Meanwhile, thousands of people get to eat nutritious fish instead of the stringy pork and stone-baked weeds they were eating before. The population's mean IQ increases a couple of points over the course of a generation. They experience an accompanying rise in various standards of living, from their high-school graduation rate to their average lifespan.

Eventually, the tuna are overfished and the agricultural conglomerates switch to farmed tilapia. Everybody complains loudly... but by now, nobody but a few old fishermen remember how much subsistence farming sucked.

Not quite sure what the follow up is supposed to teach ?

Is it a critic of EU/US development plans in developing countries in Africa. Come in, transform self-sustaining economies into EU/US dependent one (eg: replacing traditional crop by commercial crop complemented by food import), ruin them for profit, and then rebuild them for profit (or using public funds) ?