It's important, though, to distinguish the kind of fish-harvesting appropriate for Haiti. Coastal fish farms have multiplied around the world over the last three decades and they have spawned a host of problems: fish sewage that pollutes waters and grows algae blooms, shrimp ponds created by clear-cutting mangrove forests in Southeast Asia and Mexico, densely packed fish farms that too easily spread disease and parasites in the contained populations (and in the wild when fish escape).
Wild-fish harvesting is also not an option for Haiti. Its waters are overfished and stressed, creating a crisis for those who depend on fisheries for their livelihoods.
Why fish are more efficient
That leaves a new method in aquaculture that is just getting going around the world. It's being developed farther offshore, taking advantage of optimum currents for cultivating "free range" fish that are not sequestered in polluted bays and estuaries. These operations deploy cages in offshore waters, where currents quickly whisk away waste. And improvements in feed for farmed fish are reducing concerns about overharvesting of small fish that are used to nourish captive larger fish.
Open-ocean marine aquaculture would do much to provide food security if it were adopted in poor, coastal countries. Haiti has 1,100 miles of coastline, and its waters extend seaward 200 miles as an exclusive economic zone. Free-range fish farming would augment Haiti's agricultural economy.