One beautiful morning in early April I hitched Seahorse to the divemobile, and headed across to Gordon’s Bay for a special project. The boat had been chartered to assist the Two Oceans Aquarium with the release of two ragged tooth sharks: Kay, a large female who’d been in the predator exhibit since 2009, and a juvenile male that had been on display in Pretoria for the last two years (the aquarium does not keep male raggies). The project was supported by Shark Spotters and by Gemini (who, coincidentally, built Seahorse).
The sharks were brought to Gordon’s Bay harbour in special tanks on the back of a truck. They’d been given a sedative that was timed to wear off just around the time that they’d be released. The care and attention of the aquarium staff was amazing. Everyone had a specific task, and they all did it. No one was standing around basking in the spotlight or getting in the way. The teamwork was very impressive and they made sure the sharks were very well cared for. Clare volunteers at the aquarium once a month and speaks highly of the staff there; now I had a chance to see them in action.
The sharks were lifted out of their tanks on the truck in a sling, and moved to a tank on the aquarium rubber duck. While the first shark was transported to the release site, the other shark waited on the truck. Aquarists made sure they were upright and comfortable and then the rubber duck set out very slowly from the harbour. As it travelled water was pumped into the shark’s tank, and the temperature was slowly adjusted to match that of the surrounding sea water. Every aspect was monitored.
My job was to transport some aquarium staff and Steve Benjamin, a local underwater photographer who would capture the release on film, at a short distance from the aquarium rubber duck carrying the sharks. One shark was taken out to sea at a time, and lowered over the side of the rubber duck in a blue sling. The release site was a couple of kilometres outside of Gordon’s Bay.
The sharks were initially slightly hesitant, and swam slowly for a couple of seconds with aquarium divers on either side of them to make sure they were all right. Then they smelled the open water and headed off at high speed. Can you imagine how it must have felt? Do you think the memories of what it was like to live in the ocean came back all at once, or like hazy, distant recollections? The aquarium staff also must have had very mixed feelings about the release. After caring for an animal for years, watching it grow in size and strength, there must be a big emotional investment.
The Two Oceans Aquarium does not keep sharks on display indefinitely; there is a rotation program and after a few years on display the sharks are released. Since 2004, eight ragged tooth sharks have been released from the aquarium. Kay, the large female who was released this time, weighed about 50 kilograms when she arrived at the aquarium. She weighed over 200 kilograms on release. Ragged tooth sharks are placid and well suited to performing a public education role. Their fearsome looking teeth belie their quite lazy demeanours. They are also able to breathe while stationary, something that not all sharks can do.
In other countries ragged tooth sharks are known as grey nurse sharks or sand tiger sharks.
There are two blog posts on the TOA website that give some behind the scenes shots and detail of how Kay was removed from the exhibit. Check them out here and here. There are some of the underwater photos taken on the day in this News24 slideshow. You can scuba dive in the I&J Predator Exhibit at the aquarium. I’d recommend it!
