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... The particular genre of bubble-blowing documented in the report took the form of perfect circles, similar to ones described by biologist Roger Payne as "madly spinning doughnut-shaped clouds that look like giant smoke rings about three feet in diameter that rise rapidly to the surface."
two photos side by side, one shows bubbles emerging from ocean in a rough spiral pattern, the other in a neat white ring

Two distinct bubble structures, including (a) bubble net and (b) bubble ring. Note that they are very different physical structures. (Sharpe et al., Mar. Mam. Sci., 2025)

An international team of biologists and photographers reviewed videos and photos of whales producing bubble rings, taken from below the water by a swimmer or overboard from a boat, and above the surface either from a boat, a plane, or a drone.

a four by three grid of photos, each one showing different variations of bubble rings in blue ocean water.
At least one bubble ring from each of the 12 episodes analyzed in this study. (Sharpe et al., Mar. Mam. Sci., 2025)

This variety of sources adds to the context in which the whales produce their rings, particularly important if we want to know whether they're meant as communication with humans or not.

Their data included a dozen separate examples of rings being made by the whales, equalling a total of 39 bubble rings generated by 11 different humpback whales. ...