Pressure and Survival

At the bottom of the Mariana Trench, pressure reaches 1,086 bars — equivalent to stacking 50 jumbo jets on a single person. No air-filled cavity can survive, which is why deep-sea fish lack swim bladders.

Instead, organisms use trimethylamine N-oxide (TMAO) to stabilize their proteins. The deeper the creature lives, the more TMAO it contains. This compound sets a theoretical depth limit for fish at around 8,200 meters.