Since the mid-2010s, fishermen and researchers have noted a decline in the size of small pelagic fish, a group that includes fish living in the water column such as sardines and anchovies, to name but the most emblematic. By conducting four major research programmes, three of which focus specifically on this group of fish, Ifremer is seeking to anticipate the problems that this reduction in size could pose for ecosystems, industries and the consumption of these small pelagics. To this end, the institute has led the DEFIPEL programme , which looks at integrated fisheries management, the OMEGA programme, which looks at the omega-3s present in these fish, the DELMOGES programme, which looks at incidental catches of dolphins, and the FORESEA programme, which looks at the availability of seafood in general by 2050. Ahead of the TRANSPEL conference , which will report on this research in April 2025, we took stock of these fish populations and the fishing industry, as well as the associated socio-ecosystemic issues.
by Maud Lénée-Corrèze
Cover photo : Bank of sardines © T. Pentagana – pexels
Eaten fresh or processed using a variety of preservation processes, sardines have been a key component of the human diet and economy since at least ancient times. This is illustrated by the famous garum, a condiment made from salted and fermented fish – particularly sardines – which was highly prized by the Etruscans right through to ancient Rome. Some French towns on the Atlantic seaboard are deeply marked by this sardine culture. Douarnenez, for example, with its remnants of garum vats dating back to Roman times, its canning factories that are still major sources of employment, and of course its bolincheurs that head out into the bay every night to catch the blue fish. But the industry could be shaken by the reduction in the size of these fish, a key factor in the canning process. With this in mind, Ifremer has launched a number of research programmes, which have just been completed, on small pelagics, a group that includes the sardine, anchovy, various species of horse mackerel, shad and mackerel, sprat, sardinella and bogue.
Sardine boats in the port of Rosmeur in Douarnenez, at the end of the 19th century. Sardines were an important driving force for ports like this one, and still are to a lesser extent. Credit: Office scientifique et technique des pêches maritimes
What do they have in common? Biologically, they share the same prey, zooplankton and phytoplankton, and the fact that they spend most of their adult phase in the water column, from the surface to a depth of around 200 metres. From an economic point of view, small pelagics account for around 30% of world catches (2022, FAO), and 48% of catches in France (FranceAgriMer, 2022). It is therefore a crucial resource, especially as these fish are rich in omega-3s, fatty acids produced exclusively by phytoplankton that small pelagic fish ‘ then accumulate in their bodies’, explains Mathieu Doray, a researcher at Ifremer who took part in the small pelagic programmes for the ecology section. The omega-3s are then passed on to the many predators of small fish, including dolphins, birds and humans. They are also known as ‘forage’ species, because they transmit energy and organic matter up the trophic chain’.
But these are fragile, short-lived species that reproduce by dispersing large numbers of eggs – only a small percentage of which reach adulthood – and are highly dependent on environmental parameters such as water temperature and plankton composition, which in turn is highly dependent on nutrient inputs and water quality. A reduction in the size of sardines and anchovies has been observed over the last ten years or so,’ adds Mathieu Doray. This is undoubtedly due to changes in zooplankton, in particular the gradual disappearance of the largest zooplankton organisms as a result of climate change ‘.
The MONALISA project (2016-2019) explored this issue further for sardines in the Gulf of Lion, carrying out numerous experiments to study how sardines and anchovies reacted to particles of various sizes. The result: the consumption of smaller particles by sardines and anchovies would require more energy from the fish, limiting their growth. This reduction in size, combined with the disappearance of the largest individuals, indicates that French sardine populations are in ecological imbalance. This is compounded by exploitation by fishing, which this year led to the Bay of Biscay sardine being classified as an overfished population in Ifremer’s annual assessment (24,000 tonnes landed each year).
In the 2023 assessment, the sardine population was categorised as overfished and degraded, and quotas were therefore revised downwards. Credit: Ifremer 2024/J. BarraultThere is now a real fear of more drastic management measures, as happened with anchovy around ten years ago. Following the collapse of the population in the 2000s, anchovy fishing was banned in the Bay of Biscay until 2010. But when the activity was re-authorised, the French Atlantic anchovy fleet had dwindled and buyers, mostly Spanish, had turned to Moroccan and Portuguese fishermen.
We currently have around eighty boats fishing for sardines,’ explains Sigrid Lehuta, a fisheries expert who has also worked on a number of Ifremer programmes. Among them, twenty-five bolincheurs in Brittany, less than 18 metres long (fishing in the Bay of Douarnenez and Audierne), land around 80% of French sardines. They also fish for anchovy, sea bream, sea bass, horse mackerel and mackerel, but 90% of their income comes from sardines. They sell almost exclusively to canneries, as fresh fish is rarely consumed. In addition to the bolincheurs, there are also trawlers in Brittany, Pays de la Loire and Vendée, landing between five and seven thousand tonnes. These boats are more versatile, fishing for hake, mackerel and sea bass in winter and anchovy and sardines in summer. The largest (16 to 24 metres) target tuna offshore in summer. Lastly, in the Basque Country, there are five bolinch boats and a few trawlers that fish for sardines, although their priority in the summer is sea bream and bluefin tuna. Historically, this fleet has shown itself to be adaptable: in the event of a bad year for sardines, they have been able to compensate with other species (sea bass, hake, tuna). But falling quotas for other target species are threatening this flexibility and forcing them to specialise in unregulated sardines, increasing the pressure and dependence on this species, as was the case for mackerel and is still the case for bluefin tuna’. The horse mackerel fishery is completely closed this year.
The sardine has also lost its MSC Sustainable Fishing label, which ‘may undoubtedly affect the image of the fishery’, says Sigrid Lehuta. Credit: WWF
In addition to these ecological difficulties, fishermen, particularly those from Brittany, are also under pressure from downstream in the industry. They are very dependent on canners’, explains Sigrid Lehuta. And therefore on their requirements ‘. Among these, the format of the cans determines the size of the sardines purchased by the canners. And if the sardines shrink… Does this already have a major impact on fishermen?’ asked Fabienne Daurès, an economist who studied the entire industry, right through to consumers. This is a complex economic sector, which has seen a sharp rise in demand for canned sardines and a fall in demand for fresh sardines. To meet this demand, canners seem to be turning to imports. Indeed, even though the majority of canned sardine brands on supermarket shelves are French, many of the sardines in the tins are in fact imported, often from Morocco. Sardines are plentiful there, but if fishing pressure is not properly managed, this could pose a supply problem in the future’, adds the economist. Not to mention the harmful impact of too much pressure on the ecosystem of these regions ‘. And the potential price competition with African countries, which are major consumers of canned sardines.
The economist also looked at the consumption of sardines in French households. While price is still a buying argument, it’s not the only one, ‘ since canned sardines are very popular, even though they cost more (11 euros per kilo) than fresh sardines (6 euros per kilo) ’. Other reasons identified were the omega-3 content, the sustainable aspect and the local origin of the product. We can therefore wonder about the consequences for consumer choices of a reduction in the supply of French sardines in tins sold in France’, continues Fabienne Daurès. As for the omega-3 content, it could fall as a result of the reduction in the size of the sardines and changes in the composition of the plankton, which could also have an impact on purchases.
What has emerged from these various studies is the interdependence between economic and ecosystem dynamics. In France, climate change is said to have an impact on sardines in the Bay of Biscay and on the behaviour of dolphins, which are moving closer to the coast and therefore closer to fishing grounds. These changes would therefore have consequences for fishermen, who would have no other fishing opportunities. Canners, for their part, can mitigate these resource shocks, at least in the short term, by turning to international markets. But this increased demand will undoubtedly have an impact in these countries, both economically and in terms of the environment and fish biomass. If, in return, consumers are less interested in cans of imported sardines, canners could also lose out in the long term.
Scientists therefore need to anticipate. And that was the aim of these research programmes, which have led to the creation of future narratives and management tools incorporating both ecological and socio-economic parameters. They should make it easier to envisage the future of the industry. It would seem that the response must come from all levels of the industry, from fishermen, who may need to be even more versatile, to canners and consumers.
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