Efforts are being made in the Netherlands to reintroduce the critically endangered European sea sturgeon into Dutch rivers, 71 years after the fish was last seen. 

On Friday, some 29 young sturgeon will be released into the Biesbosch nature reserve south east of Dordrecht, all of which have been fitted with trackers so their progress can be followed. 

The fish were bred in Bordeaux and are currently being held in tanks immersed in the waters of the Biesbosch so they can acclimatise to the different conditions. A further 46 will be released at a later date.

This initial research is to establish if Dutch waterways are clean enough to support the fish and if they can find their way to the sea. The project has been set up by Ark Natuurontwikkeling with finance from the Worldwide Fund for Nature.

The last known European sturgeon in Dutch waters was caught near Dordrecht in 1952. “It would be fantastic if we managed to expand the number of different animals in the Netherlands with a fish that belongs here,’ ARK spokesman Bram Houben told local broadcaster Omroep Brabant.

The fish can grow to over three metres in length and weigh 300 kilos. The oldest fossil of a sturgeon ever found dates back to 220 million years ago. 

A final decision on bringing back the sturgeon will be taken in in 2030, and will also involve other countries where the giant fish was once found. The Biesbosch nature reserve was also the starting point for rewilding projects involving beavers and otters.