We’ve written before about fungal infections devastating amphibian, honey bee, and bat populations, but this winter we wanted to delve more deeply into this issue. First, we’ll learn a bit about fungi and why they can be such virulent pathogens. In the next few posts, we’ll explore the emergence of these infections in bats, honey bees, frogs, and yes, even in humans.
Killer airborne fungus. Photo from National Geographic, courtesy of Edmond Byrnes and Joseph Heitman, Duke Dept. of Molecular Genetics and Microbiology
What is a fungus?
A fungus is not an animal or a plant. It isn’t a bacteria either. Fungi belong to a separate kingdom that includes molds, yeasts, lichens, and mushrooms. Animals and fungi do share certain features: they breathe oxygen and get energy by eating food. Their cells are similar. Yet fungi don’t eat and digest their food as animals do. Their feeding style breaks down dead plants and animals, decomposing them. But they can also switch their diet from dead animals to live cells.
Fungi can retreat into spores and survive for long periods without food. They can live independently, outside their hosts. As spores they can float through the air, get lodged into the treads of a shoe, or float in water. Unlike bacteria and viruses that may burn themselves out when they kill their victims, fungi can wipe out whole populations without being destroyed themselves.
Why are certain types of animals so vulnerable to fungal diseases?
There isn’t one conclusive answer. Those animals that are immunosuppressed, however, tend to be more vulnerable to fungal infection. But why are these animals so unhealthy? The answers are complex and may have to do with many different causes, perhaps a “perfect storm” of causes: the overall decrease of biodiversity, use of pesticides, climate change, clear cutting of forests and habitat destruction and degradation, and other issues.
Readers of Frogs Are Green are familiar with the the chytrid fungus, Batrachochytrium dendrobatidis, which has wiped out hundreds of species of amphibians.
In 2006 the white-nose syndrome, an infection caused by the fungus Geomyces destructans killed a few bats in New York; since then it has killed more than 5 million bats in 21 states and four Canadian provinces.
Recently honey bee populations have been devastated. There is evidence that co-infection with multiple pathogens, including fungi, is one cause.
A fungus called Cryptococcus neoformans ravages humans with compromised immune systems. It is spread primarily by the guano of pigeons and contracted by inhaling spores. More than 1 million immunosuppressed patients are infected annually around the world.
What is the Causing the Spread of the Emerging Fungal Diseases?
Fungal spores can be easily spread by humans so fungi that were once isolated in different parts of the world can now exchange genes and create new and more virulent pathogens.
As reported in a recent e360 (Yale) article: “Fungi have driven more animal species extinct than any other class of pathogens by quite a long way,” according to Matthew Fisher, an epidemiologist at Imperial College in London.
A couple of weeks ago, there was quite a brouhaha in the news about the inclusion of God into the Democratic and Republican party platforms at the convention. Personally, I don’t think God cares too much about party platforms.
But I do think God might wish that we humans were better stewards of this beautiful planet and the animals that inhabit it along with us. Around the time of the conventions, the Zoological Society of London published a report by the International Union for Conservation of Nature’s Species Survival Commission that listed the one hundred most threatened species of animals. These animals are unique and interesting in their own way, but they may die out simply because they don’t offer obvious benefits to humans. Are we being good stewards by letting this happen?
Volunteers in Utah from Interfaith Power & Light, a faith-based environmental coalition, went on a search for the rare boreal toad (Bufo boreas), which occupies only 1 percent of its historic breeding places and is under evaluation for possible Endangered Species Act protection.
The most serious threat to the boreal toad is the chytrid fungus, a disease that is devastating amphibian populations worldwide. Biologists believe habitat protections can help reduce stress and can keep outbreaks in check.
Boreal toad. Photo courtesy of the State of Utah Natural Resources Department: Division of Wildlife Resources.
The interfaith group didn’t find any boreal toads, but their excursion wasn’t in vain. One of the volunteers was quoted in the article as giving her reason for the importance of their outing, other than the fact that kids love frogs and toads: “More and more we become so disconnected from nature. We might go to church on Sunday, but I feel like we’re called to do more than that.”
The search was organized by Jason Brown, a Mormon with theology and forestry degrees who teaches ethics at Utah Valley University. As quoted in the article, Brown said: “Depending on the faith tradition, biodiversity can be sacramental of God, or [indicate] God’s presence.”
We say Amen to that.
For more information:
The Interfaith Power and Light website has links to articles about different religious faith traditions (Christianity, Judaism, Islam, Buddhism, and others) and the environment. Please click here.
See Vernal.com for more information about the boreal toad.
University of Michigan mycologist Tim James and colleagues conducted a genetic analysis and have found that the global trade of live bullfrogs is helping to spread the deadly chytrid fungus, which has devastated worldwide amphibian populations. The results were published in the journal Molecular Ecology.
As Revkin notes, it isn’t clear why the fungus is devastating to amphibians in some areas, but seems to be harmless to those in other areas. For example, although there are deadly strains in the Northeast, there are no chytrid-related declines reported. Environmental conditions or other issues might account for this.
The researchers examined the role of bullfrog farming in spreading the chytrid fungus between the forests and frog farms of Brazil and then to the United States and Japan. They collected and analyzed bullfrogs sold at Asian food shops in seven U.S. cities and found that 41 percent of the frogs were infected with chytrid fungus, which is harmless to humans. Frogs in these shops are imported live primarily from farms in Taiwan, Brazil and Ecuador and sold as food for their legs.
“A lot of the movement of this fungus is related to the live food trade, which is something we should probably stop doing,” James said. “We don’t need to have millions of live frogs being shipped from foreign countries into the United States.”
When was your organization founded? Please tell us a bit about its mission, goals…
Save the Frogs is the first and only public charity devoted to amphibians. It was founded in May 2008. Our mission is to save and protect amphibians, as well as to respect and appreciate nature and wildlife.
I founded Save the Frogs because frogs were rapidly disappearing around the world. About one-third of amphibians are on the verge of extinction. At least 2,000 species are threatened and if nothing is done, will likely go extinct. Most of the work previous to Save the Frogs was done by scientists helping amphibians, but educating the public about the issue is also very important.
Save the Frogs has education programs and works to get laws in place, for example, to get frogs legs out of restaurants, provide schools with alternatives to dissecting frogs, and prevent non-native frogs from being imported.
The biggest thing is environmental education so I created Save the Frogs Day, an event which comes around each year. This April 28th will be the 4th annual Save the Frogs Day and there will be 200 events in 30 countries, which will top last year’s 143 events in 21 countries.
The events bring awareness around the world, especially on that particular day and it receives significant publicity in the media.
What is your educational background and what lead to creating this organization?
I was always interested math and science and studied mechanical engineering as an undergraduate at the University of Virginia, but soon realized I wanted to pursue environmental science. I went back to school to study biology in preparation for graduate school.
I spent a summer in Hawaii volunteering with PhD students who were studying birds. It was then that I knew environmental science was my path. I loved hanging out at streams, so thought about what types of animals live in streams and then found out that frogs were disappearing. I thought frogs would be great to study for my PhD, so I went to Australia and came across Mark Hero in South East Queensland, who became my supervisor. I studied frogs, and the disease, chytrid fungus, which is driving amphibians to extinction.
I finished my PhD, came back to the United States and founded Save the Frogs. I love my work because it’s a combination of communicating awareness, educating the public and science.
What are some challenges you have faced and how did you deal with them?
The first challenge was funding, because we founded in 2008 during the economic recession. Raising funds for a non-profit is hard in the best of times, plus saving frogs is still somewhat of an obscure topic. Most people still don’t know why we should protect frogs.
Save the Frogs works hard on awareness by using the web and speaking to the public directly.
I try to get publicity through newspapers and for-profit corporations involved. Some of them have practices that are harmful to the environment. Many companies when approached don’t necessarily care about what they are doing and only care about making money.
At least one billion frogs are taken out of the environment for use as food in restaurants (frogs legs) and farm-raised frogs carry diseases and if you approach restaurants and ask them to stop selling them, they only see it as a monetary loss.
I have and will continue to approach tech firms in nearby in Silicon Valley for funding. Many of them have no environmental program.
How is climate change effecting amphibians?
Climate change is a huge problem, so it’s good that it gets a lot of attention. We need more people in the government looking seriously at climate change and what to do about it. It’s very important to amphibians because they are very connected to precipitation levels.
“Amphibian” means two lives, one on land and one in the water. Frogs either lay their eggs in water or in leaf litter and the ones who are not in the water are in cloud forests in tropical countries. As the temperature rises, the cloud level rises and the leaf litter dries up. This means that the frogs must continually move up and eventually will run out of space. Many of the frog species live on a particular mountain and only that mountain, so if something happens to that species it can go extinct.
It’s not just tropical forests that are in trouble, Yellowstone National Park in the U.S. has had droughts. About one fourth of the ponds have started to dry up and many frog species are on the decline.
Save the Frogs had five posters up in airports around the country and the one in O’Hare is still up and has been seen by hundreds of thousands of people.
How do you reach your targeted audience? Is it through your website, advertising or social media or another route? Which is most effective and why?
The best way I can reach people is through our Save the Frogs website which has helped make it a worldwide organization. Our e-newsletter is also a great tool because whenever we need help and send it out, we can reach tens of thousands of people. We recently sent out an email with a free download of “The Wild World of Frogs” and it got 40,000 downloads in the first day! Many of those downloads were from friends forwarding the newsletter to their friends.
We create a variety of flyers people can post around their towns. Most things we do are free and up on our website and if you give people the tools they will help spread the word.
Some of the other ways we reach people is through our Facebook page with frequent updates, as well as through Twitter.
I give live presentations and did 65 this year. I believe you can get more people involved by interacting with them face-to-face. I’m trying to get more teachers involved and Save the Frogs Day on April 28 is a great way and to get lots of people talking about it.
What can people do to help?
There are lots of ways to help Save the Frogs! Our website has over 250 pages of information. I feel that educating yourself on the issues is the first step and then subscribing to our newsletter to stay informed.
Learning how you can change your ecological footprint is a great way to help. Everything you do effects the environment.
There are lots of ways to volunteer and many things can be done through the internet so you can be from anywhere! There is a form on our website you can fill out. We have various campaigns and also need help writing letters to the government, for example, the campaign to ban Atrazine. Visit our “take action” page.
Save the Frogs is a 5013C public charity and has a wish list of things we need which is also posted on our website.
Tell us about your events around the world and some of the campaigns you have started.
Save the Frogs is an international organization because amphibians are disappearing all over the world. A few years ago I was asked down to Panama to give a five day talk on molecular biology and also taught the scientists there how to detect the chytrid fungus disease. If you cannot detect the disease, how can you do any research on it. The materials and information is available on the Save the Frogs website. “QPC” is the technique for detecting the disease and the materials have been downloaded by scientists in over 30 countries.
Last year I got invited to Korea and was the representative for the 1st Amphibian International Symposium. I traveled around Korea for 10 days doing environmental work. Seeing what types of problems they had, coming up with solutions and giving presentations to communities, groups and schools. We have applied for a $50,000 grant that would go to helping Korea’s amphibians.
In September, 2011 I spent a month in Ghana and helped them start Save the Frogs Ghana. We are registering it as a NGO with the government of Ghana. It will be an independent Save the Frogs working on it’s own. We have written a proposal to help the Squeaker Frog (Arthroleptidae: Arthroleptis) and also to make the Atewa Hills a national park. We are trying to save the Togo Slippery Frog (Conraua derooi) which lives in only two streams and are threatened by mining. They are a fully aquatic frog and swim as fast as a fish.
What is in the works for the future?
Save the Frogs is coming to New York, New Jersey and Connecticut in March 2012. I will be looking for schools and community groups for presentations.
Save the Frogs Day is April 28th and we have a 5k race planned in Seattle and another event in San Francisco. There will be “Ban Atrazine” rallies and we will be raising awareness about it.
New campaigns include a petition to Governor Gerry Brown to stop the importation of American Bullfrogs. About 3 million are imported to the state of California each year. Being native to the east coast, when they come to California, they eat the native wildlife and they are primarily for pets, dissection and frogs legs in restaurants. They carry the chytrid fungus so are spreading the disease.
Nathan’s Famous is now selling frogs legs and I want to get this to stop. The executive and CEOs have refused to address the issue. They need to take some environmental responsibility.
Helping Save the Frogs Ghana
Ghana is a poor country and frogs are in trouble because of illegal foresting. There are now programs in place to teach mushroom farming and bee keeping which can change a family’s life. We will be working to get the Atewa Hills a national park.
To learn more about Save the Frogs visit the links below:
Researchers at Oregon State University have discovered a freshwater organism that might help in fighting the chytrid fungus, which is a principal cause for the worldwide amphibian decline. A freshwater species of zooplankton, called Daphnia magna, could provide a tool for biological control of the deadly fungus whose impact, one researcher has called “the most spectacular loss of vertebrate biodiversity due to disease in recorded history.”
Daphnia magna is a variety of water fleas of the genus Daphnia, some species of which are commonly used as food for aquarium fish. It was known that the zooplankton could devour some types of fungi. Oregon researchers wanted to find out whether Daphnia magna could also consume the chytrid fungus that has been devastating amphibian populations worldwide, including Colorado’s endangered boreal toad.
Through extensive research, scientists confirmed that Daphnia magna could consume the free swimming spores of the fungal pathogen. According to lead researcher Julia Buck, an OSU doctoral student in zoology, in an Oregon State University press release:
We feel that biological control offers the best chance to control this fungal disease, and now we have a good candidate for that. Efforts to eradicate this disease have been unsuccessful, but so far no one has attempted biocontrol of the chytrid fungus. That may be the way to go.
Now scientists need to conduct field studies to confirm the zooplankton’s effectiveness in a natural setting. The OSU scientists have found that Daphnia inhabits amphibian breeding sites where chytrid transmission occurs and may be able to stem the unprecedented population declines and extinctions.
For background on the chytrid fungus, please see the video below that we found on the Save the Frogs site, produced by the National Science Foundation:
The Oregon State University research was reported in the journal Biodiversity and Conservation, and was supported by the National Science Foundation. Click here for the full report.
Eating frogs legs is a bit of a joke to Americans. Most of us would never consider eating them. Yet we need to take this very real threat to frogs seriously.
A recent article in Scientific American, “How Eating Frogs Legs Is Causing Frog Extinctions,”* listed some pretty amazing statistics:
Over two thousand metric tons of frog legs are imported into the U.S. each year. Another two thousand metric tons of live frogs are imported every year for sale in Asian-American markets.
The European Union imports an annual average of 4,600 metric tons of frog legs, mostly to Belgium (53 percent), France (23 percent) and the Netherlands (17 percent), the equivalent of about one billion frogs.
According to Alejandra Goyenechea, acting director of international conservation programs for Defenders of Wildlife:
Humans have been eating frogs for ages. But today the practice is not sustainable on a global scale. Billions of frogs are traded internationally each year for human consumption, and that industry is responsible for depleting wild populations, spreading deadly disease, and allowing invasive species to destroy the health of native ecosystems.
This huge demand for frogs legs is contributing to frog extinctions for two reasons:
Too many frogs, collected from the wild, are depleting natural populations
The international trade in frogs legs and live frogs is the major reason for the spread of the deadly chytrid fungus (Batrachochytrium dendrobatidis), which has already been blamed for amphibian extinctions around the globe.
According to the report, most frog and frog leg imports to the U.S. come from China, Taiwan, Ecuador, Brazil, the Dominican Republic, Vietnam, Mexico and Indonesia. One of the species farmed is the Bullfrog, an American native species that has spread around the world. But Bullfrogs are one of the most notorious carriers of the chytrid fungus. According to Save the Frogs, as quoted in the SciAm article:
A recent study estimated that 62 percent of the bullfrogs entering California from Asian frog farms are infected with the chytrid fungus. Bullfrogs serve as perfect vectors for fungus, as the frogs can survive infection loads of millions of chytrid zoospores. Because the infected frogs don’t die from the fungus, they are able to spread the pathogen to native amphibian populations.
Bullfrogs are usually resistant to the chytrid fungus and rarely, if ever, die from exposure to it. Most other amphibian species have an 80 percent mortality rate when exposed to the fungus.
Exact statistics on which species are being imported and eaten are incomplete, because most imports are already skinned, processed and frozen, making them hard to identify.
The three organizations behind this report are now calling for increased regulation of the frog trade under the Convention on Trade in Endangered Species of Wild Fauna and Flora (CITES). That agency has the authority to restrict some hunting and harvesting, create humane standards for frog handling and killing, set monitoring criteria for wild populations, and require that all imported meat be frozen, which would slow the spread of disease.
Last year, the U.S. Fish and Wildlife Service asked for public comments on a proposal to ban the import of live frogs under the Lacey Act, which regulates the import or transport of wildlife species that are either dangerous to humans or the environment. The public comment period ended in December, but so far there is no word yet on if the proposal will become law.