In this world, a progenitor has created a mass of order out of chaos, with the possibility of entropic fluctuations increasing the further out from the center you get. What do I mean by entropic fluctuations? I mean that earthquakes, shifting gravity, and brief dissolution become more and more likely the further out you get. Livestock on the edges need wings to avoid being tossed up and splatted by shifting gravity or falling off a cliff/engulfed when earthquakes occur. While raw vacuum is never introduced for more than a split second, air pressure might fluctuate due to the violation of earth and sea. Imagine massive amounts of energy pulling things apart and the resulting whoosh of air filling that space.
But that brings me to my question. Part of the reason that oceans were where life began on Earth is because of the ocean's relative inviolability: once you get a couple hundred feet down, the temperature, pH, and medium (water) don't change much. What kinds of adaptations would sea creatures need to survive earthquakes, gravity shifts, and brief but sudden introductions of void (possibly cavitation)?