Pabulum is the "fuel" consumed by gastrines, taking the form of a lumpy soup packed with nutrients. It is fed to them via special hatches and chutes and the waste discharged by the gastrines feeds into a vessel's bilge, from which it is pumped into the water. The combination of pabulum and waste gives the organ deck its distinctive smell. Nadderers have developed a taste for gastrines and their effluent, providing an incentive for them to surface and seek these out as a food source.
Pabulum is another term for food, in particular that consumed by animals and plants.