April 2017 - article Nature: "Drivers of salamander extirpation mediated by Batrachochytrium salamandrivorans"

An article published in the prestigious journal Nature (April 20th) paints a grim picture for European salamander species. After the introduction of an invasive chytrid fungus (Batrachochytrium salamandrivorans or Bsal) in Western Europe many salamander populations in the Netherlands, Belgium and Germany have collapsed. Fire salamanders (Salamandra salamandra) are the most notable and vulnerable victims in Western Europe. The research group from Ghent University, led by Dr. An Martel and Dr. Frank Pasmans, describe this disease as “the perfect storm”. Its range is still expanding and many other European salamanders species are at risk. Especially several genera that are highly susceptible to the disease and species that occupy small ranges could suffer dramatic population declines or extinction should Bsal reach them.

The article (Stegen et al., 2017) can be found here. Ghent University and Reptile, Amphibian and Fish Conservation the Netherlands also issued a news item on this new study. Matthew Fisher (Imperial College of London) wrote an informative article on this study.

The most important items of this study are:

• An infected population of Belgian fire salamanders were continuously monitored from the initial signs of infection (2014). Six months after the onset of the infection only 10% of the original population remained. Two years later less than 1% of the population was present in the study area, mainly consisting of sub adult animals

• Animals had a 33% chance of becoming infected between 10 day monitoring intervals. The mean survival of infected animals was six-fold lower than the mean survival of non-infected animals. 

• Bsal isolates from the initial outbreak and recent isolates were equally deadly. This suggests that there are no sign of host-pathogen co-evolution.

• Lethal infection was observed in fire salamanders exposed to both low and high doses of Bsal isolates and at both low (4°C) and high (15°C) temperatures.

• Infection trials failed to prove an immune response for the disease. The inability of salamanders to mount resistance against B. salamandrivorans infection largely excludes vaccination as a mitigation measure for susceptible salamander species

• Bsal releases infectious, motile zoospores. The study describes a new type of spore which can persist without a host (water or soil) for long periods of time while remaining infectious. This encysted spore has a thick, hydrophobic cell wall and can float on the water surface (increasing passive motility). This type of spore can also stick to the feet of waterfowl and potentially be carried to other areas via this means. 

• Midwife toads (Alytes obstetricans) and Alpine newts (Ichthyosaura alpestris) can act as reservoirs for the disease.

• Eliminating the disease in situ is not possible as of yet. For certain susceptible populations and species with restricted ranges it might be necessary to establish captive assurance colonies in order to secure their survival. The European Union has provided funding in order to make further research possible. RAVON is participating in this project.

• April 2017: RAVON created a hygiene protocol for field workers. This protocol has been updated and can be found here. In addition RAVON created a protocol on disinfecting heavy equipment which can be found here. At the moment both protocols are only available in Dutch. An excellent English protocol can be found here. More information on field hygiene can be found on our page dedicated to hygiene. 

• March, 2017: A research team from Belgium (Ghent University) and Vietnam (Vietnam National Museum of Nature, Vietnam Academy of Science and Technology) published the results of the first large scale Bsal screening in Vietnam in the journal Scientific Reports. Almost 600 individuals of eight salamandrid species were tested for Bsal and Bd presence. Specific habitat traits, like water temperature, were also measured. Bsal was widespread in contrast to Bd. Overal prevalence in both chytrid species was low and all tested individuals did not show signs of clinical illness or reduces fitness. Bsal was found at higher temperatures that previously know which suggest a broader thermal niche. This study suggests low level pathogen endemism and co-existence with Bd in Vietnamese salamandrids. In addition this region may acts as a disease reservoir. The entire paper can be accessed here.

• February 2017, Belgium: Currently several branches of the Belgian Government that are responsible for nature conservation are conducting a public inquiry for a National Bsal Action Plan. Comments on the plan can be made until 16 February 2017 via this website. The conceptual plan can be downloaded here.e.

• November 2016: A German Research team published in the journal Plos One a new study on the possible future spread of Bsal in Western Europe. The models used in this study were based on ecological- and climate data and predicted areas suitable for Bsal in the Netherlands, Belgium, Germany, Luxembourg and France. The paper can be found here: Feldmeier et al., 2016.  

• October 2016, France: The French Herpetological Society (FHS) initiated in response of the imminent threat Bsal poses to French salamanders and newts a citizen science based program in order to detect sick and dead salamanders (due to Bsal) as soon as possible. This program started as a response to the detection of Bsal in Belgium near the French border. Permits to collect (dead-) salamanders can be obtained via regional FHS coordinator José Godin. Please visit this link to read more on the program.   

• April 2016, Belgium: Unfortunately a new case of Bsal has been reported from Wallonia (Belgium) in a population of Fire salamanders. This constitutes the fourth case of Bsal in Wallonia and the fifth case in Belgium. This new case is close to the French border and approximately 70 km south of previous outbreaks in Belgium. AmphibiaWeb and partners (including RAVON and Ghent University) made an informative video about this new case and a crowdfunding campaign targeted at disease surveillance in Wallonia. 

• March 2016: Together with other amphibian researchers, RAVON published an update for the current distribution of the fungus Bsal. The paper was published in the journal Emerging Infectious Diseases. Not only is Bsal present in populations of wild newts and salamanders in the Netherlands and Belgium but also in Germany. Up till it has been discovered in three host species.

• February 2016: Joint letter from conservationists and researchers to the EU with a call for funds for monitoring, research and short-term plans. Also an import ban on Asian salamanders species should be considered. 

• January 2016: The US Fish and Wildlife Service (UFWS) took action by imposing a temporary moratorium on the importation of 201 species of salamanders which are seen as ‘injurious’ to North American salamanders. It is hoped that this ban will help prevent the introduction of Bsal to the US. More information, a FAQ and permit applications can be found here. 

• January 2016: Deadly amphibian fungus (Bsal) in Europe could emerge in United States: U.S. Geological Survey (USGS) identifies research needs & management actions in a new report released on January 21st 2016.

• December 2015: The Standing Committee of the Bern Convention published the following document: Recommendation No. 176 (2015) on the prevention and control of the Batrachochytrium salamandrivorans (Bsal) chytrid fungus [document T-PVS (2015) 9]

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