I have a 60L fish tank in my Tokyo apartment on around the 10th floor. It's sitting on stand that is not bolted to the wall. I have several friends with similar setups.

In the last 6 years there have been two or three earthquakes that caused enough water to slosh on to the floor.

Of those only the 2021 Fukushima earthquake caused any fish to slosh out - perhaps 10 medaka if I recall correctly. Luckily I was home and I was able to save all the fish, however there was one adult red cherry shrimp that didn't make it because I had trouble picking it up off the floor. I cleaned up the water with some paper towels and it didn't seem to cause any lasting damage.

I think if I had a 600 lb (270L?) tank or expensive fish though I would probably have a different perspective.