I consider that the topic discussed fits perfectly both in economics, since it is an alternative way to obtain benefits as in business, for the same reason, on the other hand, fish farming is linked to agriculture and the concept of this is well remarked "Set of economic activities".
I agree, but reading your post, I couldn´t find any phrase that made reference to monetary gains, marketing, supply, and demand of the cachama.
This is the single line related to commerce:
The fish are marketed directly or sold to markets, fresh from the ponds.
You could have emphasized the economic part but you didn't.