What's the problem?

Lotters et al. 2011
Amphibians are threatened by the fungal disease chytridiomycosis, which has already killed frogs around the world. Chytridiomycosis is caused by the pathogenic skin fungus, Batrachochytrium dendrobatidis, and is the largest disease threat to biodiversity at the present time (Wake and Vredenburg 2008). In Central America, species like the Panamanian Golden Frog can no longer be found in the wild because of Bd.

Bd is currently absent from the island of Madagascar, but this pathogen will likely arrive at any time (Lotters et al. 2008, Vredenburg et al. 2012).  Madagascar is a biodiversity hotspot, home to over 400 species of frogs. The map shows the areas where Bd will thrive in red, which is also where most of the frogs live (Lotters et al. 2011). Bd has spread rapidly around the world, so we predict that it is only a matter of time before the pathogen reaches Madagascar where it will likely decimate the diverse frog fauna. It is imperative to consider a prevention and mitigation strategy now in order to prevent catastrophic declines and extinctions in Madagascar like those seen in other tropical areas.

Why are frogs important?

Frogs are vital members of the ecosystem.

  • Tadpoles are important for cycling essential nutrients, including carbon and nitrogen in ecosystems.
  • Tadpoles and frogs are critical links in the food chain.
  • Frogs are one of the best natural controllers of biological pests, such as mosquitoes

Frogs have value to humans.

  • Frogs provide important food resources in some cultures.
  • Frogs produce compounds that reduce high blood pressure, relieve pain and inhibit HIV.
  • Frogs stimulate economies through ecotourism.

What can be done?

We consume yogurt to restore a beneficial microbial community in our guts and protect us from disease.  The same concept works for frogs. The addition of beneficial bacteria to a frog's skin is a promising disease mitigation strategy based on growing evidence that microbes are an important defense for both plants and animals. Addition of locally-occurring protective bacteria to amphibians has effectively prevented disease in laboratory trials and recent fields trials (Harris et al. 2009 a,b, Becker et al. 2009, Vredenburg et al. 2011, Muletz et al. 2012). Our goal is to develop probiotic conservation strategies using our recently developed six-phase filtering protocols to preserve Madagascar's remarkable amphibian biodiversity (Bletz et al. 2013).

We have developed two strategies:

Strategy One (Species-Specific Approach):  Find probiotics for critically-endangered species in Madagascar, such as Mantella aurantiaca.  These probiotics can be administered by individual probiotics baths.

Strategy Two (Community-based Approach): Find probiotics that can protect amphibian communities by treating breeding sites where amphibians congregate. 

** We stress that bioaugmentation approaches must use bacteria found on amphibian in the local environment to improve success and minimize biosafety concerns.

Filtering Protocol: Six phases

What will it take to implement probiotic conservation strategies?

What are the conservation implications?

Probiotic disease mitigation for wildlife is a new conservation frontier (Bletz et al. 2013).  Significant progress has been made in the field of probiotics as a possible tool for mitigating amphibian chytridiomycosis in the laboratory and in the field. Applying these techniques before the arrival of Bd is still a novel concept, but is well worth investigating in Madagascar.  Probiotic conservation strategies offer the possibility of conserving species while keeping then in their native habitats. This is important because the capacity does not exist to house all the species that need to be protected from Bd.  Finding effective probiotics for frogs has the potential to prevent catastrophic declines in Madagascar.  Once Bd is detected in the country, we aim to have a bank of local probiotics that can stem the devastation of the spreading pathogen.  Preserving frog populations is critical to the ecosystems and for the people of Madagascar.

Landscape of Risk

We plan to develop a landscape of risk to identify populations and communities of frogs in Madagascar that are at the greatest risk of decimation based on their lack of or limited abundance of anti-Bd bacteria. To read more about our "landscape of risk" concept click here.

To donate to our project click here:
ASA-Take Action, and select "Probiotic Conservation" from the Direct my Donation menu.

For more information about this project and for assistance with the donation process please contact: Molly Bletz or Reid Harris.

**All photos were provided by Devin Edmonds from Association Mitsinjo.**

** Madagascar Bd map was provided by Stefan Lotters.**

For general information about amphibian conservation work in Madagascar please visit: