After 3 beers, found this live biomass hiding under the crushed ice, served under a bed of fresh $1 oysters during happy hour. Possible refugium use? I've tried looking up edible brown seaweed, haven't had any luck.
Looks to be an egg wrack seaweed, known as
Ascophyllum nodosum. It could also be some other "wrack" type species. They do indeed occur in the northern Atlantic Ocean of America. I am not familiar with Atlantic Ocean species so it took me a bit of searching to find for you.
Ah thanks, that looks like it, I've found the word "wrack" also, but didn't recognize it. Yes, it doesn't look like it'll do well in warm waters, if its growing in from Maine to Norway. Was hoping it was something like sargassum. Well, I threw a piece with my tangs, see if they like it.