Skip to content

Reefs.org: Where Reefkeeping Begins on the Internet

Sections
Personal tools
You are here: Home » Library » Aquarium.Net Article Index » 1096 » Aquarium.Net Oct 96 The Great Barrier Reef

Aquarium.Net Oct 96 The Great Barrier Reef

Alf Nilsen describes his trip to the The Great Barrir Reef. Oct. 1996 Index for Aquarium Net, Aquarium Net has numerous articles written by the leading authors for the advanced aquarist

AN AQUARISTIC TOUR AROUND THE WORLD

Part 2

The Great Barrier Reef Aquarium

By Alf Jacob Nilsen Originally printed in Das Aquarium

A long the docks of Townsville lies "Great Barrier Reef Wonderland"-- a center that houses all kinds of information on The Great Barrier Reef. Just like the mountain "Castle Hill," the building complex has been a landmark in Townsville. In a modern, friendly and large complex of buildings we find a variety of shops, restaurants, and the office and administration of "Great Barrier Reef Marine Park Authority" (G.B.R.M.P.A). Do not miss the book shop near the entrance of the aquarium. Here you will find all the available literature on Australia Coral Reefs as well as many unique souvenirs. There is also a three dimensional cinema called "The Omnimax Theatre" worth visiting. The main attraction is the huge and very impressive "Great Barrier Reef Aquarium." The Great Barrier Reef Wonderland is a place where several days can be spent seeking information on the reef and its organisms. A curiosity is the transferred satellite-information of the wind and weather out on the reef-edge. On a TV-screen every 10 minutes, you get information on weather conditions -- very useful to us divers who soon were on our way out into the tropical sea.

I have often wondered what it would have been like to live next to a coral reef and to have easy access to fresh live-rock to corals and other organisms from the reef and to use our well known technique and knowledge from reef-aquaristic in such an environment ? My imagination tells me that the excitement connected with the reef-aquarium might not be as high here as if the aquarium was operated in Europe simply because the access to organisms was so much simpler. Nevertheless the results must be relative easy to catch (?). So, when I entered the gate of "The Great Barrier Reef Aquarium" I was very excited ! Would the aquarium house a living reef ??

Technical facts

CORAL REEF TANK :

  • Volume of water: 2.500.000 litres (high tide)
  • 1.100.000 " (low tide)
  • Volume of rock: 700 cubic metres (= 420.000 litres of water.)
  • Length: 38 metres
  • Width: 17 "
  • Depth: 4,5 " (high tide)


TIDAL TANK:

  • Volume of water: 750.000 litres (low tide in reef tank)
  • 350.000 " (high tide in reef tank)


TUNNEL:

  • Length: 17 metres
  • Width: 3 "


PREDATOR TANK:

  • Volume of water: 750.000 litres
  • Length: 10 metres
  • Width: 17 "
  • Depth of water: 4,5 "


It would, however, have been impossible to learn so much of the aquarium on a limited period of time if it was not for the extremely friendly and polite staff of the Great Barrier Reef Aquarium. Arrangements were made prior to our departure and we were given day and time of visit and Dr. Jan Morrissey showed us the whole facility herself. Let me use this opportunity to tank everyone at the GBR-Aquarium for an informative and unique visit!

The Great Barrier Reef Aquarium is the worlds largest reef coral reef aquarium and was opened on 24. June 1987. One should think that Australia, a country that houses the largest reef on the earth, should not need to bring corals into an aquarium. However, the Great Barrier Reef located very far from land and is in fact very difficult to explore even if one is a SCUBA diver. You would need to operate a boat or to join a commercial trip to the barrier reef. The distances are very long, and in practise the reef is "unreachable" to the majority of people in Australia. So the major goal with the Great Barrier Reef Aquarium is "to bring the reef to the people". The Great Barrier Reef is put on the "Worlds Heritage List" and the people of Australia (and the rest of the world) should have the opportunity to know "why". The Great Barrier Reef Aquarium idea is aimed at contributing to the GBRMPA's principle goal:

"To provide fro the protection, wise use, understanding and enjoyment of the Great Barrier Reef in perpetuity through the development and care of the Great Barrier Reef Marine Park."

Quote: Graeme Kelleher,

Chairman, GBRMPA.

When you enter the entrance of GBR-Aquarium, you will understand that the complex is much more than just the large reef and predatory tank. You walk through a dark corridor with several very high quality slides on the walls - slides that tell you about the development and the life at the Great Barrier Reef. You can also visit a small cinema and look at a 15 minute show that takes you through the history of- and the life on the Great Barrier Reef. Then there is a hall full of smaller tanks containing among other sea-snakes and even an aquarium with the box-jellyfish ( Chironex fleckeri ), the most poisonous Cnidarian in the world. A sting from this animal can kill you ! In the nature the jellyfish live in fresh- and brackish water on the northern coast of Queensland. The specimen in the GBR-Aquarium was introduced to the tank as a juvenile and had grown to an adult. There is anemone fish and small gobies in other tanks, but perhaps the best thing with this section is the great "touch-tank" upstairs where people can touch the reef animals. Here sea cucumbers and the blue starfish ( Linkia laevigata ) crawl, and there is even a small shark in the touch-tank - a very wise thing to put in such a tank to underline that sharks are in fact not as harmful as often told. Another unique room is the "investigating room" where visitors can examine objects from the reef, use binocular lenses and microscopes and literature to find facts of reef organisms. There is also a couple of small aquariums here where especially interesting animals are put.

Further inside the building you enter the "Viewing Tunnel" which is actually inside the large reef aquarium. The tunnel is made out of Plexiglas (acrylic) and has a shape like half a circle. On your left is the reef-aquarium and on your right is the predatory tank. You walk under water ! This part of the construction is very impressive indeed ! Before we walk any further, let us take a look of the technical principles and facilities in the Great Barrier Reef Aquarium...........

Algae Turf Scrubber

This reef-aquarium is filtered over a large number of algae filters, called "algae turf scrubbers". As a principle the algae accumulate nutrient (nitrogen and phosphorus) which are removed when the algae are removed by scrubbers. The algae grow in shallow beds outside in full sunlight during daytime and under artificial light during night-time. Water from the aquarium flows over the bed of algae at regular intervals and overflows back into the aquarium. The theory is that the removal of algae from the scrubber shall keep the water low in nutrient and remove the waste products from the organisms in the reef tank. Similar scrubbers are among others used at the Smithsonian Institution in Washington (Adey, 1983) and in Space Biosphere's Ventures in Arizona, USA.

Waves and tides

Technicaly impressive is the way the waves and tides are achieved. A tidal holding tank of 750.000 litres of water makes it possible to alter the water level in the reef aquarium, a factor that is important for the animals. The tides are altered between tow high- and two low tides pro day, slightly longer than six hours apart. The average tidal range of the Great Barrier Reef is about 3 metres, but since the aquarium is "only" 5 metres deep, a compromise with a tidal range of 1 metre has been made. These together with temperature and moonlight are the factors that stimulate to sexual reproduction, factors that in smaller scales should be considered by aquarists as well.

The current at the Barrier reef is typically 0.5 m/sec. in the southern region and 0.25 m/sec. in the northern region as an average, but current can reach 2.0 m/sec in reef passages.

The Great Barrier Reef Aquarium has used compressed air to create waves. The wave-machine creates a flow of 1000 m2/hour from the upper end of the reef-tank to the other. This gives a turnover rate of about once every 24 hours.

Light and temperature .

The reef-aquarium is exposed to open air that means that the illumination is coming from natural sunlight. Townsville has more than 300 sunny days a year that was one of the reasons for choosing this city as the place of the aquarium. No artificial light is used. This gives a natural light and a natural variation in light intensity. It also means that rainfall will add freshwater to the aquarium. The salinity of the reef is about 33.5 o/oo and a rainfall of 100mm would have needed 2.5 tons of salt. However, so far this has not been a major problem and the extreme salinity values have been 34 o/oo as the lowest and 37 o/oo as the highest value. Normal temperature of the Great Barrier Reef is 24-29 oC. The temperature can cause a problem as warm days with temperature of more than 36 oC. Bleaching of corals are linked to clear water combined with high temperature (more than 30 oC) and the aquarium is shaded during such periods.

Decorations

Very surprisingly the decorations are made out of 700 tons of dead, dried calcareous rocks collected on a Hayman Island. 200 tons of sand was collected at the lagoon floor of Flinders Reef. The reef-profile shall resemble a typical mid-shelf-reef with section of "reef-front", "alga-crest", "back-reef-slope", "lagoon" and "bommies". All sections are clearly marked so that the viewers can read about the each viewing section . The water - 4.5 mill. litres - was collected at Myrmidon Reef on the outer edge of the Great Barrier Reef, which means water of the best quality.

S o, all this technique and the fact that the aquarium is located in a reef area and operated by coral-reef biologist should create a wonderful reef in a well run closed system (?). The answer is both "yes" and "no" ! "Yes" because the many soft-corals that were put in the tank thrive and had grown to sizes of many metres. "Yes" because the fish are in an excellent condition. "Yes" because the public was overwhelmed by the tank and very obviously learned a lot about the reef ecosystem by spending some hours in the Barrier Reef Wonderland. "No", because there was no sign of growth of any calcareous-fixing-plant or animal. The many stony corals were dying and showed no sign of asexual reproducing or growth as we are used to in our small European tanks. There was very little growth of calcareous algae. The water was not transparent, but greenish and seemed to be too rich in organic. That many coral-eating fish were introduced to the aquarium was a fact that we observed, but in what extent that they did eat the corals we cannot tell. The predatory tanks housed many large predatory fish and look very much like all public predatory tanks.

All in all it seemed that something was wrong. It seemed very odd that a facility like this, situated almost "on" the very reef could not make stony corals grow. In our small home-tanks calcareous water is added, and when I asked Dr. Jan Morrissey we were told that nothing like this was used here. We were also told that the aquarium was not allowed to collect live rocks for decoration when the aquarium was started. However, the staff at Great Barrier Reef Aquarium worked very hard with the problems and they seemed to be aware that the situation could be improved. I really look forward to the day when I can return to Townsville and have another look at the Great Barrier Reef Aquarium to compare the situation.

Next ..... "The Coral Sea".

Created by liquid
Aquarium.Net
Last modified 2006-11-20 03:05
Advertisement