Mark Gordon, co-director of the Knife River, Minnesota-based Sea Change Expeditions, gives Chassell Township Schools students a tour of the Amicus II during its stop in Houghton Tuesday. Sea Change Expeditions does an annual tour of Lake Superior focused on citizen science and educating schools about environmental issues affecting the lake. (Daily Mining Gazette photo by Garrett Neese)

HOUGHTON — Sea Change Expeditions stopped in Houghton this week as part of a Lake Superior voyage to raise awareness of environmental issues affecting the lake.

Directors Mark and Katya Gordon make the trip each year in their 40-foot steelboat with a fresh crew of young adult volunteers from universities around the Lake Superior area.

Students from Lake Linden-Hubbell and Chassell Township visited for presentations, games and tours of the boat Tuesday.

The Gordons launched an adventure sailing business in 2007. They decided to begin teaching about environmental issues in 2012, after sailing up the Atlantic Ocean coastline and seeing the decimation from Hurricane Sandy.

“We figured everyone needs to find their niche and how to serve the world,” Katya Gordon said during a presentation at the Portage Lake District Library Monday. “We have a strong conviction about climate change, and we’re also sailors, so let’s just combine the two.”

They also wanted to use a more optimistic, solution-focused approach. Adding a young adult crew, they began making annual trips with presentations at public schools.

“We felt like there’s a lot of scientists out there to talk about what’s going to happen, what’s happening, but what we want to talk about is how to solve it,” Katya Gordon said. “And we want to be part of solving it with young people and their students.”

They talk with students about simple ways to reduce their impact on the environment.

They don’t tell students to eliminate plastics entirely, Katya Gordon said. Instead, they distinguish between reusable plastics — like the sturdy chairs people sat on during Monday’s presentation — and single-use plastics, which account for about 80% of the plastics in Lake Superior, she said.

“If you use your Ziploc bag 100 times instead of once you have now reduced your plastic by 100 times,” Katya Gordon said. “We try not to talk in absolutes, like that there should never be plastic again, because here we are, we live in this world. Plastic is everywhere.”

The presentations the Gordons give to students have three main focuses: how the climate around Lake Superior is changing and how to address it, pollution from plastics and microplastics, and invasive species such as zebra mussels and sea lampreys.

“The engagement that we’ve received and the connection — that these students come together about keeping the lake clean, cold and clear — is just really unifying,” said crew member Pearl Krieger. “And so that’s just outstanding to see the connection that comes from the lake and how it forms our communities.”

Monday’s presentation included information about those three issues and how they intersect.

There are about 90 invasive species in Lake Superior, about half the number present in lakes Huron and Erie. However, a warmer Lake Superior means invasive species that are in the lower Great Lakes can gain a greater foothold. Zebra and quagga mussels filter plankton, which makes the water clearer but wreaks havoc on the food chain.

Zebra mussels have now been spotted at every major port in Lake Superior, and a reproducing population has been discovered at Isle Royale, Mark Gordon said.

The crew conducts citizen science projects of its own. They trawl for microplastics and invasive species. They use a Secchi disc — a white circular disc lowered into the lake — to determine how clear the water is; their record is 70 feet, crew member Catherine McComas-Bussa said.

Volunteer student crew members are picked each year on a first-come, first-serve basis, provided they’re suitable, Mark Gordon said. That means not just performing the tasks of the crew, but helping lead educational presentations and games.