A team of Australian marine archaeologists, specialists in aquatic forensics, have studied ancient bones discovered on ships, revealing their owners’ circumstances after death. Aquatic forensics is a discipline marrying anthropology, marine science, subsea archaeology, and marine biology. Aquatic forensics are applied every time a drowned body is recovered from water whether that be through murder, floods, tsunamis, shipwrecks, or air crashes.
Researchers at the Western Australian Museum have spent many decades studying bones collected from the many ancient historical shipwrecks along Australia’s coastlines. But with severe weathering, and most bones having been eaten away, it is almost impossible for scientists to determine if underwater bones are human or animal.
However, by taking advantage of “ taphonomy research” unique characteristics of bones and teeth have been revealed, which have helped investigators better understand the causes of death of the people to whom the recovered bones or teeth belonged.
Many shipwrecks also contain human remains, but only advanced aquatic forensics can provide clues about the dead that tell us more about them. Human remains near the commemorative plaque to the Japanese Servicemen located towards the stern of the Aikoku Maru, Chuuk Lagoon, Federated States of Micronesia. (Kelly Jandik / ResearchGate)
Aquatic Forensics On Bone and Teeth Decay Through Taphonomy
Taphonomy is the study of how organic remains transfer from the biosphere to the lithosphere from the time of death. A recent article published in The Conversation , describes the results of underwater archaeological excavations of historical shipwrecks off the coast of Western Australia in which a team of aquatic forensics experts from Western Australian Shipwrecks Museum studied four historical shipwrecks off the coast of Western Australia.
Getting historical information from a bone or tooth found on an ancient, submerged shipwreck has been impossible until now. Australian experts in aquatic forensics are using high-tech to figure out how old the remains are and who they belonged to!
The DNA of sheep, pig, and cow bones discovered in decayed wooden barrels on these shipwrecks have been dated to between the early 17th – 19th century. Sometimes old subsea human bones are protected by hard structures, for example, a ship’s hull or in the cabin areas of crashed airplanes. Those bones not encased and protected in some way from the vagaries of the sea are open to being eaten by marine creatures , which pull things apart, including human bodies.
An example of a bone enclosed in a marine concretion, from Rapid (1811). ( The Conversation )
Old Sea Bones Entombed In Iron Graves
Bones can become enclosed in iron concretions formed by the iron objects aboard ships or aircraft and over time this causes the chemical components of bones to change. It is by understanding the combination of all these variables that marine investigators are able to reconstruct the fate of individual bodies after death.
Single-celled organisms called foraminifera affect the dissolving spaces inside submerged bones , and these microorganisms, which are generally studied within ecological and paleontological studies, are providing new insights into how much time has passed since any given person died in a shipwreck.
Australia’s oldest recorded shipwreck is that of the Trial, also spelt Tryall or Tryal. The Trial was a ship of the English East India Company which was sent to the East Indies in 1621 under the command of John Brooke. ( Twisted History )
Old Finds Can Now Produce New Historical Insights
Intense archaeological dive operations were conducted in the 1960s and 1970s around Australia’s coast. Divers revealed four historic ships containing hundreds of unbroken artifacts, and hoards of silver coins. While sailing towards Jakarta, following the infamous Brouwer Route , the Dutch East India Company ships called the Batavia, Vergulde Draeck and Zeewijk all sank in 1629, 1656 and 1727, respectively. The fourth ship was the Rapid, an America-China trader that was wrecked in 1811 sailing from Boston to Canton (modern Guangzhou).
The new research has analyzed the submerged bones that were gathered in the 60s and 70s. While most of them are almost worn away by the salty seawater and erosive marine sediments, after between 169 and 347 years, the scientists discovered special chemical clues or “ geochemical fingerprints .”
This was achieved through a scientific process known as diagenesis. This term describes the physical and chemical changes found in seabed sediments caused by repeated “water-rock interactions, microbial activity, and compaction after their deposition.” Therefore, in a nutshell, diagenesis refers to the decomposition changes that are monitored occurring on skeletal material.
A Crucial Step Ahead
The team of Australian researchers said “increased pressure and temperature” only start to affect old bones as sediments become buried much deeper in the Earth’s crust .
In conclusion, after having been encased for a long time within wrecks and aircraft, old bones decay, are scattered and battered, or chemically change due to their “iron coatings.” Now experts in aquatic forensics, using taphonomy and diagenesis, are able to reconstruct the events after death, which is a “crucial” step forward in marine forensic investigations, and especially within the field of archaeology.
Top image: Australian aquatic forensics experts working on a wreck off the coast of Western Australia, in an attempt to understand what happens to bones over time in shipwrecks. Source: The Conversation / Western Australian Museum
By Ashley Cowie