Hi - 8doubles - I take it that is a joke about your fishing prowess.
But who can say - it might be worth bringing some back and fermenting it out like comfrey leaves and offering it diluted in water. The stuff I use is pretty expensive to buy, but it is dried and nice and easy. It says on the bag Seaweed Meal, and from memory when I was researching it a few years ago I would guess that any seaweed will do.
I use it on the garden beds, round the flowers, and give it to the animals and birds I keep. Certainly the flowers have a more vibrant colour, and I think my veg eggs, and dare I say it chickens sheep pigs cattle etc all taste better. It might be subjective but - I think -therefore it is.
All the best
Sue