22 Jan 2016

About the Decline of Amphibian Populations

Por: Jorge Ventocilla


The decline and possible extinction of amphibian populations worldwide is both a warning sign and a reality. We have been facing a significant crisis for a long time now. This crisis affects global biodiversity probably more severely than any other event witnessed by human beings. We are urged to react to this tragic situation which could be the symptom of more complex and serious changes happening in the biosphere that could foretell potential adverse effects on the world we share.

Starting from this Full Moon, we will be talking about this important topic.

Fifty specialists from the scientific community, including a representative of Panama, Dr. Roberto Ibáñez, informed the prestigious Science magazine 10 years ago (July 7, 2006) that one-third of the 5,743 amphibian species identified in our planet were under the category of threatened species. This article also mentioned that, in the past 25 years, more than a hundred species have become extinct. Amphibians (frogs, toads, salamanders, and caecilians), which have been on Earth for over 300 million years, could disappear in just months, according to the report.

This warning started to be a public issue in the 80’s. During the following decade, scientific studies (including field studies conducted in Panama by local and foreign biologists) confirmed it had reached pandemic status. Certainly the scientific community today has a better understanding of the causes. Predictions can be made regarding the behavior of the decline in geographic terms. However, this situation is rapidly getting out of control. 

Some traditional conservation actions like the protection of habitats are essential, but they are not enough for dealing with an emergency like this one.  What has happened to entire amphibian populations tells us we need to do something drastic and immediate in order to save some endangered species. Build an Ark, as Noah did, perhaps?

The problem is known to be the result of the destruction of the habitat of these animals, their commercial exploitation, and the negative effects of the introduction of exotic species. In addition, we know that there is an infectious disease caused by Batrachochytrium dendrobatidis, a fungus that is the primary cause of the decline of amphibian populations.  This fungus was identified in 1998 following simultaneous reports in Fortuna, to the west of Panama, and in Australia.  Recent studies suggest that climate change could also be a factor affecting the dispersion and persistence of this fungus.

Panama has a large variety of amphibian species. Some of these species can only be found in this country. There is also a wealth of research about amphibians in Panama, including continuous research about the decline of amphibian populations spanning 15 years.

Dr. Karen Lips (Southern Illinois University) and her research team, with the support and authorization of the Autoridad Nacional del Ambiente (National Environmental Authority: ANAM) and sponsored by the  Smithsonian Tropical Research Institute (STRI), have been recording valuable data about this infectious disease. They have documented, for example, its effect on amphibian populations in Fortuna (Chiriquí), Santa Fé (Veraguas) and, between 2004-2005, in El Copé (Coclé). Dr. Lips’ studies revealed the existence of a predictable geographical progression of the infection, which spread from Costa Rica to the western areas of Panama in the late 2000’s and early 2010’s, with devastating results on the amphibian populations near El Copé in late 2004. 

Based on their observations, the disease was predicted to travel East, with the possible devastation of amphibian populations near El Valle de Antón at some point in 2006. Unfortunately, these predictions were accurate. The first frogs affected by this fungus were found on February 2006 near El Valle. Infected amphibians in the El Valle region, including the highly regarded Panamanian Golden Frog (Atelopus zeteki) eventually died in large numbers. No countermeasure for stopping the devastation caused by this disease was found at the time, and it was expected to spread east of Panama.

Many fundamental questions about Batrachochytrium dendrobatidis were still unanswered at that time. Where did it come from? How did it spread? Why is it so devastating for tropical amphibians in medium-/high-altitude? The disease is believed to be spread by amphibians themselves, probably through interaction with other wild animals, or probably through vehicles, people or cattle. 

[to be continued in February’s Full Moon…]