A Japanese professor wants to turn the tide on a global problem: the millions of tons of plastic waste littering our oceans.
He says it doesn't disappear. Instead, it breaks down into tiny fragments over time. These microplastics are wreaking havoc on marine ecosystems.
Japanese researchers looking for microplastics only need to go as far as Tokyo Bay.
Professor Hideshige Takada, from the Tokyo University of Agriculture and Technology, is a global leader in this field of research.
"We use a net designed to catch plankton. We then filter the water to find pieces of plastic larger than 0.3 millimeters," he explains.
Microplastics come from shopping bags, bottles and synthetic fibers from clothing. Takada says the world's oceans are filled with a staggering 5 trillion of the particles.
His research shows that these particles contain high concentrations of harmful chemicals.
Some of them -- PCBs -- were banned in the '70s. They were widely used before they were discovered to cause cancers and skin disorders.
Takada investigated 64 anchovies caught in Tokyo Bay and he found most of them had swallowed microplastics.
"Pollutants in microplastics intensify as they move up through the food chain. Ultimately, these chemicals may affect the immune systems and reproductive health of humans and animals," he says.
Scientists are also concerned about the effects microplastics are having on the ocean floor and the soil beneath it.
They investigate using a device that collects soil from the ocean floor and measures chemicals.
That's where Takada discovered PCBs, even though they've been banned for 40 years.
He believes the buried chemicals are disturbed by fish. So when microplastics fall to the ocean floor, they get coated with PCBs, regenerating past pollution.
Takada attended an international symposium on oceanic plastic pollution that was held in Tokyo in December.
A British researcher, Erik van Sebille from Imperial College London, presented a simulation of how microplastics move through ocean currents.
"Japanese plastic may end up on US coast lines. Everything ends up everywhere and it is really important to collaborate, and for governments around the world to sit together and do something about this," he said.
Takada says that Japan, being one of the world's major producers of plastic waste, needs to take a more proactive role.
"Japan lags behind on taxation and restrictions to reduce plastic waste such as plastic bags and bottles. We also need to lead efforts to develop materials to replace plastic."
He says the choice is ours: eat fish contaminated with toxic chemicals, or cut down on the excessive use of plastic products.