PORTLAND — When the Department of Environmental Protection called for help, seventh-graders at King Mddle School answered.

The DEP asked a group of students at the school to build 35 submersible, remotely operated vehicles to investigate invasive species of aquatic plants. The students began building the frames of the devices this week, using plastic pipes and pool floats.

Scott Comstock, a scientific communications teacher at the Expeditionary Learning school at 92 Deering Ave., said the students are building Sea Perch ROVs with the help of the Portsmouth Naval Shipyard. The Sea Perch Program was invented by the Massachusetts Institute of Technology’s Sea Grant College Program in 2003.

Comstock said the goal is to fit the vehicles with cameras and a mechanical arm to grab samples for the DEP. After they finish building the ROVs, the students will take them to the YMCA for a test run to see what modifications are needed. Later this fall they will take the ROVs to nearby lakes.

“It’s all grounded in our learning targets,” Comstock said.

Math teacher Pamela Otunno Porensky learned to build the devices at a workshop this summer at the Portsmouth shipyard, and decided it would be an opportunity to advance King’s science, technology, engineering and math curriculum.

“A big piece was having the kids take part in engineering,” Porensky said. “I wanted them to see how math was used in the real world.”

She said once they decided they wanted to do the project with the students, they looked for organizations that needed such work done. The DEP jumped, hoping for devices that could take photos and samples.

She said the students will write qualitative research reports, outlining how they built the ROVs and the field work. Porensky said they are collaborating with Massabesic Middle School, where a teacher did a similar after-school project, but without field work.

“You build upon the work others have done, and share work for others,” she said.

The reports will ultimately go to a state database and be presented to the DEP. Porensky said as students work, they will revisit how the four STEM disciplines are interconnected. She said all her lessons will come from this project.

“We’re going away from the model of worksheets and textbooks,” she said.

The students will build the ROVs over three days. Comstock said there are between 80 and 90 students involved, as well as four core teachers, himself, and seven people from the shipyard. The shipyard provided all the materials, and the project was funded by the shipyard and the National Defense Education Program.

Rick Cecchetti, outreach program manager for the Portsmouth Naval Shipyard, said the shipyard helped build 400 ROVs last year in various middle schools.

He added the hope is to reach students who may never have heard of engineering and at least get the to think about it.

“There’s a huge need for people interested in STEM careers,” Cecchetti said.

Students Audrey Watson and Evan Haapala and their peers began the project with a short presentation on dangers of aquatic invasive plants from the DEP las week.

“(The DEP) gave us the objective to make a rover that can take pictures or samples,” Haapala, 12, said.

Watson, 11, said the reason they are building the rovers is to find out what effect invasive species have on the environment.

“We don’t usually use these real-life mechanics,” she said. “We’re drilling holes in piping and using real-life tools.”

“It’s a very hands on experiment,” Haapala added.

Colin Ellis can be reached at 781-3661 ext. 123 or cellis@theforecaster.net. Follow him on Twitter: @colinoellis.

Seventh-graders Ayden Grimm, left, and Demario Lopez at King Middle School in Portland on Monday, Sept. 21, construct a remote operated vehicle to investigate invasive plant species.