Surrounded by students, Dana Coggon pulled back the long, orange handle of a weed wrench with both arms.

The jaws of the wrench crunched into the base of a Scotch broom stalk and, with an audible rip, a clump of roots and dark earth were pulled from the ground.

It was another opportunity for Coggon, noxious weed coordinator for Washington State University’s Kitsap County Extension, to tell students one of her cheesy yet inescapably memorable principles of weed control.

“You have to get to the root of the problem,” she said.

At Blakely Harbor Park Thursday a group of Odyssey Program 7th and 8th graders were digging into a few of the problems facing one of the island’s most ecologically and historically vaunted places.

For this, their first field trip to the harbor, they were concentrating on the dramatic impacts of just a few non-native plants. They learned to battle the English ivy that blankets ground at the park and strangles the trunks of trees. How to beat back the poison hemlock, blackberries and Scotch broom that suck nutrients from native species.

Commodore Options School teachers, supported by graduate students from Seattle University, naturalists from IslandWood and volunteers from a growing list of local organizations, are planning to make invasive weeds just one field in a study the harbor’s salt marsh ecosystem.

In coming months students will measure pH levels and water salinity, beach seine for fish and record data vital to the health of a nearshore habitat. University of Washington biologist Jim Brennan has helped shape the project and will oversee its scientific findings.

Teacher Elizabeth Vroom said study will give students real world experience in ecology, and show them how their work can have a tangible impact.

“The more we can get them out doing service, the more likely they’ll continue to be stewards of the environment in the future,” she said.

After reading and discussing invasive plants in the classroom for weeks, students took eagerly to the field Thursday. They split into six groups, each assigned to a 10-foot by 10-foot square of the park. Their task was to inventory the non-native plant in their quadrant, then destroy it.

Taking inventory was easy for the English ivy team; the leafy vines covered every inch of dirt in their square. The students dove into their work, wrestling out armloads of ivy to pile on a blue tarp.

Nearby the poison hemlock team determined their leafy green problem plant had conquered 45 percent of the study area and was dueling with three other invasive species for the remaining ground. Seattle University teaching student Lachlan Willis showed students how to dig out the hemlock’s root ball and asked them what they remembered from studying the plant

“It’s what Socrates was killed with,” one student recalled.

Elsewhere groups assaulted a patch of blackberries and waged war on Scotch broom, holly and Queen Anne’s lace. A roving “Early Detection Rapid Response” team led by Coggon hunted for plants just beginning to take hold in the area, like bull thistle and daphne.

They saw the importance of pulling out those scattered immigrants before they could build into thriving colonies like the English ivy.

“One plant a day keeps millions away,” Coggon told them.

For two hours, with sweat and a few chafed hands, students grappled with the immensity of the plant problem.

“In the classroom we can’t really experience how bad it is,” 7th grader Katie Gildner said, as the group spread out along the beach for lunch. “When you get out here you really realize how many invasive species there are.”

Ideally the scope of the program will reach beyond ecology.

Walking toward the old generator building with a group of students, Vroom reminded them that the head of Blakely Harbor was once the hub of the largest lumber mill in the world.

“You remember the photos of the old mill,” she said gesturing to the sweep of the bay. “It used to cover all this area.”

History adds yet another dynamic to restoration plans for the harbor. Planners at City Hall want to restore balance of a naturally functioning ecosystem of the salt marsh.

Others are fighting to safeguard the historical aspects of Port Blakely including the generator building, mill pond and pilings. Landowners and developers have added their concerns about regulations and buffers along the bay.

Vroom said the project wouldn’t ignore the community tugging match over the harbor. Armed with some objective evidence, she hopes her students can add insight to the debate.

“Decisions might be made based on who has the most money, or who talks the most,” Vroom said. “We’d like to get students involved.”

When the students work was done Thursday, the weeds in each quadrant had been devastated. Only scattered leaves remained in the square of English ivy.

Freshly turned black dirt was the only evidence of an uprooted blackberry patch.

The students loaded their collected brush into a truck supplied by the city, and Ty MacVane triumphantly toppled a 14-foot holly tree he had been sawing on for the better part of a half hour.

At each site the classes left signs explaining their project and sharing information about the species.

According to the plan, when those middle school students become high schoolers in a few years, they’ll get to teach younger students entering the program about Blakely Harbor, while sharing thier collected knowledge with older community members.

“These are the kids who I hope have my job in a few years,” Coggon said, watching her fast-response team attack a patch of thistles. “They’re getting more information at their age than I got in my first years at college.”

Then she couldn’t help but throw in one more catch phrase.

“We’re spreading the word,” she said, “not the weeds.”