MANCHESTER — A lot of 11-year-olds might run lemonade stands to make a few dollars in the summer.

Gloucester resident Mackenzie Plante, on the other hand, has spent her summer running her own business — selling mats made of lobstermen's rope, for $35 or more apiece. And she has sold more than 400 to date.

The business, christened Mac's Mats, offers what Mackenzie says stands as the original reclaimed fishing rope doormat, and draws in many ways off a Maine state mandate regarding lobstermen's gear.

The twine she uses in her mats comes from Maine, where regulations require lobstermen to use twine that sinks, rather than floats. The mandate is designed to help protect the Northern Right Whale, which can entangle itself in the floating line.

In compliance with the law, lobstermen turned in the old line, and David Carter — a former lobsterman from Waldoboro that Plate and her grandparents Mel and Diane Myler met at a lobster festival in Port Clyde, Maine — purchased the line for re-use.

That re-use turns out to be Mac's Mats. Carter constructs the actual mats, and Plante — who is already serving 14 clients in New England — sells the product. Her mats are sold at marinas and farm stands between the two states, with Utopia Farm Stand in Manchester the first store to sell the product.

"It started as a summer project," Mackenzie said, "I want to be a business woman, and it's a good start."

Her mother, Marcey, said the "summer project" turned quickly into a full-time job, and that the work has taught her daughter the basics of business as well as important life skills, such as eye contact, and phone etiquette.

She said that her daughter works with the stores herself, and that she and Mackenzie's grandparents help with transportation to and from stores and to and from Maine.

Mackenzie launched her endeavor with a yard sale to finance purchasing mats from Carter.

She handpicks each mat, rather than having them shipped down to the various stores.

She said this helps with variety. So far, she said, a combination of blue and orange rope has proven a favorite among customers.