About two weeks ago, when down at our dock on the Connecticut River, I was surprised to see three large, gelatinous spheres attached to a rope that ties the dock to the shore. Each was slightly larger than the next. I’d never seen anything like them before, and assumed they were frogs’ eggs.
From Wikipedia, this description seems to fit:
Bryozoans grow in clonal colonies. A larval Bryozoan settles on a hard substance and produces a colony asexually through budding. These colonies can grow thousands of individual zooids in a relatively short period of time. Even though colonies of zooids grow through asexual reproduction, Bryozoans are hermaphrodites and new colonies can be formed through sexual reproduction and the generation of free swimming larvae. When colonies grow too large, however, they can split in two. This is the only case where asexual reproduction results in a new colony separate from its predecessor. Most colonies are stationary. Indeed, these colonies tend to be settled on immobile substances such as sediment and coarse substances.https://en.wikipedia.org/wiki/Bryozoa#Habitats_and_distribution
Here’s a close-up photo:
Here’s an underwater photo (thanks, Apple iPhone!):