Bubble Snail Die-offs
Last Friday, I posted an entry in the Museum’s social media (Facebook, Instagram) describing how the wrack line on the eastern end of Sanibel (Lighthouse Beach) was littered with empty, mostly juvenile shells of the Western Striate Bubble, Bulla occidentalis. I ended the post with a vague “we wonder what could happened.”
The post prompted a number of comments and suggestions from our audience. We learned that the phenomenon occurred at least from Naples and Keewaydin Island in Collier County north through Bonita and Fort Myers beaches, and most of Sanibel Island. Some readers reported similar bubble snail die-offs in other occasions on Sanibel, Anna Maria Island (Manatee County), San Francisco Bay, and on the north shore of Oahu, Hawai’i.
Suggestions for possible causes ran the gamut from mass breeding, “something eating them?”, high water temperatures, decreased salinity due to rainwater and septic tanks runoff, oxygen depletion, “chemical pollution,” blue-green algal blooms, to “Companies, Governments.” However good these suggestions may be, we are still trying to better understand such incidents and identify what causes them.