Barnacles are encrusting arthropods that attach to all kinds of surfaces, including rocks, boats, and even human remains. In 2002, police discovered a highly decomposed human body in the water on the southwest coast of Italy. The forensic pathologist on the case didn’t have a lot to go on to determine how long the body had been in the water. The only clue found was barnacles on the victim’s pants and shoes. The pathologist contacted a forensic biology doctoral student at the University of Turi— Paola Magni.
Magni was fascinated by the challenge. She began researching ocean temperatures in the region as well as barnacle growth rates in different marine environments. From there, Magni determined that the body had been in the water 65 to 90 days, and she was the expert forensic pathologist at the trial. Her research for this case, however, highlighted how little we know about barnacles as it applies to forensic science.
“If an estimate derived from barnacle growth rates says a body was in the water for 10 days, a defense lawyer is going to wonder whether that information came from barnacles growing in a natural environment, such as on a rock, or in an unusual environment, such as on a shoe,” Magni recently told Hakai Magazine.
Not all barnacles are created equal, and their growth rates differ based on water temperature, location, and species. Magni now works at Murdoch University in Perth, Australia, and Singapore. Her experience with the barnacle-encrusted shoe stuck with her and led her to start collecting some very specific data – how barnacles grow on shoed.
In 2016, Magni and her team submerged 128 pairs of shoes (of varying materials) in Boston Harbor, Massachusetts. Within two weeks, the team could see signs of juvenile barnacles on the shoes, and after seven months, there were hard, encrusted adults firmly attached to the shoes, especially the patent leather ones.
But Magni isn’t stopping at just shoes. In concert with Murdoch University oceanographer, Jennifer Verduin, and undergraduate student Elysia Tingey, Magni is researching barnacle colonization on fabrics such as satin, velvet, cotton and neoprene. The result will undoubtedly impact future forensic and law enforcement investigations.