A Quarter of All Fish Sold At Markets Contains Man-Made Trash

It ain't easy being a fish.

Between accidental sex changes, worms, and millions of pounds of marine life being thrown out because of indiscriminate fishing, they face no shortage of obstacles, both natural and man-made.

And if that weren't enough, they also have to contend with literal tons of trash floating around in the oceans and ending up in their bellies. And these are the very same fish which, in turn, end up in our bellies.

Despite the much-touted health benefits of fish, consumers may be getting more than just lean protein in their servings of seafood. A new study by a joint team of UC Davis and Hasanuddin University researchers found that roughly a quarter of fish and other seafood sold at markets contain "man-made" debris.

The study, recently published in Nature's Scientific Reports journal and titled "Anthropogenic debris in seafood: Plastic debris and fibers from textiles in fish and bivalves sold for human consumption," claims to be one of the the first to make a direct link between plastic and the food which end up on the plates of consumers.

Specifically, researchers found that approximately one quarter (25 to 28 percent) of the 152 fish they sampled fish markets in California and Indonesia contained man-made debris—plastic or fibrous material—in their "guts."

"It's interesting that there isn't a big difference in the amount of debris in the fish from each location, but in the type — plastic or fiber," lead author Chelsea Rochman, said in the same press statement. Because of the state's very efficient recycling system, very little plastic was found in Californian fish, something that researchers theorizes is caused the 200 wastewater treatment plants in offshore California, where the water from laundry washing machines is processed. Meanwhile, not a single fiber was found in Indonesia species.

Because of a severe lack of recycling, landfills, and waste collection in Indonesia, huge amounts of plastic are just chucked into the ocean. But it's also a country with an overabundance of aquatic species.

"Indonesia has some of the highest marine life richness and biodiversity on Earth, and its coastal regions—mangroves, coral reefs and their beaches—are just awash in debris," co-author Susan Williams of UC Davis said in a statement. "You have the best and the worst situation right in front of you in Indonesia."

And once again, waste seems to be the main culprit. "We think the type of debris in the fish is driven by differences in local waste management," Rochman said, adding that "to mitigate the issue in each location, it helps to think about local sources and differences in waste management strategies."

Since all of the debris seem to be concentrated around the entrails of the fish, there is little chance that humans will be ingesting any fibers or plastic—unless the fish are being eaten whole, like sardines and anchovies. While the authors also acknowledge that there is no clear evidence suggesting that chemicals from plastic are transferred into fish meat, they also see this study as a "a first step in understanding potential impacts of anthropogenic marine debris on human health."