Shark Queen's Lair Bloodblooms

Hi! I don't know a way to tag Loot Tavern in this. I purchased the Shark Queen's Lair and there is a strange omission I can't figure out.  Spoilers below if you haven't read this module. There are things called Bloodblooms that seem integral to the threat of the second wave. But I don't see any information on where they appear or how many should appear. Thanks to any with suggestions.

I believe the bloodblooms spawn out of the bloodkelp? I think during some of the lair actions bloodkelp rises from below. When they explode, bloodbloom takes up the place the kelp was in before. I think I had mine at 10'x10' for the blooms but I ran this one shot offline so I could be misremembering.

You are right, but where do the bloodkelp come from? more importantly, how many are there supposed to be?