Its existence is threatened not only by climate change and the urban spread of wetlands: fungal diseases are spreading all over the world, killing newts, amphibians and frogs. The reason is the international trade in strange-looking frogs
Dark green, perhaps 30cm high and seemingly infinitely long: blue plastic fences are being erected all over Germany to keep frogs, amphibians and toads off the streets. It’s also mating season for amphibians – and because this causes some neglect, such fences are essential for survival. Because amphibians are also very threatened in this country. The Federal Agency for the Protection of Nature classifies amphibians and reptiles in Germany as more vulnerable than groups of other species.
On the other hand, people’s pressure to settle and farm is causing more and more wetlands and ponds, the basis of life for gill-bearing larvae of amphibians, to disappear. On the other hand, climate change is putting animals under stress as temperatures rise and periods of drought increase. A study by the Potsdam Institute for Climate Impact Research found that stocks are declining and areas of range are getting smaller or changing so much that the species in question must go completely.
In Asia, animals had time to build defenses
“Recently, salamander eaters, a fungal disease that has no cure, have been added,” says aquatic ecologist Malvina Hubei. It is the Batrachochytrium salamandrivorans, Bsal for short, that comes from Asia. “There, local amphibians were able to adapt to the presence of the pathogen over millions of years,” says Hoppe, who is responsible for amphibian protection at the State Association for the Protection of Birds in Bavaria (LVB).
Here, however, newts and amphibians are at the mercy of the fungus: if an animal is injured, this means a quick death, and the fungus literally eats holes in the skin. Hopi: “The fire salamander dies after about two weeks, and the alpine salamander and the apex salamander are also threatened. The alpine salamander lives, but transmits disease to other amphibians.”
In Eifel, in the Ruhr region, in Bavaria – Germany has developed into a real hot spot for the “salamander plague”, as Hopi calls it: especially in the border area with the Netherlands, many sites have been recorded. It is suspected that the disease reached Germany through the Netherlands through international trade in amphibians, and in the neighboring country, the number of salamanders has already decreased by 95%.
In order to find out more about the spread of the disease, the state association is now calling on residents in Bavaria for help: “Anyone who notices a dead fiery salamander while walking should photograph it and inform us of the coordinates,” asks Malvina Hoppe at Feuersalamander @lbv.de. Experts will then attempt to recover and examine the dead animal.
Basil is not the only fungus that threatens domestic amphibians. Another species called Batrachochytrium dendrobatits, for short Bd, is named after the “Dendrobatids” of Central America, poisonous frogs, which die en masse. “The fungi have been transported fairly safely by humans around the world,” says Stefan Lötters from the University of Trier.
Asian newts for our garden ponds: In addition to the trade of live animals, pathogens can also be transmitted indirectly, for example by aquatic plants or frog legs for a cooking pot, says a professor of biogeography: “While onion affects almost only tailed amphibians, and can That Bd is transmitted to all amphibians.”
Mass extinction of an entire population
After all, Bd is not aggressive in Europe. “These fungi have a negative impact on amphibians when other threats are present, such as stress from climate change,” says Lötters. Tropical species are highly threatened by Bd, especially in South America and Australia. “In these areas, Bd caused a local mass extinction of an entire population.” Science assumes that many species became extinct after infection.
Is there a “medicine” that can be used to protect amphibians? “In principle, you can treat Bd and Bsal with an antifungal,” says Lötters, a drug that treats fungal infections. In the case of Bsal, the heat treatment will succeed, and the mushrooms will die in the process. “However, everything is impractical outdoors: you won’t get all infected animals.” In addition, there are probably previously unknown reservoirs, for example there are indications that Bsal can also survive on dead leaves.
For amphibian protectors like the Bavarian Society for the Protection of Amphibians and Reptiles, the fungus harbors a worst-case scenario: With a lot of effort and money from the authorities, they set up a healthy habitat for a fish or frog, and suddenly it’s empty from one watch to the next. The salamander mushroom first appeared in Bavaria in 2020, and since then its spread seems unstoppable. This is why the association is working with the LBV, the Bund Naturschutz, and the University of Trier: the chair in Trier must be informed of the finds of dead salamanders outside Bavaria that did not die when they were run over.
Insects, reptiles, birds and fish: Everywhere on the planet, wild animals are going extinct at a rapid rate. Currently, about 150 species are lost forever every day – animals and plants. But herpetologists warn that these mass extinctions are not happening anywhere as quickly as they are among amphibians, species that live on land but need water to reproduce. Professor Lötters rules: “In the long run, we will also cut our branch off if we do not protect amphibians.”