Fresh-water invasive weeds, of which milfoil is the most common culprit but far from the only one in New Hampshire , don’t and walk from lake to lake – we carry them. And often we carry them on boats or the trailers hauling boats.
That’s why New Hampshire has tightened a law against not cleaning your boat/trailer when leaving a lake, adding a $200 fine, as NHPR notes. The story ends with this cheerful sentence: “New Hampshire has 74 infested lakes and 11 infested rivers.”
“Infested”!