Global Frog Pandemic May Become Even Deadlier as Strains Combine
By Morgan Erickson-Davis
A fungus that has decimated frog populations around the world could get even deadlier, according to new research. The study found that hybridization of different types of the fungus creates strains that can cause greater mortality in frogs. And it warns that deforestation could make this impact worse.
The fungus is called Batrachochytrium dendrobatidis—Bd for short—and it causes a disease called chytridiomycosis that affects a frog's ability to absorb water and electrolytes through its skin. Scientists first started to take notice in the 1970s when frog populations in Central and South America started disappearing.
By the 1990s Bd had spread around the world, likely aided by the laboratory trade in African clawed frogs and invasions of American bullfrogs. By 2007 it had been implicated in the decline or extinction of some 200 species.
Today, biologists consider it one of the biggest threats to amphibians globally.
Some research has offered a bit of hope for frogs, with a study published earlier this year in Science finding populations may be able to develop resistance to Bd.
But a new study published last week in Scientific Reports adds another hurdle for frogs, finding that hybridization between a native strain of Bd in Brazil and the one that's caused the global pandemic can lead to greater infection rates and illness strength than either can alone.
The study was conducted by researchers from universities in Brazil and the U.S. who looked at infection in several frog species native to Brazil's Atlantic Forest. They chose that region because of its high amphibian biodiversity (despite being one of the most deforested ecosystems on the planet) and because it's the only known region in the world where multiple strains of Bd coexist and hybridize.
Deforestation for agriculture and other development has reduced Brazil's Atlantic Forest to less than 15 percent of its original extent.Mongabay
Scientists believe the Brazilian strain of Bd (Bd-Brazil) evolved along with amphibian populations there and, because of this, is not as harmful to them as the Global Pandemic Lineage (Bd-GPL). But when the team compared infection and illness rates of the two types of Bd and a third hybridized one, they found that the latter had a significantly worse impact on two of the three frog species they examined.
The researchers write that this effect may be due to a phenomenon called "hybrid vigor" (also referred to as "heterosis"), by which the sudden surge in genetic diversity caused by hybridization leads to a more dramatic expression of advantageous physical traits. Take, for example, mules, which tend to be stronger (and smarter, according to at least one study) than either their horse or donkey parents. The same might be happening for Bd. Combining the genes of different strains of Bd could make a hybrid strain even stronger than Bd-GPL.
Another reason why hybrid Bd may be affecting frogs so profoundly is reduced genetic diversity in the frogs themselves. The authors write the pumpkin toadlet (Brachycephalus ephippium), one of the frog species that experienced high death rates when infected with the strain, lives in isolated, patchy habitats that "may have limited its exposure to pathogens throughout its evolutionary history or lowered its immunogenetic diversity."
The study's results appear to be already playing out in the real world, with previous research from the team finding that frog populations are declining and disappearing more quickly in the zone where the two Bd strains are known to hybridize.
And they warn that deforestation "may tip the host-pathogen balance further in favor of the pathogen" as habitat loss stands to increasingly isolate frog populations, further reducing their genetic diversity, while "even the most fragmented landscapes in the Atlantic Forest" don't seem to be a barrier to Bd.
The researchers say their results indicate frogs may face a future even more dire than anticipated as different strains of Bd spread around the world and combine into more harmful forms. They call for increasing global monitoring efforts to detect these shifts before they lead to new outbreaks.
"With globalization facilitating pathogen spread across continents, hybridization of chytrids might lead to new epidemic waves reducing amphibian biodiversity in both tropical and temperate regions," said study coauthor Gui Becker, assistant professor of biological sciences at the University of Alabama.
Some Tropical Frogs May Be Developing Resistance to a Deadly Fungal Disease – But Now Salamanders Are at Risk… https://t.co/xdA3kEf1Fy— EcoWatch (@EcoWatch)1526548206.0
Reposted with permission from our media associate Mongabay.
Typhoon Molave is expected to make landfall in Vietnam on Wednesday with 90 mph winds and heavy rainfall that could lead to flooding and landslides, according to the U.S. Embassy and U.S. Consulate in Ho Chi Minh City. To prepare for the powerful storm that already tore through the Philippines, Vietnam is making plans to evacuate nearly 1.3 million people along the central coast, as Reuters reported.
EcoWatch Daily Newsletter
How does your burrito impact the environment? If you ordered it from Chipotle, there is now a way to find out.
- Food's Environmental Impact Varies Greatly Between Producers ... ›
- Panera Bread Becomes First Chain to Use Climate-Friendly Label ... ›
Are you noticing your shirts becoming too tight fitting to wear? Have you been regularly visiting a gym, yet it seems like your effort is not enough? It's okay to get disappointed, but not to lose hope.
By Sarah Steffen
A stretch of coastline in the Philippine capital, Manila has received backlash from environmentalists. The heavily polluted Manila Bay area, which had been slated for cleanup, has become the site of a controversial 500-meter (1,600-foot) stretch of white sand beach.
Sand Makeup Crucial for Ecosystems<p>While UNEP/GRID-Geneva generally supports finding <a href="https://www.dw.com/en/not-enough-sand-for-construction-industry-despite-abundance/a-49342942" target="_blank" rel="noopener noreferrer">alternative sources of sand</a> so as not to disrupt ecosystems in rivers and oceans when extracting them, Vander Velpen stressed it was vital to use sand which closely matches the makeup of the native sand to protect beach fauna.</p><p>"If you change the core characteristics of the native sand, the original sand, you need to do an environmental impact assessment (EIA) to find out how it's going to impact the ecosystem and nearby ecosystems," he told DW.</p><p>But according to Torres, such an assessment was not done in Manila.</p>
Beautification Stunt Instead of Proper Cleanup?<p>Manila Bay's waters are heavily polluted by oil and trash from nearby residential areas and ports. A huge "No swimming" sign warns visitors to stay away from the ocean.</p><p>Philippines' <a href="https://denr.gov.ph/index.php/priority-programs/manila-bay-clean-up/25-priority-programs/1825-frequently-ask-questions-faqs-on-the-dolomite-and-the-beach-nourishment-project" target="_blank">Department of Environment and Natural Resources (DENR)</a> has denied dolomite sand poses any risk to human health and the ecosystem.</p><p>However, scientists of the University of the Philippines have come forward disputing the DENR's claims. A <a href="https://biology.science.upd.edu.ph/index.php/ib-statement-regarding-dolomite-in-manila-bay/" target="_blank" rel="noopener noreferrer">statement by the Institute of Biology</a> said that using crushed dolomite did not address any of the rehabilitation phases and instead was "even more detrimental to the existing biodiversity as well as the communities in the area," pointing to the case of water birds. "The dumping of dolomite in Manila Bay has effectively covered part of the intertidal area used by the birds thereby reducing their habitat."</p><p>At peak migration season, Manila Bay is home to 90 aquatic bird species, including species of international conservation concern that are facing a very high extinction risk in the wild. </p><p>Authorities should focus on protecting and conserving biodiversity, the Institute of Biology added. "Rehabilitating mangroves is an example of a nature-based solution that is cheaper and more cost-effective than the dolomite dumping project," the scientists said.</p><p>Moreover, <a href="http://www.msi.upd.edu.ph/" target="_blank" rel="noopener noreferrer">the Marine Science Institute</a> has warned that prolonged inhalation of finer dust particles of dolomite could "cause chronic health effects," leading to discomfort in the chest, shortness of breath and coughing.</p><p>They also warned dolomite sand grains would erode during storms and be carried out to sea, essentially being washed away.</p>
Rehabilitation vs. Reclamation<p>Environmentalists say covering up the beach doesn't address the real issues of the bay. Torres and others believe the best way to clean up Manila Bay is not to add anything, but rather remove trash and pollution.</p><p>"There have been studies saying much of the waste comes from already collected waste — so these are open dump sites along the coast that get washed up because of the rain," Torres said.</p><p>She criticized the authorities for continuing to push reclamation projects she says are at odds with each other. These projects will affect large areas of mangrove forests, she said, and experts warn that this, in turn, exacerbates coastal erosion.</p><p>"If you've removed the areas that helped trap the sand, like mangrove forests, then the likelihood increases that you will have to nourish a beach. Same as building right up to the waterfront," said Vander Velpen of UNEP/GRID-Geneva.</p>
Plenty of Sand in the Sea?<p>The question of Manila's contentious white beach echoes larger questions about sand mining worldwide. <a href="https://unepgrid.ch/storage/app/media/documents/Sand_and_sustainability_UNEP_2019.pdf" target="_blank">Global sand consumption has tripled</a> over the past two decades, UNEP/GRID-Geneva has found. A huge chunk of it is now taken up by construction.</p><p>"Many operate on the assumption that natural sand is endless in its supply," said Vander Velpen.</p><p>Sand scarcity is a concern shared by Stefan Schimmels of <a href="https://www.fzk.uni-hannover.de/fzk_start.html?&L=1" target="_blank">Forschungszentrum Küste</a> who's done extensive research on shore nourishment to stop coastal erosion. And as climate change and rising sea levels are threatening coasts, demand for sand will grow even more.</p><p>A large study, the <a href="http://www.stencil-project.de/wp-content/uploads/2019/10/STENCIL_SWOT_Analyse_191026.pdf" target="_blank">Strategies and Tools for Environment-Friendly Shore Nourishments as Climate Change Impact Low-Regret Measures (STENCIL project)</a>, focused on the German island of Sylt, a popular vacation spot.</p><p>About 1 million cubic meter of sand per year is used to maintain the coastal area of Sylt, STENCIL project head Schimmels said. That's about 100 million 10-liter buckets of sand.</p><p>When sand was extracted off the coast of Sylt, underwater craters were formed. "You can still detect these craters even decades later," Schimmels told DW.</p><p>"Also when you add a couple of meters sand onto the beach — you essentially bury all things that do creep and fly," he said. "How quickly will they recover?" Schimmels said more research was needed as there was still too little known about long-term effects on the environment. </p>
Criticism Piling Up<p>As for Manila's artificial white sand, it looks like some might have already been blown away by a recent storm. DENR claims it wasn't washed away, but said that grayish sand, stones and other material had simply piled up over the dolomite sand. People in Manila have tweeted photos showing how the storm has ravaged the beach. </p>
<div id="adc0b" class="rm-shortcode" data-rm-shortcode-id="98f9390db6bb81cb421aaf0bb9d9a6fb"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1318816633280851969" data-partner="rebelmouse"><div style="margin:1em 0">Exactly one month after giving excited netizen a glimpse of Manila Bay white sands, look what happened now after ju… https://t.co/X0Z9i0bPB0</div> — M*A*S*H (@M*A*S*H)<a href="https://twitter.com/Magtira_Matibay/statuses/1318816633280851969">1603265362.0</a></blockquote></div><p>Authorities have been called tone-deaf for spending around 389 million pesos ($8 million) on a beach nourishment project in the middle of a raging pandemic.</p><p>An image of cake iced with the words "It really hurts - that's [worth] 389 million pesos?" has since gone viral.</p>
<div class="rm-shortcode" data-rm-shortcode-id="4387aad52ea316e4db7330052318ca2f"><div class="fb-post" data-href="https://www.facebook.com/theweekendpatisserie/posts/144564207350008"></div></div><p>"It's just a waste of precious resources," Torres said. </p><p>The environmental activist now also worries that she might be labeled a terrorist for speaking out under the <a href="https://www.dw.com/en/philippine-anti-terrorism-law-triggers-fear-of-massive-rights-abuses/a-53732140" target="_blank" rel="noopener noreferrer">Philippines' controversial new anti-terrorism law</a>. She says she could be arrested for inciting fear when talking about environmental dangers.</p>
- 8 World Cities That Could Be Underwater as Oceans Rise - EcoWatch ›
- Endangered Migratory Birds on Collision Course with New Airport ... ›
- How Is Climate Change Affecting the Philippines? - EcoWatch ›
A pair of studies released Monday confirmed not only the presence of water and ice on the moon, but that it is more abundant than scientists previously thought. Those twin discoveries boost the prospect of a sustainable lunar base that could harvest the moon's resources to help sustain itself, according to the BBC.
- Scientists Find Rust on the Moon 'Puzzling' - EcoWatch ›
- Historic NASA/SpaceX Mission Could Pave the Way for Space ... ›
- NASA Study of Increasingly Dire Global Water Shortages Finds ›
- Groundbreaking NASA Announcement: Evidence of Liquid Water on ... ›