Tohri, Keri and Yaori all come from an island chain where the primary source of Fuel Oil is in the form of giant Lagoon Avocados.
This plant grows in giant lillypad lagoons and floats to the surface when sufficiently oil-laden. Crews with special skiffs and cargo barges will harvest and process the fruits to extract minerals, salts, and of course the oil.
This gets cracked into Biodiesel, or turned into Polymers, lubricants and waxes.
The pits are hollow and make excellent buoys and barrels.
@Motodrachen
That's very cool, it sounds like they are doing the ethane/propane>ethylene process after removing any acid groups from the fat to get polymer feedstock!