The Crystal River National Wildlife Refuge encompasses 20 islands and numerous small parcels around Kings Bay, protecting the warm spring-fed waters that manatees depend on for winter survival. The refuge is the only place in the United States where it is federally permitted to swim with wild manatees, under the rules of a long-running educational swim program. Several local outfitters run guided snorkelling tours that depart in the early morning, before boat traffic picks up.
Beyond manatees, the bay and its surrounding marshes shelter ospreys, great blue herons, roseate spoonbills, and a healthy population of river otters. Kayaking through the refuge's quiet channels, especially in the early morning, you'll find yourself in a landscape that feels genuinely wild — a rarity on this stretch of Florida coast.
Sources: - https://en.wikipedia.org/wiki/Crystal_River_National_Wildlife_Refuge