Scientists searching Great Lakes for microplastics

A team of scientists begins a 10-day trip on the Great Lakes Sunday searching for microplastics, tiny plastic balls that researchers fear could be harming fish.

Last year a team of researchers discovered huge numbers of tiny plastic beads, less than a millimeter in diameter, in Lakes Superior, Huron, and Erie. This summer they'll extend their search to Lakes Michigan and Ontario.

Chemist Lorena Rios Mendoza at the University of Wisconsin-Superior said some fish she has analyzed in Lake Superior are eating the plastic.

"When they try to pass (the plastic) through the guts, it can block the guts or get stuck in the stomach," she said.

It's still unclear where the plastic comes from. But researchers suspect they are abrasive micro beads that are used in personal care products like facial and body washes.