Zoo and Aquarium Design: 360 degree viewing tunnel at the Shinagawa Aquarium

This is the second post about the Spotted seal exhibit. (Click here if you want to read the first one.)

The 360degree viewing tunnel is what got me most excited about this exhibit. But while I am posting about it, I might as well do a complete job and show the entire seal exhibit.

The aquarium guide calls this new, two story building addition

Observatory for Spotted seal behavior.

Below a bird's eye view. I circled the Spotted Seal building. The main aquarium is to the right of the circle.

from Bing maps

Below two photos that show the Observatory from the outside. You can see, if you click and enlarge the photo, the main aquarium on the right (white tiled building and probably over 20 years old) and the new Observatory addition in fair-faced reinforced concrete (probably less than 2 years old).

Notice the roof covering the visitor area on the 2nd level and the hole in the middle of the roof, allowing the animals to get a dose of rain or sunshine.
I like it that the animals have access to the outside air with it's ever changing smells. Being open to the elements is something every caretaker or designer should strive to provide for all animals (even fish - if possible. And, agreed, there are climate and disease restrictions for some species, but I would guess for 99% of animals in captivity these restrictions don't apply - or not at all times).

Below a video clip of the above water area - 2nd level deck:

Photos of upper level:

click photos to enlarge

Allowing the visitors above water and below water within such a small area creates the challenge for any designer. At the Shinawaga Aquarium they solved it with a staircase and an elevator. Neither are ideal in a zoo setting, but sometimes unavoidable.

Photo: visitor staircase to underwater viewing area.

And below a video clip where I take the elevator to the underwater viewing hall.

By making the back wall of the elevator out of glass, the designers turned the ride into part of the exhibit experience; But I'm wondering how much it had cost (glass and extra acrylic, not to mention the maintenance of window cleaning) and I wonder whether this is paying off in terms of overall visitor experience. If you watch the movie clip you'll notice how fast that thing gets me down, which is nice, but doesn't do much for animal observation.

Riding the elevator down I was able to spot a window in the outside facade which allows the seal to look out. Seals are curious critters and there is not much they can see on the upper deck - I loved it for the seal: an exhibit with a view!

Talking about view: There is a hole in the concrete slab allowing the seal to poke their head through.
From below it looks like this:

From above it looks like this:

Why, I was asking myself, would the seals want to use this hole if they have a much larger open water surface a few feet away? Oddly enough they did. In the roughly fifteen minutes that I spent there, it happened about three times that a seal, suspended upright in the water, kept looking up through the hole. But never long enough for me to take a photo, although I sprinted the staircase two times when I spotted an animal in the hole from below, just to have it dive away when I got there.

The look down glass floor in the tunnel

Glass was used for the floor in the otherwise all acrylic 360 degree viewing tunnel. The glass was "pocked marked" to prevent visitors from slipping. The anti slip worked perfectly: no slip and only minimal impact on the view through the glass.
I was curious what they did to the glass to roughen it up in places.
Here a video of me scratching the glass: