from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
SEA WEED. A species of grass which grows in the sea.
2. When cast upon land, it belongs to the owner of the land adjoining
the sea shore; upon the grounds, that it increases gradually, that it is
useful as manure and a protection to the ground, and that it is some
compensation for the encroachments of the sea upon the land. 2 John. R. 313,
323. Vide 5 Verm. R. 223.
3. The French differs from our law in this respect, as sea weeds there,
when cast on the beach, belong to the first occupant. Dall. Dict. Propriete,
art. 3, Sec. 2, n. 128.