You may have seen this …glob.. mostly on water lines. I believe the pod is called a Bryozoan colonies. You might say the coral of fresh water. We have a picture of a colony attached to my dock..they filter the water so ..don;t be too aggressive cleaning them off.
Though they are not closely related to corals, bryozoans are superficially similar in that they are tiny colonial aquatic creatures that effectively filter particles from the water. The large gelatinous species is native to North America and often grows on docks and other submerged wood. Check of this simplified Ask A Naturalist web site..if you want more detail simply search the word. Click the site link to read the rest of the article.
Under Water Picture of our dock side