Yachting Art Magazine

When we think of sturgeons, we think of caviar, the luxurious delicacy made from their eggs. We also think of the impressive size of these freshwater giants, some species of which exceed 7 metres in length. And perhaps more generally, we think of the drastic decline in population that these fish have experienced since the end of the 19th century.

Indeed, sturgeons are now the most endangered group of species on Earth, and this should be a cause for concern.

Sturgeons are best known for the caviar made from their eggs and their highly prized flesh, which has made them a particularly sought-after fish since the Middle Ages and, more recently, since the early 19th century.

Caviar, sometimes known as “black gold”, is thought to have been eaten since ancient times. However, it was in the Middle Ages that the Byzantines imported it into medieval Europe. At that time, it was still far from being considered a delicacy. In 1431, on his return from a trip to Asia Minor, Bertrandon de la Broquière described it as a dish that ‘when there is nothing else to eat, is only worth eating for the Greeks.’

However, in the second half of the 18th century, Russia gave the caviar trade a new lease of life, becoming the main exporter of caviar from the Caspian Sea. It was then imported all over the world, establishing itself as an exceptional delicacy and gaining in popularity throughout the 19th and 20th centuries.

Today, caviar sells for between £1,200 and over £30,000 per kilo for the rarest varieties, such as Iranian white Beluga Almas caviar. This commercial value makes sturgeon particularly vulnerable to overfishing. However, before becoming a luxury gourmet product, sturgeons were first and foremost a large and ancient family of fascinating fish with astonishing characteristics.

Sturgeons are large freshwater fish whose distinctive shape sets them apart from other large fish. Like sharks, they have an elongated snout, but that is perhaps where the similarities end. With a bony skeleton, a body covered with five rows of bony plates and a head encased in a solid dermal bone shield and extended by a rostrum (which explains the elongated snout), one might imagine that the sturgeon is a river fighter.

But no. This natural armour does not make it an aggressive or territorial fish. Most sturgeon species are not even aggressive towards other fish, and none are aggressive towards humans.

Because they feed mainly on molluscs, which they suck up from the riverbed with their toothless, trunk-like mouths, sturgeons are considered gentle giants of the rivers. And giants they are: with sizes generally ranging from 2m to 5 to 7m in length for the largest species, sturgeons are undoubtedly one of the most impressive families of freshwater fish.

There are more than twenty recognised species of sturgeon, including the black sturgeon, the European sturgeon, the beluga, the Sevruga and the Beluga, which is the largest freshwater fish in the world, reaching over 7 metres in length and weighing over a tonne.

Of all these species, only three are not yet endangered: the yellow sturgeon, the white sturgeon and the black sturgeon (which is near threatened). The Yangtze Sturgeon officially became extinct in the wild in 2020, and all other sturgeon species are considered endangered, including thirteen that are critically endangered and therefore at risk of imminent extinction in the wild.

This is tragic for several reasons.

Firstly, it reflects the damage caused by human activity, whether through pollution and the resulting degradation and disruption of their habitat, or overfishing, poaching or the illegal trade in caviar. All these human activities are directly responsible for the drastic decline in sturgeon populations in the wild.

And yet today, trade in sturgeon is restricted under Appendix II of CITES (Convention on International Trade of Endangered Species) and most sturgeon species are protected because they are listed in Appendix III of the Bern Convention.

But when you consider that the European sturgeon, still found in the Garonne, is the most endangered fish in Europe, with only a few hundred adults remaining, it is right to be concerned. Although this species has been the subject of a restoration plan since 2007, the real success of such an operation depends on many factors, none of which are very positive.

The European sturgeon is not only the largest migratory fish in French rivers, it can also live for up to 100 years, reaches sexual maturity very late (between 10 and 13 years) and has a rare reproductive cycle (every 4 to 8 years). even rarer if their environment is disturbed by human activities (pollution, dams, fishing, etc.). Thus, the last natural reproduction of European sturgeons took place in 1994 and none have been recorded since.

This is a problem that affects many other sturgeon species, such as the Chinese sturgeon, for example. Disturbance of their environment prevents them from reproducing and because they continue to be fished despite this, their numbers are steadily declining. This is what caused the extinction of the Yangtze sturgeon and is likely to cause the extinction of many other species.

However, before falling victim to human activity, sturgeons were already remarkable for their resilience.

One of the oldest vertebrates on our planet, they belong to one of the oldest families of bony fish still swimming in the seas and oceans: the Chondrostei, which reached incredible diversity during the Mesozoic era (Triassic period, 245 to 208 million years ago) and of which only a few relic species remain today.

Once described as “living fossils” because of their resemblance to extinct species, sturgeons are nevertheless a highly evolved family of fish, despite their slow growth and rare reproduction.

They are not just pretty fish with highly prized eggs, they are a real window into our planet's past. Their physical characteristics, which are similar to those of their ancestors, offer us a glimpse of an era that we will never see except through them.

The water that dinosaurs drank was already populated by sturgeons. During the Triassic-Jurassic extinction that occurred at the end of the Triassic (around 200 million years ago), sturgeons survived while 20% of marine species disappeared. And when the dinosaurs were brutally wiped out by the Cretaceous–Paleogene extinction event, which also saw the disappearance of 75% of marine species, sturgeons survived.

Today, it is not an asteroid or a volcanic crisis that is causing the sixth mass extinction on our planet; it is us. It is humanity as a whole, which has been destroying its environment for thousands of years. We are responsible for the Holocene extinction, undoubtedly since the beginning, and particularly at this moment in time.

Although human activity has been implicated in the disappearance of terrestrial species since prehistoric times (as it always coincides strangely with the arrival of humans in the regions concerned), these early extinctions were sporadic compared to what has been happening over the last few hundred years and especially today.

Sturgeons are one of many species threatened with complete extinction because of humans. Among the most unfortunate marine species is the Steller's sea cow (or sea cow), which was discovered in 1768 and immediately subjected to intensive fishing. The species became completely extinct in just 27 years; today, it is nothing more than a skeleton among many others.

And if the majority of sturgeon species are on the brink of extinction, it is for the same reason. Intensive fishing aimed at harvesting resources that are not essential to humanity (especially not in large quantities). So yes, today, sturgeon fishing is regulated, sometimes even banned.

But it may already be too late.

That's the real tragedy: by the time we realised we were destroying sturgeons, we may have already condemned them to irreversible extinction. We have never been less certain that there will still be sturgeons in 100 years' time, and when we consider that we have wiped out more than 80% of their global population over the last 100 years, there is real cause for concern.

But then, what should we do?

Well, we must hope that the measures in place will be sufficient, we must continue to protect sturgeons, we must support the funding of species restoration programmes, we must ensure that their habitat is no longer degraded and restore it as much as possible. And we must encourage even stricter regulations for their preservation.

Because if we say today that caviar is more important than sturgeons, tomorrow we will regret not having acted sooner and we will have no caviar left at all.