Pacific Southwest RegionCalifornia, Nevada and Klamath Basin
A juvenile salamander clings to the moss and rock on the side of a hill on San Diego National Wildlife Refuge. While many are charmed by the aesthetic splendor of salamanders, they are also important indicators of environmental health, according to USGS biologist Robert Fisher. Credit: Lisa Cox/USFWS
Monterey salamander finding at San Diego National Wildlife Refuge prompts biologists to test for deadly fungus
By Lisa Cox
April 2, 2019
Cold, dark and rainy nights are not your typical postcard picture of San Diego, but these are just the type of nights that reptile experts wait for in early spring.
Robert Fisher from the U.S. Geological Survey is one of those reptile experts, known as herpetologists. On a hunch and from his extensive knowledge of amphibians in Southern California, he set out in early February with a small team of biologists in search of a specific species; located in a closed area of the San Diego National Wildlife Refuge.
Biologist Robert Fisher holds an adult salamander as he collects a tissue sample to test for a deadly fungus specific to the species, called chytrid fungus. Credit: Lisa Cox/USFWS
Fisher predicted that with the unique soil and plant types found on San Miguel Mountain, along with its higher elevation and longer exposure to moisture in the air, he might find the species he had in mind: the Monterey salamander (Ensatina eschscholtzii eschscholtzii). Then if any were found, they would come back to collect tissue samples to test for a deadly fungus specific to salamanders, called chytrid fungus.
“Found one!” said Jeff Nordland of the North American Field Herping Association, as the rain poured down on him and the team. The other cold and wet biologists brave enough to join him and Fisher that night were Carlton Rochester of USGS, John Martin with the U.S. Fish and Wildlife Service (San Diego National Wildlife Refuge) and Robert’s son, Sam Fisher, an aspiring biologist who attends Southwestern College in Chula Vista, California.
It was a great find for them and for the refuge because the species had never been recorded there. In fact, this documentation expanded the salamander’s known distribution by six miles beyond the next closest known site on Otay Mountain.
“It was very exciting to discover this population of salamanders on San Miguel Mountain,” said Fisher. “We had predicted they could be there based on geology and plant communities, but to actually find them in this ‘habitat refugia’ was amazing.”
While many are charmed by the aesthetic splendor of salamanders, they are also important indicators of environmental health, according to Fisher.
They play essential roles in various food webs such as regulating invertebrate populations, providing a high quality food source for predators such as birds and small mammals, and overall biodiversity and ecosystem resilience.
Biologist Chris Brown measures the length of a juvenile salamander. Since North America has the highest salamander diversity in the world – home to nearly half of all species worldwide – the introduction of Bsal, a deadly fungal pathogen (native to the Asian population), could be particularly devastating to them and potentially other amphibians. Credit: Lisa Cox/USFWS
“Animals like these salamanders are an example of what makes San Diego the most biodiverse county in North America,” said Martin. “They play a key role in maintaining our strong and diverse ecosystem.”
Although salamanders are indeed unique and important creatures, they unfortunately have a looming threat global in scale.
Finding Monterey salamanders on the San Diego National Wildlife Refuge has provided documentation that their known distribution has expanded six miles beyond the next closest known site on Otay Mountain. Credit: Lisa Cox/USFWS
A type of chytrid fungus, specifically Batrachochytrium salamandrivorans or Bsal, is a deadly fungal pathogen native to Asian salamanders, which can cause chytridiomycosis in other species. In the past few years, it has spread throughout Europe due to the pet trade, causing major die-offs and alarming scientists around the globe.
Since 2016, scientists across the U.S. have been tracking the spread of Bsal, especially near major ports of entry, with a nationwide bio-surveillance effort.
Since North America has the highest salamander diversity in the world – home to nearly half of all species worldwide – the introduction of Bsal could be particularly devastating to salamanders, newts and potentially other amphibians.
Because of this threat, the U.S. Fish and Wildlife Service halted importation of 201 species of salamanders from outside the United States under the Lacey Act.
With Robert Fisher’s involvement in this nationwide surveying effort, he knew he had to go back on another rainy night. This time, with the right equipment to obtain tissue samples so he could test for the fungus.
Since North America has the highest salamander diversity in the world – home to nearly half of all species worldwide – the introduction of Bsal could be particularly devastating to salamanders, newts and potentially other amphibians. Credit: Lisa Cox/USFWS
“These salamanders are located in a high-risk zone for chytrid fungus due to their close proximity to major ports of entry,” he said. “So it was crucial we go back to collect samples. Add to the fact we haven’t been able to collect many in the past year due to drought, now is the time we need to act.”
On the next night they could coordinate, the scientists gathered their sampling equipment and suited up for a misty walk up San Miguel Mountain.
Nestled in a nook on a hillside and shrouded in poison oak, Robert Fisher found a brilliantly colored orange juvenile Monterey salamander, the second one that night.
With the darkness and lingering moisture from recent storms, the tiny creature felt comfortable enough to venture out of its burrow… now lit by headlamps, the moon and the surrounding urban city lights.
Chris Brown, another biologist from USGS, obtained the skin samples from these two salamanders for future lab testing.
Along with a team of biologists around the country collecting the 10,000 samples needed to complete the study, this information could eventually lead to efforts in controlling the introduction of the pathogenic chytrid fungus in native salamander populations.
Martin is happy the refuge is a part of these efforts. “I am ecstatic that that we not only found this species on the refuge, but that we’re contributing to keeping amphibians like these salamanders healthy and strong in the wild,” he said.
About the writer...
Lisa Cox is a public affairs specialist for the San Diego National Wildlife Refuge Complex. Her lifelong passion is to educate people about endangered species and their habitats and inspire them to take action. She is also a fire public information officer and most recently responded to the Thomas Fire in Ventura and Santa Barbara. In her free time she loves backpacking the high Sierras with her friends and her dog, Lexi.
More stories by Lisa: