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First Satellite Tracks of Young Sea Turtles in the South Atlantic Ocean

NOAA scientists are working to understand the migratory behavior and dispersal patterns of loggerhead sea turtles (Caretta caretta) in the South Atlantic Ocean.

Where do sea turtles go in the South Atlantic?

The preliminary data suggest that young loggerhead turtles in the South Atlantic are influenced by seasonal changes in ocean currents. Turtles move south during early/mid season and north later in the season.

This information helps us identify loggerhead turtles' vulnerability to fishing activity based upon seasonality and ocean currents. This study complements our ongoing research in reducing incidental capture of sea turtles in pelagic longline fisheries.

How did we find out where they go?

Working with University of Central Florida (UCF) and Projeto Tamar collaborators in Bahia, Brazil, NOAA scientist, Yonat Swimmer, tagged 19 neonate loggerhead turtles using modified small-scale solar-powered satellite tags, developed by Dr. Kate Mansfield of UCF.

The loggerhead turtles were lab-reared until they were 4-13 months old (about 4-10 inches long and about 0.5-6 pounds). They were released at different times throughout the nesting season to coincide with changes in the current pattern along the coast of Bahia, Brazil, where the turtles were born:

Oceanographic drifters were released along with the turtles to collect simultaneously information on current patterns and to examine the probability that turtles were passively drifting with the prevailing ocean currents.

ocean currents off brazil during different seasons
Sea surface currents in the South Atlantic Ocean offshore loggerhead neonate turtle release sites by season.


We tracked the transmission for an average of about 2 months (though two transmitted for less than 5 days). Throughout the tracking period, the turtles traveled about 350-2,950 miles (575-4,755 km).

loggerhead turtle tracks off brazil
Tracks of 17 neonate turtles after their release from Bahia, Brazil during four releases in 2012-2013.

Initially, all turtles followed a general circulation pattern observed with initial drifter trajectories following large-scale current patterns. While some of the turtles traveled along the continental slope (north or south depending on the prevailing current pattern), others also moved to oceanic waters. Unlike loggerhead turtles in the North Atlantic that drift off the continental shelf, turtles here moved parallel to coast. 

What did we learn?

The preliminary data suggest that young loggerhead turtles in the South Atlantic appear to be influenced by seasonal changes in ocean currents. This information is helpful to identify loggerhead turtles' vulnerability to fishing activity based upon seasonality and ocean currents.

Updated: June 18, 2014