What looks like a macabre pattern of detached, mostly right human feet turning up on British Columbia's southern coast is probably the result of an odd, but explicable, confluence of natural events.
"This could be a rather sick hoax by someone with access to cadavers and running shoes," said Richard Thomson, a physical oceanographer with the federal Institute of Ocean Sciences on Vancouver Island. "But I think there is another explanation."
The hoax theory got a boost on Thursday when the B.C. Coroners Service announced that what was apparently a sixth human foot, found on a beach near Campbell River, was really "a skeletonized animal paw," that had been inserted into a shoe stuffed with seaweed.
But that doesn't explain the previous five real human feet found scattered around the Strait of Georgia, which the Coroners Service continues to investigate.
Mr. Thomson said the strait's tidal currents (which rotate like a giant, endless spin cycle), the simple fact that most people tie their right shoes tighter and the design of modern runners with air bubbles in their soles, are all factors to be considered.
Mr. Thomson is not a crime scene investigator, but as an expert on ocean dynamics he knows a lot about how things float around in the Strait of Georgia.
And flotation, he thinks, is the key to explaining this mystery.
"I think it's mainly due to shoe design," he said. "I've got Nike shoes that have a cushion in them and that cushion is low-density material that makes the running shoe more buoyant … new running shoes in general are lighter and have air devices in the soles … so sneakers today will float with a foot in them."
Although two feet (Nos. 4 and 5, one right shoe, one left) were found at the mouth of the Fraser River, on Westham and Kirkland Islands, Mr. Thomson said that doesn't necessarily mean they floated downstream.
They could have drifted in from the strait with the ocean tide, he said, which drives a wedge of salt water as far upstream as New Westminster.
Foot No. 1, a right foot in a size 12 Adidas sneaker, was found washed up on Jedediah Island.
Foot No. 2, a right foot in a size 12 Reebok, drifted onto Gabriola Island.
No. 3, a right foot in a size 10½ sneaker, was found on Valdes Island.
Mr. Thomson said if the feet had all come from the Fraser River, he'd have expected at least some of them to have been found to the south, in Juan de Fuca Strait, where 80 per cent of the water in the Strait of Georgia flushes out to the open Pacific.
Instead most of the feet were north of the Fraser's mouth.
Mr. Thomson said possible source points include the Fraser, but also the Squamish River, the Gulf and San Juan Islands, Burrard Inlet, and sites in northern Washington State including Birch Bay and Boundary Bay.
"My guess is that the bodies fall or are placed in the water where they eventually sink to the bottom. They are then eaten by benthic animals such as crabs and worms while they also decay through microbial (bacterial) processes," he said in an e-mail.
"Eventually, the foot/sneaker combination becomes separated from the body and floats to the surface. Once on the surface, the foot/sneaker drifts around under the action of the winds and surface currents."
Mr. Thomson said a "surface drifter" in the Strait of Georgia can be repeatedly cycled by currents, giving it a chance to drift ashore.
And he noted the strait's currents are relatively weak, which means less buffeting to force a shoe to lose its contents.
"It's gruesome, but if there is a decaying foot in a shoe, eventually it's going to come out and there are probably all kinds of running shoes floating around, that end up on the beaches without any feet in them," Mr. Thomson said.
Why are four of the five right feet?
"One possible explanation is that right feet tend to be larger than left feet … and therefore fit more tightly into the shoe. Right feet take longer to fall out of the shoe than left feet during the drift and decay process," he said. "Another possibility is that right shoelaces are typically tied tighter than left shoelaces because most people tend to be right footed."
While the B.C. Coroners Service is continuing to investigate the five cases of human feet, no new information was available yesterday.
Forensic scientists on the television drama CSI: Crime Scene Investigation solve mysteries within an hour, but experts say that's not how it happens in real life.
The severed feet that washed ashore are proving a major challenge, said Gail Anderson, a forensic expert at Simon Fraser University.
She said it could take years to identify who the feet belong to, because analysts have to wade through missing persons databanks, nationally and even internationally, to find possible matching samples of DNA.
"You can't just look at the DNA and say 'aha.' You need to have something to compare it with," Dr. Anderson said.
With a report from Caroline Alphonso
Mark Hume