Researchers from Granada clarify the status of Guadalquivir sturgeons

That means that a sturgeon species which was thought up to now to be exclusive of the Adriatic Sea, lived for years in the Andalusian river. But the repercussion of the study goes further away. The importance of this finding is fundamental for sturgeon repopulation in our community and the recovery of which was a fruitful caviar industry decades ago.

An only species

Science has stated for years that there was an only sturgeon species in the waters of the Andalusian river. It was the Acipenser sturio, a type of sturgeon that gave rise to a productive caviar industry in our region between 1932 and 1970. To be precise, there was a factory in Coria del Río (Seville). The hydroelectric dam of Alcalá del Río, impassable for sturgeons, prevented them from the sixties from reaching the appropriate places to spawn. This fact, combined with urban, agricultural and industrial pollution of the final stretch of the river and an average of more than 500 captures a year, led to the extinction of such example in the Guadalquivir.

The novelty of the study presented this morning is as follows: The Acipenser sturio was not alone, but cohabited with other type of sturgeon, the Acipenser naccarii. The scientist from Granada Manuel Ruiz-Rejón said that in 1997, but his theory was questioned. Today he has had the opportunity to argue that eight years ago he was not wrong.

He has worked closely with the laboratory of Legal Medicine of the UGR [http://www.ugr.es]. Professor José Antonio Lorente has explained it: “Our analysis underwrites what Professor Ruiz-Rejón´s group had already determined. In science it is necessary to work in parallel to obtain independent results, and in this case they are also coincident”.

Unarguable result

Professor Lorente´s group has applied in the analysis forensic techniques. This kind of proceeding is used when the material is in a poor condition, a technique similar to that applied in the analysis of Columbus’s remains. There were only three sturgeon examples captured in the Guadalquivir in 1992 and preserved in ethanol since then in the Biologic Research Station of Doñana.

The forensic techniques applied in the study guarantee the results. This is the first time that five specific molecular markers have been studied in such animals, and the conclusion of the study is unequivocal.

There is no doubt, Acipenser sturio has coexisted with Acipenser naccari from the Adriatic Sea to the Iberian Peninsula. In consequence, as it is an indigenous species of western Europe, Acipenser naccari can be used in recovery programs in the Guadalquivir without endangering its habitat. In this point the result of the study connects with the commercial interest: the possibility of recovery with the Acipenser naccari is tangible, as culture techniques are very developed.

Andalusian caviar

The Acipenser naccari has been repopulated in several European rivers, where very developed recovery programs have been implemented. That is not the case of the Acipenser sturio, that was thought to be endemic of the Guadalquivir, and whose controlled reproduction is more difficult.

In fact there is fish farm in Riofrío (Granada) that has been breeding Acipenser naccari for years and obtains top-quality caviar. River Guadalquivir could be in a few years another producer of competitive Andalusian caviar.