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The return of the Atlantic sturgeon in the Rhine system

July 31, 2012

For many years, people in the Netherlands and surrounding countries were talking about it. Last spring, it finally happened. The Atlantic sturgeon (Acipenser sturio) was reintroduced to his former homeland, the Rhine system! Only a few people know that this prehistoric fish, reaching sizes of even 3,5 meters, once flourished there. Nowadays the sturgeon is just as endangered as the black rhino.

The sturgeon is known for its caviar or “black gold”: the unfertilized eggs are a delicacy to people when eaten raw and a little bit salted. Unfortunately, this is also one of the main reasons why almost all sturgeon species worldwide are threatened by extinction. On top of this, overfishing, damming of rivers, degradation of habitats and pollution of rivers take their toll. These are main reasons why sturgeon populations have decreased worldwide and are still decreasing dramatically.

A century ago, the Atlantic sturgeon inhabited almost all main rivers in Western Europe. Nowadays, only one population remains: in the Gironde Estuary and the Garonne and Dordogne rivers in France. Indications that another population exists in the Rioni River, Georgia, cannot be reliably confirmed.  The survival of this last French population is the result of efforts by French biologists, nature organizations (Irstea) and policy makers. Atlantic sturgeon is protected by different legislation (EU Habitat Directive, CITES, Bern Convention and others). After 13 years of putting a lot of effort in research, conservation and communication by the French, a major breakthrough in sturgeon conservation was been reached: the French hatchery now breeds successfully. Young sturgeons were released in the wild in huge numbers in France during the last years, providing hope for the future!

Living rivers

Different French and German conservation organizations developed “the European action plan for the conservation and restoration of the European sturgeon”.  The main goal of this action plan is to restore the historical distribution of sturgeon throughout Europe. The Rhine used to be a very important river for the sturgeon. In 2010 WWF-Netherlands, the Dutch Sport Fishing Association and ARK Nature, supported by our French colleagues of Irstea, set up a Dutch sturgeon project. For decades, WWF-Netherlands, together with many partners from public and private sectors, have been working on the restoration of the Dutch Rhine, Scheldt and Meuse as “natural, living rivers”. This has been a great success, biodiversity increased with almost 80% due to the “rewilding” of the river systems. In addition, governments took many other measures, such as improving water quality, restrict commercial fishing, building fish ladders so that migrating fish is able to pass dams to reach spawning areas and so on.  As a crown on the work, the time had come for the reintroduction of the Atlantic sturgeon as a symbol of a successful Living Rivers programme!

After a long time of preparation, the first 50 sturgeons from the French breeding program came over to the Netherlands in spring 2012. The project started with a research experiment, as a first step in a larger reintroduction program in the Rhine system. All 50 sturgeons were provided with a transponder and a tag to enable to study the migration of each individual. They can be followed by the magnificent Nedap research system in the Rhine, developed to study fish migration.

The first sturgeons

In the beginning of May, the first fish arrived and were released by Princess Laurentien van Oranje during the WWF Annual Conference in Rotterdam, marking the 50th Anniversary of WWF. A big event, and a very exciting moment for the project. It took a lot of “sweat and blood”, but seeing the first sturgeon being released and swimming in the Rhine, was extremely rewarding and an unforgettable moment. It gave an unbelievable feeling to see this magnificent fish returning into his former spawning grounds!

The second release of Atlantic sturgeon took place mid June. This time, it was more relaxed because of less publicity, enabling us to enjoy the moment even more and to take good care of the fish. We released 30 beautiful, strong and vital sturgeons of 1.5 to 2.2 kg, 60-80 cm long. After being in quarantine for three days, we released the sturgeons at a quiet spot along the main river and witnessed them swimming away quietly with strong strokes.

The first release of Atlantic sturgeon in the Rhine system marks a successful rewilding programme that was run for more than 20 years, with a lot of positive impact, both from a conservation and socio-economic point of view, and done by some of the key partners in Rewilding Europe. It’s a remarkable, historic and inspiring experience for other rewilding initiatives in Europe.

For more information, have a look at www.steureninnederland.nl

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