Video and photos courtesy Amber Beth-Roberts Mascio.

Mad River Beach, just south of McKinleyville, was dotted Monday afternoon with hundreds if not thousands of gelatinous iridescent blobs — the jiggly corpses of beached jellyfish, by the looks of them. 

We’ve reached out to Brian Tissot, director of Humboldt State University’s Marine and Coastal Science Institute, for confirmation on that amateur identification and, hopefully, some educated theorizing on what may have caused the event. We’ll update this post when we hear back. 

[UPDATE: Tissot responded via email, “My guess is they are moon jellyfish and it isn’t uncommon for them to wash up after strong winds.” He later confirmed his own guess after looking at more detailed photos, which revealed the moon jellies’ distinctive “horseshoe-shaped gonad.” This is why we contact experts. Tissot also included a word of warning: “They can sting so best not to touch them.”]

The videos and photos here were submitted to the Outpost by Amber Beth-Roberts Mascio of McKinleyville. The apparent jellyfish, which appeared to interest Mascio’s canine companion, stretched “as far as the eye can see,” she said.

Jellyfish washed ashore at Mad River Beach.