Yes, there is a small amount of bromine in sea water, this is where it is from. In fact, all that bromate bleach and fire retardant made from bromine, is made from sea water, they evaporate the salt in a way that allows them to isolate the sodium chloride from the trace minerals, and this is where the main industrial source of bromine comes from. So obviously the body needs a small amount of it. But the majority of the human dietary intake that comes from the sea, especially sea vegetables, concentrates iodine, not bromine.