Taxonomy
- The name "sardine" applies to many small oily pelagic fishes of the herring family (Clupeidae). These include the “true sardines” (genus Sardinops) as well as related fishes of the genera Harengula, Sardina, Sardinella and Sprattus [FishBase 2002; USFDA 2002]. Variously known as sardines, sprats, brisling, herring, and pilchard, a concrete definition is hard to come by.
- What is meant can depend on region. The United Kingdom's Sea Fish Industry Authority, for example, classifies sardines as young pilchards. One criterion suggests fish shorter in length than 6 inches (15 cm) are sardines, and larger ones pilchards. The FAO/WHO Codex standard for canned sardines cites 21 species that may be classed as sardines; FishBase, a comprehensive database of information about fish, calls at least six species "pilchard," over a dozen just "sardine," and many more with the two basic names qualified by various adjectives.
Species of Commercial Interest
- Most species of commercial interest fall under three geni: Sardina, Sardinops, and Sardinella. Because sardines (as a group) are fairly global in distribution, the specific species of interest for a particular fishery depends largely on the region.
Distribution
- Pacific Sardines: Recent studies suggest three stocks of Pacific sardines along the North American west coast: a Gulf of California stock, a stock off the Pacific side of Baja California, and the main northern stock which historically ranged up the coast from Baja California to Alaska and was known to migrate as far north as British Columbia. The northern stock, which was subject to intense fishing pressure, has recovered from a dramatic decline and is currently found mostly off Central and Southern California [Hill et al., 2000]. In addition, there is now evidence for a significant summer presence of sardines off Oregon and Washington, near the outflow plume of the Columbia River.
- Atlantic Sardines: Atlantic species (most notably Sardina pilchardus) occur off the coast of the eastern North Atlantic, from Iceland and the North Sea, southward to Bay de Gorée, Senegal, as well as in the Mediterranean, Sea of Marmara, and Black Sea. The Mediterranean sardine fishery is considered the world's largest, with Morocco, Italy, Montenegro, Albania, Greece, and Turkey exhibiting the highest pressures on Sardine stocks.
Biology
- Sardines as a group are characterized as small (less than 16 inches) coastal pelagic fish, usually residing at 25 to 55 or even 100 m by day, rising to 10 to 35 m at night. Daily vertical migration aside, sardines also exhibit large-scale geographical migrations in large schools (up to 10 million individuals) in conjunction with yearly food abundance. Sardines feed mainly on planktonic crustaceans, closely linking them with krill populations. This schooling behavior makes them especially important prey for many other species, including tunas, bonito, yellowtail, barracuda, marlin, mackerel, salmon, hake, sharks, pelicans, gulls, cormorants, seals, sea lions, dolphins, porpoises and whales.
- Sardines reproduce rapidly, but their populations depend on favorable marine conditions which foster high recruitment levels. Spawning occurs within the school, with males and females broadcasting gametes into the water column. Spawning takes place in the upper 165 feet (50.3 m) of the water column [Wolf et al., 2001], in the open sea or near to the coast, and occurs wherever waters are between 55° and 63° F (13°and 17°C) [Wolf et al., 2001]. As such, spawning occurs at different times in different parts of the sardine’s range. A single female can release 50,000- 60,000 eggs per bout, equating up to 200,000 eggs in a season.
Sustainability
- IUCN Red List Status: Least Concern (LC) or Not Evaluated (NE) depending on species)
- MBA Seafood Watch:
- Pacific sardines stocks off the coast of North America are thought to be in good standing, making them a highly sustainable choice. However, it is worth noting that a natural, periodic "boom and bust" cycle, which occurs in Pacific sardine populations every 30-40 years, could cause this rating to change.
- Atlantic stocks, especially those in the Mediterranean, have been harvested extensively and for many of these fisheries, population size is unknown. The populations that are being monitored show that many are declining or depleted. Management of sardine fisheries in places such as Morocco, Italy, Montenegro, Albania, Greece, and Turkey is critically ineffective. These nations frequently ignore scientific advice when setting regulations and existing regulations are poorly enforced. As such, Sardines caught in these regions are best avoided.
Potential Health Concerns
- Because they are low on the food chain, sardines are very low in contaminants relative to other fish commonly eaten by humans.
