Effective reassessments of freshwater fish species: a case study in a Mediterranean peninsula

IUCN Red List assessments for fish species can quickly become out of date. In recent years molecular techniques have added new ways of obtaining information about species distribution or populations. In this work, we propose the Iberian Peninsula as an example of reassessment needs in its endangered freshwater fish fauna. We compiled the list of freshwater fish species occurring in continental Spain and Portugal and examined their conservation status in global and national Red Lists. We retrieved records for these species in the Iberian Peninsula and calculated several biological indexes (richness and vulnerability indexes). Our results showed a patchy data coverage of fish records in the Iberian Peninsula. Threat levels reported within national Red Lists are higher than their global counterparts, reinforcing the necessity of improving and maintaining up to date national Red Lists. Iberian watersheds have moderate levels of threat and high levels of out of date assessments. The nearly fully completed genetic databases for Iberian fish species, along with the limited distribution of many endangered species and the necessity of update their assessments constitute an excellent opportunity to use data obtained from eDNA to improve species monitoring practices and their conservation status.