Pigs help solve puzzle of human decomposition in deep ocean

VANCOUVER— Criminologists at a British Columbia university are exploring uncharted waters with a first-of-its-kind study that monitors decomposing pig carcasses to better understand how human bodies break down hundreds of metres underwater.

The Simon Fraser University study, which was published earlier this month in the journal PLOS ONE, revealed the decaying process at depth is dramatically different than what takes place in shallower Pacific waters.

The study’s authors, forensic specialists Gail Anderson and Lynne Bell, said the results stand to help investigators learn more about bodies that are recovered at depth.

The pair’s research involved strapping the bodies of several pigs to metal grates and submerging them 300 metres via submarine to be deposited beneath a pre-existing monitoring installation.

Pig bodies can last weeks or even months when deposited near the ocean’s surface, said Anderson in an interview, but at 300 metres they’re whittled down to bone in as few as three days.

She described video footage showing a colony of amphipods, common- ly known as sea lice, swarm the animals’ bodies and drive away other scavengers, such as spot prawns and crabs.

“They just covered the bodies in four- to five-inches-deep layers of amphipods, which just inhaled — basically ate — the entire carcass, inside out,” she said.

Sensitive monitoring instruments also measured a sharp decrease in oxygen levels around the feeding site, which Anderson speculated may help repel other would-be feeders.

“That’s not been seen before,” she said, describing the discovery as exciting.

Anderson reasoned that this deoxygenation, coupled with the noise projected from the mass of moving creatures, may one day allow investigators to pinpoint the location of missing bodies from a distance.