In-water behaviour and long-term movements of oceanic-stage juvenile sea turtles are not well described or quantified. This is due to technological or logistical limitations of tracking small, fast-growing animals across long distances and time-periods within marine habitats. Here we present the first long-term offshore tracks of oceanic green turtles (Chelonia mydas) in western North Atlantic waters. Using a tag attachment technique developed specifically for young (<1 year old) green turtles, we satellite tracked 21 oceanic-stage green turtles (<19 cm straight carapace length) up to 152 days using small, solar-powered transmitters. We verify that oceanic-stage green turtles: (i) travel to and remain within oceanic waters; (ii) often depart the Gulf Stream and North Atlantic Subtropical Gyre currents, orienting toward waters associated with the Sargasso Sea; (iii) remain at the sea surface, using thermally-beneficial habitats that promote growth and survival of young turtles; and (iv) green turtles orient differently compared to same stage loggerhead turtles (Caretta caretta). Combined with satellite tracks of oceanic-stage loggerhead turtles, our work identifies the Sargasso Sea as an important nursery habitat for North Atlantic sea turtles, supporting a growing body of research that suggests oceanic-stage sea turtles are behaviourally more complex than previously assumed.

Please contact data owner for additional details or refer to the published article. Data collected via ARGOS satellites and small solar-powered satellite tags. 

Please contact data owner for additional details if needed. 

Loggerhead file:

Turtle ID refers to the unique tag identifying number assigned to indivirual turtles

GMT: Greenwich Mean Time

Local: Greenwich Mean Time converted to local time (local meaning the location of the turtle at the time the latitude and longitude was received).

Green turtle file:

tag_id: refers to the unique tag identifying number assigned to indivirual turtles

UTC: refers to Coordinated Universal Time (and date) for each location (latitude and longitude) received by the tags.

lc: refers to ARGOS/CLS America location codes for each loccation receoved (Codes range from 0-3, A, B, and Z).

Dir 1: refers to the direction relative to the Equator for each location. This is associated with the longitude; all locations are  within the northern hemisphere or N)

Dir 2:  refers to the direction relative to the Prime Meridian in Greenwich, UK for each transmitter locatoin. This is associated with the latitude; all locations are  west of the Greenwish Prime Meridian, therefore W.