Anthony,
According to the Mass. Wildlife website, you do need a fishing license.
Resident Minor Fishing (age 15-17) $11.50.
[url=http://www.mass.gov/dfwele/dfw/dfwfees.htm:d5c7b]http://www.mass.gov/dfwele/dfw/dfwfees.htm[/url:d5c7b]

And yes, they can take your gear and give you a fine if you don't have a license.
$11.50 is a small price to pay when you divide it by the number of days that you fish.
Bob