to mass strandings of beaked whales. However, it is still not clear if it is simply the sound of the sonar , or other aspects of the military exercises, such as multiple ship maneuvers, that resulted in the strandings.
Mass strandings of beaked whales are rare, with only 136 mass stranding events reported from 1874 to 2004. Of these, two reported details on the use, timing, and location of sonar in relation to mass strandings. Ten other mass strandings coincided in space and time with naval activity that may have included military sonar. As of 2014, there are five additional documented events of beaked whale stranding in association with military sonar exercises. TAll these events had three consistent features: (1) the stranding locations were less than 80 km from the 1,000-m depth contour (that is, where deep water occurs near shore); (2) they occurred in areas where beaked whale mass strandings had previously been reported; and (3) all included Cuvier’s beaked whales, a species that does not commonly mass strand.
Although these beaked whale strandings were closely related in time and location to the use of military sonars by many nations, whether the sonar sounds caused the strandings has still not been determined. In five well-documented cases, there is sufficient information about the military exercises and the times and locations of the strandings to determine that multi-ship exercises with sonar contributed to the strandings. These events occurred in Greece (1996), Bahamas (2000), Madeira, Portugal (May 2000), and the Canary Islands (2002 and 2004). The necropsies that were performed (described below) found similar injuries, but none of the animals were found to have acoustic trauma. There are currently few peer-reviewed scientific publications that describe and discuss these strandings. The majority of authoritative information on these strandings can be found in official investigation reports of the events.
Additional details about standing events can be found on the DOSITS Marine Mammal Stranding page.
Effects of Sound Tutorial Sections:
- Thompson, D’Arcy Wentworth; Aristotle (c. 350 BC). 1910, “The History of Animals.” Translated by D’Arcy Wentworth Thompson. Clarendon Press, London. 231pp.
- Filadelfo, R., Mintz, J., Michlovich, E., D’Amico, A., Tyack, P. L., and Ketten, D. R. 2009, “Correlating military sonar use with beaked whale mass strandings: What do the historical data show?” Aquatic Mammals. 35, 435-444.
- D’Amico, A., Gisiner, R. C., Ketten, D. R., Hammock, J. A., Johnson, C., Tyack, P. L. and Mead J. G. 2009, “Beaked whale strandings and naval exercises.”Aquatic Mammals. 35, 452-472.
- National Research Council. 2003, “Ocean Noise and Marine Mammals.” The National Academies Press, Washington, D.C.
- Evans, D.L., and England, G.R. 2001, “Joint Interim Report Bahamas Marine Mammal Stranding Event 15-16 March 2000.” Department of the Navy and Department of Commerce, National Oceanic and Atmospheric Administration. Washington, D.C. (Link)
- Ketten, D.R. 2014, “Sonars and Strandings: Are Beaked Whales the Aquatic Acoustic Canary?” Acoustics Today. 10(3): 46-56. (Link)
- Frantzis, A. 1998, “Does acoustic testing strand whales.” Nature 392(6671): 29.
- D’Amico, A., and Verboom, W. eds. 1998, “Summary Record and Report, SACLANTCEN Bioacoustics Panel, La Spezia, Italy, 15-17 June 1998.”SACLANT Undersea Research Centre.
- Ketten, D.R. 2005, “Beaked Whale Necropsy Findings for Strandings in the Bahamas, Puerto Rico, and Madeira, 1999-2002.” Woods Hole Oceanographic Institution Technical Publication WHOI-2005-09. 36 pp. (Link)
- Ketten, D. R., Rowles, T., Cramer, S., O’Malley, J., Arruda, J., and Evans, P. G. H. 2004, “Cranial trauma in beaked whales.” Proceedings of the Workshop on Active Sonar and Cetaceans. European Cetacean Society News 42, 21-27.
- Freitas, L. 2004, “The stranding of three Cuvier’s beaked whales, Ziphius cavirostris, in Madeira archipelago.” European Cetacean Society Newsletter, 42:28-32.
- Jepson, P.D., Arbelo, M., Deaville, R., Patterson, I.A.P., Castro, P., Baker, J.R., Degollada, E., Ross, H.M., Herraez, P., Pocknell, A.M., Rodriguez, F., Howie, F.E., Espinosa, A., Reid, R.J., Jaber, J.R., Martin, V., Cunningham, A.A. and Fernandez, A. 2003, “Gas-bubble lesions in stranded cetaceans.” Nature 425(6958): 575-576.
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- Fernandez, A., E. Sierra, V. Martin, M Mendes, S. Sacchinni, Y. Bernaldo de Quiros, M. Andrada, M. Rivero, O. Quesada, M. Tejedor, and M. Arbelo. 2012, “Last “Atypical” Beaked Whales Mass Stranding in the Canary Islands (July, 2004).” Journal of Marine Science: Research & Development 2:107, 3 pp. doi:10.4172/2155-9910.10001077.
- Finneran, J.J. 2003, “Whole-lung resonance in a bottlenose dolphin (Tursiops truncatus) and white whale (Delphinapterus leucas)” Journal of the Acoustical Society of America 114(1): 529-535.
- Houser, D.S., Howard, R. and Ridgway, S. 2001, “Can diving-induced tissue nitrogen supersaturation increase the chance of acoustically driven bubble growth in marine mammals.” Journal of Theoretical Biology 213(2): 183-195.
- Tyack, P.L., Johnson, M., Aguilar de Soto, N., Sturlese, A., and Madsen, P.T. 2006, “Extreme diving of beaked whales.” The Journal of Experimental Biology. 209: 4238-4253.
- Fahlman, A., Olszowka, A., Bostrom, B. and Jones, D. R. 2006, “Deep diving mammals: Dive behavior and circulatory adjustments contribute to bends avoidance.” Respiratory Physiology and Neurobiology. 153, 66-77.
- Zimmer, W. M. X. and Tyack, P. L. 2007, “Repetitive shallow dives pose decompression risk in deep-diving beaked whales.” Marine Mammal Science. 23(4), 888-925.
- Hooker, S. K., Baird, R. W., and Fahlman, A. 2009, “Could beaked whales get the bends? Effect of diving behaviour and physiology on modelled gas exchange for three species: Ziphius cavirostris, Mesoplodon densirostris, and Hyperoodon ampullatus” Respiratory Physiology and Neurobiology.
- Moore, M.J. and Early, G.A. 2004, “Cumulative sperm whale bone damage and the bends.” Science 306 (24 December 2004): 2215.
- Crum, L.A., and Mao, Y. 1996, “Acoustically enhanced bubble growth at low frequencies and its implications for human diver and marine mammal safety.” Journal of the Acoustical Society of America 99(5): 2898-2907.
- Crum, L. A., Bailey, M. R., Guan, J., Hilmo, P. R., Kargl, S. G., Matula, T. J. and Sapozhnikov, O. A. 2005, “Monitoring bubble growth in supersaturated blood and tissue ex vivo and the relevance to marine mammal bioeffects.” Acoustics Research Letters Online 6(3): 214-220.
- D’Spain, G.L., D’Amico, A., and Fromm, D.M. 2006, “Properties of the underwater sound fields during some well documented beaked whale mass stranding events.” Journal of Cetacean Research and Management. 7(3):223-238.
- Tyack, P. L., Zimmer,W. M. X., Moretti, D., Southall, B. L., Claridge, D. E., Durban, J. W., Clark, C. W., D’Amico, A., DiMarzio, N., Jarvis, S., McCarthy, E., Morrissey, R., Ward, J., and Boyd, I. L. 2011, “Beaked Whales Respond to Simulated and Actual Navy Sonar.” PLoS ONE 6:e17009. doi:17010.11371/journal.pone.0017009. (Link)
- Cox, T.M, Ragen, T.J., Read, A.J., Vos, E., Baird, R.W., Balcomb, K., Barlow, J., Caldwell, J., Cranford, T., Crum, L., D’Amico, A., D’Spain, G., Fernandez, A., Finneran, J., Gentry, R., Gerth, W., Gulland, F., Hildebrand, J., Houser, D., Hullar, T., Jepson, P.D., Ketten, D., MacLeod, C.D., Miller, P., Moore, S., Moundain, D.C., Palka, D., Ponganis, P., rommel, S., Rowles, T., Taylor, B.,Tyack, P., Wartzok, R. Gisiner, Mead, J., and Benner, L. 2006, “Understanding the impacts of anthropogenic sound on beaked whales.” The Journal of Cetacean Research and Management. 7(3):177-187.
- Fernández, A., Arbelo, M., Deaville, R., Patterson, I.A.P., Castro, P., Baker, J.R., Degollada, E., Ross, H.M., Herráez, P., Pocknell, A.M., Rodríguez, E., Howie, F.E., Espinosa, A., Reid, R.J., Jaber, J.R., Martin, V., Cunningham, A.A. and Jepson, P.D. 2004, “Pathology: Whales, sonar and decompression sickness (reply)” Nature 428(15 Apr 2004)
- Houser, D. S., Dankiewicz-Talmadge, L. A., Stockard, T. K., and Ponganis, P. J. 2010, “Investigation of the potential for vascular bubble formation in a repetitively diving dolphin.” Journal of Experimental Biology. 213, 52-62.
- National Marine Fisheries Service. 2000, “Annual Report to Congress: 1999-2000 Administration of the Marine Mammal Protection Act of 1972.”National Oceanic and Atmospheric Administration, National Marine Fisheries Service (NOAA Fisheries), Silver Spring, Maryland. 105 pp. (Link)
- Piantadosi, C.A. and Thalmann, E.D. 2004, “Pathology: Whales, sonar and decompression sickness.” Nature 428(15 Apr 2004)