Civilization: How to make it happen under the sea.

[MisterMan]

There's a whole lot of civilization to go through before your get sufficiently advanced technology to render a primarily aquatic amphibious species sufficiently comfortable on land so as to live there full time. That's a milestone present-day human technology hasn't yet crossed at the very least.

That’s precisely why I suggest that they would adapt physically to the more successful environment before becoming industrialized to the point that physical adaptation to dry living ceases. I’m suggesting physical mutation, not technological adaptation. Becoming amphibious is a presumably biological change, and would trend toward more full-time land dwelling than anything else. You can’t become amphibious with sheer technology, although there’s a famous short story attempting that.

Food storage is an excellent topic. Presumably they need external storage and transference of chemical caloric energy so that their members can become specialized in their pursuits. In an oceanic environment, this must be done with living tissue and not with dehydration, refrigeration, or other methods of “dry storage.” It’s called that for a reason, after all. And it must be available locally where civilization is developing, preferably in portable form. I say this to forestall irrelevant discussions of how there’s ice in some parts of the ocean. That is similar to discussing cooking with thermal vents.