According to a new U.S. Geological Survey, amphibians like frogs, toads and salamanders and disappearing at an alarming rate.
Researchers found that overall, amphibians declined 3.7 percent annually from 2002 to 2011. If this rate continues, these species will disappear by half in the next 20 years.
The more threatened species, considered “Red-Listed” in an assessment by the global organization International Union for Conservation of Nature, disappeared from their studied habitats at a rate of 11.6 percent each year.
While researchers have known for quite some time that some frog, toad and salamander species were decreasing, they didn’t discover until now a broad picture of how fast they were disappearing.
“We knew they were declining and we didn’t know how fast,” said Michael J. Adams, a research ecologist for USGS and the lead author of the study, Trends in Amphibian Occupancy in the United States, published in the journal PLOS ONE. “It’s a loss of biodiversity. You lose them and you can’t get them back. That seems like a problem.”
Scientists analyzed nine years of data from 34 sites spanning across 48 species. The study did not evaluate the cause of declines in amphibians, even though it’s been linked that amphibian losses have been because of development, disease, chemical contaminants, climate change and even introduced species. While a fungal disease blamed for frog die-offs in other countries is found in the United States, Adams said, “we’re not seeing patterns that would help us make that link.”
The study by USGS scientists and collaborators concluded that U.S. amphibian declines may be more widespread and severe than previously realized, and that significant declines are notably occurring even in protected national parks and wildlife refuges.
The study did offer surprising insights. For example, declines in population occurred even in areas managed for conservation of natural resources, such as national parks and national wildlife refuges.
“The declines of amphibians in these protected areas are particularly worrisome because they suggest that some stressors – such as diseases, contaminants and drought – transcend landscapes,” Adams said. “The fact that amphibian declines are occurring in our most protected areas adds weight to the hypothesis that this is a global phenomenon with implications for managers of all kinds of landscapes, even protected ones.”
“Amphibians have been a constant presence in our planet’s ponds, streams, lakes and rivers for 350 million years or so, surviving countless changes that caused many other groups of animals to go extinct,” said USGS Director Suzette Kimball in a news release. “This is why the findings of this study are so noteworthy; they demonstrate that the pressures amphibians now face exceed the ability of many of these survivors to cope.”
The Amphibian Decline Crisis
One third of all amphibians are threatened with extinction. Dr. James Hanken, Director of the Museum of Comparative Zoology at Harvard University explains why and how the loss of amphibians may affect human health.
6,000 Amphibian Species could be Extinct by 2100
Nearly half of the world’s 6,000 amphibian species could be extinct by the end of this century, noting increased global temperatures, fungal diseases, and pesticides as some reasons for their decline.
Frogs, toads, salamanders and newts are not as prevalent as they once were. Researchers say amphibians are facing a rapid decline across the globe, and some 165 species are believed to be already extinct.