The walk-through tunnel offers viewers a 270-degree view of the marine world. Image Credit: Supplied picture

It’s 7.30am and Adrian Tolliday, head curator at Dubai Aquarium & Underwater Zoo, has already donned his diving suit. He plunges into the aquarium at The Dubai Mall to check on the thousands of aquatic animals. More than 51 metres in length and 20 metres deep, the tank is the largest suspended aquarium in the world.

There’s also a 48-metre walk-through tunnel that provides 270-degree views from 11 metres below the surface of the tank. Responsible for the operations here, Adrian ensures that each member of his curatorial team completes their checks and tasks before it opens to the public at 10am.

These include studying the health of over 80 different species, including 85 sharks and rays, thousands of fish as well as several penguins, sea horses, garden eels, tarantulas, Burmese pythons and water rats. 

Adrian verifies that the 30-strong team of divers and cleaners have done a good job maintaining the area, ‘vacuuming’ the floor, checking the salinity level of the water and keeping the largest single acrylic viewing panel in the world algae-free.

At 750 millimetres thick and weighing 245,614 kilograms, the panel is built to withstand the enormous pressure of 14 million litres of water used in the aquarium, but transparent enough to give visitors clear views of the many marine animals on display.

He checks the floor of the aquarium to make sure there is no algae build up, that the viewing panel is clean and the aquatic animals are healthy. Satisfied, he surfaces, and using state-of-the-art equipment checks that the temperature of the water and the water chemistry is perfect.

The ideal temperature is 25 degrees Celsius and the pH level should be 7.8 which mimics the seawater in the region. Stepping out of the water, he takes a walk around to ensure that the aquarium and underwater zoo are ready to receive guests before returning to his office in the mall.

Crocodiles prove popular

Last year alone more than 1.2 million people visited the aquarium and this year the authorities are expecting a lot more, particularly with the introduction of a new species into the zoo – Cuvier’s dwarf caiman and West African dwarf crocodiles, which it acquired for its Crocodylia project.

Gordon White, general manger of the aquarium, says, “With this, zoo visitors will get an opportunity to come face to face with one of nature’s toughest survivors that have been on the earth for more than 84 million years.’’ 

Regular shows will also offer people new insights into the behavioural patterns of the reptiles, including the fact that they are closely related to birds and that they exhibit genuine parental care.

“The shows will tell the fascinating story of crocodiles, how they survived and how their existence is being threatened by illicit trade in crocodile hide and artefacts,’’ says Gordon, who has been heading the team for almost four years. “Whether they fascinate or frighten you, they are a key element to our environmental balance.’’ The crocs are housed in the underwater zoo, located on Level 2 above the main aquarium. The new exhibit has become a huge draw for children and adults, all eager to see the crocs up close.

Ecological zones

The underwater zoo is divided into three zones. First is the Rainforest Area that has freshwater animals found in tropical rivers such as otters, piranhas and catfish. The second is the Rocky Shore zone that is inhabited by Humboldt penguins and spider crabs and the recently recreated southern Antarctic area for the new entrants – the  gentoo penguins.

Ice beds have been created and ambient temperatures are regulated at zero to sub-zero in this area. Like all varieties of penguins, gentoos are awkward on land and have a waddling walk. But they are pure grace underwater and are a pleasure to see diving and swimming.

Gentoo numbers are increasing on the Antarctic Peninsula but have plummeted in some of their island enclaves, possibly due to local pollution. The third zone is the Living Ocean and it has all the marine animals found in temperate oceans, such as sharks and Moray eels.

Feeding time

Feeding the animals begins as early as 7am. Every day, about 150 kilograms of food that includes freshwater fish, squid, lettuce, cucumbers and other vegetables, sourced from registered vendors to ensure the best quality, are fed to the various creatures depending on their food preferences.

“The sharks  have streamlined bodies and are well adapted to eating only when it’s necessary,” explains Gordon. “They are fussy eaters who prefer fresh fish such as mackerel, mussels, squid and milkfish. Despite their size, they have just two small meals a week.  “Sharks as a rule are lazy creatures in their natural habitat and prefer to forego eating if their meal – fish – is too far away.

“The prey has to be really close for them to make the effort of chasing and devouring it. They change their preferences often and food items have to be rotated to suit their palate. We also include vitamins and nutritional supplements in their diets. “The reptiles are relatively easier to manage. Crocodiles, for instance, have a very slow metabolism and do not need to eat on a daily basis. We feed them twice a week with meat and fish. And they particularly enjoy mice. 

“The otters eat twice a day and enjoy tilapia, clams and prawns. Their favourite food is fish. We also have some animals such as iguanas and certain fish that are herbivores. A food-preparation team delivers the special meals for them.’’

Challenges abound

The aquarium uses natural seawater which is brought to the mall in tankers and pumped in. Depending on various factors including water quality, salinity and chemical composition, a certain amount of water is removed from the aquarium and an equal amount of clean seawater is pumped in daily.

“It is a challenge handling 14 million litres of water,” says Gordon. “The aquarium is equipped with special sand filters that trap sand particles. We have a team of 30 full-time experts looking after the fish health, life support systems and the dives.”

The zoo also has a panel of veterinary technicians and consultant veterinarians who visit the zoo twice a week to keep a close eye on the health of the inhabitants. “Since we opened in November 2008, there have been many births on site such as that of Humboldt penguins, sea horses, grey reef shark and the carpet python,” says Gordon. “That means taking extra care of the little ones and ensuring they have the right conditions to grow.”

The aquarium chooses its animals ethically and brings in only those creatures that are not endangered and are cleared by international treaties such as the CITES [Convention in International Trade of Endangered Species] and WAZA [the World Association of Zoos and Aquariums]. “Modern aquariums are about conservation of marine life and we are dedicated to operating rescue and conservation programmes in 2013,” Gordon adds.

Issues of breeding

Every day there are new challenges to be met as dealing with live creatures is a tricky job. For instance, maintenance of the gentoo penguins is a tough task as the sub-zero temperature needs to be maintained.

“The staff follows a specialised cooling plan for them where their tank is replenished with freshly shaved ice every day.’’

Despite the large population of a diverse variety of creatures, the aquarium is not very active in breeding programmes although some of the creatures like the Humboldt penguins and a few reptiles have bred in captivity.

“Factors such as the constant change of water and the use of filters are not conducive to breeding,” explains Gordon.

But with more and more species being added all the time, the aquarium is a fascinating place where you can get to see nature’s water world without getting your feet wet.