Sleeping with the Fishes: Body Breakdown on the Ocean Floor Varies

Everyone tends to get a strange idea in their head from time to time, wondering about the oddest of things. That's likely what happened when a pair of researchers from Simon Fraser University (SFU) found themselves wondering how long it takes for a human body to decompose in the ocean. However, these wonderers had the means to find out, so they did.

According to a study recently published in the journal PLOS One, SFU criminologists Gail Anderson and Lynne Bell determined that the sea floor is a mobster's dream, stripping a body of nearly everything - including incriminating evidence - in a matter of two to three weeks.

Of course, to determine this, the scientists didn't actually drop human bodies to the bottom of the ocean. Instead, Anderson and Bell sent three pig carcasses to "sleep with the fishes" at three different locations.

Pig carcasses were chosen for this study because they boast a decent approximation of size, skin, and amount of body hair to humans. Pigs even have similar immune systems and gut microbe populations - which can influence what microorganisms will be willing to help decompose a body.

According to the researchers' observations using cameras and water chemistry, two of the pigs decomposed in under three weeks - stripped down to the bone by crustaceans. However, a third pig, dropped deeper into the Saanich Inlet in British Columbia, took more than 90 days to be completely eaten away by local scavenging fauna.

"Saanich Inlet is hypoxic (deficient of oxygen) most of the year and anoxic (without oxygen) at some times," Anderson stated in a press release. "While the animals there are adapted to low oxygen, the last carcass was deployed when it was extremely low, which kept out all the big scavengers such as the shrimp and Dungeness crab, leaving the Squat lobsters, which were unable to break through the skin. This now gives us a better understanding of what happens to bodies in such waters."

Interestingly, the secret behind the morbid phenomenon of "floating feet" was also revealed in this study. The researchers found that feet on pigs and humans alike naturally are one of the first things to break away from the rest of the body - where the foam soles of sneakers could carry feet back to nearby shores.

They add that knowing more about these factors is extremely helpful in forensics, in which understanding the rate of decay of a region can help professionals determine when a body first laid down for "the long rest" on the ocean floor.