Dirty lake? Who you gonna call? Pond Patrol!

Litterbugs at Prospect Park Lake better be on the lookout — thanks to the Pond Patrol!

Brooklyn’s embattled lagoon now has 23 new advocates who are only 4-years-old and hail from a nursery school in the no-man’s land of Manhattan.

Dubbed the “Pond Patrol,” the adorable environmentalists are helping reclaim the lake from the litterers, arsonists, and animal entrail-dumpers after reading about the many strange goings-on in the newspaper (this one!).

The tykes’ teacher at the Beginners Nursery School, Lynnette Arthur, explained that the inspiration for the students’ love of the lakebegan last September when the class bumped into Anne-Katrin Titze, the park’s unofficial watchdog who, as usual, was on the lookout for any signs of trouble.

Titze told the tykes about the fanciful adventures of Honey Bear, Beaky (the swan with the missing beak), John Boy (may she rest in peace), and other lake critters — and a new superteam was born.

“All they kept saying was, ‘Where are the swans, where are the swans?’ ” laughed Arthur.

Afterwards, the teachers decided to create an entire environmental curriculum based on the ongoing saga at the lake.

Arthur stoked her students’ interest with several more trips to the lake, including one last month, when the squealing squad — equipped with T-shirts with “Pond Patrol” written on them and 200 anti-litter pamphlets — first became a pint-sized civic force.

“They were yelling and chasing down joggers, asking them if they could save the lake and stop Beaky’s beak from getting broken,” said Arthur.

Some in the triumphant crew even pleaded their case with a few choice words: “If we don’t do something about this, who else is going to help?” weighed-in Alexandra, 4, who fed geese and visited a swan’s nest with her classmates.

Four-year-old Noah was as hard-boiled: “People putting garbage in the lake is not fair to Beaky and his friends,” he waxed.

As for Beaky, “He’s awesome, he’s doing really well, we were so happy so see him,” said Arthur, noting, “He’s a celebrity to us.”