This blog post is the third in a series about Ember the juvenile loggerhead. If you have not done so already, we suggest checking out our initial post, which covers Ember’s rescue and rehabilitation at the Georgia Sea Turtle Center and initial travel up the eastern seaboard, and second post on Ember’s travels further out into the Atlantic. If you are all caught up, keep reading!
We last left Ember the juvenile loggerhead on January 16th, heading out into the Atlantic Ocean. Since then, Ember has traveled 1,587 miles in 51 days. Even though Ember is actively swimming to do things like catch prey, these are localized movements and the bulk of the distance covered comes from the Gulf Stream current that Ember is swimming within. The animation below shows how Ember moves fastest when traveling in the main current and slows down when swept into its meanders or eddies. You can also see how the Gulf Stream is pretty streamlined up the East Coast, but begins to meander more and more as it crosses the Atlantic Ocean.
Upwell Oceanographic Researcher Tony Candela at Mercator Ocean International makes the animations in this blog using the location data transmitted by Ember’s tag. On January 28th, the tag stopped transmitting for 10 days at which point Tony assumed it had gone offline permanently, until Ember reappeared on February 7th, 115 miles away! Ember’s tag has been transmitting regularly since then, and as of March 7th is just 61 days short of the 192-day record set by the tag on Peniche, a juvenile loggerhead tagged in the Azores. The prototype microsatellite tags that Upwell uses are designed to fall off a turtle's carapace naturally as it grows, and when a tag detaches, it will stop transmitting.
Since Ember is pretty much in the middle of the Atlantic Ocean, what does the road ahead look like? The Gulf Stream will eventually split into two main branches (along with their multiple meanders), the North Atlantic Current flowing toward northern Europe and the Azores Current flowing toward the Azores archipelago (area shown as a yellow dot on the map below).
The image above shows a compilation of currents on March 7th, and while it doesn’t capture the splitting of currents as clearly as a graphic showing the climatology over a long period of time would, at around 44°W you can see the meanders beginning to follow the general directions described above.
Prior research into the Lost Years period for West Atlantic loggerhead sea turtles has shown that loggerheads departing nesting beaches in Florida will follow the Gulf Stream and Azores current to waters around the Azores. If Ember is following the same trajectory, there are only about 870 miles left to go before reaching the archipelago. Getting swept into the North Atlantic current could be dangerous for Ember, because even though loggerheads are found in the waters of Northern Europe, the colder temperatures put smaller juvenile turtles at risk of cold-stunning.
“ “The long journey Ember has undertaken since release epitomizes the incredible life history and hurdles these small turtles overcome on their way to adulthood. Against many odds, Ember has survived a menagerie of threats so far in the open ocean and the data we’ve gathered helps fill important knowledge gaps about these incredible creatures.” ”
Upwell is committed to generating and mobilizing scientific data from turtles like Ember to improve conservation efforts because, as Executive Director George Shillinger puts it, “To improve management and conservation for any migratory species, it is essential to understand where the animal goes, when it goes there, what it does along the way and thereafter, and why. We aim to piece together the puzzle of loggerhead movement ecology across the Atlantic.”
We are grateful that Ember’s tag has continued transmitting long enough to let us gather so much important data to illuminate how juvenile loggerheads use ocean habitats during this cryptic and enigmatic life history phase.
