fucoidan and iodine are medicines batman and robin?

I have stumbled upon both Iodine and fucoidan and was wondering if anyone new the differences between the 2? and if they are basically the same thing? or if one is better than the other? just curious as if when they found Iodine in seaweed as the culprit to the great health benefits and why we need it, if they missed the fucoidan that is also in the seaweed making the health benefits even better??