Amphibians' health

Amphibians are the most threatened vertebrates on Earth, with over 40% of species at risk of extinction according to the International Union for Conservation of Nature (IUCN) Red List of Species. The primary cause of this amphibian crisis is the emergence of infectious diseases, particularly the global emergence of chytridiomycosis. The demise of amphibians probably started in the 1970s and, since them, chytridiomycosis alone has been responsible of the decline of 501 species and the extinction of at least 90 species worldwide. Indeed, the chytridiomycosis panzootic represents the greatest loss of biodiversity attributable to disease ever reported.

Anthropogenic movements and animal trade have broken down dispersal barriers, facilitating the spread of pathogens that threaten the planet’s biodiversity. These human activities have certainly caused the spread of amphibian pathogens across large scales, including the fungal agent causative of chytridiomycosis. In 2008, amphibian chytridiomycosis and ranaviral disease were the first wildlife diseases to be included in the OIE list of notifiable diseases, reflecting the importance of the international trade on its spread. Systematic surveillance is, therefore, essential to assess the health status of amphibian populations and to diminish the risk of unnoticed introduction of pathogens into new areas.

Aiming to contribute to amphibian conservation, our group has developed the Amphibian Surveillance Program of Catalonia (ASPrCAT). We work closely with local agencies and groups in order to sample a wide range of species and habitats, which act as proxies for the amphibian populations in our region.

We also study the population dynamics and infection dynamics of chytridiomycosis in amphibian communities from alpine ecosystems. The aim of our research is to investigate the contribution of different host species to pathogen dynamics as well as to assess the impacts of the disease in these fragile communities. To achieve this, we perform capture-mark-recapture surveys in multiple species at several study sites in the Pyrenees.

Insights from our study system will likely have broader national and international implications as they will guide future research and management strategies for the conservation of threatened amphibian species worldwide.