alt Hacker NewsTL;DR: Rubber. Industrial adhesive. Nobody knows why this is there or who is responsible yet.
> I’m quite confident that the sample that I handled was PVA butylene rubber,” [Dr. Kozak] said in a phone interview, describing a mix of synthetic rubber and polyvinyl acetate, known as PVA. That polymer, he said, is “the active ingredient in white glue — the kind of white glue you have at home is a very dilute, kid-friendly version of this stuff.”
> Globs of the white sticky substance, which have a spongy interior and range in size from a coin to a dinner plate, have been found for miles along Placentia Bay since at least September
> Dr. Kozak said that one of the first things he noticed was that the blob had “a kind of petrochemical odor to it, kind of like if you walk down the turpentine aisle of your hardware store.”
A number of these sorts of "What is this" posts on Reddit about mysterious yellowish blobs, end up being polyurethane expanding foam.
They float, and their default state is "mysterious blob", the only action necessary to create this is to puncture the aerosol container. Most people who use them end up throwing away an aerosol container that's still half full, but which has hardened at the dispenser tip.