Off topic aquarium points...
Bent acrylic was first used at Kelly Tarlton's in NZ (to the best of my knowledge), prior to this acrylic tunnels with three straight sides had been utilised... Bent acrylic tunnels actually are both the best and worst way to view aquatic life; the effect of being under the water gives many the feeling of diving (the best) and the effect of refraction (a problem whenever looking through "glass" into water) causes the fish to appear in a different position (the worst view) as shown by this diagram:
Image
encil in a bowl of water.png - Wikipedia, the free encyclopedia
While the curve in the acrylic acts as a lens making the fish appear 2/3 to 3/4 their actual size (another negative) as demonstrated by the fourth lens from the left here:
Image:Lens2a.png - Wikipedia, the free encyclopedia
A perfect tank would have innovations such as the double dipper tank etc., as previously linked, with tunnels of as large diameter as possible and many flat vertical sheets looking in to give more undistorted views...
This tunnel was constructed in 2002:
Napier Aquarium - Photo Gallery
It has a relatively small distortion of 3/4 size representation, the seals and joins are quite seamless and the acrylic is of obviously high quality (manufactured in Whangerei, NZ), this expansion to this aquarium (Napier Aquarium in 2002 cost NZD $8 million), the main oceanarium also has a large sheet giving "unobstructed views":
Napier Aquarium - Photo Gallery
When this is compared with a similar (tunnel) shot of an aquarium built in 1985:
Kelly Tarlton's Underwater World - Photo Gallery
One can see the acrylic in the older aquarium has a "wave" in it, this is partly because the creators saved money by flying flat sheets in from Germany and bending themselves in a large home made oven (a very crude process), this aquarium cost NZD (1985) $2 million. Additionally the joins are beginning to "bubble" in the mid sheet joins partly I suspect because of the crude bending method and also the pressure and corrosiveness of salt water but technically acrylic should last unchanged (if correctly manufactured and cared for) for 100+ years...
These photos show the different distortions in the tunnels:
2002 (built) aquarium (photo through acrylic):
Napier Aquarium - Photo Gallery
1985 (built) aquarium (photo through acrylic):
Kelly Tarlton's Underwater World - Photo Gallery
Both shots are with the flash on with the first and newer aquarium giving much more clarity in the picture...
Anyway all this shows is the improvements that there have been in the last 23 years and due to the fact acrylic is a type of plastic its uses are basically limited by the designers mind...
General notes:
Aquariums are different from zoos in that many can turn quite a healthy profit (at least in Asia and Australasia)...
Acrylic is under utilised at zoo’s, IMO, many exhibits could be better designed for the animals using it, for example primate exhibits with 4 or 5 large trees in a huge cage could use a 360 degree acrylic tunnel passing through the middle at many metres off the ground showing the primates arboreal life...
Zoo’s have begun creating exhibits with the natural environments in mind, in the case of aquatic life, apart from places to hide, the water is much more important and new filter and life support systems are being developed (mainly due to large inland salt water aquariums) to much more closely replicate the fish’s natural water (I’ve visited one in Leigh, NZ) which actually produces plankton blooms:
Aquarium studies
Anyway back on topic this is why I enjoyed the Melbourne aquarium, I find the different designs (such as the amazing fish bowl tank) just as intriguing as the new species I saw, I enjoy how the various layouts are set out as hopefully when I finish my studies I can join one the NZ aquarium firms:
MJ Murphy Ltd > Home
http://www.marinescape.co.nz/wb_pg/cont_fla.html
Or Australian:
Aquatic Environmental Systems
Or Singaporean:
Nature Exhibit Design and Consultancy - Green Chapter
If you’re still reading cheers..!