Tony Verhulst wrote:

And what matters in the atmosphere? The air above you.

You don't think it's all additive?


Sure, but the effects of air pressure are second order, if that.

Wunderbar! Then there is absolutely no reason why the fish would be
worse off at altitude, unless you are worried about gasses in the water
leaving faster and relegating the poor widdle fishies to a less
oxygenated environment.


Jack