Environment

Study points to ship hull coatings as a major source of microplastic pollution

Study points to ship hull coat...
Many ships' hulls are treated with special paint that resists biofouling and corrosion – but that same paint could produce waterborne microplastic particles
Many ships' hulls are treated with special paint that resists biofouling and corrosion – but that same paint could produce waterborne microplastic particles
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Many ships' hulls are treated with special paint that resists biofouling and corrosion – but that same paint could produce waterborne microplastic particles
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Many ships' hulls are treated with special paint that resists biofouling and corrosion – but that same paint could produce waterborne microplastic particles

When we hear about microplastic particles polluting the ocean, the usual suspected sources are degraded consumer plastic goods and synthetic textile fibers from washing machines. A new study, however, suggests that much of the blame lies with protective hull coatings on ships.

Led by Dr. Barbara Scholz-Boettcher, a team from Germany's University of Oldenburg started by collecting water samples from a region of the North Sea known as the German Bight. The samples were collected in the autumns of 2016 and 2017 from various locations in the bight, which encompasses some of the world's busiest shipping lanes.

Utilizing stainless steel sieves, the scientists proceeded to filter sub-millimeter-sized plastic particles out of the water samples. Those particles were then heated to nearly 600 ºC (1,112 ºF), causing them to break down into even smaller fragments that could be chemically identified. In this way, it was possible to not only count the number of particles in the water, but also to determine which types of plastic made up what percentages of the total combined particle mass.

It was found that while packaging plastics such as polyethylene and polypropylene were more common near the shoreline than elsewhere, they accounted for only about one third of the mass of the collected particles. The rest – particularly those collected in the open ocean – consisted mainly of polyvinyl chloride, acrylate polymers, and polycarbonates.

"We believe that these particles originate from ship coatings, where these plastics are used as binders in acrylic paints or epoxy resins, for example," says Scholz-Boettcher. "Our hypothesis is that ships leave a kind of 'skid mark' in the water which is of similar significance as a source of microplastics as tire wear particles from cars are on land."

A paper on the research was recently published in the journal Environmental Science & Technology.

Source: University of Oldenburg

9 comments
Douglas Bennett Rogers
Ahoy! A big shipping cost increase on the horizon!
Aross
Another reason why we should be getting away from plastics of all kinds. Although we ar trying to recycle the stuff, production still vastly outstrips these efforts. An outright world ban is the only way to stop this pollution.
buzzclick
Hard to accept that the coatings from big ships are significantly a cause for micro plastics in the ocean, but now that we have this finding...let's ban the big ocean liners and tankers!
Username
This is no surprise, ablative bottom paint is designed to wear off into the water.
Bob Flint
Next thing is the flags & laundry we expose to the wind. If it didn't come from nature, it doesn't belong there? Are we not just shuffling molecules around, that will inevitably be repurposed in decades, centuries, millennia, eons...
Signguy
Operative word here is "could".
Catweazle
I believe the plastic anti-fouling coatings are a less environmentally damaging replacement for the TBT (tri-butyl tin) that used to be used.
ljaques
Did they, perchance, test all the river outlets during that study? If not, why not?
PACK0
I have a novel concept, how about we stop dumping 100's of millions of liters of raw sewage in the ocean every day!!!