One reason for visiting Okinawa was to see the Churanmi Aquarium which is the second largest aquarium in the world. It was an amazing experience to view gigantic fishes from a huge window with unheard dimensions of 8.2 m in height and 22.5 m in width.
The design intention was that visitors will be unaware of the presence of the window. Everything opaque were removed from their sight except fishes and water, so that visitors feel that they are totally immersed in the sea. This was made possible by joining together super large acrylic panels (measuring 8.5 m (H) x 3.5 m (W) x 4 cm (D)) without using any reinforcing materials.
The acrylic panels were glued together. The panels not only have to resist very high hydraulic pressures but also have to accommodate large variation in dimensions as a result of temperature changes and water absorption; this was altogether quite an engineering challenge.
Also, the aquarium has adopted an open system which intakes sea water from the ocean, circulates in the tank and discharges back to ocean once again.
The aquarium is divided into three sections according to the depth. In the shallower part, we can see coral reefs and coral fishes.
There are as many as 800 different coral colonies representing 70 different species of coral. Fishes swimming jovially in and out of the coral reefs help in controlling seaweed and zoanthids which inhibit the growth of coral.
With that we descended into the deepest and mysterious part of the aquarium.
In the deepest part of the aquarium, you can see creatures like a transparent type of shrimp which only lives at very big depths. There are lots of other small creatures living at deep seas, some feeding on bacteria which in turn feeds on deep sea nutrients in the seabed.
There was so so much to see even when we were back on the surface. The dolphins show in the Okicha Theatre nearby gave us some hearty laughs when the clever dolphins come up every time from the water and making splashes.
The trip to Okinawa was unforgettable and I must say, the aquarium is the best part. We were fortunate to have seen three big whale sharks (with babies) coming together and took their photos. It was indeed an eye- opening experience which can rarely be seen in other places!