The Peruvian anchoveta is a small fish that lives in the southeast Pacific Ocean, primarily off the coasts of Chile and Peru. It lives in the productive waters of upwelling zones, where deep nutrient-rich seawater is brought to the surface by the prevalent currents. Peruvian anchoveta feed in these zones and form absolutely massive schools that may be several kilometers across. These schools are heavily exploited by commercial fisheries, making the Peruvian anchoveta by far the largest fishery, by both numbers of individuals and by weight, in the history of fishing.
Peruvian anchoveta are filter feeders that rely, in some seasons, on microscopic algae (called diatoms) as their primary food source. During other times of the year, they rely more heavily on small, pelagic crustaceans. Though they filter very small prey, they use their relatively large eyes and exceptional eyesight to increase the density of prey in the water that they filter. This strategy is in stark contrast to that used by the very large bodied filter feeders (like whale sharks and basking sharks), which essentially feed blindly and rely on large volumes of water to obtain sufficient prey.
This species matures quickly (at about one year) and produces high numbers of eggs. It reproduces via broadcast spawning, where several females release their eggs and several males release their sperm into the water column at the same time. This method increases the likelihood that eggs will become fertilized and increases the genetic variability in the population.
The fishery for the Peruvian anchoveta is enormous, with a peak annual catch of over 13 million metric tonnes in 1971. As a result of heavy fishing pressure, catches have decreased over time and have been between 4 and 8 million metric tonnes per year for the last several years, still the largest in the world. Peruvian anchoveta population size is also closely tied to natural climate patterns in the south Pacific. Natural variation can be significant, with some year classes being much smaller than others. This variation is a result of the planktonic food supply, which in turn is a result of nutrient availability. The vast majority of the Peruvian anchoveta catch is processed in large plants that reduce the fish to fishmeal or oil to be used as animal feed, fertilizer, and other industrial products. Conservationists consider this practice to be wasteful, and there are several campaigns throughout South America to encourage people to eat this species directly. Due to its large natural numbers and speedy recovery time, even though this species is very heavily exploited, it is not at risk of extinction.