The “Red Book of Freshwater and Diadromous Fishes” (freshwater fish that migrate from freshwater to saltwater and vice versa) studied 43 species of fish, 32 of which are resident and 10 are migratory, also confirming the extinction of a species in Portugal, the sturgeon.

According to the results of the project, which was coordinated by the Faculty of Sciences of the University of Lisbon, there are six species that deserve the greatest concern for being “critically endangered”.

In this group are the lamprey, the lamprey of the sado, and the western ruivaco. The group is joined by three migratory fish, Atlantic salmon, sea trout and river lamprey.

Another 15 fish are endangered, including the shad, the saramugo or the Portuguese bogue, and the project places another five species in the vulnerable category. As a result, 26 of the native species, 60%, are classified in one of the three threat categories of the International Union for Conservation of Nature (IUCN).

Pedro Raposo de Almeida, director of the Center for Marine and Environmental Sciences (MARE), who participated in the current one as well as in the previous one, said today that the book is an instrument to help conserve migratory and freshwater fish, and warned that the next 10 are crucial for us in the management and conservation of nature with regard to the aquatic part because there is a risk of extinction of many species.

Along the same lines, Filomena Magalhães, general coordinator of the project, in the book presentation session highlighted “the strength of numbers”, exemplifying only 19% of the species with a classification that represents little concern.

And she recalled that there are species that it was not possible to assess, which may be threatened and at risk of being lost.

“We lack data on populations, but the perception we have is that the scenario could be even more worrying. The costs of inaction are too great,” she said.

To illustrate the seriousness of the situation, the official recalled the existence of Lusitanian endemisms, which means that they do not exist anywhere else in the world besides rivers in Portugal and that if the species is lost, it is the global loss of the species.

“Nine of the 10 Lusitanian endemisms face an extremely or very high risk of extinction”, say those responsible, according to which seven of the 17 endemisms of the Iberian Peninsula are also threatened.

To reverse the situation, Filomena Magalhães, a professor at the Faculty of Sciences, defended as essential measures such as habitat restoration, improving the conditions of aquatic systems and riparian areas, and trying to counteract interventions such as water collection. And constantly monitor the situation.

Structures such as dams, pollution from domestic and agroforestry sources or climate change are other dangers for fish in Portuguese rivers.

Of all the 43 species analysed, only eight do not need any kind of concern.

The Red Book project on fish began in 2019. Today, the National Freshwater and Migratory Fish Information System, SNIPAD, was also presented, a platform that aims to gather and facilitate access to information on fish in Portuguese rivers and serve to support scientific research and conservation of these species.