The Two Oceans Aquarium regularly collaborates with other organisations for the purpose of conservation research. One such organisation is Bayworld Oceanarium in Port Elizabeth who are extremely active in the rehabilitation and release of distressed seals, particularly stranded visitors from the Southern Ocean.

We recently sponsored four satellite tags, valued at approximately R100 000, for the release of several seals rehabilitated by Bayworld. The rehabilitation of these seals was overseen by Dr Greg Hofmeyr, Bayworld's Curator of Marine Mammals. Dr Hofmeyr will use the data retrieved from these tags to gauge the success of the rehabilitation programme, and to gain insight into why South Africa is seeing increased numbers of visitors from as far south as Antarctica.

The release story

On 20 December 2018, a joint team from Bayworld, Two Oceans Aquarium and the Department of Environmental Affairs took five seals approximately 40 nautical miles out of Algoa Bay for release into the warm Agulhas Current.

Christine is fitted with a satellite tag which will send back data about her location until it's batteries are depleted or the seal moults its fur. Credit: Devon Bowen/Two Oceans Aquarium

"These seals were kindly rescued by two organisations' people: the Stranded Marine Animal Rescue Team (SMART) in Mossel Bay and the East London Aquarium, and also by Yvonne de Kok and Abel & Brian in Cape Town. Thanks to the fantastic and hard work of our live animal staff here at Bayworld, the seals are ready for release. All have recovered from their starving condition and have a good layer of blubber to tide them over the first few weeks of their return to the wild. And thanks to our Claire Taylor and our collaborators from Two Oceans Aquarium, they will be equipped with satellite tags. This means that we will be able to follow them at sea, which should generate fantastic publicity for conservation. The data will go into a research project, that is run in collaboration with M'du Seakamela of the Department of Environmental Affairs." - Greg Hofmeyr, Bayword Curator of Marine Mammals

Four of these seals are Subantarctic fur seals that had been found on the South African coast. Christine and Endurance are both yearlings that were rescued at Mossel Bay. Abel is also a yearling and was rescued in Cape Town. Iggy is estimated to be about two years old, but was not fitted with a tag as there was concern that it would detach as he was still shedding after a recent moult.

Abel, one of the rehabilitated Subantarctic fur seals to be tagged and released. Credit: Devon Bowen/Two Oceans Aquarium

The other seal, Herold, is a two-year-old Antarctic fur seal that was rescued in Herold's Bay - a much more unusual visitor to South Africa. Fitted with a satellite tag, it will be incredibly interesting to see what data is returned.

Abel and Iggy take some time to "play" in the open ocean before swimming off to their Southern Ocean homes. Credit: Greg Hofmeyr/Bayworld

Before their release, DNA, hair and whisker samples were taken from each seal for research purposes. Numeric identification tags were also attached to each of their flippers, which will allow them to be easily identified long after the satellite tags fall off.

Claire Taylor (Two Oceans Aquarium) and Greg Hofmeyr (Bayworld) examine a satellite tag before attaching it to Endurance at the Bayworld Marine Rehabilitation and Conservation facility. Credit: Devon Bowen/Two Oceans Aquarium

Seeing these young animals swim off into the ocean was a truly rewarding experience, and the Two Oceans Aquarium is grateful that we have had the opportunity to join the incredible work being done at Bayworld in Port Elizabeth. It is our hope that the data returned by the satellite tags will not only allow us to see if these seals are able to return to their homes in the Southern Ocean, but also give us the chance to figure out why they are coming to South Africa in the first place.

“We need to be able to find out if the programme is successful if we put them back into the sea. Are they going to survive? That’s why we put the satellite tags on them.” – Greg Hofmeyr

Follow the seals' journeys

28 December 2018: The seals are certainly in a hurry to explore the ocean! Herold the Antarctic fur seal has swum 863km since release. He seems to be making his way southwest and has moved off the continental shelf, passing the Natal Seamount. He is now about 390km south of Cape Agulhas.

Christine has swum 537km, and like Herold she seems to have a very good idea of where she is going, moving directly SSW, past the eastern side of the Natal Seamounts (the opposite side to Herold). Christine is now 410km south of George.

Abel has travelled 804km SSW of the release site. Abel has been heading around the western edge of the Agulhas Plateau and is currently 680km south of George.

Endurance has swum 317km and is currently mulling about in waters between Plettenberg Bay and Cape St Francis. He has yet to cross the Agulhas Current and begin his journey to the Southern Ocean in earnest.

22 December 2018: Herold the Antarctic fur seal seems to be in a hurry.  He has travelled 495km already! Herold is currently 150km south of Knysna on the edge of the 23.5°C Agulhas Current. Has crossed the current twice.

Christine has already swum 295km, has crossed the Agulhas Current and is now swimming with an easterly side current of about 0,72km/h. She is about 250km south-southwest from Humansdorp.

Endurance has travelled 188km and is currently about 90km southwest of Humansdorp. He is still on the coastal side of the Agulhas Current where the waters are taking him northeast at a slightly cooler at 21°C.

Abel's transmitter has pinged us, so we know he is on the move but we have not yet received any location data.

Herold's journey back to Antarctica has begun! Good luck little one. Credit: Claire Taylor/Two Oceans Aquarium

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