Finding “The Lost Year” Sea Turtles: The potential threats and conservation implications

by Ashley Hill,
Marine conservation student

Open ocean habitats are innately difficult to access. As a result, the majority of research on sea turtles is restricted to beach and coastal areas. However, there is a time span of several years from when hatchlings venture offshore to when the larger, juvenile turtles return to coastal waters. It is thought individuals of this life stage must live in the open ocean, but the lack of concrete, direct evidence has led to the term “the lost years” (Carr et al. 1978). The majority of the open ocean is desert like, with vast areas of minimal amounts of food or shelter. Oceanic processes push water together to form areas of convergence. These areas typically contain higher levels of plankton and therefore a higher abundance of other organisms that take advantage of the increased food source. In the Atlantic, Caribbean and Gulf of Mexico, convergence areas are often traced by lines of a branching, floating alga called Sargassum (Thiel and Gutow 2005, Butler et al 1983). Each individual clump of Sargassum is less than 80cm, but mats spanning hundreds of meters wide and tens of thousands of meters long can be formed in convergence areas (Butler et al 1983). In a way, these Sargassum drift communities can provide an oasis of nourishment and shelter for an assortment of organisms, including sea turtles.

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