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By Kaitlin Prince<br />Spring 2011<br />Animal Behavior 4411.001<br />Causes of Live Strandings in Cetaceans<br />
Outline<br />Overview of cetaceans and strandings<br />Most susceptible species<br />Possible causes<br />Parasites<br />P...
What are Cetaceans?<br />Figure 1: Order: Cetacea<br />Animalia<br />Chordata<br />Mammalia<br />Cetacea<br />Whales, dolp...
Basic Information<br />Complications<br />Strandings are when cetaceans swim or float into shallow water and become unable...
Basic Information<br />Possible Causes<br />Mass strandings occur when multiple organisms become stranded at once. <br />T...
Basic Information<br />Possible Causes<br />When one organism becomes stranded by itself.<br />More common than mass stran...
More Susceptible<br />Less Susceptible <br />Species that live in pods<br />Species that spend most of their time away fro...
Possible Causes: Parasites<br />Parasites have been found in necropsies of stranded cetaceans in various locations across ...
Toxic Pollution<br />Material Pollution<br />Bacteria<br />47% of bacteria likely originated from fecal matter (Parsons, &...
Possible Causes: Age<br />Table 1: Juveniles present in strandings in South Australia between 1881-1989<br />28% of strand...
Possible Causes: Geomagnetic Disturbances<br /> Cetaceans use weak geomagnetic signals for orientation, navigation and/or ...
Determination of Biological Significance<br />Open Questions<br />Area affected vs. available habitat<br />Behavioral disr...
Possible Causes: Sonar cont.<br />Greece 1996<br />Low to mid-range sonar frequencies<br />Cuvier’s beaked whales<br />Bah...
Figure 2: Temporal Distribution of Strandings in Oregon and Washington between 1930-2002<br />Figure 3: Temporal Distribut...
Possible Causes for Temporal Distribution<br />Long Term Increases in Stranding Occurrences<br />Increased human traffic<b...
Figure 3: Spatial Distribution of Strandings in Oregon and Washington between 1930-2002<br />Possible Causes for Spatial D...
Increased human traffic
Patterns in prey movement</li></ul>Entire Slide: (Norman, et. al., 2003)<br />
Conclusion<br />Strandings have many possible causes and each case should be examined to determine the most likely cause.<...
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Causes of Live Strandings in Cetaceans

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Causes of Live Strandings in Cetaceans

  1. 1. By Kaitlin Prince<br />Spring 2011<br />Animal Behavior 4411.001<br />Causes of Live Strandings in Cetaceans<br />
  2. 2. Outline<br />Overview of cetaceans and strandings<br />Most susceptible species<br />Possible causes<br />Parasites<br />Pollution<br />Age<br />Geomagnetic disturbances<br />Sonar<br />Possible reasons for spatial and temporal distribution<br />Conclusion<br />References<br />
  3. 3. What are Cetaceans?<br />Figure 1: Order: Cetacea<br />Animalia<br />Chordata<br />Mammalia<br />Cetacea<br />Whales, dolphins, porpoises<br />(http://www.politicsandcurrentaffairs.co.uk/Forum/world-events/67461-whaling-commission-head-says-japan-must-compromise.html)<br />
  4. 4. Basic Information<br />Complications<br />Strandings are when cetaceans swim or float into shallow water and become unable to return to deep water.<br />Cetaceans can become stranded dead or alive. <br />Dead strandings occur due to tides.<br />Skin damage and overheating (caused by sun exposure)<br />Respiratory distress (caused by body weight not supported by water)<br />Dehydration<br />Drowning (high tide moves in and covers the blowhole)<br />What are Strandings?<br />
  5. 5. Basic Information<br />Possible Causes<br />Mass strandings occur when multiple organisms become stranded at once. <br />These strandings point to causes that would affect the entire group.<br />Parasites<br />Pollution<br />Age<br />Geomagnetic disturbances<br />Sonar<br />Mass Strandings<br />
  6. 6. Basic Information<br />Possible Causes<br />When one organism becomes stranded by itself.<br />More common than mass strandings.<br />Most likely caused by factors that only affect one individual, rather than the entire group.<br />Disease<br />Parasites<br />Old age<br />Injury <br />Individual Strandings<br />
  7. 7. More Susceptible<br />Less Susceptible <br />Species that live in pods<br />Species that spend most of their time away from the shore in deep waters<br />Toothed whales<br />Beaked whales<br />Solitary species<br />Species that spend most of their time in shallow waters<br />Baleen whales<br />Which Species are Most Susceptible?<br />Entire Slide: (Norman, Bowlby, Brancato, & Calambokidis, 2003) <br />
  8. 8. Possible Causes: Parasites<br />Parasites have been found in necropsies of stranded cetaceans in various locations across the world.<br />Stranding can be due to multiple parasitic infections, rather than just one.<br />Parasites can damage organs, including the brain, which can lead to sickness, stranding and/or death.<br />Common parasitic infections<br />Trematodes (flatworms or flukes)<br />Nematodes (roundworms)<br />Entire Slide: (Daily, & Stroud, 1978)<br />
  9. 9. Toxic Pollution<br />Material Pollution<br />Bacteria<br />47% of bacteria likely originated from fecal matter (Parsons, & Jefferson, 2000)<br />Organochlorine compounds (such as PCBs) <br />Ingested by eating infected prey (Jarman, Norstrom, Muir, Rosenberg, Simon, Baird, 1996)<br />Fishing nets<br />Trash/debris<br />Boat propellers <br />Possible Causes: Pollution<br />
  10. 10. Possible Causes: Age<br />Table 1: Juveniles present in strandings in South Australia between 1881-1989<br />28% of strandings between were juvenile<br />Percent of juveniles varied greatly among species<br />Highest percent = Minkewhale<br />Possibly caused by lack of experience<br />Entire Slide: (Klemper, & Ling, 1991)<br />
  11. 11. Possible Causes: Geomagnetic Disturbances<br /> Cetaceans use weak geomagnetic signals for orientation, navigation and/or piloting (Kirschvink, Dizon, & Westphal, 1986). <br /> High prevalence of cetacean strandings in areas with local magnetic activity (Kirschvink, et. al., 1986). <br /> Migratory animals follow lines of magnetic minima and avoid areas of magnetic gradients (Kirschvink, et. al., 1986). <br /> The pattern of the disturbance is more important than the absolute level (Klinowska, 1986). <br />
  12. 12. Determination of Biological Significance<br />Open Questions<br />Area affected vs. available habitat<br />Behavioral disruption<br />Long-term exposure<br />Trauma due to sound impact or reaction to sound<br />Aspect of sonar that is harmful (pressure, frequency, signal usage)<br />Gradual interaction or sudden onset<br />Possible Causes: Sonar <br />
  13. 13. Possible Causes: Sonar cont.<br />Greece 1996<br />Low to mid-range sonar frequencies<br />Cuvier’s beaked whales<br />Bahamas 2000<br />Mid-range sonar<br />Examined specimens showed cerebral ventricular and subarachnoid hemorrhages<br />Madeira 2000<br />Cuvier’s beaked whales<br />Inner ear hemorrhages<br />Canary Islands 2002<br />Three different Ziphiidae species<br />Inner ear hemorrhages and edema<br />Entire Slide: (Norman, et. al., 2003) <br />
  14. 14. Figure 2: Temporal Distribution of Strandings in Oregon and Washington between 1930-2002<br />Figure 3: Temporal Distribution of Strandings in South Australia 1881-1989<br />Temporal Distribution of Strandings<br />(Norman, et. al., 2003) <br />(Klemper, & Ling, 1991)<br />
  15. 15. Possible Causes for Temporal Distribution<br />Long Term Increases in Stranding Occurrences<br />Increased human traffic<br />Increased species abundance<br />Oceanographic changes<br />Speed, sudden changes, pressure, etc.<br />Migration patterns<br />Changes in observer effect<br />Increase in human interest/population/coastline activities<br />Changing governmental policies concerning strandings<br />Increased possible causes<br />Pollution due to human population<br />Sonar usage due to military activity<br />Temporal Distribution of Strandings cont.<br />Entire Slide: (Norman, et. al., 2003) <br />
  16. 16. Figure 3: Spatial Distribution of Strandings in Oregon and Washington between 1930-2002<br />Possible Causes for Spatial Distribution<br /><ul><li>Summer migration into shallow waters
  17. 17. Increased human traffic
  18. 18. Patterns in prey movement</li></ul>Entire Slide: (Norman, et. al., 2003)<br />
  19. 19. Conclusion<br />Strandings have many possible causes and each case should be examined to determine the most likely cause.<br />Strandings have been increasing over long periods of time either due to increased reporting or increased causes.<br />More research is needed to determined which causes are most prevalent and how strandings can be prevented.<br />
  20. 20. References<br />Daily, M., Stroud, R. Parasites and associatedpathology observed in cetaceans stranded along theOregon coast. J. of Wildlife Diseases. 14, 503. 1978.<br />Jarman, W., Norstrom, R., Muir, D., Rosenberg, B., Simon, M., Baird, R. Levels of organochlorine compounds in the blubber of cetaceans from the west coast ofNorth America. J. Marine Pollution Bulletin. 32(5), 426-436. 1996.<br />Kirschvink, J., Dizon, A., Westphal, J. Evidence fromstrandings for geomagnetic sensitivity incetaceans. J. Biol. 120, 1-24. 1986.<br />
  21. 21. References cont.<br />Klemper, C., Ling, J. Whale strandings in south Australia (1881-1989). Transactions of the Royal Society of S. Australia. 115(1), 37-52. 1991. <br />Klinowska, M. Cetacean live stranding dates relate togeomagnetic disturbances. J. Aquatic Mammals. 11.3, 109-119. 1985.<br />Norman, S., Bowlby, C., Brancato, M., Calambokidis, J. Cetacean strandings in Oregon and Washingtonbetween 1930 and 2002. J. Cetacean Res. Manage. 6(1), 87-99. 2004.<br />Parsons, E., Jefferson, T. Post-mortem investigations onstranded dolphins and porpoises from Hong Kongwaters. J. of Wildlife Diseases. 36(2), 342-356. 2000.<br />

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