Batrachochytrium salamandrivorans, better known as Bsal, is a fungal pathogen that causes chytridiomycosis, a deadly disease that’s contributing to an amphibian decline across most of the world. But it hasn’t reached North America. A new paper published by scientists from the North American Bsal Task Force confirms that after a decade of testing and monitoring, there’s no evidence that Bsal is on the continent, and points to efforts such as import policy restrictions in the U.S. Lacey Act in keeping infected salamanders from being imported.
This international collaboration between Mexico, Canada and the United States is a rare and successful example of a voluntary, cross-border effort to prevent a globally devastating pathogen from spreading even further, and provides a blueprint for similar efforts to prevent the spread of other kinds of wildlife diseases.
However, podcast guest Deanna Olson, a wildlife ecologist with the U.S. Forest Service and principal author of the study (and founding co-chair of the task force), stresses that it’s not a matter of “if” but “when” the fungus will reach North America.
She joins Mongabay’s podcast to talk about lessons learned in combating the deadly pathogen, what knowledge gaps remain, and how North American wildlife managers are now much better prepared than during previous amphibian disease outbreaks.
Bsal’s sibling, Batrachochytrium dendrobatidis (Bd), devastated frog populations globally, and led to the decline or extinction of around 200 species by 2007, with North American scientists blindsided by its spread. However, with Bsal, scientists have had more than 10 years to study, prepare, and work to keep the fungus from arriving.
“We didn’t know that Bd was even occurring until 20 years after it had been establishing itself, and having the outcome of population declines. So, we were ‘behind the eight ball,’ so to speak, with Bd. And now we had an opportunity to get in front,” Olson says.
Subscribe to or follow the Mongabay Newscast wherever you listen to podcasts, from Apple to Spotify, and you can also listen to all episodes here on the Mongabay website, or download our free app for Apple and Android devices to gain instant access to our latest episodes and all of our previous ones.
Mongabay published a six-part podcast miniseries on Bsal in 2020 under the “Mongabay Explores” podcast feed. Episode four details the duties of the Bsal task force a few years into operation from the perspective of Jake Kerby, a former chair of the task force, listen here.
To hear Mongabay’s award-winning coverage of Traditional Ecological Knowledge featuring National Geographic photographer Kiliii Yuyuan, listen here.
Banner image: Fire salamander (Salamandra salamandra), a European species greatly affected by Bsal, photo courtesy of Isselee Eric Philippe.
Mike DiGirolamo is a host & associate producer for Mongabay based in Sydney. He co-hosts and edits the Mongabay Newscast. Find him on LinkedIn and Bluesky.
Transcript
Notice: Transcripts are machine and human generated and lightly edited for accuracy. They may contain errors.Dede: I guess we, we just have common interests and, and a conservation ethic among the three countries that we want to maintain sustainability of our unique fauna. Each of the countries really have a biodiversity that they would like to maintain over time and are working hard for that purpose. And, and so we were united in some, you know philosophies and understanding that there is an amphibian decline going on for many reasons and not just disease.
We have habitat degradation, chemical contamination in some places, climate change. In North America, in particular, invasive species is a huge threat to amphibian species. And so the threat list is starting to get long.
Mike: Welcome to the Mongabay Newscast. I’m your cohost, Mike DiGirolamo, bringing you weekly conversations with experts, authors, scientists, and activists working on the front lines of conservation, shining a light on some of the most pressing issues facing our planet.
And holding people in power to account. This podcast is edited on Gadigal Land. Today’s guest on the Newscast is research ecologist Deanna Olson with the Forest Service of the United States Department of Agriculture. Olson is the founding co-chair of what is known as the Bsal Task Force, an international, voluntary collaborative effort between Mexico, the United States, and Canada to prevent the spread of a devastating amphibian fungal pathogen.
Known as Batrachochytrium salamandrivorans, otherwise known as Bsal. I’m no stranger to Bsal. I reported on it four years ago for Mongabay in a six part podcast miniseries, which I encourage you to check out. But for both the familiar and the uninitiated, this conversation provides a lot of helpful insight on how North American nations have come together to combat the spread of this catastrophic wildlife disease.
Established 10 years ago, the Bsal Task Force has gleaned significant lessons from its decade in operation, which Olson outlines in our conversation. In a paper published in Frontiers in Amphibian and Reptile Science earlier this year, the Task Force scientists say that due to the specimen sampling efforts, they are more certain that Bsal is not already present in North America.
Also credited are policy changes to import restrictions, which helped keep the disease from coming to the continent. It’s an impressive level of collaboration, which could help inform how the United States deals with wildlife disease or prevents its spread. However, Olson stresses there is still much work to be done to prepare for Bsal’s arrival.
Hi Deanna, welcome to the Mongabay Newscast. How are you?
Dede: I’m wonderful today. Thank you.
Mike: And thanks for joining us to talk about this topic.
What is Bsal?
Mike: So it’s, for me, this conversation has been four years in the making because it was four years ago that I first reported on Bsal, but there may be some folks that are listening who aren’t acquainted with this topic.
So can you kind of give a, like a high level overview for our listeners? What is Bsal and why is it such a big deal?
Dede: Yeah. Well, most of us had never heard of Bsal until the recent years. It was first described by An Martel et al. in 2013. And it really took us by surprise as it being a second amphibian chytrid fungus that is a pathogen, a skin pathogen on amphibians.
And it was causing disease in European salamanders. And so this was a new species to science. And it followed on the tail, so to speak, of a global pandemic of another chytrid fungus called Bd. So Bd and Bsal are sister species. They’re related because they are pathogens that are naturally found on the skin of amphibians in Asia, where they do not cause disease.
But as these, these pathogens have been translocated to other places. in the world. They seem to cause disease in some susceptible species. So Bsal had been translocated to Europe and was causing die offs in the fire salamander, and the very first paper was reporting on that in 2013. One year later, in 2014, the same authors Martel et al.
had completed experimental studies of the susceptibility of a variety of species to Bsal, and there were species from North America that were affected by Bsal and were dying from Bsal within a few days of infection. And so this set up an alarm because it was a new disease and we were just getting over the pandemic of Bd around the world where population declines and some extinctions had been recorded from Bd, and now we have another pathogen, and it was just emerging now in Europe, and and there were animals in North America that laboratory tests show that they were susceptible and we were concerned.
We, we want to keep it out of North America if we can.
Mike: Right. And maybe not around the time that happened, but you know, some, sometime after that, I had the opportunity to speak with someone that was involved with the Bsal Task Force, which I believe you’re, a founding co chair of.
The Bsal Task Force Assembles
Mike: So can you tell our listeners really quick about what was the purpose of this task force?
Dede: Yeah. Okay. So in this timeline, first, we have the Bsal being discovered in 2013, and then recognition that it infects animals from around the world in 2014. Um, a workshop was planned in the summer of 2015 that brought together disease ecologists and epidemiologists from North America, but also a few from around the world, including Europe, where this first die off had, had been occurring.
And, and so we strategized on what the next steps ought to be. And there were a couple immediate outcomes of that. That one week workshop and one was providing information for managers in terms of, um, decision support of what managers need to be doing to help keep Bsal from invading North America. But secondly, we assembled this Bsal Task Force as a collaborative group of volunteers that were scientists or managers or students or people interested in amphibian conservation to work together to see if we could forestall another pandemic of amphibian disease that seemed to see, have a focus on salamanders this time, rather than Bd, which was the pandemic The former pandemic that was raging in the 1970s, 80s, 90s, and early 2000s.
affecting mostly frogs So now we have a different subset of the amphibians being affected. So the Bsal Task Force was, um, initiated in the summer of 2015. And, and so now that’s been going on for 10 years. And so it sounds like you’ve got sort of an interim, uh, perspective of what had been happening halfway through that time series.
On the Hunt for a Silent Killer
Dede: And, and now we’re taking stock of what have we done? Have we helped? What are the challenges and what are the next steps that we need to do?
Mike: And we’re going to reflect on some of that in this conversation. So A lot has obviously happened since I spoke with Jake Kerby in 2020, notably, in the paper you state that Bsal is not present in North America.
So I just want to clarify from you is that that is the case. How were you able to calculate and arrive at that assessment right now?
Dede: So I’ll say it in a slightly different way. So the Bsal task force really was initiated to, to prevent Bsal getting a, a ground hold in North America and several different working groups were assembled, uh, for different purposes.
And you mentioned Jake Kerby and he was one of the first leaders of the diagnostics working group pushing forward how we might diagnose if Bsal is present and develop laboratories in the United States and Canada that can, we can send samples and have it run to see if Bsal is here. The other working groups, some of the main ones, well, I’ll just, I’ll just run them through.
There was the research working group that was focusing on both epidemiology research and susceptibility research trying to figure out how Bsal works as a, in the physiology of, of both the host and the pathogen, and then which species were susceptible to Bsal in North America. So a lot of laboratory testing was done to keep Bsal contained, but then expose various species to it to see what happened.
So that was the research working group. There was a decision support working group that was developing mechanisms for managers to easily make decisions. If something happened in their area, they could quickly decide what needed to happen. There was a surveillance and monitoring working group. And so that was initiated, was conceived in 2015, really initiated the next year in 2016.
And that was, broad scale, continental scale surveillance for Bsal. And that’s really the basis for the statement that we have no support for Bsal being in North America, largely because of the broad scale surveillance efforts that were conducted through the task force and then other individuals, which may be students or other researchers independently looking for Bsal, and it has not yet been found in North America.
So, we’ve got 10 years of surveillance and it’s very broad geographically. There’s some gaps in it and it’s still going on. So that’s the basis, mostly from the surveillance and monitoring working group. The other working groups, there was a data management working group, which assembled all the survey sites that had been completed as well as those that are planned.
And that’s still going on today, the ones that are planned. So we can inform people and not, you know, waste time and effort of having two groups of people investigating whether Bsal is present in a certain area. That data management working group compiles the data, it’s online for community use, and it includes the world Bd data as well.
So the Bd and Bsal data sets are housed in the same location. A couple other working groups, there was the response and control working group, which really was developing, if we find it, what do we do? And immediately we put together a rapid response template. And that was actually something that’s in revision right now.
So the work always continues. We, we figure out how to do things better, but the rapid, the rapid response template was very, um, reactive to emerging information and the diagnostics group–and you mentioned Jake Kerby. He was part of that–they determined that different laboratories were receiving different information when they were, they did a ring test where they sent the same samples out to a bunch of laboratories and some had Bsal positives and some had Bsal negatives.
So it was different results coming from the same exact samples. And so there were some uncertainties happening with the diagnostics. Um, because of that, our rapid response template evolved, and we now require, if Bsal were ever to be detected, we need a result from multiple labs showing Bsal positive, because there are uncertainties with the diagnostic techniques, and that work is still ongoing.
So there’s still research on how to refine diagnostics. You think it would just be, you know, straightforward, clean cut. Is it there? Is it not there?
But there’s a lot of ways that samples get contaminated or things go kind of haywire in the laboratory. So outreach and communication was a working group that we felt was very important because when you think of a pathogen like Bsal and a disease that we call Bsal chytridiomycosis, you kind of lose the public eye and, and the interest in that gets swallowed up in the literature or in the, you know, the news of the day.
And so we developed an outreach and communication working group to help us speak to the public, to managers, speak to, you know, if something comes out from our work that needs resonating. We get it out in the media if we can or on social media. Most recently, we started another working group that hasn’t been there all the time, but it’s very active right now, and it’s called Healthy Trade.
The trade markets, the pet markets, is one way that Bsal seems to be getting around the world. It, it, amphibians, maybe they’re not really popular pets for people in some places, but nevertheless, they are popular pets for some other people and collections of live animals in homes or in zoos or museums.
These are, um, These happen, and if animals are being shipped around the world, they can transmit that pathogen on their skin. Not all species are susceptible to the disease. And so you can get the pathogen moving without knowing about it. Healthy Trade Working Group is trying to promote trade markets that are disease free, essentially. And this is a challenge because that means they need to have diagnostics in the trade markets and be testing, testing, testing all the time to make sure things are clean. So anyway, this, this structure of the different working groups led us to understand that at this time, we have no support for Bsal being in North America.
Literally thousands and thousands of samples have been run and there’s more samples being collected every year. At this point, the surveillance and monitoring working group has moved to be a university and college endeavor, and students in classes and in clubs around North America are engaged in that surveillance.
And so we’ve, we have a workforce that’s growing and doing kind of backyard science, so, so to speak, and learning of, of amphibians and then some of the risk factors or threats to amphibians as well. So it’s, it’s integrated a teaching tool as well as, you know, a very extensive workforce that we can continue with surveillance and monitoring.
One of the most foremost challenges in that is that it is costly to run the samples in a laboratory. And so finding money for all the samples that are possible to be collected, that’s a challenge right now for us.
Mike: Yeah. Hey there, listener. I just wanted to drop a little note to say, thank you so much for listening to and supporting the Mongabay Newscast.
Now, normally I’d take this time to remind you to subscribe to us on the podcast provider of your choice rather than listening to us on your browser, but I have some exciting news to share. We, the Mongabay Newscast, just won an award. My colleague Erik Hoffner and myself were awarded second place for best coverage of Indigenous communities in a radio or podcast at the Indigenous Media Awards for 2024.
The episode in question features a conversation with National Geographic photographer, Kiliii Yüyan, who details his experience covering traditional ecological knowledge of Indigenous communities around the world. I highly encourage you to give it a listen if you haven’t already. It’s linked in the show notes.
So thank you to the Indigenous Journalists Association for this award. We are absolutely honored. If you’re really enjoying this podcast, and you want to support us further, please do share this episode with a friend and tell everyone you can about the work that we’re doing at the Mongabay Newscast.
Thank you so much as always for listening. And now back to the conversation. I have to say, it’s really impressive what the task force has done. But something important that I want to highlight is that it’s a voluntary task force.
The Team Behind the Scene
Mike: The collaboration between the three nations, Mexico, Canada, and the United States, I was very impressed by this.
So, can you talk about the nature of that international collaboration and how that played out and aided the research you’ve done and keeping Bsal at bay?
Dede: Yeah, so that initial meeting that we held, and I’ll acknowledge that it was the United States Geologic Survey that initiated that first workshop in 2015.
They invited key players that they felt had been involved with amphibian disease. And the geographic scope was the United States. And it blebbed over, I think there were Canadian representatives there, as well as European representatives. And it was quickly understood as we started to model, well, what species seem to be vulnerable to Bsal, and it went across the borders.
And so into Canada and into Mexico, there are salamanders of the same families that were thought to be vulnerable to Bsal disease back in 2015. And there are scientists in these countries that have been working on that parallel chytrid fungus Bd all along. And so they were interested and concerned for their fauna as well.
So it was liaisons between scientists that maybe started, you know, talking to each other and then also the managers, the wildlife managers, which is a different sector of the community in each of these locations in the United States and Canada, there’s a very strong, um, government influence on wildlife management.
And so we were able to integrate with government agencies. In Mexico, the torch for Bsal disease is really being held by the scientists, I think, and they are the foremost leaders to push forward information for that country. And we, I guess we, we just have common interests and, and a conservation ethic among the three countries that we want to maintain sustainability of our unique fauna. Each of the countries really have a biodiversity that they would like to maintain over time and are working hard for that purpose. And, and so we were united in some, you know, philosophies and understanding that there is an amphibian decline going on for many reasons and not just disease.
We have habitat degradation, chemical contamination in some places, climate change. In North America, in particular, invasive species is a huge threat to amphibian species. And so the threat list is starting to get long. And when we recognize Bsal, it’s like, oh, here we have something else. What have we learned from the Bd pandemic that we can get in front of now with the Bsal?, because we didn’t know that Bd was even occurring until 20 years after it had been establishing itself and having the outcome of population declines. So we were behind the times. behind the eight ball, so to speak, with Bd, and now we had an opportunity to get in front and there for wildlife, there’s other pathogens that are emerging right now and understanding how we might do a proactive strategic approach for such things is not well understood, but, but maybe we have some lessons learned just from the Bsal Task Force of how, how we might get in front of a problem instead of always reacting to it.
Mike: Right.
Lessons Learned and Broader Implications
Mike: Um, and you do state in the paper that you release that the lessons learned we outlined in this paper can serve as a model for other strategies to manage wildlife disease. So can you elaborate on this for us? Like, how does this work go into informing the planning and management of other emerging wildlife diseases?
Dede: Well, we’ve talked about some of those elements already, and it’s this collaboration among volunteers and getting scientists to talk to managers and other interested parties in conservation. And so it’s, it’s a network. It’s really a social network. That integrates people that have different hats for their vocation, different geographies, um, you know, this conservation versus basic science of learning new information of, of what’s happening in the world.
So that was one, one thing is that. It’s a multi sector problem. It’s not just amphibian scientists or, or the zoos that are doing captive rearing and trying to save the last of a few individuals of a species that, that might be on the brink of extinction. It’s not a subset of people. It’s really a coalition.
The one example that I think the Bsal Task Force has assisted are people that are looking at diseases in marine situations, and there were some new diseases over this last 10 years that really ballooned in some, , in some marine situations, for example, there was the sea star wasting disease that was being found along the Pacific coast of North America.
And at first they didn’t know what was causing it. And so there was this knowledge discovery and scientific endeavor that, that needed to get initiated to figure out, well, what is it? And, and then where is it? And there’s other diseases there in, in marine systems as well that, over time, I think, for amphibians, there has been almost a discipline of disease ecology and disease epidemiology that has developed, and that was kick started by the Bd chytrid fungus and other diseases.
There’s one called ranavirus. There’s different people looking at these different systems. And altogether, an entire sub discipline of science has developed. One, looking at the physiology or the epidemiology of what’s happening at the molecular level with these diseases and then another, the ecology, what, what does it mean for populations or the species existence even?
And so some knowledge with the amphibians has, has helped to inform as disease epidemics are being seen in so many other taxonomic groups and how it’s not just the problem of a, you know, wildlife veterinarian. It’s a problem of a multi sector group of people that all have some stake in a place, the biodiversity there, , the type of future that we want to have for our ecoregions, our, our locations, and for the human population as well.
So I think for the Marine, we, that’s, we’re kind of at a point where we are discovering the tip of the iceberg of marine diseases. And so coalitions of people have been put together and are looking at things like the sea star wasting disease to try to crack, crack the code and be proactive there.
Community Involvement and Cultural Significance
Mike: So you mentioned the human population in there.
And so just so we can conceptualize this and make it relevant to everyone listening right now, can you elaborate on that? What do you mean by that?
Dede: Well, just like people may have close relationships with their family or their place where they live. There are close relationships with nature as well, and the resources in nature, you know, it can be the parks or the vegetation that they have near them that, that they admire, and they would like to maintain and sustain.
And in some places that are known for biodiversity, it’s retaining that biodiversity because it’s different everywhere. and there’s a signature of the organisms that live near individual people. So for example, I live in the Pacific Northwest of North America in Oregon and we have a biome here called the moist coniferous forest.
These are cathedral old growth forests that are, you know, 300 plus feet into the air, giant conifer trees, and there are over 1000 known late successional or old growth forest species associated with these areas. And there is quite a bit of effort afoot to keep these things going, uh, manage for their restoration or sustainability, and that includes amphibians. So we’re, you know, in when we get down to a certain group like amphibians, there’s probably 30 species of amphibians highly associated with these late successional or old growth forests, and they become iconic. For our region and and people get to know about them and they want their iconic species to be retained over time.
It’s a signature of our place and we can see references to them in our Indigenous Tribes, how they honored them. For example, where I live here, the local tribes have many stories in their traditional ecological knowledge of how amphibians signaled the change of seasons and that initiated, it was that amphibian signal that initiated the people’s change of what they were doing in the various seasons. For example, when the frogs call in the spring, the Indigenous tribes stop telling their stories. storytelling was a winter activity when frogs weren’t calling. When the frogs started calling, well, you had to go and, and get busy and get your, get your food for the year.
That’s spring through fall is, is the harvest season. And so there’s, there’s stories even back tens of thousands of years of how people and amphibians were attuned to each other. And I think that is recurring today. And at a local level, you know, there’s even people that cherish, you know, what’s happening in their local pond in their town or, or whatever that situation is.
So getting the public involved, they have ownership in these and they would like to have sustainability and they mourn when things are lost.
Policy Gaps and Biosecurity Challenges
Mike: So that said, you know, there’s been a lot of success with this task force, but you’ve mentioned that there’s still gaps that remain and you’re still working on those.
Notably, in the paper you outlined that there’s no rapid mechanism to include iterative updates relevant to import policy restrictions for amphibian species that might transmit Bsal. Now when I spoke with Jake Kerby four years ago, he mentioned that changes to the Lacey Act were instrumental in helping combat this.
So what rapid mechanism is still lacking to help this situation?
Dede: And so the Lacey Act is a law in the United States that speaks to the importation of species. And very readily, and I think by probably it was the early 2016, an interim rule of the Lacey Act went into play that restricted the import of salamander species of the genus. So there’s different taxonomy of of salamanders, but those different species and genera that had known from laboratory experiments to have susceptibility to Bsal were restricted for import to the United States without a permit. I think there’s a way that you can do it for science, for example, but you couldn’t just import these animals any longer.
That was called an interim rule and it was pretty fast the way it got put into place, but that was really instrumental to stop the salamander imports to the United States. So on the skin of those salamanders could be hitchhiking, Bsal, and that’s why. You know, it was important not to just have animals be brought in unless they were healthy.
So now we’re 10 years later, that interim rule still exists. It has not been changed. There have been discussions of, of upgrading it. We now know that there are some frogs. and toads that are susceptible to Bsal. And so it’s not just a salamander fungus. It is mostly a salamander fungus, but there are some frog and toad species that can be carriers of it and some that are susceptible to the Bsal disease.
So that would be an example of something that could be updated in the Lacey Act. It’s very difficult to change government rules in the United States. And, um, so the Bsal task force is, I think most of the folks there are very supportive of the Interim Act and what it has been doing and, and, revising it so it can be upgraded with our current knowledge.
That would be great to do as well. It hasn’t happened yet. It’s not just the United States. So Canada instituted the same thing. And so in Canada, there is also a rule that prohibited the import of salamanders that are susceptible to Bsal. And, and so that was, yes probably the, the biggest thing that happened right away and has had the best consequences for, you know, North America seeming to be Bsal free to date, is that imports were prohibited.
There’s other issues with imports that, that could be resolved as well, because I think in some places, like I think Canada, and I may, I don’t know this as well as I do for the United States because a lot of salamanders are aquatic and they are transmitted in water essentially. Um, they’re kind of lumped with, with fish with import rules and, and the scrutiny of the import.
Uh, salamanders gets blurred when you put it into a multi species, , category like that. And so there’s, I think, improvements that can be made to recognize that there’s a difference between fish and, and salamanders.
Mike: Yeah, just a little bit. Um, I, well, that said, what are the most glaring gaps other than the, the policy, the iterative policy restrictions that you mentioned?
What are the most glaring gaps that still keep you up at night?
Dede: So, in North America, speaked about the United States because I know the United States better. So it’s animals are really under the jurisdiction of states, not the federal government. If an animal is rare to the extent that it becomes listed under the Endangered Species Act, then there is federal guidance for that animal.
But otherwise, species are under the jurisdiction of states. We have 50 states. 50 different rules. And so our communication and outreach program, we’re trying to inform all the wildlife managers in all the states about what our updates are with Bsal and why this is important. But the truth of the matter is those, those Wildlife biologists and the wildlife veterinarians are overwhelmed with issues for birds and mammals.
They don’t have much bandwidth to spend to keep up with what’s going on with amphibians and reptiles. And so that science management interface is a challenge and trying to keep people informed. that need to be informed at, at the state level, uh, the importance of, of salamanders and these diseases, that’s a big challenge.
And there’s just a lot of people and we’re just not sure we’re, we’re making, we have good communication all the time with them. So bridging science and management. is difficult. We have a lot of science going on, and that science communication goes out in published papers. But the wildlife managers don’t have time to read all the published papers.
So, almost for every article that goes out, we try to do a translation of it for managers, a one pager. You know, something that they can digest very quickly. And those are often fact sheets. So we’re developing a program to inform managers, at least in, you know, a cursory manner that. Here’s, here’s what the scope of the issues are, and we have materials for you if, if this becomes important, we have the rapid response template, and we have management actions that we are looking at and, and options for dealing with Bsal that were to come to North America, we can be part of your incident command team, if and emergency arises, and we do see Bsal.
So so bridging science and management is a challenge. Biosecurity is a big challenge. We have a lot of freedoms in North America, and imposing restrictions on those freedoms is difficult and really Bsal is a microorganism that can adhere to, to boots and dogs. And as people are moving around, they could be moving these microorganisms around.
So there’s a biosecurity question. And can we set up systems that can protect wilderness areas or, or protected areas. Well, we’ve devised them getting them implemented. That’s, that’s something else. Cause we have freedoms that people can go on public lands anywhere. And, and can do pretty much, you know, many things that, um, are not biosecure in, in those areas.
So adopting such best practices for biosecurity is a challenge. You’ll see, and maybe people have noticed that initially when we were working with amphibians and diseases, you would see someone holding a frog or a salamander to show, you know, here’s, here’s an example. Well, now you better see a glove on that hand.
So even the scientists and managers working with these organisms, we want to not have those microorganisms on our hands and being transmitted animal to animal, change our gloves between animals. And so that’s another example of adopting best practices and then showing others what we’re doing and, and hopefully others will adopt that as well. Another challenge is we have some models of where the risk of Bsal is in North America. The, there’s been a series of models over time where we’ve taken, you know, what species we think are susceptible to Bsal, what habitat conditions might be. Be appropriate for Bsal to thrive in the environment and where those ports of entry could be for Bsal if it’s coming in through airports, for example, or through people that might have contaminated gear in their suitcase.
So those are forecasts of where we think Bsal could emerge first. And those are getting better because we’re getting better information about what species are susceptible, the habitat parameters of the pathogen of what Bsal, and then the habitats of those species that can host Bsal. The biggest challenge for us is capacity of people.
And I think the Bsal task force would grow if we had more capacity. Um, it’s a volunteer organization, so we have like all volunteer organizations, people coming in with great enthusiasm and then they move on to something else. We have to all make livelihoods and so life interrupts. So capacity of maintaining a volunteer organization is tough, especially when there are some costs involved.
So surveillance and monitoring, there’s a cost of running those samples. We don’t have volunteer laboratories because those laboratories, you know, we need to pay the people that run the laboratories and there’s chemicals and, and materials involved with those organisms. Even though we’ve been dealing with both the Bd, chytridiomycosis disease, and now Bsal disease, we don’t have a great, um, mitigation response.
We don’t know how to rescue. animals that, that get infected and populations that start dying off. Even for Bd, we’re still trying to figure it out. How do we save these animals? There have been animals brought into zoos for captive breeding. And then rescue operations where either they’ve been put back out into their habitat, so reintroduction or moving to different habitats, translocation to a new place.
These are still experimental for Bd, and we haven’t cracked that code for, for Bsal, so that’s a big challenge. What, how are we going to rescue, if we get animals on the brink of extinction, what do we do? There’s, there’s research involved with that. Those partnerships to, to rescue at risk species are also a collaborative group.
Scientific Innovations and Experimental Approaches
Dede: The zoos and aquariums are the best at captive rearing. And so we’re, we’re developing coordination and collaborations with zoos. all over the United States and Canada for that purpose. The scientists need to be involved because we don’t really know how to make an animal resilient to these diseases yet.
There’s some ideas afoot. We think that the skin microbiome is a community of microorganisms, and this fungus is one of them. But there’s a lot of different bacteria and fungi on the skin of these animals, and they form a community. There’s some, for example, bacteria that are antifungal. And if we can crack the code on that, if we can figure out how to use the microbiome, we might be able to manipulate and develop probiotics for the skin of these animals.
That is experimental at this time, and we don’t know yet. We haven’t figured it out for Bd quite yet, and we haven’t figured it out for salamanders and Bsal either. There’s other scientific ideas in play. Immune priming, if you expose an amphibian to a disease and then clear them of the disease. Are they less susceptible to fatal disease the next time they’re exposed?
And so the analogy is a bit with COVID. Now, if you’ve had COVID, do you get it as bad the next time? And so there’s some immune priming, , research going on to see if we can, , develop immunity. , and if, if we can, is it relative to, you know, that individual and their lifetime? Or is there some way that we can push adaptation, evolutionary change of these organisms so they can withstand, they can become more adaptive to disease threats over time?
We don’t know that that can happen, but, but these are thoughts that are going on and we’re trying, and there’s some experiments at this time.
Mike: I believe, I believe over here in Australia, some researchers just developed a kind of simple way to treat chytrid fungal infections with frog saunas. I don’t know if you saw that.
The frog saunas in question, unfortunately, don’t come with towels and scrub brushes, but they do resemble little tents, or artificial hot spots that can be placed in the wild. And they also contain bricks that the frogs can nestle in. Researchers at Macquarie University in Australia performed a study on green and golden bell frogs, and found that the frogs that were given access to these warm shelters cleared chytridiomycosis infections faster and developed resistance to future infections. They published their findings in the journal Nature. Mongabay’s Liz Kimbrough reported on it earlier this month.
Dede: Yeah, so, so Bd and Bsal have a thermal regime. And so they, they’re kind of like, they’re wet. They live in water and they are associated with cooler temperatures.
And so what you’re describing is, you know, a way that they can get, a fever, essentially. And as, as we know, for people, when you’re sick, you get a fever and then your fever breaks. Well, you, that fever has killed that microorganism causing your cold or your flu or whatever. And it’s the same thing with amphibians and these diseases.
If you raise the temperature, you can make that that habitat for the pathogen unsuitable. And, and so I think that’s what those, what you describe as sauna is raising that temperature and that heat can make it unsuitable for the pathogen to persist. So amphibians also have a, another physiological mechanism.
Many of them shed their skin. and shedding can shed those fungal pathogens as well. In the life history of many amphibians, there’s an aquatic phase and then there’s a terrestrial phase. Well, Bsal is an aquatic fungus, and if the animals go to terrestrial environments, then their skin can dry out, and it won’t be suitable for the Bsal either.
That has been considered for Bd at that terrestrial, the, the animals that are able to go into a terrestrial habitat. For example, if they go to a pond or a stream for breeding, and then after breeding, they go up into the dry land into the upland somewhere. Some of those species seem to be less, less susceptible to the disease and they, they, it’s thought that they dry out and their habitat really is less suitable for the aquatic fungal pathogen in that dry upland. These are ideas, , and we can, we can work with those to manipulate either the animals or their habitats to help them gain a resistance. I remember, so I started my work with toads in 1982 and I did mark recapture studies of populations per five years running.
And I think it was my second or third year. Every toad I picked up, it’s, it’s, skin was coming off in my hands. It was shedding, they were shedding and I’d never seen shedding before and it was during breeding season. So they were at a pond and it was kind of gross, right? You pick up an animal and its skin just falls off in your hand.
Now retrospectively, I think that Bd was, was going through that population at that time. And, but these were toads, they were explosive breeders in the water for only five days or maybe a week for breeding. And then they go upland. And once they’re upland and they have this shedding response, they could have been, sort of adaptively set up to be disease free in the upland.
And those, those populations all still persist today. , so if they were susceptible to the disease, they were able to withstand it, I think, by this, , complex life history of having, You know, one part of their life cycle in the water for a very brief time, only a week, and then they moved to uplands. And it could be that, you know, moving into uplands was an escape from many things in the water for amphibians over evolutionary time, predators, but these complex, , interactions with the microbiota communities has not really been studied as much as, as predator prey communities, for example. And it could offer sort of a, almost in a COVID sense, they could go up into the uplands and have COVID lockdown. So like Bsal lockdown or Bd lockdown in the uplands.
Not “If” But “When”
Mike: Well, DeeDee, I want to, I’m conscious of your time here. I do have one last question for you. So, back when I was reporting on this story, sort of the prevailing sentiment was, you know, it’s not if Bsal comes to North America, it’s when. Is, is that still the case? Is there still the assumption that at some point this is gonna arrive and we need to be prepared for it?
Dede: Yes. Absolutely. I think it’s a, not an if, it’s a when situation. Pathogens can be transmitted by natural factors in nature, and they can be transmitted by people. Carrying it about on their gear inadvertently or, or by moving animals around the world. And we know that the animal trade is extensive. In fact, this yesterday I saw a box of snakes that got loose on an airplane or coming off an airplane.
I’m, I was reminded, well, you know, reptile snakes. They also have. fungal pathogens on their skin causing diseases, just like the amphibians. So, yes, it’s a question of when. It could be because of aquatic birds, you know, during their migration routes. It just, it could, these are microorganisms. They, you know, you have a water spout bringing water into the air that’s bringing everything in the water in the air and it deposits it somewhere else. So a lot of ways it could happen. There have been some studies that are inconclusive that, that Bd spread along roadways and, you know, maybe tires of, of cars as they’re driving along. It’s inconclusive of, of the, of the roots of how things are getting around.
Um, but I. I would agree that it’s not a question of if, but it’s when, and I think the Bsal Task Force has, has helped us to get ahead a little bit, but there’s going to be this reactive response, and that’s going to, that’s a challenge for us of, you know, oh, it’s here now, what are we going to do, you know?
And there’s, so we’re trying to address that a little bit better now, and to get information ready, depending on which of the 50 states it might happen in, and for Canada and Mexico as well, that we work together, we have this collaborative approach, and I would very much hope that that collaboration extends to providing insights for what the response will be.
When Bsal is found in North America.
Credits
Mike: Dede, thank you so much for speaking with me today. It’s a, it’s been a pleasure and I wish you and the task force all the best.
Dede: Thank you very much. It’s been a pleasure to meet you as well. And, um, I hope this is of interest to some folks out there and they’re welcome to email me if they, they have further questions.
Mike: If you want to check out Mongabay’s six part series on Bsal, please see the links provided in the show notes to season one. of Mongabay Explores. As always, if you’re enjoying the Mongabay Newscast or any of our podcast content, like our sister series, and you want to help us out, we really encourage you to spread the word about this show because it’s the best way to help expand our reach and keep growing.
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