Frogs, lizards and other amphibians and reptiles living in places they don’t belong to cost the world at least $ 17 billion between 1986 and 2020, a group of international researchers concluded in a new study.
But the true cost of these invasive species is much greater, said the authors of the article published in the journal Scientific Reports.
The first-of-its-kind assessment calculated the economic cost of just 27 species reported in a worldwide database – 10 times more reptiles and amphibians are classified as invasive, said lead author Ismael Soto, a PhD student at the University of South Bohemia in the Czech Republic.
Invasive species, from parasites to pythons, have become a global problem with the expansion of trade. Some species, such as frogs and iguanas, are sent away from their homelands as exotic pets. Others, such as spiders and cockroaches, hitchhike in packs and crates carrying produce.
Depending on the circumstances, once a non-native species arrives at its new destination, it can spread rapidly, wipe out native species, carry exotic diseases, and cause other problems.
These invasions are widely expected to grow even worse with climate change as warmer temperatures provide more comfortable homes for species on the go.
It’s “a huge problem,” said Catherine McKenna, Canada’s former environment and climate change minister and chairman of a new UN global climate task force.
More than 6,500 non-native species have been identified in the United States, costing about $ 100 billion in economic damage each year, according to a 2005 US Geological Survey study, the most recent estimate available.
Invasive species can increase the costs of water and electricity supplies, degrade recreational opportunities and discourage tourism, said Rachel Pawlitz, head of public relations for the Geological Survey.
The researchers also found cases of decline Property values after coqui frogs, which are native to Puerto Rico, have infested the areas with their “extremely loud” mating songs.
Working with the worldwide database called InvaCost, a collaboration launched two years ago by a couple of French researchers, Soto and others hope to better understand the economic toll of invasive species around the world. But as Soto’s group found, reporting on economic data is still incomplete, particularly in areas like Africa and South America.
The total economic costs for all the thousands of invasive species identified in the world would be many, many times higher, said Andrew Kramer, assistant professor of biology at the University of South Florida.
The new study is at least the third this year to call on authorities around the world to step up efforts to reduce risks by more closely monitoring the movement of potentially invasive species.
As the climate warms, species can carry new infectious viruses to other animals and humans, according to a study conducted in April by Georgetown University researchers Colin Carlson and Gregory Albery.
In Canada, tick-borne cases of Lyme disease have quadrupled, McKenna said. Scientists have also seen increasing damage along the Great Lakes and the St. Lawrence River, where nearly 200 invasive species have been identified.
Of the nearly $ 17 billion in costs that Soto and colleagues counted for the 27 reported species, $ 10.4 billion was attributed to reptiles and $ 6.3 billion to amphibians. Costs were unavailable for 94% of the world’s invasive reptiles and amphibians.
The vast majority of the costs of the amphibians studied by the group were spent on efforts to eradicate or manage the American bullfrog in European countries.
More than 99% of the money spent on reptiles went to control the damage caused by the brown tree snake in the South Pacific. In Guam this year, the Department of the Interior was expected to spend more than $ 4.1 million on snake control, which caused power outages across the island and the extinction of 75% of bird species. native to the island.
Florida is infamous for its explosive population of invasive Burmese pythons that devour mammals in the Everglades.
In June, biologists captured the state’s largest ever python, a 215-pound colossus that measured nearly 18 feet in length. Inside its abdomen, the Conservancy of Southwest Florida reported a record of 122 eggs and the remains of an adult white-tailed deer.
Pythons reflect the destruction that invasive species can cause in native ecosystems. Studies have shown that pythons wiped out rabbit and fox populations in the southern part of Everglades National Park.
The state has removed 16,000 Burmese pythons since 2020. Its 10-day annual python hunt, the Python Challenge, begins Friday.
Soto and his colleagues have suggested that the world needs more investment to limit the transport of potentially invasive species and detect them once they arrive. He acknowledged that it would be difficult, but said authorities could regularly update a “blacklist” of species that cannot be traded.
Since the consequences are unpredictable, Kramer said, not moving species at all or “doing better to prevent their settlement is the best way to save money.”
“We must do better to keep the species they belong to”,
Dinah Voyles Pulver deals with climate and environmental issues for USA TODAY. She can be reached at firstname.lastname@example.org or at @dinahvp on Twitter.