Was the Rosita Ancient Extraction Method used to isolate other liver oils?

Rosita’s ancestors consumed seal and whale blubber, and other fish liver oils which were procured using the same methods used to obtain the oil from cod livers. An example is shark liver oil which was probably consumed long before cod liver oil. Shark liver oil is a very ancient remedy. The oils obtained from specific shark species had special therapeutic and body-strengthening properties and were very different to the shark liver oils currently available to the consumer today. Shark liver oil has considerably greater stability than cod liver oil and this may be, in part, due to the lower content of polyunsaturated fatty acids present in shark liver oil and the greater levels of antioxidants. Cod liver oil is therefore much more prone to rancidity and the old-time Norwegian fishermen knew this. When they wanted to produce cod liver oil for their family (and not for export purposes) they treated the livers from cod in a very different way compared to the livers derived from shark which could simply be thrown into large oak vats, or skins, and left there for a period of time without damaging, to a considerable extent, the oil.