Yoshi the turtle celebrates freedom with a record journey

An endangered turtle that spent two decades living in a South African aquarium tank is on track to set a new record for sea animal migration after her return to the wild.

Yoshi, a loggerhead aged about 25, has racked up more than 35,000km, often swimming against the tide, since she was lowered into the Atlantic off Cape Point two years ago.

Scientists had expected the 183kg marine reptile to head for established African breeding beaches closer to the Equator on the Atlantic or Indian Ocean coastlines.

Yet after a year-long feeding trip up the west coast of Africa to Angola, she swam back towards Cape Town, rounding the Cape of Good Hope and heading out into the ocean. Her satellite tracking device shows she is now in an area off Western Australia.

Maryke Musson, 44, was a young biologist working at the Two Oceans aquarium in Cape Town when Yoshi was brought in for rehabilitation at the age of three or four, weighing 2kg and the size of a dinner plate.

She had been picked up by the crew of a Japanese fishing vessel that was docking in Cape Town. ‘‘She was the cutest little thing and we had never had a turtle before so we needed to learn how to look after her,’’ Musson said. Such was the success of Yoshi’s rehabilitation that the Cape Town scientists’ acquired expertise has, since then, resulted in more than 600 rescued sea turtles being rehabilitated and released.

The species make ideal candidates for rehabilitation. From the minute they hatch loggerhead turtles never have parental care, Musson said, so never lose their instinct to find food. Mammals, in comparison, are much harder to get back into the wild.

After caring for Yoshi for her first four years at the aquarium, Musson left to conduct her own research, returning 16 years later to find the turtle was huge, healthy and very popular with visitors.

‘‘She was the queen of the aquarium, but I thought, ‘Hold on, she should be back in the ocean’,’’ she said.

Colleagues were sceptical that a creature that had been in captive care for so long would have a reasonable chance of surviving the hazards of the wild. The case of a loggerhead turtle called Adelita, that was released off the Mexican coast in 1996 after 10 years in captivity and immediately swam 10,000km across the Pacific to Japan, offered Musson hope.

It took 18 months to prepare Yoshi for freedom with a fitness programme to help her cope in the open seas. Training sessions involved the turtle swimming lengths of her 20m tank, with a diver at each end giving her a treat for every one. – The Times