Inspired (loosely) by societies like the Gunditjmara and natives of the Pacific Northwest, I always have envisioned a system of aquaculture for one of my concultures, though agricultural studies are hardly my forte, so I figure I should make sure that my system is feasible, and that there are no glaring mistakes.
The society in question lives in a cool temperate climate; summer highs are in the low 60s Fahrenheit, winter lows drop into the 20s Fahrenheit, with low pressure systems from the west bringing rain year-round. It's roughly analogous to the southern tip of Chile.
Broadly speaking, the west is mountainous fjord country and the east transitions from higher land in the interior to a coastal plain. The eastern side is a bit more continental and much drier than the western climate, due to föhn winds as well as more persistent winter cold fronts.
My idea was that people on the northern part of the western coast would invent a form of aquaculture, maybe first by harvesting tide pools and littoral environments, and then by building small structures where they would grow products like kelp, mussels, sea slugs, and fish together in a kind of mini-ecosystem, resembling modern Integrated Multi Tropic level Aquaculture (IMTA).
This would be supplemented by learning to grow tubers and peas, as well as trading for livestock (llamas, maybe sheep) from herders in the highlands.
I know that neither my western nor eastern regions are the kind of subtropical river valley paradises where complex societies emerge the best, but I'm willing to have these people take some more time to have a food surplus and create a civilization in their own, cool temperate environment. I'd just like criticism on whether this is a feasible path and whether the eastern coast is actually a better place than the west for the emergence of a civilization (I always imagined a vibrant urban and maritime culture emerging along the west coast).