ENVIRONMENT Dané The Ragged-tooth shark returns to sea

By: Melissa Mc Alpine

There was much excitement among community members gathered at Struisbaai’s main beach on 29 March 2023, when Dané, a large ragged-tooth shark weighing in at around 200kgs was successfully released back into the ocean after having spent the last five years in the ‘Save Our Seas Foundation Shark Exhibit’ at the Two Oceans Aquarium in Cape Town.

Dané was collected off the coast of East London in 2017 by the Two Oceans Aquarium with the assistance of a local angler, Mike Dedericks, who gave the ragged-tooth shark her name.

Dr Ilse Jenkinson, a vet for the Two Oceans Aquarium, explained: “Catch and release is a central component of the Ragged-Tooth Shark Conservation Programme at the Two Oceans Aquarium. The reason for including them in our exhibits is for them to be an ambassador species for sharks, educating our visitors on the wonder of what is under the ocean. The message these sharks deliver is not to be scared of them, but rather to be in awe and wonder of these complex animals.”

During her time at the Aquarium, Dané became a true ambassador for her species, educating visitors and highlighting the importance sharks play in the marine environment.

“Dané grew into a large adult weighing 202kg and measuring 275cm in length. Given her weight of 69.4kg and length of 251cm on her arrival to the Aquarium, her growth was significant. She is now sexually mature, so we would like her to have the opportunity to reproduce and contribute off-spring to the wild population,” said Dr Jenkinson.

In the days and weeks leading up to her release, Dané was thoroughly checked and monitored. When the big day came to transport her from the Two Oceans Aquarium to Struisbaai, she was cautiously placed in a secure tank on the back of a large truck, accompanied by six curatorial staff members from the Aquarium to ensure a calm and safe return to the ocean.

Dané was tagged with a spaghetti tag so her movements along the coast can be tracked and scientists can learn more about her species. Dr Nathalie Viljoen, Head of Research at the Two Oceans Aquarium, mentioned that the reason Dané was released at Struisbaai is because there’s an existing population of ragged-tooth sharks just off the coast of Struisbaai currently that are slowly making their way towards the warmer waters of Kwa-Zulu Natal.

Once Dané was carefully lifted out of her holding tank supported by a large stretcher, the Two Oceans Aquarium curatorial team carried her into the ocean where they remained by her side for a few minutes while she acclimatised. The team knew Dané was ready to be released when she started to push against the constraints of the stretcher. Two divers then accompanied the ragged-tooth shark a little deeper into the ocean so that she could swim off on her own. The release was declared a success by Dr Jenkinson and the curatorial team.

A huge thank you to everyone involved in this extraordinary release, especially the Two Oceans Aquarium curatorial team for their ongoing dedication, passion and commitment to the preservation of our marine environment. May Dané go on to live many more years in the deep blue sea.

Raggie Facts:

• They’re referred to as ‘Raggies’ because of their protruding, ragged teeth.

• Despite their scary appearance, raggies are generally harmless to humans.

• Their pointy, needle-like teeth are used for gripping onto slippery fish.

• They’re the only species of shark that swallow air bubbles for buoyancy.

• Raggies are critically endangered due to over-fishing, a slow reproductive process and getting caught up in fishing nets.

• Ragged-tooth sharks are found in oceans across the globe and go by many names, i.e., grey nurse sharks, and sand tiger sharks.

• They’re long-distance swimmers and can travel up to 3 000 kms in a year.

• Raggies grow to about 3.2m and can live up to around 30 years.