With regards to human consumption of fish we can no longer safely use the expression, "there's plenty of fish in the sea" since more than ever most of the world relies on official quotas and more than ever we're attempting to preserve many species in their natural habitats by farming.
Just as in the organised world the native populations are in the process of observing this same idea, none more so than the people hunting wild species of arapaima, a long slender torpedo-shaped black fish with red markings that lurks in the Amazon river of Brazil. Possibly the worlds largest freshwater fish, can reach up to 15 feet (3m) in length and weigh as much as 200 kilograms (440 pounds). The arapaima are very unique among fish since they breathe air with their very primitive lung, and for this reason are known by the common names "pirarucu" in Portuguese and "paiche" in Spanish.
"Because they rise to the surface to breathe every 5 to 15 minutes, they are easy to locate and fishermen harpoon them to sell their valuable meat or to feed their families. That combination of high value and vulnerability has led to widespread depletion of their populations and they are now listed as endangered" (Sciencedaily).
Often referred to as the "Cod of the Amazon", since the natives often salt and dry the meat, rolling it into a cigar-style tied package and can be stored for a long time without rotting, which is very important in a region where few have refrigeration.
Whilst the arapaima of South America are threatened with extinction due to overfishing they are "also threatened by deforestation, because the fish prefers to swim into flooded forests during the wet season to spawn and guard their young. The young are vulnerable to predators and need to find cover among the flooded vegetation". (newswatch)
Whilst they may remain on the critical list of endangered species in the Amazon, as a way of preserving the species: "The arapaima has also been introduced for fishing in Thailand and Malaysia. Fishing for this species in Thailand can be done in several lakes, where one often sees arapaima over 150 kg landed and then released". (Wikipedia)