They NEED bigger space. There are LOADS of them being kept in big enough tanks. At the aquarium in MN we had the option of the 85,000 gallon tank and didn't put them in there, but opted for the 500,000. The 85,000 didn't have enough foot print for them to swim as they need to. Shipping is one thing, but living is totally different as to the impact it has on the shark. We ship fish in bags, it doesn't mean you can keep fish in bags their whole life. Sharks are the same way. I've moved sharks all over the world, and wouldn't dream of keepig them in the same size as a shipping box.
It's not about dividing up the space among the sharks. There is more to shark keeping than space. Water volume is offsetting waste production. Sharks are one of the highest ammonia/waster producting fish you can have - and part of the volume is to keep water chemistry stable.
Those black tip reefs in the 5000 I have will be moved out soon as they are out growing it. The 12 foot diameter is too small even now. That one is out of my hands for now. They also have FAR MORE swimming space due to it being round than a tank like you described. A narrow tank is a pain for sharks like these to turn around in. The 90 degree corners are not usable space. To see the usable space, draw an oval inside the tank using a line they can swim without having to go 'nose up' in the water. You'll see how much of a square/rectange tank isn't usable. A three foot shark will need 5 or 6 feet as the shortest side, and a much longer 'glide length' for the longer sides. Also remember to account for growth. My two 2 year old BTRs are over 4 feet at this point and still growing fast.
Small tanks for free swimming sharks leads to two major issues.
Spinal development: The back grows wrong and tends to curve. You'll cut the life span in half and if you don't put them down, you'll end up watching a shark that will die as it eventually sinks to the bottom because it can no longer move itself throught the water.
Liver/Renal failure: Liver and kindey function is critical to sharks. It's why they don't take well to most meds that directly impact those two systems. When you stress the body, those two systems tend to fail first and will lead to death if not corrected.
It's not about dividing up the space among the sharks. There is more to shark keeping than space. Water volume is offsetting waste production. Sharks are one of the highest ammonia/waster producting fish you can have - and part of the volume is to keep water chemistry stable.
Those black tip reefs in the 5000 I have will be moved out soon as they are out growing it. The 12 foot diameter is too small even now. That one is out of my hands for now. They also have FAR MORE swimming space due to it being round than a tank like you described. A narrow tank is a pain for sharks like these to turn around in. The 90 degree corners are not usable space. To see the usable space, draw an oval inside the tank using a line they can swim without having to go 'nose up' in the water. You'll see how much of a square/rectange tank isn't usable. A three foot shark will need 5 or 6 feet as the shortest side, and a much longer 'glide length' for the longer sides. Also remember to account for growth. My two 2 year old BTRs are over 4 feet at this point and still growing fast.
Small tanks for free swimming sharks leads to two major issues.
Spinal development: The back grows wrong and tends to curve. You'll cut the life span in half and if you don't put them down, you'll end up watching a shark that will die as it eventually sinks to the bottom because it can no longer move itself throught the water.
Liver/Renal failure: Liver and kindey function is critical to sharks. It's why they don't take well to most meds that directly impact those two systems. When you stress the body, those two systems tend to fail first and will lead to death if not corrected.
