LOOK: SA aquatic science community tracks sea turtles’ journey on Agulhas Current

Donny, a female juvenile loggerhead sea turtle, was released on July 13, 2022, off the coast of Durban by the Saambr team. Picture: Don Hunter.

Donny, a female juvenile loggerhead sea turtle, was released on July 13, 2022, off the coast of Durban by the Saambr team. Picture: Don Hunter.

Published Aug 3, 2022

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Durban - Various entities within South Africa’s aquatic science community have come together to release and track three juvenile loggerhead sea turtles as they journey southwards on the Agulhas Current.

The satellite tracking project is headed by the Two Oceans Aquarium, along with the Bayworld Oceanarium, East London Aquarium, Nelson Mandela University and the SA Association for Marine Biological Research (Saambr).

Two male turtles, Pan and Caddy, and one female turtle, Donny, were released at various spots along the East and West Coast.

All were rescued between 2019 and 2020 and were rehabilitated by the Two Oceans Aquarium prior to their release back into the wild. They were fitted with a satellite tracking system.

According to the team overseeing the project, Donny seems to be the most rebellious of the bunch, while the boys have stuck to the currents.

But when Donny arrived, she was beat up and had developed metabolic bone disease due to her compromised immune system and struggled to eat and dive.

She received extensive treatment before making her way back to full health.

Donny was named and adopted by an underwater photographer, Don Hunter. Hunter, a Durban resident, also sponsored some of her rehabilitation costs.

On July 13, Donny, 19 hatchlings and a sub-Antarctic fur seal were released just off the coast of Durban. She was flown to Durban by The Bateleurs and tagged by the Saambr team.

Her journey has been tracked and updated by Maryke Musson, the executive director of uShaka Sea World, and Talitha Noble, who co-ordinates the turtle rescue and rehab and the Two Oceans Aquarium.

Don Hunter also joined the release team and captured images of Donny just before she could be released.

About 16km from her release site, Donny’s first satellite transmission came through to the team, providing them with data from her tracking system.

Donny, a female juvenile loggerhead sea turtle, was released on July 13, 2022, off the coast of Durban by the Saambr team. Picture: Don Hunter

“On day 1 she covered about 25km, which we thought was quite impressive, especially straight into the surface. On day 2 she veered left, in a north-westerly direction and moved much closer to shore, covering about 35km cross-current all the way to Sheffield Beach. It is quite incredible to observe how these turtles orientate themselves back in the ocean.

“On the third day after release, Donny decided to head out offshore again, and covered 25km cross-current before making a sharp right turn towards Durban.

“Day 4 for her was a joy ride in the current and she covered about 40km , crossing her day 1 track in the process. By day 5 she made her way to just outside Durban harbour and moved along the Durban coastal area over the next two days, covering about 25km,” Musson wrote.

Caddy was released further down the coast, off East London, and travelled around 200km in his first week, making his way to Port Alfred.

Pan, the fastest swimmer of the lot, was released off Cape Point in the Western Cape. He was tagged by BayWorld and Nelson Mandela University.

The team said Pan and Caddy made good use of the current during the first week back in the water, whereas Donny had plans of her own.

On the second week of updates, Musson said Donny finally entered the Agulhas Current, which heads southwards, moving around 73 billion litres of water per second.

“Donny finds herself in a lovely and warm 24ºC sea surface temperature and she is around the Southwest Indian Seamounts MPA, a 7 500m2 marine protected area that was proclaimed in 2019, which is a great place to be in, especially since we will be celebrating Marine Protected Areas Day on the 1st of August,” Musson said.

The project is the first time the science community in South Africa has released and tracked three turtles simultaneously at different locations and is also a first to track juveniles.

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