The Dolphins of PerneBook - 1994
When the first humans came to settle the planet Pern, intelligent dolphins also crossed the stars -- to colonize Pern's oceans. Then came disaster: Thread fell like rain. Humans struggled to survive. Now -- centuries later -- dragonriders and dolphins face a new era, reviving the bond between land and ocean dwellers.
Publisher: New York : Del Rey/Ballantine Books, c1994