The Two Oceans Aquarium will this week be introducing ragged-tooth sharks into the newly renovated Predator Exhibit. Two females and a male will be introduced on 27 June from 08h30. Three more sharks will be introduced on Friday, 30 June.
Ragged-tooth sharks grow up to three metres in length and approximately 290kg in weight. They annually migrate along the southern African coast from KwaZulu-Natal down to the Cape coast and are widespread across the globe.
During the last couple of months, the Aquarium’s collection team has been hard at work near the town of East London, collecting the animals for the exhibit.
The team used rod and reel to catch the sharks after which they were transferred to a holding facility at Pure Ocean (marine fish farm) in the East London Industrial Development Zone.
The sharks were housed in 150 000l and 30 000l pools. They were then transported to the Aquarium via road. “I am really excited about having some impressive-looking ragged-tooth sharks back, not just because they contribute to a beautiful and somewhat dramatic display with a strong ocean conservation message, but because we can also continue with our shark research. Once again we will showcase our ability to combine art and science to tell remarkable underwater stories,” said Maryke Musson, Curator of the Two Oceans Aquarium.
The sharks constitute the start of the reintroduction of animals into the exhibit, which closed one year ago for renovations and repairs. The exhibit is already open for public viewing, but remains a work in progress, as animals will be introduced over the span of a number of weeks.
The renovated exhibit’s water capacity remains at two million litres, but unlike the comprehensive mix of species it previously housed, its new inhabitants will be predominantly ragged-tooth sharks.
As the water temperature in the exhibit ranges between 18 and 21 degrees Celsius, the Aquarium is also investigating the possibility of introducing a shoal of sardines and perhaps one or two other predatory fish species, like large kob, at a later stage. This exhibit’s main attraction will however, remain sharks.
The exhibit has been a firm favourite with Aquarium visitors and since its temporary closure last year, was missed by many. The renovations and repairs were necessitated as time had started taking its toll on this exhibit (previously the I&J Predator Exhibit), which has been one of the flagship exhibits of the Aquarium since opening in 1995. The waterproofing of the exhibit had started to fail and the silicone seals between the windows had started to leak. According to Mike de Maine, Technical and Projects Manager at the Two Oceans Aquarium, “We needed to start work on the exhibit before any extensive damage would necessitate completely demolishing the exhibit and rebuilding it. We have been planning these renovations and repairs for a number of years and it is really immensely satisfying and exciting to see the progress and the fruition of this project.”
The extensive work to the exhibit included completely stripping everything out of the exhibit, with the internal concrete structures as well as the windows being removed. From there, new internal structures, which include a medical pool, were constructed, waterproofing re-applied, the original windows reinstalled and a new centre rockwork structure built.
Well-known artificial rock construction company, Wild Exposure, constructed the exhibit’s new centre rock. The structure consists of a plastic pipe framework, covered by fine plastic mesh that was then sprayed with cement slurry. The final touches of adding colour and fine detail were done by hand. The rock holds a hidden secret. Tucked into the top left-hand section of the structure is a medical pool which will be used to tend to any animal in the exhibit, should the need arise.
The construction of the exhibit also gave rise to an opportunity to change the filter media used in the exhibit filters. The new media, known as OC-1, has been imported from the United Kingdom. Each 9kg pack of OC-1 replaces the same volume of sand, which would, in comparison, weigh 75kg. Particles are not trapped in the media, but rather settled. Backwashing the filters is therefore made a lot easier and saves a lot of water. The filter media was kindly sponsored by Certikin and Fluidra Waterlinx.
The waterproofing of the exhibit is fibreglass, like that of a home swimming pool, but it is of a higher specification as it has to deal with the depth of water and also divers and fish scraping against it. Hand-woven fibreglass matts were used in areas where normal fibreglass application could not be done and to strengthen some of the surface areas.
“We are finally reaching the end of what has been an incredibly long journey for many of the staff at the Aquarium. Although the Predator exhibit has only taken 12 months to renovate, it was the necessity of these renovations, which prompted the construction of our new I&J Ocean Exhibit that we opened in June 2016. The opening of the new exhibit gave us the opportunity to tag and release the sharks and then move the fish, previously housed in the Predator exhibit, into their new home. Once done, we were able, for the first time in 21years, to empty the Predator exhibit and start the renovations. To get to where we are now has taken 10 years of financial, architectural, structural, and curatorial planning with too many skilled and dedicated people involved to mention here. My heartfelt thanks and appreciation goes out to all of them,” said Michael Farquhar, CEO of the Two Oceans Aquarium.
Statement supplied by the Two Oceans Aquarium
