Lion's Mane Jellyfish Showing Up In "Unusually Large Numbers" Off Cape Cod, Harbormaster Says

CBS Boston

July 16, 2026

Giant jellyfish are becoming a popular sight at Massachusetts beaches this summer.

The Sandwich harbormaster said Tuesday that Lion's Mane jellyfish, the largest jellyfish species in the world, "are currently appearing in unusually large numbers off Cape Cod."

"While Lion's Mane is normally seen from late spring through summer, this year reports began in May, with exceptionally high densities observed by mid-June," the harbormaster posted to Facebook. "Experts believe factors such as water temperatures and available food sources may contribute to these increases."

Click here for the full story via CBS Boston

CBS Local Digital Media personalizes the global reach of CBS-owned and operated television and radio stations with a local perspective.