Tropical to temperate latitudes of the Indian and Pacific oceans
Coastal to open ocean
Order Clupeiformes (herrings, anchovies, and relatives), Family Clupeidae (herrings and relatives)
The Pacific sardine is a wide-ranging species that lives throughout the Indian and Pacific oceans. It has been divided into several subspecies and is an important fishery species wherever it lives. Subspecies include the Californian sardine, Chilean sardine, Australian pilchard, Japanese pilchard, and South African pilchard. It lives in the productive waters of upwelling zones, where deep nutrient-rich seawater is brought to the surface by the prevalent currents. Pacific sardines feed in these zones and form huge schools that are heavily exploited by commercial fisheries.
Pacific sardines are filter feeders that feed on a variety of phytoplankton and zooplankton. 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. Pacific sardines are important prey for a large number of pelagic species, including seabirds, marine mammals, sharks, bony fishes, and even pelagic invertebrates.
Individuals reproduce by their second year and produce a large number of eggs. They undertake long migrations each year and spawn several times along the way. During each spawning event, females release up to 45 thousand eggs. This species 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. Max size is less than about one foot (30 cm).
Throughout its range, the Pacific sardine is fished for a variety of purposes. Historically, this was an important species for human consumption and supported large cannery operations around the Pacific. It is still an important food fish in some places (e.g., southern Africa) but is processed in large plants that reduce the fish to fishmeal or oil for agricultural and industrial purposes in other places (e.g., Mexico). This species is known to exhibit natural variability in population size that often occurs in an opposite cycle to several anchovy species that overlap with its range. When anchovy numbers are up, Pacific sardine numbers are down and vice versa. 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.