EMBARGOED UNTIL 1200 CEST (1100 BST), Tuesday June 18, 2024
The Atlantic sturgeon, a keystone species, was driven to functional extinction in Europe in the middle of the twentieth century. However, a pioneering initiative supported by a grant from Rewilding Europe’s European Wildlife Comeback Fund has seen this iconic fish reintroduced in a Swedish river for the first time ever.
Today, Tuesday June 18, 2024, marks a historic day as six juvenile Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) were released into the Göta River – the largest river in Sweden. This marks the first time ever that Atlantic sturgeon have been released in the country, thanks to the “Return of the Sturgeon” initiative managed by the Swedish Anglers Association. The release was made possible by a 42,000-euro grant from Rewilding Europe’s European Wildlife Comeback Fund, with a number of prominent guests attending the event.
According to project leader Linnéa Jägrud, a limnologist working for the Swedish Anglers Association, “This is a unique and incredibly exciting event. The reintroduction of a regionally extinct species is very uncommon in Sweden. I’m looking forward to the day when we can look at the river and say ‘there are Atlantic sturgeon spawning below the surface here’.”
The Return of the Sturgeon initiative aims to re-establish the species in the Göta River, with a total of 100 juvenile sturgeon being translocated from a breeding facility in the village of Born auf dem Darß, on Germany’s Baltic sea coast. These fish will be released in the river over the next two weeks, with each fish being 60 cm in length and weighing around 1kg.
The Göta River was once home to spawning populations of Atlantic sturgeon, but the species became locally extinct in the early twentieth century due to overfishing and deteriorating water quality. However, historic specimens of Atlantic sturgeon at the Gothenburg Museum of Natural History, taken from the Göta, provide evidence that the species once existed and spawned in the river. With three of these specimens being juveniles, it is clear that the fish once hatched in the river.
Today, the water quality in the Göta has improved and the river system is relatively biodiverse, making it a suitable habitat for the reintroduced sturgeon. Prior to reintroduction, suitable spawning habitats and food sources were identified over a large area. While the sturgeon are not expected to stay in the river their entire lives, they will migrate to the estuary and ultimately the sea as they develop a higher salinity tolerance with age and size. The juvenile sturgeon were initially kept in riverside pools to allow them to acclimatise to their new aquatic environment.
The Atlantic sturgeon, also known as the Baltic sturgeon, is a species of sturgeon native to Europe and North America. This impressive fish can live for 90 years or more, with some specimens reaching lengths of over 4 meters and weights over 350 kg. They are both keystone and indicator species, playing a crucial role in maintaining the health and balance of aquatic ecosystems. They disturb riverbeds as they feed, enhancing oxygenation, moving organic matter along waterways, and creating spawning grounds for smaller fish. They also act as hosts for species such as lampreys and freshwater pearl mussels, and eat invasive species that would otherwise disrupt natural food webs. Their presence is dependent on a network of suitable habitats providing them with the necessary conditions for feeding, migrating, and spawning.
“The sturgeon can become a symbol for the overall health of the Göta River,” says Linnéa Jägrud. “It will be an ecological ambassador for the river.”
The sturgeon reintroduction is a collaborative effort between the Swedish Anglers Association, the University of Gothenburg, the Swedish University of Agricultural Sciences, and the Gothenburg Museum of Natural History, as well as sturgeon experts from the German Leibniz-Institute for Freshwater Ecology and Inland Fisheries in Berlin. The institute, considered the leading European authority on the ecology of the Atlantic sturgeon, has been working on reintroduction efforts for many years.
The grant from the European Wildlife Comeback Fund was used to cover various costs, such as the translocation of the sturgeon from Germany and accommodation for researchers and volunteers involved in tagging the fish prior to their release.
According to Rewilding Europe’s rewilding manager Sophie Monsarrat, “Reintroducing Atlantic sturgeon in Sweden after an absence of more than a century is a huge milestone. I’m so pleased the fund was able to support this release. There is an urgent need to restore the functionality of terrestrial, freshwater, and marine ecosystems across Europe by bringing back keystone species.”
The Atlantic sturgeon can tolerate
Derick is an experienced reporter having held multiple senior roles for large publishers across Europe. Specialist subjects include small business and financial emerging markets.