Sturgeons return to the southern area of the Po Delta
On 3 October 2017, the Cesenatico Research Centre (Degree Course in Aquaculture and Fish Production Hygiene) of the University of Bologna, in collaboration with the Aquarium of Cattolica, the Oltremare Theme Park of Riccione, and the municipal and provincial administrations of Ravenna, released 200 subadult Adriatic sturgeons into the southern area of the Po Delta and transferred another 1000 young specimens to the facilities of the Parco Lombardo del Ticino natural park.
This was made possible by means of an agreement with the Parco Ticino Lombardo natural park, and by the cooperation between the University of Bologna, the Aquarium of Cattolica and the Oltremare Theme Park of Riccione on the Con.flu.po Life Nature Project (www.life-conflupo.eu).
The work team at the Oltremare Theme Park of Riccione
The project, co-financed by the European Union through the LIFE instrument, has enabled the reopening of an ecological passageway for fish in the Po River, interrupted in the early 1960s by a damn serving the Isola Serafini hydroelectric power plant. Moreover, the project also envisages targeted actions aimed at supporting endangered fish species, including the Adriatic sturgeon (Acipenser naccarii).
The 200 specimens released in the southern area of the Po Delta, in the province of Ravenna, were spawned artificially in the Ticino Park, in collaboration with the Department of Veterinary Sciences of the University of Bologna, and bred by the University in collaboration with the Aquarium of Cattolica and the Oltremare Theme Park of Riccione. These fish join the 6,000 microchipped young sturgeons and the 100 adult sturgeons fitted with a sonar emitter already released in the Po as a result of the Con.flu.po project, thereby increasing the chance of recovery for a species that remains at risk of extinction.
This operation forms part of the measures carried out for the conservation of the Adriatic sturgeon in the Reno River, south of the Po Delta, where the species has been extinct for over 50 years.
Una fase del rilascio
The fish, taken from the tanks of the Aquarium of Cattolica and of the Oltremare Theme Park of Riccione, were released in collaboration with the volunteers of FIPSAS (Italian Federation of Sport Fishing and Underwater Activities of Ravenna) and with the Associazione dei Capannisti, sports fishermen who occupy the traditional huts (or Capanni) on the Po Delta and who for months have been serving as “guardians" of the area.
Another 1000 specimens, just a few months old, were instead transferred to the Parco Lombardo del Ticino natural park, where they will be reared on a natural diet before being transferred into large, semi-natural habitats to ensure the greatest possible chance of survival once released into nature.
The collaboration on the Con.flu.po Life project, which encompasses this operation, falls within the scope of the broader “Salva una specie in pericolo” project (established in 2010) for the protection of endangered species, organised by the Costa Edutainment parks with a view to raising awareness and educating the public on conservation and responsible management of the environment, and to broadening general knowledge on animals. The educational and awareness-raising activities developed by the EC parks and centring on the sturgeon are designed to support similar initiatives devoted to the widespread dissemination of issues concerning the Po River and its flagship species, the Adriatic sturgeon.
“This collaboration and the release of new specimens constitute another important step of the ‘Salva una Specie’ project, which sets out to enhance and promote those entities that actively work towards the protection and conservation of endangered species such as the sturgeon, penguins, bees, sharks, sea turtles, dolphins, flamingos, and even corals (www.salvaunaspecie.it),” declared Dr. Christian Da Rugna, zoological manager, and Stefano Gridelli, Aquarium manager of Costa Edutainment (Adriatic).
Once upon a time, many rivers were rich in sturgeons that would swim upstream from the sea to spawn. Unfortunately, over the last 50 years, pollution, indiscriminate fishing, dams and river flow changes have prevented the reproductive migration of the sturgeon, leading to the inexorable decline of its species.
The Adriatic sturgeon has a mainly cartilaginous skeleton, bony plates that replace the traditional scales along the body, a heterocercal caudal fin similar to that of sharks, and four barbels around the inferior mouth. It is an “anadromous” species that lives in the vicinity of the estuaries and then returns to fresh water to spawn. Adult sturgeons can reach a length of 2 meters and a weight of 80 kg. They reach sexual maturity between the ages of 5 and 16 years (20 and 30 kg in weight). Males can reproduce every year, while females reproduce every 2 or 3 years, and can spawn more than one million eggs. The sturgeon is a docile fish that feeds on crustaceans and insects and, as adults, also on small fish, which it is able to seek out in turbid river waters.
All texts and images may be used, citing the source, the author, the Life Project naturaLife11NAT/IT/188 “Restoring connectivity in the Po River basin, opening a migratory route for Acipenser naccarii* and 10 fish species in Annex II”, and the support of the European Union.