In Europe, the Danube is the last river with populations of Beluga or European Sturgeon (Huso huso), Russian Sturgeon (Acipenser gueldenstaedtii), Stellate Sturgeon (Acipenser stellatus), and Sterlet (Acipenser ruthenus). However, the intense exploitation of these populations and the alteration of their habitats have pushed them to the brink of extinction. In fact, as of 2010, the sturgeon genus was identified as the most endangered animal genus on the planet: 63 percent of the 27 sturgeon species on the Red List were classified as critically endangered.
As a result, the capture of sturgeons in the Danube and the Black Sea is no longer permitted. Since 1998, all sturgeon species have been listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and in 2000, a unified labeling system for caviar was implemented to combat illegal trade.
149 Samples Analyzed
However, how confident can buyers be that they are actually receiving genuine and legal products? Poaching and illegal trade are anecdotally known in many states where sturgeons are found, essentially in Serbia, Romania, Bulgaria, and Ukraine. However, there is a lack of extensive research on how well the fishermen adhere to these regulations. A significant WWF project for sturgeon conservation, in which WWF Austria also participated, has shed some light on the issue of sturgeon eggs using the latest analytical methods.
For this investigation, which was outlined in broad terms in 2021 and was published on Monday in the journal Current Biology, experts led by Arne Ludwig (Leibniz Institute for Zoo and Wildlife Research) obtained genetic and isotopic data from a total of 91 sturgeon meat and 58 caviar samples. Genetic profiles were utilized for species and hybrid detection, and isotopic values were employed to distinguish between wild and farmed fish as well as to identify their geographical origin.
Illegal Sturgeon From Wild Catch
The isotope analysis revealed that in all four countries mentioned, by-products from wild-caught sturgeon were being sold. A total of 31 samples (21 percent) originated from wild-caught sturgeons. The DNA analysis indicated the presence of all common sturgeon species in the Danube River samples, in varying proportions. The sterlet was the most prevalent species in the Danube and was also the most frequently encountered in the survey. Only through DNA testing could these inaccurate claims be exposed.
Seventeen of the caviar samples (29 percent) violated environmental protection and EU regulations regarding the trade of wild animals and plants, as well as the corresponding national laws. Four samples were sold without the required labels (two in Romania and two in Bulgaria).
Among the samples sold in Romania, eleven were falsely labeled. Seven of them inaccurately stated the genetic species, three had incorrect codes for the country of origin, and one had a wrong code for both species and country of origin. Cases of consumer deception included 25 samples declared as wild-caught but actually originating from aquaculture, indicating a sustained demand for wild-caught sturgeon.
The WWF recommends local consumers meticulously adhere to legal regulations when purchasing and importing sturgeon caviar. Each caviar tin must mandatorily be labeled with a CITES code providing information about its origin. Up to 125 grams of caviar per person can be imported without authorization for personal use. The tin must be legally acquired and carried in personal luggage. MSC-certified eggs of other fish species, such as salmon or whiting, are viable alternatives to sturgeon caviar.