This is just something that I thought of at one time, and I know it probably won't be addressed in game, but I was just wondering, what would happen if the Jonah Town Whale somehow dies? Like of old age, or some unnatural cause.

There would be a lot less imported spices.

All joking aside, you would likely see many pelicans attempting to flee the Great Whale. The crime syndicate in the Gullet would likely be thrown into a pit of chaos, and capture and raid these fleeing pelicans to attempt to keep full control and power over the situation. There would be an attempt to overthrow the Frogfather in which a completely corrupt enemy would take over. A certain hero would be called upon to bring balance to Jonah Town and restore peace to the area.

After successfully restoring order to both the civilians and the criminal order by reinstating the Frogfather as protector of the realm, areas of Rapa Nui, Skull Island, Scrimshaw, Flotsam, and even Puerto Mico would receive an influx of Jonah Town characters. The whale would likely wash up against the side of a cliff, and the criminal order would continue business from there.

But that is just a theory.