The sturgeon is an ancient fish. Like the crocodile, it is a living fossil that has never changed since prehistoric times. In 1952 the last specimen was fished up in the Merwede near Dordrecht. On June 2, the fish will get a new chance and dozens will be released in the Biesbosch. “This beautiful fish simply belongs in the Netherlands,” says naturalist Bram Houben of the ARK Foundation, who will release the sturgeon together with the World Wildlife Fund.
There are sturgeon fossils from 220 million years ago. With this you can rightly say that the sturgeon is an ancient fish. Overfishing, pollution and the construction of weirs and locks drove the sturgeon out of Dutch waters. But the fish returns again, hoping that it will stay here.
“It would be great if we could expand the number of animal species with a fish that simply belongs to the Netherlands,” says Houben enthusiastically. There is even a chance that Dutch caviar will be available again one day. “If we succeed, that means we have done a great job. But first let’s make sure that the sturgeon really stays here.”
“Like the rhinoceros, the sturgeon has bony plates.”
300 kilos clean on the hook and at least 3 meters long: the European sturgeon definitely not a small fish. They can live 50 to even 100 years. And they also have something in common with the rhinoceros. “They don’t have scales, but a kind of armor skin made of bony plates. It’s a bony plate fish.”
The fish that are released in June are still swimming in a special breeding center near Bordeaux, along the river Gironde. This is the only place in Europe where the sturgeon still occurs in the wild.
In 2012 and 2015, sturgeon was also released in the Rhine, some of which with transmitters. It is known that they swam back to the North Sea. But the fish spawn in the Rhine, across the German border.
“A sturgeon of five meters long, weighing 400 kilos, was once landed in Antwerp.”
Now it remains to be seen whether the Biesbosch will catch on as a ‘growing area’ between the sea and the German Rhine. Because the Haringvliet sluices are slightly open, some salt water also enters the Biesbosch via ebb and flow. This makes the area even more attractive for sturgeons.
The sturgeons also receive transmitters in the Biesbosch. They are followed by 80 receivers on Rijkswaterstaat buoys. Niels Brevé is a researcher at Wageningen University and will be mapping the movements of the primeval fish for four months. “Among other things, I want to know where they find their food and what their routes are to the sea.”
“If we get that fish back here, that’s great!”
In the 1980s, the beaver was reintroduced in the Biesbosch. The rodent is now causing a nuisance. But Brevé sees it differently: “If a stork, a beaver or an otter comes back, I don’t call it a plague but a gift. An enrichment for recreation, for people and for the experience of nature.”
And Brevé is already looking forward to adult sturgeons, which can become really ‘huge’: “A sturgeon of five meters and 400 kilos was once brought into the port of Antwerp. And in Rees in Germany one of 4 meters and 375 kilos. If we to have those fish back here, that’s great!”
