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The last image of Yoshi (Image credit: Dr. Cleeve Robertson)

Yoshi: the amazing story of a loggerhead turtle

By:

Maryke Musson
Maryke is the CEO of the Two Oceans Aquarium Education Foundation. She is a scientist by training, but an absolute superwoman in general, juggling the daily operations and fulfilling the mission of the Aquarium Foundation.

In 1997, the crew of a Japanese fishing vessel rescued a small injured loggerhead sea turtle somewhere in the Indian ocean and kept it onboard, looking after it like a much-loved pet. On arrival in the port of Cape Town, they contacted the Two Oceans Aquarium, which opened to the public only two years prior, and asked the aquarium team to take over the care of this little reptile. She was named after the vessel’s cook, Yoshitaro, a man of small stature just like the little turtle.

Yoshi may have been small in size, but her big personality was obvious right from the beginning. She was the very first rescued sea turtle at the aquarium and was closely monitored and cared for. The team learnt a tremendous amount about sea turtle husbandry from this feisty animal which prepared them well for what was to become a very successful turtle rescue, rehabilitation and release programme.

For the time being Yoshi was safe, well cared for, and a firm favourite to many aquarium visitors. She knew just when and how to perform and generally stole the show during many events hosted at the aquarium. She shared her space with beautiful animals such as yellowtail kingfish, ragged-tooth sharks, black musselcrackers and, of course, divers.

 

Little Yoshi, the loggerhead turtle

Young, sub-adult Yoshi, when she first arrived at the Two Oceans Aquarium (Image credit: Two Oceans Aquarium)

Yoshi did not remain small and before long was the true queen of the aquarium. She was eye-catching, imposing, impressive and rather spectacular at 183 kilograms. She had her favourite sleeping corners, her favourite snacks (she proved to be quite the foodie) and her favourite tickle spots.

Sea turtle hatchlings wrestle their way out of the eggs and have to immediately fend for themselves. They need to navigate to the warm ocean waves as quickly as possible, avoiding and escaping predators such as birds and crabs. They tend to lose 10% of their body weight just trying to get from nest to ocean. Without any parental care they then enter the ‘lost years’, following the currents until they are strong enough and big enough to return to foraging grounds closer to where they were born. Only 1 out of 1000 sea turtles survives to maturity; the odds are really stacked against them. Turtles under rehabilitative care do not imprint on their medical team or care givers. Some love the personal care more than others, and Yoshi truly enjoyed a good old chin tickle and back scratch.

 

Yoshi in the Ocean Exhibit at the Two Oceans Aquarium

Yoshi in the Ocean Exhibit at the Two Oceans Aquarium (Image credit: Two Oceans Aquarium)

We often wondered: ‘Yoshi, where are you from?’. There are loggerhead nesting sites in northern Kwazulu-Natal and Mozambique, Oman and Western Australia. It is believed that juveniles from these rookeries follow the currents in the Indian ocean for many years, and depending on where Yoshi was actually rescued, her origin could have been from any of these nesting areas.

The range of loggerhead turtles (Image credit: Wikimedia/ Public domain)

In 2015, the turtle team at the aquarium initiated a satellite tagging programme of sub-adult and adult turtles released after recovery. The results of these studies were incredibly promising, with healthy turtles, after two years of treatment and care, adapting back to life in the ocean with great success.

At this point in time, Yoshi had been a temporary resident at the aquarium for 18 years during which time she grew into a formidable, strong and healthy adult sea turtle. She still had at least another 60 years ahead of her, and was going to outlive all her carers. We knew release was possible and that Yoshi, this incredible oceanic traveller, should go back to where she was from.

Preparation for her release was not taken lightly as we knew we had to get her fit and ready for the open ocean. She trained hard every day for 18 months, swimming her lengths like an Olympic athlete and getting the mileage in which was going to serve her well on the ultimate journey.

Yoshi in the Predator Exhibit at the Two Oceans Aquarium (Image credit: Two Oceans Aquarium)

After a fantastic farewell celebration, honouring Yoshi’s favourite and long-time friends, she was medically cleared for release and fitted with a satellite tag. She was joined by her dedicated team of carers and friends as well as a truly skilful team of photographers. Ocean inspired and Yoshi-loving paparazzi captured her last moments before release.

With a final countdown she was set free 27 nautical miles southwest of Hout bay. She did not waste any time, and used her superior fitness and strength, swimming off into her infinite blue home. It was an emotional release. There were tears of joy, to see this magnificent queen back in her true home, but also a sense of sadness letting go of a turtle that truly was like family.

Yoshi surprised us when she started moving up the west coast of southern Africa, instead of the east coast which is what we expected. We suddenly wondered whether she could be from the Atlantic loggerhead populations at Cape Verde, or the Mediterranean, or possibly even Brazil or Florida and the Bahamas. Within six months she covered over 3 000 kilometres and reached Angola. She decided right then and there that she was going to turn around and head back. Another six months later and she was right where this journey started, just off Cape Point. One year, three countries and a very big loop.

Release time for Yoshi (Image credits: Olivia Anderson)

By February 2019 she headed offshore, straight to the Southeast Atlantic Seamounts marine protected area (MPA), a rich feeding ground, protected and with good food. After more than 10 000 kilometres in the ocean, this was a great area to be in. During her journey Yoshi would have faced many risks out at sea, from ghost fishing gear to large vessels, and plastic pollution. Not only did she navigate her way past three countries, she also managed to navigate her way around these threats. Yoshi started picking up her pace and made good progress crossing the Indian ocean.  Eighteen months after she started her incredible journey she was covering more than a marathon per day and moving along the Southwest Indian Ridge, heading straight towards Australia. Not only was she now already recognised as an absolute celebrity, but this journey could very well be the very first recorded movement of a loggerhead sea turtle between Africa and Australia. By December 2019 Yoshi had an impressive 34 000 kilometres behind her.  That is a staggering 46.5km/day for 730 consecutive days. A definite oceanic traveling Olympian and one of the greatest journeys of all times. At this point it looked like she was going to make land on the Western Australian coastline, near Shark bay, which is a loggerhead nesting site. Did Yoshi’s built in GPS, her innate ability to navigate, her instinctive need to reproduce, lead her straight to her natal area?

Is Australia Yoshi’s homeland? 

The Australian scientists were incredibly excited about possibly having Yoshi home. We believed she was still on a journey of discovery and exploration. Yoshi, our strong-willed ocean queen, went right past this well-known loggerhead nesting area, and entered Australian water by the end of February 2020 near Port Sampson, a fishing village in the Pilbara district of Western Australia.

We realised a plan had to be made to try and retag Yoshi. We have not had a tag that lasted as long as hers, and were worried that the battery pack would run out any day. Scientists from the Western Australia Department of Biodiversity, Conservation and Attractions (DBCA) headed to Port Sampson towards the end of March, hoping to find Yoshi for a retag and quick observation. Her satellite transmission led them to quite an unexpected discovery. They stumbled upon a forage site with more than 40 other loggerhead sea turtles of varying sizes. They had no idea of such an area along the Western Australian coast. Yoshi was not just a celebrity, world record holder and much-loved ocean ambassador, but now also a field researcher. Even though the scientists saw many other loggerhead turtles, Yoshi did not surface to be re-tagged. In typical Yoshi behaviour, she likes doing her own thing.

From April 2020, Yoshi decided to go into her own bit of lockdown, remaining along Eighty Mile Beach, a beautiful and remote 220 km stretch, between Port Hedland and Broome. She has slowed her pace right down to about 12km/day, which still puts her overall average pace over the last 30 months at an impressive 41km/day.

She is clearly enjoying this area, home to many flatback turtles, rich in marine life and biodiversity, warm and beautiful. The Biyandanga community, which is the largest aboriginal community in Western Australia, has their rangers aware of this special guest (or should we say local) along this exquisite stretch of beach. Yoshi was welcomed to Australia with open arms and hearts. Can we safely say she is home?

Post-hatchling loggerhead turtles, from the Western Australian rookeries at Shark Bay, follow the currents in the Indian ocean towards Madagascar and move around in the south Indian ocean for many years before returning to the coast. The post-hatchlings, from rookeries in South Africa and Mozambique, and even from Oman, make use of the western Indian ocean, with many juveniles seen around Reunion Island. Most of these, however, make their way back up to Oman or down to the east coast of South Africa. Is it possible that Yoshi was rescued closer to South Africa, and is thus a South African loggerhead on an extended holiday in Australia? It seems more and more likely that this legend of a turtle has found her native land, Australia.

Eighty Mile Beach off the coast of Western Australia (Image credit: Linear77 / CC BY)

982 days. 40 011 kilometres. 2 continents. 4 countries. 23 167 satellite messages. 6 098 satellite passes. Millions of followers.

Yoshi has shown us the resilience, survival instincts and the will of rescued animals being reintroduced to their natural environment. She has shown us that there is still so much we do not know and can learn (she is indeed the first record of a loggerhead sea turtle moving between Africa and Australia). She has shown us that collaboration makes a difference. We might compete on the rugby field, but when it comes to conservation we work together. Her journey showed us the beautiful west coast of southern Africa. She passed the seal colonies at Cape Columbine and Kleinsee, and cruised past the beautiful coastal sand dunes of Namibia. She really enjoyed spending time at Ghost Island, in the Tiger’s Bay area, and eventually turned around in the middle of the richest fishing grounds off Angola.

She headed back, remaining offshore, and crossed the Walvis ridge before rounding beautiful Cape Point and heading across a number of significant offshore marine protected areas. The mighty Southwest Indian Ridge, with all its impressive fracture zones, definitely served as a guide (or highway) to get Yoshi to Australia. The Agulhas current, together with the West Wind Drift and the East Australian current all contributed to this impressive 40 011 km journey.

Home is where the heart is, and it seems as if Yoshi’s heart, for the time being, belongs to Western Australia.

Over the last decade, our turtle conservation team has successfully rehabilitated and released more than 600 endangered sea turtles. But Yoshi will always be our number one.

 

If you want to help turtles like Yoshi, please consider making a donation. You can do so here.
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Training Bob to be release-ready

Bob, a green turtle in our care, has been with us since November 2014. While he is not ready for release yet, we are preparing him so that he has the best chance of survival back in the big blue. Alex Panagiotou, one of our turtle team specialists, is working with Bob through enrichment programmes and research.

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