Great white sharks may be fearsome apex predators, but they’re not above a little junk food in the form of plastic.
This revelation was confirmed recently by marine researchers who dared to take feces samples from live sharks in the Northwest Atlantic Ocean.
The potent poop was put under a microscope and, sure enough, it had strands of microplastics in it, according Dr. Harley Newton, a veterinary pathologist working with OCEARCH.
“Every white shark we’ve looked at so far does have microplastics present in their fecal sample,” Newton said in a video shared Dec. 14 by OCEARCH. “The concern is that we don’t know what kind of impact that really has on animals or ourselves.”
Tons of plastic are tossed away by humans each year and it often ends up in the world’s oceans, where it enters “the food web,’ OCEARCH says. Microplastics are the broken down particles of “less than 5mm in size,” the nonprofit says.
OCEARCH has been capturing sharks as big as 17 feet in recent months, giving researchers like Newton a chance to prod the predators for research projects. Blood, muscle and skin samples were taken from the sharks, and bacteria was scraped from their teeth. Females also got ultrasounds, OCEARCH says.
Fecal samples often came with hair attached, which experts credit to the seals that sharks eat in the Northwest Atlantic, OCEARCH says.
As for how white sharks are accumulating microplastics in their systems, it could be from eating plastic directly or consuming fish that ate the plastic, experts say. Some species of “filter feeding” sharks (whale sharks, basking sharks) may absorb it through their gills, which could result in plastic being in their blood stream, Newton said.
“With microplastics, one of the other concerns with them is they can actually absorb other environmental pollutants because of their size … and accumulate those as well,” Newton said. “So you are not just taking in this plastic, you are taking anything that is stuck to that plastic and it’s getting inside you and accumulating.”