I remember back in the late 80's and early 90's, there was a active program to teach the "Islanders" to net catch fish.
It was not well accepted due to the increased effort effort required to catch fish, and lower ROI.
We actually donated money to buy them nets back then.
But, we kept right on buying the Cyanide poisoned fish, and wondering why they would die after a few months in our care. We actually thought it was our fault (it was in many cases) butit was the burning of their gills with cyanide that was killing them over time.