Chytridiomycosis in amphibian populations – risk evaluation, threats and conservation implications in Schleswig-Holstein

Project description

The two invasive fungi Batrachochytrium dendrobatidis (hereafter referred to as Bd) and B. salamandrivorans (hereafter referred to as Bsal) originate from Asia. Bd is known to infect more than 700 species of amphibians of all three clades (caecilians, salamanders, frogs). A Bd infection can lead to clinical disease and ultimate death of affected animals. Clinical disease though, like the characteristic skin lesions, are not present in all cases. The so-called  chytridiomycosis is therefore versatile and difficult to predict. Bsal was first discovered in Europe in the Netherlands in 2013, where the pathogen has been associated with a decline of more than 95% of the fire salamander (Salamandra salamandra) population since 2010. Since then, outside of Asia, it was found in several European countries, including Germany. The overall aim of the project is to provide better knowledge of the actual distribution of both invasive fungi Bd and Bsal in Schleswig-Holstein over a period of two years. Therefore, different amphibian species sharing the same habitats in Schleswig-Holstein are targeted. Sampling uses sterile skin swabs, which represents an amphibian friendly method. Right after sampling, animals are released. Ideally, the outcome of this pilote study will give first ideas of regional, seasonal and species specific characteristics of the pathogens and will thus shape future research in this field.

The following questions will be addressed:

• Is there a direct link between the detection of Bd and Bsal and clinical symptoms or even an increased mortality?
• Which species typically show symptoms of clinical disease? Which species are infected without symptoms (subclinically), function as asymptomatic carriers or as a reservoir?
• Are there regional differences in the prevalence of the pathogens?

Due to the critical situation of Schleswig-Holsteins amphibians, it is of utmost concern to apply management measures to protect amphibian populations of additional threats like infectious diseases. Additionally, the outcome of the project will therefore directly serve conservation efforts and help improve reintroduction efforts and management measures for amphibians.