Before Two Degrees: The Silencing of a Symphony
It is clear: the consequences of climate change for biodiversity are already in full throttle.
In collaboration with Global Wildlife Conservation, I will examine the inextricable link between climate change and wildlife extinction through the stories of those most at risk. The consequences of these losses are paramount and jeopardize not only the security of the species’ surrounding ecosystems, but also to us—our economies, our health and even our own identity. So join us over the coming weeks and months as we examine the changing climate’s effect on the fabric of life: biodiversity.
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There’s an air of nostalgia in Panama, especially on August 14. On this day, the streets of El Valle de Anton are filled with a kaleidoscopic of yellow and black dots to honor one of the country’s most ubiquitous cultural and ecological icons: the Panamanian Golden Frog (Atelopus zeteki). On this national celebration, Panamanian Golden Frog Day, there is a week’s worth of festivals and fanfare. The Panamanian Golden Frog, however, is not a luminary to the Panamanian people, but rather a spirit, something of the divine. The last wild Panamanian Golden Frog was spotted in 2009. Although the amphibian faces many threats, the chytrid pathogen may have decimated up to 90 percent of remaining populations by the early 2000s. Today, beyond what we find in zoos and private reserves, the golden frog has vanished.
The rate of global extinction is likely far greater than at any other period over the last 100,000 years. And within this sixth mass extinction, amphibians are considered the most threatened vertebrate class on the planet. Most often, direct human-caused threats are to blame—habitat destruction, pollution, and the exotic pet trade—compounded by amphibians’ narrow habitat preferences and small, isolated distributions. Although these are still considered the biggest drivers of decline, we are now entering an era of enigmatic, or “indirect” threats driven by the manifestations of a changing climate.
“Climate change aggravates all threats,” says Helen Meredith, executive director of the Amphibian Survival Alliance. “Climate change compounds a system and species’ stress, and because threats never act in isolation, you end up with the perfect storm.”
Ripples from the Chytrid Wave
The Panamanian Golden Frog is a vibrant species in appearance and behavior, and moves with what conservationists describe as elegance.
“It’s one of the most beautiful frogs I’ve ever seen, although I never got the chance to see it in the wild,” says Robin Moore, communications director of Global Wildlife Conservation. Instead he was able to see juveniles of a similar species, Atelopus limosus, at a private reserve in South America. “It’s an incredible experience to see those small frogs clambering[RM1] around rocky streams. They are like jewels.”
Alarms first sounded in 1989 at the first World Congress for Herpetology in Canterbury, England. At the Congress, ecologist Martha Crump explained to colleagues that for the second year in a row, Golden Toads in Monteverde were not gathering at their traditional breeding pools. The Monteverde Reserve, in a brief period, went from hosting thousands of frogs to one single male that year.
“After she made her announcement, she found that people started approaching her with similar stories and concerns, and suddenly this picture started emerging that amphibians, all over the world, were disappearing—Australia, Latin America, Europe,” Moore says. “No one knew why.”
Ten years later, in 1999, conservationists identified the newly understood chytrid fungus, Batrachochytrium dendrobatidis (“Bd”), and how the disease inhibited the frogs’ ability to breathe through their skin. Yet a solidified call to action did not come until 2004, when researcher Karen Lips distinguished the geographic and ecological patterns of the frog-killing fungus across the Latin American landscape. Her findings communicated the pathogen’s ability to singlehandedly eradicate amphibian populations in predictable waves.
Although conservationists finally identified the how, they were left with the why. Why was the disease continuing to spread along these courses, further and faster?
Although many questions remain, it is highly likely that climate change possesses a disastrous relationship with the chytrid fungus, nursing its spread. Evidence supporting this claim continues to grow around the world.
A Global Ecological Disruption
According to the Intergovernmental Panel on Climate Change, warming temperature is causing a global ecological disruption, and is clearly linked to human industry and consumption. The IPCC states that the climate system is experiencing unequivocal warming and that we have experienced successively warmer temperatures for the last three decades in a row.
That’s bad news for the frogs.
According to research from Jamie Fisher, Bd thrives in cool, moist environments. Amphibians seeking refuge in higher montane regions were once safe from the fungus, since temperatures remained below the pathogen’s temperature range. Over the last few decades, however, balmier evenings have temperatures shifting closer to Bd’s thermal optimum, according to a study by Andrew R. Blaustein.
Each year’s warming trends have allowed Bd to climb further into the highlands of Central and South America, while simultaneously reducing amphibians’ ability to fight disease, diminishing critical water supplies, and causing more frequent and extreme severe weather events. For a class of species already fighting to stay healthy, these threats diminish their chances even further.
The Case for Optimism
What lies beyond the damage done? The streets of El Valle de Anton in Panama already know the answer. Frogs play an invaluable role in the larger ecosystems, communities, and cultural heritage. Research by Helen Meredith, Collin Van Buren, and Rachael Antwis for Conservation Evidence lists amphibians’ contributions to human medicine; their vital role in ecosystem services, from soil bioturbation to nutrient cycling; and their timeless cultural appeal.
As for now, the IUCN Red List of Threatened Species classifies the Panamanian Golden Frog as Critically Endangered. Most researchers believe it is extinct in the wild. Disparate populations remain in captive-breeding programs in zoos across the United States. Yet Meredith and Moore remain hopeful.
“If I ever become seriously pessimistic, I must find another job,” Meredith says. “You simply can’t be a pessimistic conservationist. There are fantastic projects all over the world that can act as templates for environmentalists everywhere. The heart of these projects work, and the more they can achieve, the more likely our collective efforts will spread.”
Global Wildlife Conservation, the Amphibian Survival Alliance, IUCN’s Amphibian Specialist Group, and a number of zoos are a few of the several organizations already taking action. Together, international experts are collecting data, tracking trends, and conserving as much land as possible in their precious race against time.
“It is now close to twenty years after chytrid was first described and we still don’t know how to get rid of it in the wild,” Moore says. “We need creative, out-of-the-box thinking. We need to be bold.”