Sturgeon, specifically the European white sturgeon complex, faced extinction in Spain during the mid twentieth century due to overfishing and river barriers that blocked essential biology and reproduction. Today, a European initiative aims to reestablish this species in Spanish river systems.
In a restocking effort, 44 juvenile sturgeon from a French research center were released into the Ebro River several weeks ago under the European Commission’s LIFE MigratoEbre project. Sturgeon disappeared from the river for decades and are now present in Europe primarily in France and Germany, with the Ebro project seeking to restore natural populations and ecosystem balance.
The sturgeon arrived in Catalonia about two months ago, traveling from the INRAE Experimental Station in Saint Seurin-sur-l’Isle in the Gironde region of France to the Aquaculture Center in La Ràpita, Tarragona. During the adaptation period at IRTA La Ràpita, ultrasonic telemetry transmitters were deployed, sending data to underwater receivers positioned at various points along the Ebro. This system allows researchers to monitor development and behavior in real time.
Those responsible at IRTA emphasize careful handling of any encounters with sturgeon. Fishermen and the public are urged to report sightings or captures, noting identifying implants and capturing photos with mobile devices when safe. If a specimen is alive, it should be released after recording essential data, and authorities should be notified through appropriate channels. If a specimen dies, it should be stored in a cool place until village representatives can collect it. All observations should include a precise geolocation to aid ongoing research efforts.
The MigratoEbre program aims to recover not only European sturgeon populations in the Ebro but also to support eel, snipe eel, and lamprey species that rely on similar riverine habitats. In addition to the Ebro, river records show sturgeon catches in the Tagus, Guadiana, and Duero, extending to coastal areas near these rivers until the late twentieth century. By the 1980s the Guadalquivir sturgeon population had already declined sharply, according to government ecological sources.
A very threatened group
Sturgeon and paddlefish represent one of the most endangered animal groups on the planet. All 26 known species face significant extinction risk. The International Union for Conservation of Nature has warned about recent losses, including certain species in Europe that have vanished from major rivers. The Danube has seen the disappearance of several sturgeon relatives, and others are now listed as highly threatened within the IUCN Red List framework, reflecting ongoing pressures in Europe.
The WWF highlights a troubling trend: two thirds of sturgeon and paddlefish species are classified as critically endangered, with freshwater biodiversity and river health deteriorating worldwide. The organization points to policies often described as ambitious yet insufficient in reversing declines across the continent.
As of recent assessments, seven of eight European sturgeon species are categorized as critically endangered. The sterlet, the smallest sturgeon, now sits in the endangered category, underscoring the fragility of these ancient fishes. There are also concerns about the Danube and the Black Sea populations where protection statuses under international conventions remain crucial for survival.
Russia has reported the extinction of the sturgeon population in the Danube as a last refuge within EU territory, underscoring the urgency of conservation measures under the EU Habitats Directive and related frameworks.
Half of the caviar sold is illegal or fake
Researchers have uncovered a troubling pattern in the market: a substantial portion of caviar sold is either illegal or not genuine caviar. In a study published in a prominent journal, scientists examined 150 commercial samples of caviar and sturgeon meat across four European nations near remaining wild populations. The findings reveal widespread regulatory violations and mislabeling, highlighting ongoing challenges in enforcement and consumer protection.
DNA and isotopic analyses showed that only a minority of samples originated from wild-caught sturgeon. A significant share violated CITES regulations and trade laws, with mislabeling of species or country of origin. A notable portion of products labeled as wild sturgeon came from aquaculture, reflecting persistent consumer demand that can drive illicit activity. The study also found instances of dishes labeled as sturgeon soup using substitutes such as catfish or sea bass in certain markets.
There are now four sturgeon species known to produce caviar in Europe, all residing in the Danube region and the Black Sea and protected under international trade agreements since the late 1990s. The report calls for stronger enforcement and transparency to combat illegal trade and safeguard remaining wild populations for future generations.
Further information from environmental authorities emphasizes the need for coordinated action to protect habitat, monitor populations, and reduce illegal harvesting. The ongoing work of agencies and NGOs continues to push for sustainable practices and responsible consumer choices to preserve these ancient fish for the long term.