MISQUAH — The two loon chicks on the north end of Big Pelican are three weeks old now, visibly bigger week to week, venturing short solo paddles a body length or two off their parents’ backs — and they still cannot dive deep enough or fast enough to clear a boat wake, which is precisely the problem with the timing of the Fourth.

Greta Solberg, the high-schooler whose loon survey the library has certified, with only partial irony, as “actually science,” has logged the pair every morning since they hatched in the first week of June, recording the adults’ feeding runs, the chicks’ weight gain by eye, and the boat traffic on the north end in a notebook she will not let anyone photograph. The data, she says, are simple and not in dispute: the chicks are growing on schedule, the parents are feeding them well, and the single greatest threat to all of it arrives Saturday with the heaviest boat traffic of the year.

“A wake they can’t dive under separates a chick from its parents, and a separated chick on a busy lake doesn’t make it,” Solberg said, in the flat, unsentimental register she has learned the subject requires to be taken seriously. “This isn’t about being nice to the ducks. It’s about the difference between two chicks in August and zero. Ninety seconds off your throttle on the north end is the whole difference. That’s the entire ask.”

She has made the request to the celebration committee, which folded it into the boat parade’s no-wake rule; to Alderman Lloyd Bunde, who has adopted it as a personal cause and will tell you so; and to anyone who holds still at the landing long enough to hear it. Loons have nested on Big Pelican for as long as the survey has existed, but the pair lost a chick to a snapping turtle two summers ago — a loss the whole lake remembers, and the reason Solberg, then ten, started counting in the first place. “The eagles didn’t get these two. The muskies didn’t. The turtles didn’t,” she said. “It would be a stupid, avoidable way to lose them now — to a pontoon playing music on a holiday. So slow down. They’ve got two. Two is good. Let’s keep two.”