The region is famed for its sparkling blue waters, but potential for danger lurks below the surface, some of it too small to be seen.

Microplastics will be the focus of this year’s Freshwater Summit, taking place Fri., Oct. 30 at Grand Traverse Resort & Spa.

The presence of plastics on Great Lakes beaches is nothing new, but it’s the virtually invisible pieces that advocates say are the most dangerous. They absorb pollutants, and their small size makes them easily ingestible. Toxic contaminants can also attach to microbeads, which then are eaten by fish, and could end up in the food chain.

Nine states have passed laws that will phase out the manufacture and sale of personal care products like toothpaste and facial cleansers containing plastic microbeads. The Michigan House of Representatives is now looking at a similar ban with HB 4345.

The event’s keynote speaker will be Sherri Mason, a professor of chemistry and the Environmental Sciences program coordinator at the State University of New York in Fredonia. Mason conducted the first-ever survey of plastic pollution in the Great Lakes; she says she was dismayed but not surprised by what was found.

“Not surprisingly, we have found plastic particles within all five of the Great Lakes. The counts obtained rival those within the world's ocean,” she says.

What was surprising to Mason was the quantity of microplastics.

“About 70 percent of the plastic we skim off the surface of the Great Lakes is between one third and one millimeter in diameter," she says.

Watershed Center Executive Director Christine Crissman says the problem is that the microbeads are so small they pass through most filters. “Traverse City has a really advanced system” which catches the microbeads, she says, “but [those systems] are not that common.”

The potential for problems wasn’t identified when the beads were first introduced into cleaning and personal hygiene products like exfoliating face washes. “Now, 20 or 30 years later, we recognize it and are trying to correct it,” Crissman says.

Microbeads are the primary focus – but not the only one – at the conference. Other topics slated for discussion include Great Lakes evaporation, Great Lakes coastal wetlands and local research and restoration projects.

“We try to push topics that are hot-button issues,” Crissman adds. That includes the water levels, which area residents and visitors have seen change dramatically over the past decade-and-a-half.

“We realize evaporation plays a large part,” she says, noting water levels are also affected by snow and rainfall.

The warmer the water, the greater the evaporation, most of which takes place in the fall. The last few cold winters have helped slow the rate of evaporation, as ice packs that formed on the Great Lakes kept the water temperature colder throughout the year.

This year’s Freshwater Summit is also part of the 9th Biennial State of Lake Michigan/15th Annual Great Lakes Beach Association conference. The Summit is a collaboration of The Watershed Center, Great Lakes Environmental Center, Inland Seas Education Association, Northwestern Michigan College’s Water Studies Institute, Michigan Sea Grant, the National Oceanic and Atmospheric Administration and the Grand Traverse Conservation District.