This is not the kind of fishing most of us learned as kids.
The bait is different — these fishermen use magnets, not worms — and there's no way they would eat their catch of the day.
It's a hobby called magnet fishing — a combination of environmentalism and treasure hunting.
A local teen who aspires to be a marine biologist got a dose of reality when she recently tried her magnet fishing hobby at the Shawsheen River in the Ballardvale section of town.
Marianna Boullie, 15, of Andover was disappointed with her treasure hunting in the Shawsheen. She said the river is simply a giant trash can full of discarded junk.
"I watch videos on YouTube of people pulling cool items and junk out of the water and wanted to see what was in the waters of Andover,'' Marianna said. "It made me sad to see that I was pulling trash out of the water and people were using the river as a public trash can.''
Her catch of the day included rusty bikes, tires and a storm door.
Ever since she was young, Marianna has wanted to be a marine biologist and has always cared about marine life. Removing pollution from outdoor bodies of water will make a better environment for marine life, she said.
"I started magnet fishing about four months ago, and before that I had never heard of it,'' she said. "Magnet fishing is when you take a strong magnet with a rope and throw into a body of water.
"After using my magnet for a while, I bought a grappling hook and started to pull more things out of the water,'' said Mariana, who attends Andover High School. "My inspiration for buying a magnet and grappling hook originally came from YouTube.''
Magnet fishing is believed to have been started by boaters using magnets to recover fallen keys from the water. The magnets used are typically strong enough to remove large debris like discarded bikes and car tire rims.
While Marianna may be disappointed with the items she retrieved from the Shawsheen River, neighbors applaud her environmental activism.
"Her effort and example is rare these days,'' Ballardvale resident Barbara Burke wrote in an email to the Townsman. "So few get out and make a difference by living by their words. I hope that others will be inspired to do good locally.''