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Sick Salamanders and Frogs

A Cary Lecture on Emerging Infectious Diseases and Impacts on Amphibians
by Antonia Shoumatoff
Wed Oct 26th, 2016

Dr. Lips with one of her subjects in Costa Rica 

Dr. Lips was one of the first researchers to sound the alarm on massive frog die-offs in Panama and Costa Rica as a result of the chytrid fungus. At her study site in Western Panama in 1993, the fungus was pervasive. 

In 1992, Karen Lips, an Associate Professor of biology from the Univ of Maryland who was involved in amphibian field biology was living in a100-square foot area at the top of a cloud forest on a mountain in Costa Rica.  She was alarmed that she did not find any frogs.  She was stalked by pumas and jaguars while she was living in her shack in the jungle.

She said when she would finally find a frog that looked healthy, she would pick it up, it would jump once and die right there on the spot. Lips has since become one of the world’s leading experts in amphibian diseases, leading collaborative efforts to track and understand what we can expect as new pathogens emerge and spread. Dr. Lips’ work focuses on disease ecology and how the chytrid fungi affects amphibian species, populations, and their ecosystems, including frogs and salamanders and their differences in their resistances in different geographic areas.  Her ultimate goal: conserving frogs and salamanders. 

The trickiest part of her work is to figure out why some frogs in certain areas can live with the chytrid infection and others are wiped out by it.  Most of the endangered species globally are in the tropics which are moist and hot. There are 7,571 frog species described, which change annually.  She said that in 2004 they assessed 43% species in decline., 32% threatened. This is way more than birds and mammals. 168 species are presumed extinct, just in the past 20 years.  This ocurred without anyone noticing.

Amphibians provide important environmental services: eating bugs, producing antimicrobial chemicals and demonstrating how to regenerate limbs.  They regulate ecosystems, can transfer energy and nutrients and provide food for birds, fish and mammals.

The golden toad, was one of the species in Costa Rica that disappeared first.  Dozens have disappeared since due to historic problems, such as land use change, chemical contaminants, invasive species, and emerging infectious diseases.  Climate change is also a suspect.

This is all brand new information and Bd (chytrid) fungus has caused incredible devastation in a short period of time.  It is globally distributed and has invasive and endemic lineages and a broad host range. The number of species it can infect is huge.

All amphibians can be a host, a reservoir or a progenitor of the fungi.

North America has new captive animals coming in from other places, such as South America, and spreading it through the pet trade.

Anywhere in North America you will find bd infected frogs.  This story has yet to be investigated.  There is a lot more to be done.  There is no cure for wild populations.  The most effective form conservation according to Dr. Lips, is it to keep it out.  Yet it persists in the environment somehow. 

Dr. Lips lab has been working on  studying ecology, habitat, genetics, temperature, moisture, pathogen, time present all of the complicated aspect that determine the intensity of the infection.

She has counted thousands of frogs and snakes and lizards in Costa Rica and watched the chytrid epidemic wave for eight years.  Out of 74 species studied there are now only 40.  Here in New York there are only 33 species of amphibians.  After bd there were dozens of dead frogs.  Some species completely missing.

“Things are not normal. We could say that the situation has changed in a big way.  The species showed a wide range of responses.  We took swabs of frogs and spores and found 80% affected, from 2004-2010.  

Chytrid in certain places seems to have been there for a really long time, hundreds of years, which may explain why we have not seen so many die off’s in North America.”

Dr. Lips becaume interested in finding clues in North American where certain populations have the chytrid fungus but are resilient.  She decided to study salamanders as well.

“We have more species of salamanders than anyone else, here in North America, but  Dr. Highton, found huge declines in abundances in the ‘70’s.  We followed up on his work in the Appalachians.  We swabbed them and and found Red back salamanders was missing from 24% of the sites.  In the 1970’s a shift happened.  We thought we could point the finger at bd but that was not the case. We ran swabs on 1,400 animals and only found 4 animals with bd.  In Illinois there were many more infected salamanders.  There was evidence that climate change is involved in body size reduction.”

Lips said researchers need to build off past failures.   Chytrid goes back to 1840 in Illinois but the frogs are still there. They are immune to its effects. 

It was a Newt fungus from Asia that spread into Europe and infected wild salamanders in Europe.  In the US we imported 4 million frogs and salamanders for medicine, pets and other uses that infected our frogs. 

Threat and risk sare high.  Scientists started talking to Fish and Wildlife to stop the trade from coming into the US.  The Lacey Act is all we have but it needs to be revised because it is not designed for diseases.  US in Jan 2106 banned inter-state movement of salamanders for their own good for import.  

This also has meaning for bats, snakes, bees and sea stars.  New York is the leader of this new regulation. Senatore Kirsten Gillibrand has asked for changes to the Lacey Act to improve the regulatory process for import.  Dr. Lips encouraged citizens to call  their representatives to support this effort.  

Chytrids have been in the environment forever but we still don’t understand this complex fungus.  It could happen that epidemiologists could find clues in the species that are resistant to chytrid to figure out how to make the other species more resistant.  In the future, genetics might also be developed to help the amphibians to fight it off.

Dr. Lips is also interested in using social media to communicate science, and has become involved with policy issues related to wildlife diseases, including how they relate to trade. Learn more about the ecological significance of amphibians and Dr. Lips’ research in this American Association for the Advancement of Science video