Yesterday, Wednesday 30 December, the ocean sunfish (Mola mola) that visited the I&J Predator Exhibit at the Two Oceans Aquarium for two days was released back into the sea.
At about 1pm, Operations Manager Tinus Beukes and his team headed out towards Robben Island on the rubber duck Aquarium 1.
At a depth of 46m to the west of the island, in 16°C water, the sunfish was slowly lowered into the ocean.
It did not hang around, though – the sunfish dove straight down at a very fast speed, and out of sight.
Releasing an animal back into the ocean always leaves lumps in our throats. While in certain ways we are sad to see them go – bonds are formed quickly with these amazing animals – we are also ultimately overjoyed to be able to send them home. We consider this experience a great success.
“The Aquarium offers people a unique opportunity to see these unusual animals from an underwater perspective. The recently released sunfish was able to act as an ambassador for this iconic species and the oceans before it was returned to the open ocean,” said Communications & Sustainability Manager Helen Lockhart.
Our visitors were wowed by the sight of the mysterious Mola mola during its brief stay. Many came especially to see the sunfish and we received many comments from excited members of the public who couldn’t believe their eyes:
We were able to learn a lot about sunfish in the process, which is always thrilling, even more so when it involves such mysterious, rarely seen animals. Our resident vet, Dr Georgina Cole (actually on holiday in the United Kingdom at the moment), was in contact with Lisbon and Monterey Bay aquariums, facilities that have extensive experience with much larger sunfish, to obtain their sunfish gel food formulations as well as additional input and advice. Denture cream and antiseptic treatment was applied to the sunfish to help heal some of its scratches.
The story of the sunfish
On Sunday 27 December, aquarists from the Two Oceans Aquarium were called out to the pier near Den Anker restaurant to help the disoriented and dehydrated sunfish. It was transported back to the Aquarium so that the staff could assess its overall health. The sunfish was covered in parasites, which we proceeded to remove. Sunfish also get stressed in harbour areas when they are unable to find their way out.
Says Curator Maryke Musson: “When a sunfish is stressed, the efficiency of its immune system is reduced. It is then less able to protect itself and the parasites flourish. If not treated these parasites can eventually kill the animal.”
The sunfish was placed in the I&J Predator Exhibit for about two days. It was adapting well to the exhibit boundaries and interacting with the other animals. It had developed a particular affinity for Maryke and for Senior Aquarist Kevin Spiby, who swam with it when it was first introduced to the exhibit and who took care of feeding it.
However, on the evening of 29 December, Yoshi the loggerhead turtle – known for having a bit of attitude from time to time – took a bite out of the sunfish’s tail. Our biologists were on the scene immediately to assess the situation.
Sunfish skin is extremely hard and thick, so there was no internal damage, but Maryke and the team decided to move the sunfish out of the exhibit and into a holding pool behind the scenes. It was observed overnight and the rehydration work continued. Its health was assessed again the following morning and preparation started for the release.
Our work with sunfish
The Two Oceans Aquarium has displayed several sunfishes since it opened in 1995. Many people had never heard of sunfishes, let alone seen one, until they were displayed in the Aquarium. Those who have seen sunfishes in the sea have only caught a fleeting glimpse of a fin or a large flat disk before they have disappeared into the ocean depths.
We also assist international researchers of sunfish with the collection of DNA samples when staff members come across a sunfish in Cape Town waters.
Sunfishes come into the V&A Waterfront, Cape Town and Simonstown harbours every summer. They start appearing in October/November and are often sighted right through to May/June the following year. Unfortunately they are often injured and/or disorientated. Sometimes they are trapped in the dry docks and Aquarium staff are called out to rescue them before the docks are drained of water. Calls are also received from the public to say that a strange fish is caught in the rocks or has beached itself.
“We always respond to these calls and try to assist where possible,” says Maryke.