Habitat Utilization and Migration in Juvenile Sea Turtles

Abstract

Sea turtles are basically creatures that spend their entire lives in marine or estuarine habitats. Their only remaining reptilian ties to terrestrial habitats are for nesting and restricted cases of basking. Consequently, physiological, anatomical, and behavioral adaptations have evolved largely in response to selection in the aquatic environment, and sea turtles share many common elements with larger fishes and cetaceans in their habitat utilization and migrations. A generalized habitat model may be constructed for sea turtles based on ontogenetic stages: early juvenile nursery habitat, later juvenile developmental habitat, adult foraging habitat, and adult inter-nesting and/or breeding habitat. In sea turtles as in fishes, the numbers and diversity of potential predators and resulting mortality rates are inversely proportional to the size of the juvenile. The advantage of pelagic, oceanic nurseries is the low density of predatory fishes and sea birds there dictated by low primary production.