Signs of environmental damage are everywhere, but sometimes, those signs are very hard to see. Before dawn, on the Oregon Coast, marine biologists are on a hunt for what's nearly impossible to find – microplastics – 5 millimeters or even smaller.



The tide pools are covered with mussels and whelks, and that's just what Dr. Susanne Brander's team wants to collect. Pure ocean water flows through these shell fish, but microplastics get stuck, reports "CBS This Morning: Saturday" co-host Michelle Miller.



"We're seeing on average a couple of pieces of suspected plastic in each animal," Brander said.



Her lab at Oregon State University is part of a worldwide microplastics research effort that has found few places untouched.



"They're being found in arctic ice. It's not as if there are people are dumping plastics off the icebergs; it's coming from global air and ocean circulation," Brander said.

Scientists say every year worldwide, more than 300 million tons of plastics are produced, and half of it is for single use. But around eight million tons of it ends up in the ocean.



At the Scripps Institution of Oceanography, Dr. Jennifer Branden found more evidence deep in the ocean floor off Santa Barbara. Her sediment samples dates microplastics plastic there back to the 1940s. It gets there in many ways.



"These fibers are coming off fishing rope but a lot of them are coming off our own clothes. So as you're washing your clothes, they're washing down the drain," Branden said. "They're too small to get caught at the waste water treatment plant and they're washing right out into the ocean."

Brander said our clothes made of synthetic fabrics, plastic water bottles, straws – these things can all break down into smaller pieces. On the road, there's trouble too. Tire particles from cars on the road can get into watersheds and the air, Brander said.

A study found 7 trillion microplastic particles pollute the San Francisco Bay each year, and researchers are seeing an impact.



"We do know that in aquatic animals, that there are suggested effects on things like immune response and respiration. We see some effects and in oysters that are exposed. They lay fewer eggs," Brander said.

Brander said we don't know yet whether this all is harming us.



"What is the concern is that these microplastics are getting into our seafood, they are getting water so we know we're ingesting them but we don't yet have a measurement of what the effects might be," she said.

While America waits for more studies to be done before taking regulatory action, the European Union is already taking a stand. In March it voted ban single-use plastics 13 months from now. Those plastics alone account for 70 percent of the plastic litter found on beaches throughout Europe.

