Sardines (or pilchards) are a small, oily, and very nutritious fish widely consumed by humans and also by larger fish species, seabirds and marine mammals.
Sardines belong to the herring family (Clupeidae) of fish. The names sardine and pilchard cover a variety of species. There are at least six species called ‘pilchard’, over a dozen called ‘sardine’, and many more with both those two basic names with various adjectives. Also, some canned sardines (so-called) include Atlantic herring (Clupea harengus), and sprats (or ‘brisling sardine’, Sprattus sprattus).
The various types of sardines are considered to be sustainable because they are plentiful and are low on the food chain, but the reality is a little more complicated. They are certainly more sustainable than other varieties of fish (see the Best Fish Guide here).
Main uses of sardine
Sardines are a large commercial fishery. They are used for a variety of purposes, including human consumption (fresh, dried, canned, salted, smoked) and also as bait. Sardines are also commonly processed into fish meal for animal consumption or into fish oil which has many uses, including supplements and ointments, but also including the manufacture of paint, varnish, and linoleum.
Most (globally 90%) harvested forage fish (including sardines) are used for bait, pet food or livestock feed. This is not an efficient, sustainable use of sardines. For example, it takes 20 kilograms of forage fish to produce just one kilogram of farmed bluefin tuna.
Sardines are rich in vitamins and minerals. A small serving of sardines once a day can provide up to 13% of the RDA (recommended daily allowance) value of vitamin B2, roughly one-quarter of the RDA of niacin, and about 150% of the RDA of vitamin B12. All B vitamins help to support proper nervous system function and are used for energy metabolism, or converting food into energy. Sardines are a good source of Vitamin D as well. Also, sardines are high in the major minerals such as magnesium, calcium, potassium, and some important trace minerals such as iron and selenium.
Sardines are a very good source of protein. Sardines are also a source of omega-3 fatty acids, which studies show can reduce the occurrence of cardiovascular disease. Recent studies also suggest the regular consumption of omega-3 fatty acids reduces the likelihood of developing Alzheimer’s disease and can even boost brain function. These fatty acids may also help lower blood sugar levels a small amount.
Because they are low in the food chain, sardines are low in contaminants, such as mercury, relative to other fish commonly eaten by humans, and are therefore safer to eat.
Sardines are delicious fresh but they are more often eaten from a can. Sardines are canned in many different ways. At the cannery, the fish are washed, their heads are removed, and then smoked or cooked, either by deep-frying or by steam-cooking, after which they are dried. They are then packed in either olive, sunflower, or soybean oil, water, or in a tomato, chili, or mustard sauce.
Sardines are typically tightly packed in a small can which is scored for easy opening, either with a pull tab like that on a beverage can or with a key attached to the bottom or side of the can. Thus, it has the benefit of being an easily portable, nonperishable, self-contained food.
One issue is that sardines (and other canned fish) are processed in various places around the world and exported to many other far-flung places. For instance common sardine brands in New Zealand come from distant countries such as Norway, Latvia and Canada (Nova Scotia). So that adds to food miles.
Sardine cans, including the lids, are typically made from aluminium and can be recycled.
It would be better to not use sardines as animal feed and instead just eat them ourselves. This would feed more people.
Are sardines sustainable? Yes, they are, but you have to know where to look and which certifying bodies to trust. Do your research and then make your purchases accordingly. When buying sardines, look for brands with the Marine Stewardship Council (MSC) logo.
In summary, we can say the following about the sustainability of sardines:
- they are plentiful and also on a low trophic level and are therefore much more sustainable to eat than big predator fish like sharks, swordfish and tuna
- they are most commonly processed, rather than eaten fresh, and processing, packaging and food miles adds to their carbon footprint
- it is best to choose brands that have been ethically and sustainably sourced