Content Warning: Some images below might be considered disturbing to some.
Understanding how a body responds to certain environments is important for forensic analysts to calculate time and cause of death.
In its efforts to understand how a body would fare in the ocean, forensic scientists at Simon Fraser University in British Columbia put a pig carcass caged in the water and let sea lice have at it. It only took four days for the sea lice to reach bone.
“By the end of the fourth day, the sea lice had left and the pigs were reduced to bones,” forensic scientist Gail Anderson said, according to New Scientist.
Next the shrimp came in and cleaned up the carcass further. New Scientist pointed out that scientists observed the bone turning black for 48 hours afterward. Scientist Lynne Bell is reported as saying this was “something that has never been seen before.” The team is identifying the microorganisms on the bone in an effort to better understand the chemistry that may have caused this color change.
According to the description in the YouTube video, the team had previously seen shark activity around the carcass, so one carcass was left in open water while another was caged so only smaller organisms could access it. Here’s more from the description of what researchers observed:
[The sea lice] rapidly became several centimetres thick on the body and entered the carcass via the orifices, eating it from the inside out. The amphipods became so numerous that they covered the entire cage and bars and competitively excluded all other arthropods such as the big Three Spot Shrimp. In just a few days the carcass was entirely skeletonized and the amphipods lost interest and left. Then the Three Spot Shrimp returned to pick at the carcass, eventually removing all the cartilage. After a few days a Giant Pacific Octopus was curious about the cage, scaring off a shrimp.
Watch the time-lapsed video showing the organisms devour the carcass (Warning: Content might be considered graphic to some):
Other factors such as depth of the water and season play a roll in the decomposition observed as well.
“We have had a lot of disarticulated feet wash up on our shores in running shoes,” New Scientist reported Anderson saying. “This work is showing the public how crab and shrimp activity can result in severed limbs and that’s it’s a normal process.”