but have no idea how it is made and find it rather difficult to believe it is the same stuff that you show in your pictures. Of course I know that kelp may be called seaweed, but that seaweed is more than kelp.

That stuff you are harvesting looks like "macrocystis," the same stuff we have down here in So Cal. http://www.starthrower.org/research/kelpmisc/kelp_mp.htm