6. Loggerhead, green and hawksbill turtles are commonly observed in park waters. Leatherback turtles may be observed, but are uncommon. 7. 90% of American loggerhead turtles and 100% of American green turtles nest in Florida. 8. The six species of sea turtles found in American waters are all listed as threatened or endangered. Click on a link below to learn more about sea turtles: