This story begins more than five months ago, with the release of the Two Oceans Aquarium's famous giant loggerhead turtle back into the Atlantic Ocean. But, those of you who have been following Yoshi's journey might be surprised to know that you are not the only ones following her 4000km journey - Pemba, the olive ridley turtle jointly released by us and uShaka Sea World in KwaZulu-Natal - has picked up Yoshi's trail!
Why would two turtles of totally different species, released more than 1500km apart and with one having a head start of three months be following the same path? Let's meet the characters of this epic exodus and discuss just why Pemba is following in the footsteps of giant Yoshi.
Who are Yoshi and Pemba?
Yoshi is a female loggerhead turtle (Caretta caretta) that was part of the Two Oceans Aquarium's living collection for over 20 years, released on 16 December 2017 when studies confirmed that she still retained her natural foraging and migratory instincts. Since then, Yoshi has travelled over 4000km along the West Coast, reaching coastal Angola.
Pemba is an olive ridley turtle (Lepidochelys olivacae) that was rescued in Table Bay in December 2014 and rehabilitated over four years in a joint effort by the Two Oceans Aquarium and uShaka Sea World in Durban. Pemba was released at iSimangaliso Wetland Park on 8 March 2018 and has since travelled almost 6000 km around the southern tip of Africa. She is now heading north along the Namibian coast - hot on Yoshi's heels (yup, they have heel bones too).
Both turtles are presently cruising northwards, Yoshi passing the coast of Angola and Pemba still on the final leg of the South African West Coast, which Yoshi completed in January. Pemba appears to now be following the same route as Yoshi - but do they have the same destination?
Where are these turtles heading?
Pemba and Yoshi were fitted with advanced satellite tracking tags that keep us up-to-date with their locations - making the story of this awesome adventure possible.
Both are on an epic expedition, with two purposes - firstly to stock up on body fat in fertile feeding grounds and then, eventually, to return to the beach where they once hatched. Where are these beaches? There is no way to know for certain, but we are hoping that Pemba and Yoshi will show us (and that their GPS trackers will last long enough).
Where is Yoshi going?
Loggerhead turtles have a very wide global distribution, but Yoshi's current path suggests that she is from the Southern Atlantic population. If she continues along the coast of Africa, she could eventually reach the Cape Verde islands, by far the largest loggerhead turtle nesting site on the African coast. It is also a realistic possibility that once she has completed her feeding frenzy on the African coast, she may cross the Atlantic and nest on the eastern coast of Brazil, another huge nesting ground.
Although the Caribbean Islands and the coast of Florida, USA, are home to even larger populations of loggerheads than Cape Verde and Brazil, these turtles typically follow a circular migration in the North Atlantic and it is unlikely that Yoshi would have ended up in Cape Town in the first place if she belonged to this group. However, we cannot ignore the possibility that Yoshi might be heading into the Mediterranean Sea or may simply turn around at some point and come back around the tip of Africa - joining the huge population of loggerheads in the Indian Ocean.
The possibility that excites us most is that Yoshi may be a South African loggerhead turtle after all. Although her current determination to head north does not strongly indicate this she may, in fact, belong to the population of loggerheads that nest on the coast of KwaZulu-Natal. One subset of these turtles heads into the South Atlantic to feed, rather than towards Madagascar which is a more common option, and Yoshi may belong to this group - knowing Yoshi, she is entirely the kind of animal who would prioritise finding food over finding a mate.
Where is Pemba going?
Olive ridley turtles are not quite as commonplace as loggerheads, but still have nests across the globe. They display a behaviour called arribadas ("arrival" in Spanish) when thousands of turtles gather offshore and all nest at the same time. Arribadas? Yes, Pemba, you "are-a-bad-ass."
Like Yoshi, there is a good chance that Pemba may decide to cross the Atlantic Ocean at some point and nest on the coast of Brazil, although olive ridleys more commonly nest on the northern coasts of South America. If she continues along the African coast, she may nest on a beach off Angola, Congo or Gabon and may forage as far north as Cape Verde.
Pemba may potentially come back around South Africa to nest on the Comores or Madagascar, although this is not likely as she chose to eject herself from the easy-swimming of the warm Agulhas Current to move up the West Coast, rather than ride the current all the way back to the Indian Ocean.
What's the verdict? Will they meet?
As adorable as their reunion would be, it is unlikely that Yoshi and Pemba will cross paths. As fast as Pemba is swimming, Yoshi will likely continue to move north, out of olive ridley turtles' normal range before Pemba reaches Angola.
Pemba's exceptionally fast swimming speeds up to now have been due to her "riding the currents", but her actual swimming speed without this assistance is very similar to that of Yoshi. Luckily, Yoshi's tendency to be a little glutton every time she reaches fertile waters may help Pemba catch up - but the gap is huge. Despite this, even at a slow pace, Pemba will reach Angola before summer - well in time to find a mate, if this is her final destination.
So why mention it all if there's so little chance?
Whether they meet or not, Yoshi and Pemba's migrations are linked - they are sharing a common coastline and throughout their journey will be facing the same threats, feasting on the same blooms of jellyfish and algae and enjoying the same warm waters. Their fates are intertwined.
During their time at the Two Oceans Aquarium (and at uShaka Sea World for Pemba), both of these majestic animals had the chance to serve as ambassadors for their species - inspiring people, young and old, to fall in love with the ocean and its inhabitants. Now, even though they are thousands of kilometres from "home", they will continue to be ambassadors for the ocean that they share.
We would like to remind everyone reading this that despite the hard work or rehabilitation organisation which give turtles like Pemba and Yoshi a second chance, the future for all these animals lies in the ocean.
What kind of ocean do you want us to release turtles back into?