Moonrise Fae dance down Massachusetts Avenue during the Mermaid Promenade at the 2019 Cambridge Arts River Festival. (Photo: Cambridge Arts)

The summertime-summoning Cambridge Arts River Festival returned to Central Square on June 1, back from three years in East Cambridge with the usual food, crafts, multiple stages of live music, dance, poetry and theater, and art of all sorts. But this 40th annual free festival had a new highlight: a “Mermaid Promenade” along Massachusetts Avenue tying in with the event’s central theme of climate change.

“About a year ago, inspired by the Coney Island Mermaid Parade, I pitched the idea of bringing a version to the River Festival to my colleagues at Cambridge Arts, where I work part time,” said Greg Cook on his Wonderland site. “Festival organizers Julie Barry and Jannie Kitchen took the lead in making a great, participatory parade.”

Well over 175,000 people came to the festival, police learned from the Cambridge Arts Council Advisory Board. (Cook said great weather helped; previous years suffered from mid-event rains.) Despite the crowds, there was only one arrest – of a 49-year-old man from Lincoln, for public urination, said Jeremy Warnick, director of communications and media relations for Cambridge police.

The dozen additional images give a sense of the year’s festivities. A navigation tool is below the photos.