Watching extinction happen – another warning of the global biodiversity crisis.

The enigmatic decline of the Dutch fire salamander (Salamandra salamandra terrestris) and the discovery of a new chytrid species.

By Tariq Stark and Jordi Janssen

Not so long ago our country, the Netherlands, was home to a small but otherwise healthy population of fire salamanders (Salamandra salamandra terrestris). Their hilly forest habitat, although fragmented and under anthropogenic pressure, remained a safe haven for our only terrestrial salamander species. Several times a year, on rainy nights, we visited this population and almost always we found larvae in the creeks, and wandering juveniles and adults. You did not even have to wander of the paths of the forest. Other amphibian species like alpine newts (Ichtyosaura alpestris), common frogs (Rana temporaria) and common toads (Bufo bufo) were also abundant in this forest relic.

The fire salamander population has been monitored for a long time and several years ago (2010) declines were noticed. By 2013 only 4% of the wild population remained (Spitzen – van der Sluijs et al. 2013). Cause: unknown. To save the remaining individuals surveys were carried out to catch them and start a captive breeding program. Unfortunately 49 % of the caught salamanders died shortly after capture.

Fire salamander
Fire salamander Copyright: Christian Jansky CCA-Share A like license

A possible culprit could be Batrachochytrium dendrobatidis (Bd). This fungus infects the skin and causes rapid mortality. It has been responsible for the decline and extinction of ˃ 200 species of amphibians worldwide; mainly North-, Central and South America, Europe and Australia (Bollinger et al., 1999, Collins et al., 2003, Daszak et al., 2003, Skerratt et al., 2007, James et al., 2009). Both wild and captive fire salamanders were tested for this fungus. The results: negative. Further testing revealed the true culprit. Another chytrid fungus closely associated with Bd. The new species has been dubbed Batrachochytrium salamandrivorans (Bs.).

This new fungus also causes skin infections and mortality after seven days. Unlike Bd. the optimal temperature of Bs lies between 10-15 degrees Celsius and remains active at temperatures as low as five degrees Celsius. Growth is inhibited at temperatures ≥ 25 degrees Celsius. Bd. optimum lies between 17-25 degrees Celsius (Forrest et al. 2011). Bs. therefore occupies a different and much lower thermal ecological niche. Potentially this could spell disaster for amphibian species in countries with a temperate climate like the Netherlands. In the laboratory midwife toads (Alytes obstetricans) that were inoculated with Bs. remained unaffected (midwife toads are highly susceptible to Bd.).

September, 2012, almost exactly one year ago RAVON sounded the alarm bells. It was (and still is) one to twelve for the Dutch fire salamanders. To shed a light on the cause of decline, RAVON, Ghent University and several partners launched a broad scale campaign investigating what was happening with the only terrestrial salamander in the Netherlands. One component was the “Adopt a Salamander” campaign that we at The Wandering Herpetologist took part in. Thanks to all the donations sent from all over the world, we managed to adopt the tiny fire salamander Benjamin. This tiny fire salamander was a bit of a problem child, as he wasn’t feeling too well and therefore Benjamin was transferred to the Ghent University. There they could investigate what was wrong with him. Unfortunately Benjamin did not make it and fell victim to this fierce fungus.

As Prof. Matthew Fisher from Imperial College London, and one of the co-authors that discovered Bs stated:

“It is a complete mystery why we are seeing this outbreak now, and one explanation is that the new salamander-killing fungus has invaded the Netherlands from elsewhere in the world. We need to know if this is the case, why it is so virulent, and what its impact on amphibian communities will be on a local and global scale. Our experience with Bd has shown that fungal diseases can spread between amphibian populations across the world very quickly. We need to act urgently to determine what populations are in danger and how best to protect them.”

The death of Benjamin and the other fire salamanders taken into captivity emphasizes the need for urgent action once again.  Thanks to everyone that donated money, we already managed to raise $543, – USD for SOS fire salamander. An amazing amount, but after the devastating news of this new fungus causing chytrid in amphibians, more money is needed.

It is not anymore just a matter of saving one population of fire salamanders. This new fungus could potentially be a global disaster for all amphibians that live in the temperate regions Therefore, we decided to continue the fundraiser at The Wandering Herpetologist as this team could use all the money they can get. It’s not just one to twelve for the Dutch fire salamanders anymore, but potentially five to twelve for all amphibians in the temperate regions. Please consider donating for this cause, as we need to act now! The amount raised so far, shows that we as reptile/amphibian enthusiasts, we can make a difference!

What will the future hold? Today even Dutch politicians picked up on the news and discussed it in congress. Let’s hope money and other resources will be granted to RAVON, the University of Ghent, the University of Brussels and the Imperial College of London. Today amphibians, tomorrow us?

The whole article can be read here: http://www.sosvuursalamander.nl or Martel et al.: Batrachochytrium salamandrivorans sp nov causes lethal chytridiomycosis in amphibians. Proceedings of the National Academy of Sciences of the USA, 2013. (Link)

Acknowledgements: Thanks go out to Annemarieke Spitzen-Van Der Sluijs (RAVON), Candace Hansen for feedback on concept versions of this blog. Sara Viernum (The Wandering Herpetologist) and Matt Ellerbeck (Save the Salamanders) for their unconditional support for this fundraiser.

References

Bollinger, T.K., Mao, J., Schock, D., Brigham, R.M., Chinchar, V.G. 1999. Pathology, isolation, and preliminary molecular characterization of a novel iridovirus from tiger salamanders in Saskatchewan. Journal Wildlife Diseases 35:413–429

Collins, J.P., Brunner,  J.L.,  Miera, V., Parris, M.J., Schock, D.M., Storfer, .S. 2003. Ecology and evolution of infectious diseases. Amphibian conservation. Smithsonian Institution Press, Washington, pp 137–151

Daszak, P., Cunningham, A.A., Hyatt, A.D., 2003. Infectious disease and amphibian population declines. Divers Distribution 9:141–150

Forrest, M., Schlaepfer, M.A., Nielsen, K. 2011. Nothing a hot bath won’t cure: infection rates of Amphibian chytrid fungus correlate negatively with water temperature under natural field settings. PLOS one, Vol. 6 (12).

James T.Y., Litvintseva A.P., Vilgalys R., Morgan J.A.T., Taylor J.W. 2009. Rapid Global Expansion of the Fungal Disease Chytridiomycosis into Declining and Healthy Amphibian Populations. PLOS Pathology 5(5)

Skerratt, L. F., Berger L., Spaere, R., Cashins, S., McDonald, K.R., Phillot, A.D., Hines, H.B., Kenyon, K. 2007. Spread of Chytridiomycosis has caused the rapid global decline and extinction of frogs, Ecological Health 4, 125–134

Spitzen-Van Der Sluijs, A., Spikmans, F., Bosman, W., De Zeeuw, M., Van Der Meij, T., Goverse, E., Kik, M., Pasmans, F. & Martel, A. 2013. Rapid enigmatic decline drives the fire salamander (Salamandra salamandra) to the edge of extinction in the Netherlands. Amphibia-Reptilia, 34, 233-239.

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