The sardine: benefits for health and the environment of the queen of the night of San Juan

The Galician proverb already says: “For San Xoán, sardiña molla or bread”. On the night of San Juan (June 23) the bonfires to purify and burn the bad, giving way to new desires, usually end with the typical sardines (grilled sardines) in many coastal towns in Galicia and the Bay of Biscay and espetadas (inserted on a stick) on the Malaga coast.

It is no coincidence that we consume sardines on this date. Its fishing season par excellence is from May to October. This fish feeds on plankton, very abundant in this period, so it accumulates a large amount of fat that enhances its flavor.

The sardine is a fish with a long history. It had a fundamental role in the Spanish diet in the 18th century, since after the Treaty of Utrecht (1713-1715) the cod fishing grounds of northern Europe were closed and the sardine became –thanks to salting– the essential element to respond to the strong demand of the market –at that time in Spain there were more 150 days of annual abstinence from meat for religious reasons.







The sardine is a fish with a long tradition in Spain.


Gumersindo Feijoo, Author provided



life-extending fish

From a nutritional point of view, fish is usually classified as white or blue based on its fat content.

Oily fish has a fat-to-muscle ratio of more than 5-6%. Some examples are sardines, mackerel, horse mackerel and tuna. In addition to these lipids, oily fish also contains peptides (molecules formed by the union of several amino acids). The combined action of these bioactive compounds has beneficial properties for health, such as anti-oxidation, anti-infection and anti-hypertension.

These substances can positively affect the immune systemso they prevent and improve many diseases, including metabolic syndrome and its main risk factors such as hypertension, obesity and diabetes.

The presence of fish, white or blue, in Atlantic and Mediterranean diet it is one of its strengths and one of the key factors in life expectancy. In 2019, Spain occupied the sixth position in the world in life expectancy at birth at 83.8 years, a figure that exceeded the EU average by 2.5 years and the world average by almost 10 years.







Life expectancy (at birth) for the period 1960-2019. Spain ranked 6th in the world in 2019.


G. Feijoo / USC / World Bank Data, Author provided



How sardines are caught

The most common art for sardine fishing is the seine. It basically consists of surrounding the schools of fish (or schools) with a large net to end up closing it at the bottom, trapping the entire school.

The boats are dancing over the fishing grounds until the sonar detects the school, at which point a luminous buoy is launched into the sea – the boat that launches it first has the priority option to try to capture it. The ship then proceeds as quickly as possible to draw a fence around the fishing bank before it moves out of position. If the skipper’s expertise succeeds, the cast will be positive and, otherwise, the cast will be blank.

Another of the craft arts is the successwhich obtains a highly appreciated sardine from the Galician estuaries called xouba. It is made up of a series of rectangular nets that are placed in a line up to a maximum length of 1,000 m for each piece, since that is the maximum limit imposed by legislation.

This gear usually works from dusk until the early hours of the morning, when the schools of sardines are most visible. It depends on the criteria of the crew to define at what height of the water column the net should be placed, since the schools of sardines do not circulate at a defined depth.




‘Xeito’. Source: Frinsa La Conservera.

Environmental impact

Both fishing techniques are respectful with the environment and very selective, since they do not generate discards. Although occasionally the bank contains other species of oily fish, such as horse mackerel or mackerel, they are generally of commercial value.

If we consider its carbon footprint, that is, the amount of greenhouse gases emitted in units of CO₂ equivalent from all direct and indirect activities that allow sardines to be brought from the sea to the table, it is one of the food options with lower impact due to protein content provided. The value ranges between 0.5 kg of CO₂/kg of sardine for the purse seine Y 0.7 for the success.







Relationship between carbon footprint and protein content for different food groups. The size of the bubble corresponds to the annual consumption in Galicia.


G. Feijoo/USC, Author provided



An element of the sardines which is an example of circular economy is the tradition of closing the circle by energetically valorizing the pit of the corn cob and the remains of the vineyards, using them as the main materials to obtain natural embers.

In short, the sardine is the queen of blue fish and represents a benefit for the health of people and the planet by helping to combat climate change and achieve food sovereignty.

Gumersindo Feijoo CostaProfessor of Chemical Engineering, University of Santiago de Compostela

This article was originally published on The Conversation. read the original.

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