"Plastisphere" ecosystems may be biohazards.
This biological community starts with particles of degraded plastic no bigger than grains of salt. Bacteria take up residence on those tiny pieces of trash. Then single-celled animals feed on the bacteria, and larger predators feed on them.
"We've created a new man-made ecosystem of plastic debris," said Lopez, a graduate student at the University of San Diego, during the recent expedition.
The plastisphere was six decades in the making. It's a product of the discarded plastic — flip-flops, margarine tubs, toys, toothbrushes — that gets swept from urban sewer systems and river channels into the sea.
When that debris washes into the ocean, it breaks down into bits that are colonized by microscopic organisms, many of them new to science. Researchers suspect that some of the denizens may be pathogens hitching long-distance rides on floating junk.
Scientists also fear that creatures in the plastisphere break down chunks of polyethylene and polypropylene so completely that dangerous chemicals are leached into the environment.