Plastic for dinner: A quarter of fish sold at markets contain man-made debris

Roughly a quarter of the fish sampled from fish markets in California
and Indonesia contained man-made debris — plastic or fibrous material
— in their guts, according to a study from the University of
California, Davis, and Hasanuddin University in Indonesia.

The study, published today in the journal Scientific Reports, is one
of the first to directly link plastic and man-made debris to the fish
on consumers’ dinner plates.

“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,” said lead author Chelsea Rochman, a David H. Smith
postdoctoral fellow in the Aquatic Health Program at the UC Davis
School of Veterinary Medicine. “We think the type of debris in the
fish is driven by differences in local waste management.”

The researchers sampled 76 fish from markets in Makassar, Indonesia,
and 64 from Half Moon Bay and Princeton in California. All of the
fragments recovered from fish in Indonesia were plastic. In contrast,
80 percent of the debris found in California fish was fibers, whereas
not a single strand of fiber was found in Indonesian fish.

Indonesia has little in the way of landfills, waste collection or
recycling, and large amounts of plastic are tossed onto the beaches
and into the ocean. The problem is made worse by a lack of purified
drinking water that forces its residents to drink bottled water.

“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,” said co-author
Susan Williams, a professor with the UC Davis Bodega Marine
Laboratory who has worked on projects in Indonesia for the past
several years. “You have the best and the worst situation right in
front of you in Indonesia.”

Meanwhile, the U.S. has highly advanced systems for collecting and
recycling plastics. However, most Californians wash their clothing in
washing machines, the water from which empties into more than 200
wastewater treatment plants offshore California. The authors theorize
that fibers remaining in sewage effluent from washing machines were
ingested by fish sampled in the state.

“To mitigate the issue in each location, it helps to think about
local sources and differences in waste management strategies,”
Rochman said.

The scientists emphasize that the plastic and fibers are found in the
fishes’ guts. That means humans are likely to ingest the debris only
if the fish is eaten whole, as it is in Indonesia, or such as with
sardines and anchovies, rather than filleted. However, researchers
are still studying whether chemicals in plastic can transfer into the
meat.

The study was funded by a UC Davis Outreach and International Program
SEED Grant, the National Science Foundation’s Graduate K-12 and IGERT
programs, and the National Institute of Environmental Health
Sciences’ Superfund Research Program.