On Zetacron, the nature goddess Gaia did not create the elves, but wished to claim them as Her own (it seemed fitting to her, somehow, that elves should be bound to Nature). Thus, she used her divine powers to create a bond between Herself and the elves.
"Look, lad! You see the streak of glowing green off the larboard bow? Them's the bright waters!"
While the lad peered intently at the eerie glow, the old salt continued. "Entire ships have been lost to the Bright, lad, for once you let it surround you, you'll never touch land again!"