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Jun 10, 2009 09:50 PM | 9
Editor's note: Some readers may be disturbed by the content of this article, which refers to Air France Flight 447 and contains descriptions of human remains.
On Tuesday, Brazilian authorities recovered 16 bodies from the Air France crash in the Atlantic Ocean, bringing the total to 24.
The Airbus 330 jet took off from Rio de Janeiro on its way to Paris on May 31 when it disappeared during intense thunderstorms. Investigators are currently considering the possibility that the plane's airspeed sensors were iced over. Meanwhile the Brazilian navy is conducting an all-out search for the bodies.
Finding survivors lost at sea is a race against time because of the possibility of starvation or hypothermia. But none of the 228 people on board Flight 447 were expected to have survived the plane's impact.
So how long can a body remain intact at sea, to be recovered?
The Australian Museum has an informative Web site, deathonline.net, on how human remains change after death. On land, bacteria and other microbes in the body will rapidly multiply and break down the soft tissue. Shortly after death, flies and other insects consume the soft tissue. Vultures, dogs or other large mammals may also take pieces of the decomposing flesh, sometimes reducing the corpse into a skeleton in under two weeks.
On the open ocean, however, flies and other insects are largely absent. And if the body is floating in water less than 70 degrees Fahrenheit (21 degrees Celsius) for about three weeks, the tissues turn into a soapy fatty acid known as "grave wax" that halts bacterial growth. The skin, however, will still blister and turn greenish black. Finally, crabs and small fish may feed on the soft parts of the face like the eyes and lips, according to the book Forensic Taphonomy: The Postmortem Fate of Human Remains, by William D. Haglund and Marcella H. Sorg.
A 2002 study in the journal Legal Medicine examined nine bodies that had drifted hundreds of kilometers in cold waters off the coast of Portugal and Spain. Bodies recovered in the first week were in good condition, but the beginning signs of decomposition were present on a body recovered after eight days. The two bodies recovered after 20 days were highly decomposed and could only be identified through DNA analysis or dental records. As for warmer water, A 2008 study on two human bodies recovered following aircraft accidents found one body off of Sicily to be partially skeletonized after 34 days and a second body off of Namibia to be completely skeletonized after three months.*
Of course, sharks are an important scavenger in warm waters, like those off of Brazil, and can quickly reduce a body to shreds. "Sharks, like any predator, are opportunistic feeders, and they'll take advantage of a resource that's given to them," says George Burgess, director of the Florida Program for Shark Research at the Florida Museum of Natural History in Gainesville and the curator of the International Shark Attack File.
Low-frequency noises caused by a ship sinking or a plane crashing travel great distances underwater and can attract the animals. However, he says, "The idea that the…[seas]…are carpeted with sharks…is a misconception."
*UPDATE (6/11/09): In response to the comment by AndrewJayPollack, we have added this paragraph on the time frame of decomposition.
Image of waves breaking on a beach courtesy Mr.Thomas via Flickr
More News Blog: Next: WHO: H1N1 spread has reached pandemic level Previous: Submarines--great and small--aid search for Air France black boxes
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9 Comments
Add CommentInteresting article, but it fails to do one thing -- actually answer the question posed by the title. How long, in some common unit of time, do bodies remain intact enough for reasonable recovery and identification?
Reply | Report Abuse | Link to thisDepends on how long it takes the fishies to find em.
Reply | Report Abuse | Link to thisA similar question with a different bent, Which are the last cells to in the body to stop metabolic processes after cardiac and brain death? Also how long do they continue to function after cardiac and brain death?
Reply | Report Abuse | Link to thisWhat other scavengers could be expected to work on the remains? Sharks are only one of many. What about the currents in that area? Warm or cold? Example: The Gulf Stream is a warm one, while the Arctic is a ice cold. Either would affect the recovery effort enormously in a positive or negative way. What about "bloating"? Would any bodies be trapped in the fuselage of the aircraft? How would temperatures on the ocean floor affect preservation of the remains?
Reply | Report Abuse | Link to thisThe point is, the article does nothing to answer the question posed.
Reply | Report Abuse | Link to this42, happy now?
Reply | Report Abuse | Link to thisAnother related question: What about victims whose bodies are trapped in the plane wreckage that sank. What would happen to them at the various possible depths? Is the water so cold they would be preserved? What effect does the pressure have on them?
Reply | Report Abuse | Link to thisActually, "How long do dead bodies remain intact in the ocean?" is not significant any more. the point is how long people can live in the ocean. Probably, people who has died would no longer care where they died, in the ocean or on the continent.
Reply | Report Abuse | Link to thisThe Body in Water
Reply | Report Abuse | Link to thisThe human body weighs slightly more than fresh water. Consequently, when individuals become unconscious, they sink--regardless of fat level, which slightly increases buoyancy. Generally, a drowning victim will reach the bottom of a body of water in spite of the depth, unless it meets some obstruction on the way down. As the corpse descends further, the pressure of the water tends to compress gases in the abdominal wall and chest cavities. As a result, the body displaces less water as it sinks and, consequently, becomes less buoyant the further down it goes, until it reaches the bottom. (5)
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If a corpse does not sink, investigators should suspect another cause of death, such as heart attack. Or, perhaps, a dry drowning has occurred; in those cases, because the lungs do not contain water, the body will not descend.
Almost without exception, a corpse lying on the bottom of a lake or river eventually will surface because of the gas formed in its tissues as a result of decay and the action of internal bacteria. This results in reduced specific gravity of the body so that it rises. Witnesses to this event have described corpses breaking the surface of the water with force, like the popping of a cork.
Factors that effect the length of time for a body to surface after drowning include fat content, consumption of beverages and food preceding death, water temperature at the bottom, and depth at the location. Recent meals high in carbohydrates (e.g., candy, beer, and potato chips) nourish certain bacteria that will encourage quick refloat. (6) In warm and shallow water, the gases within the body form rapidly, resulting in a possible rise to the surface within a day or two. In deep and cold water, bacterial action takes place slowly, and the corpse may not appear for several weeks. (7) When the body becomes greatly distended with gas, the tendency to float increases. Many well-documented cases exist of homicide victims dumped into lakes and rivers and then later surfacing, even though perpetrators attached heavy weights to them.
In some cases, the body may remain immersed. Extremely deep, cold water conditions (e.g., natural glacier lakes, deep impoundments) may prevent a corpse from ever becoming buoyant enough to overcome the immense water pressure
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