Invasive species cost the world $423 billion every year and are causing environmental chaos, UN report finds
Helen Regan, CNN
Tue, September 5, 2023
Invasive species cost the world at least $423 billion every year as they drive plant and animal extinctions, threaten food security and exacerbate environmental catastrophes across the globe, a major new United Nations-backed report has found.
Human activity – often through travel or global trade – is spreading these animals, plants and other organisms in new regions at an “unprecedented rate,” with 200 new alien species being recorded every year, leading scientists said.
Of 37,000 alien species known to have been introduced around the world, 3,500 are considered harmful and pose a “severe global threat” by destroying crops, wiping out native species, polluting waterways, spreading disease and laying the groundwork for devastating natural disasters.
The global economic cost is tremendous, scientists say, having at least quadrupled every decade since 1970.
That figure is “a huge, huge underestimate… it’s the tip of the iceberg,” said ecologist Helen Roy, co-author of the UN Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) report.
Without intervention to prevent their spread and impact, the total number of invasive species globally will be one-third higher in 2050 than it was in 2005, the scientists say.
“We know that things aren’t remaining unchanged. We know climate change is worsening, we know that land and sea-use change is worsening and therefore we anticipate that the threat posed by invasive alien species will also worsen,” Roy said
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An invasive cane toad sits inside a plastic bag after being removed from a trap at a billabong south of Darwin, Australia on May 11, 2005. - David Gray/Reuters/File
‘Global roots but very local impacts’
Alien species are plants, animals or other organisms that have been moved through human activities to a new region or area.
An alien species becomes invasive when it establishes itself in that new area and creates a negative impact on the local biodiversity and ecosystems, including on people’s way of life.
Numerous examples include water hyacinths clogging up lakes and rivers in Africa, lion fish impacting local fisheries in the Caribbean and the Giant African land snail taking over villages on Christmas Island in the Indian Ocean.
Meanwhile, brown tree snakes have eliminated entire bird populations on the Pacific island of Guam and the rapidly spreading zebra mussel has colonized the Great Lakes of North America.
And elsewhere, mosquitoes are spreading diseases like dengue, Zika, malaria and West Nile Virus to new regions.
“We shouldn’t overlook the magnitude of the impact of some alien invasive species,” said Peter Stoett, co-author of the report and dean of the faculty of social sciences and humanities at Ontario Tech University.
The spread of invasive species across countries and continents is a major driver of biodiversity loss – deteriorating the complex web of ecosystems “upon which humanity depends,” according to the report, which linked invasive species to 60% of recorded global extinctions.
Once an invasive species takes hold, the impacts can be disastrous.
The dried-out non-native grasses and shrubs in Hawaii helped fuel last month’s devastating Maui wildfire, one of the deadliest in modern US history.
“It would be an extremely costly mistake to regard biological invasions only as someone else’s problem,” said Anibal Pauchard, co-author of the report and professor at Chile’s Institute of Ecology and Biodiversity.
“Although the specific species that inflict damages vary from place to place, these are risks and challenges with global roots but very local impacts, facing people in every country, from all backgrounds and in every community – even Antarctica is being affected.”
‘Prevention, prevention, prevention’
Along with invasive species, other key drivers of biodiversity loss include destruction of land and sea habitats, exploitation of organisms, climate change and pollution.
The climate crisis will only amplify the threat of invasive species, becoming a major cause of these species spreading and establishing themselves in new regions, the report said.
As well as flammable invasive plants sparking and spreading wildfires, climate change is enabling invasive species to move north – even to remote areas such as high mountains, deserts and frozen tundra.
But there is hope. The scientists are optimistic that humanity can stop the march of invasive species. What’s needed first and foremost is: “prevention, prevention, prevention, especially when it comes to marine systems,” Stoett said.
Preventing the arrival of new species into new regions is the best way to manage threats from invasive species, according to the report. This includes strict import controls and early warning systems to detect and respond to species before they are able to establish.
For invasive species that have already taken hold, eradication has been a useful tool, especially on islands, according to the report.
“One of the most important messages from the report is that ambitious progress in tackling invasive alien species is achievable,” Stoett said.
“What is needed is a context-specific integrated approach, across and within countries and the various sectors involved in providing biosecurity, including trade and transportation; human and plant health; economic development and more. This will have far-reaching benefits for nature and people.”
Last year, governments around the world agreed to the Kunming-Montreal Global Biodiversity Framework to reduce the introduction and establishment of invasive alien species by at least 50% by 2030.
The scientists hope their findings – developed over four years by a team of 86 experts – will contribute to achieving these international targets.
“Governments around the world really need this assessment to get action going to reduce this tremendous threat to biodiversity and people,” Pauchard said.
Invasive species problem will be 'worse before it gets better'
Marlowe HOOD
Mon, September 4, 2023
Snails are among the most widespread and destructive of invasive species (JOE RAEDLE)
On land and in the sea, invasive species are destroying ecosystems, spreading disease and causing hundreds of billions of dollars in damage every year, according to a landmark report Monday from the UN-backed science advisory panel for the UN Convention on Biodiversity.
AFP spoke on the eve of its release to the three co-chairs of the report, approved last week in Berlin by the 143 member nations of IPBES, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.
The co-chairs are ecologist Helen Roy, a professor at the UK Centre for Ecology and Hydrology; Peter Stoett, dean of Social Sciences and Humanities at Ontario Tech University; and Anibal Pauchard, a professor at the University of Concepcion in Chile.
The following has been condensed and edited for clarity.
Q. You conclude that the number of invasive species is rising at an "unprecedented rate". Can you quantify that?
Roy: The problem is going to get a lot worse before it gets better. On current "business-as-usual" trends, we anticipate an increase of 36 percent by 2050. But that's assuming current conditions remain constant, which they won't.
With so many drivers predicted to worsen -- population, land use, global trade, climate change -- the increase of invasive alien species and their impacts are likely to be significantly greater. But there are so many factors, it's difficult to predict how many.
Q. The report put the damages caused by invasive species at $423 billion in 2019, but calls this a "gross underestimation". Why don't you have a more accurate figure?
Stoett: We should look at this figure as the tip of the iceberg -- it's what we have been able to see and measure. There are many other hidden costs, such as on health, like with the expanding footprint of malaria.
Many are intangibles. If a species goes extinct, how do you put a price on that? Or if people are losing pillars of their cultural identity.
Then there's the labour that goes into dealing with invasive species. In some communities women are pulling invasive species out of the ground all day. They're not getting paid, or taxed, so there's no record of it.
Q. Most invasive species spread through trade, but do individual consumers play a role too?
Pauchard: Yes, they do. Take ornamental plants. With a couple of clicks on the internet you can get a packet of seeds from just about anywhere. It may be non-native species, or have contaminants. When you plant it in your garden it may not stay there.
And then there's the pet and wildlife trade. People even have snails as pets without having any clue as to whether they are invasive. When they get bored of the pet, they just throw it in the garden or the pond, but it probably won't stay there.
Q. Prevention, eradication and containment -- which is most important?
Stoett: There is no doubt: prevention, prevention, prevention. If there's one word to distill what needs to be done, that's it. It is by far the most cost-effective. You invest less, and you get more.
Q. Examples of how prevention can be effectively done?
Roy: New Zealand, Australia have amazing biosecurity, as does Hawaii. Small islands are especially vigilant. If you go to South Georgia (in the South Atlantic Ocean) they will check the bottom of your boots and all your equipment.
Stoett: Human transportation is of course important, but the biggest problems are elsewhere -- shipping vessels carrying contaminated products, or species attached to their hull or in their ballast water.
Then there's the (deliberate) use of invasive species in agriculture and forestry. Grasses imported into Maui for grazing livestock were linked to the wildfires there.
Q. The report warns against the danger of "homogenisation" of ecosystems. Can you explain?
Pauchard: We live in cities, the most homogenised ecosystems in the world. We are losing our local communities, our local ecosystems.
The native grasses I saw when I first came to Europe are invasive species in Chile, where I'm from, and in California.
Homogenisation also goes with losing species, reducing uniqueness. It threatens the resilience of ecosystems. A more diverse natural area will be more resilient to climate change.
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Marlowe HOOD
Mon, September 4, 2023
The Florida Everglades is teeming with the destructive offspring of erstwhile pets and house plants, including the Burmese python (RHONA WISE)
Invasive species that wreck crops, ravage forests, spread disease, and upend ecosystems are spreading ever faster across the globe, and humanity has not been able to stem the tide, a major scientific assessment said Monday.
The failure is costing well over $400 billion dollars a year in damages and lost income -- the equivalent to the GDP of Denmark or Thailand -- and that is likely a "gross underestimation", according to the intergovernmental science advisory panel for the UN Convention on Biodiversity (IPBES).
From water hyacinth choking Lake Victoria in East Africa, to rats and brown snakes wiping out bird species in the Pacific, to mosquitoes exposing new regions to Zika, yellow fever, dengue and other diseases, the report catalogued more than 37,000 so-called alien species that have taken root -- often literally -- far from their places of origin.
That number is trending sharply upward, along with the bill for the damage multiplying fourfold per decade, on average, since 1970.
Economic expansion, population increase and climate change "will increase the frequency and extent of biological invasions and the impacts of invasive alien species," the report concluded.
Only 17 percent of countries have laws or regulations to manage this onslaught, it said.
Whether by accident or on purpose, when non-native species wind up on the other side of the world, humans are to blame.
The spread of species is hard evidence that the rapid expansion of human activity has so radically altered natural systems as to tip the Earth into a new geological epoch, the Anthropocene, scientists say.
- Hitchhikers -
The hyacinth that at one point covered 90 percent of Lake Victoria -- crippling transport, smothering aquatic life, blocking hydroelectric dam intake and breeding mosquitoes -- is thought to have been introduced by Belgian colonial officials in Rwanda as an ornamental garden flower before making its way down the Kagera River in the 1980s.
The Florida Everglades is teeming with the destructive offspring of erstwhile pets and house plants, from five-metre (16-foot) Burmese pythons and walking catfish to Old World climbing fern and Brazilian pepper.
In the 19th century English settlers brought rabbits to New Zealand to hunt and for food. When they multiplied like, well, rabbits, officials imported ferocious little carnivores called stoats to reduce their numbers.
But the stoats went after easier prey: dozens of endemic bird species that were soon decimated, from baby Kiwis to wrybills.
New Zealand and Australia -- where a similar bad-to-worse saga involving rabbits unfolded -- are "case studies" of how not to control one imported pest with another, Elaine Murphy, a scientist at New Zealand's Department of Conservation, told AFP.
More often, however, invasive species are accidental arrivals, hitching rides in the ballast water of cargo ships, the containers in their holds, or in a tourist's suitcase.
The Mediterranean Sea is full of non-native fish and plants, such as lionfish and killer alga, that journeyed from the Red Sea through the Suez Canal.
- Vulnerable small islands -
Murder hornets capable of wiping out entire bee colonies in a single attack are thought to have arrived in the US from Asia as stowaways in freight.
Largely due to huge volumes of trade, Europe and North America have the world's largest concentrations of invasive species, defined as those that are non-native and cause harm and have relocated due to human activity, the IPBES report shows.
Invasive species are a significant cause in 60 percent of all documented plant or animal extinctions, one of five main drivers along with habitat loss, global warming and pollution, according to the findings.
These drivers interact: climate change has pushed alien species into newly warmed waters or lands where native species are often vulnerable to intruders they have never encountered.
The deadly fire that reduced the Hawaiian town of Lahaina on Maui to ashes last month was fuelled in part by bone-dry grasses -- imported decades ago to feed livestock -- that has spread across abandoned sugar plantations.
A global treaty to protect biodiversity hammered out in Montreal last December sets a target of reducing the rate at which invasive alien species spread by half by 2030.
The IPBES report lays out general strategies for achieving this goal, but does not assess the chances of it being met.
There are basically three lines of defence, according to the report -- prevention, eradication and then, failing that, containment.
Attempts at eradication have generally failed in large bodies of water and open waterways, as well as on large tracts of contiguous land. The places with the highest rate of success in removing unwanted guests -- especially rats and other vertebrates -- are also the ones that have proved most vulnerable: small islands.
mh/klm/fg
Stuart Braun
Introduced species often become pests in non-native environments, creating monocultures that dilute local biodiversity. A new report focuses on ways to repulse the invaders.
When fire ants escaped their home in Argentina and started travelling around the world, often via shipping containers, few would have imagined the damage that the displaced insect would cause.
From China and Japan to Australia and the United States, this venomous alien pushed out and sometimes killed native populations of animals and insects — including those that pollinate local plants, causing long-term changes to vegetation. The ant, which also eats and damages seeds, can severely impact crops and native ecosystems.
Researchers say that fire ants prefer a warmer climate but are marching north into colder regions as the planet warms, laying waste to biodiversity along the way. Their spread has triggered costly eradication wars, but many have come too late.
The fire ant is symbolic of an unfolding crisis that is the focus of the Invasive Alien Species Assessment Report released today by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).
More than four years in the making, and produced by 86 experts from 49 countries, the assessment aims to raise public awareness and give policymakers the tools to mitigate the impacts of invasive alien species (IAS).
"Invasive alien species are a major threat to biodiversity and can cause irreversible damage to nature, including local and global species extinctions, and also threaten human well-being," said Helen Roy, UK Center for Ecology & Hydrology, and co-chair of the IPBES assessment report.
Biological invasions have been a "major factor" in 60% of global animal and plant extinctions, said Anibal Pauchard, assessment co-chair and professor at the Faculty of Forestry Sciences at the University of Concepcion in Chile.
"These are risks and challenges with global roots but very local impacts, facing people in every country, from all backgrounds and in every community — even Antarctica is being affected," Pauchard added.
Globalized economy facilitates alien invasions
Ecosystems have long adapted to the natural migration of plants and animal species across regions.
But the propagation of alien species across borders has rapidly accelerated in the last century, says Emili Garcia-Berthou, professor of Ecology at the University of Girona in Spain, and an expert on IAS impacts on freshwater ecosystems.
In recent times, itinerant species have ridden on the back of a relatively borderless, globalized trade and transport network, he explains.
"Now we have a huge transport capacity, we bring food and commodities from all parts of the world every day," he said. In addition, people move much more than before, importing alien species as they go.
In this globalized world, once isolated regional ecosystems have become increasing vulnerable to outside species that can become monocultures that crowd out local flora and fauna.
These impacts extend to human health, such as the invasive mosquito species currently behind malaria outbreaks in the Horn of Africa.
Comparing IAS to climate change, Garcia-Berthou refers to the outsized impact of introduced animals such as snakes, cats, rats, snakes or pigs on bird and mammal species on islands that carry a high proportion of the world's biodiversity.
Invasive species are implicated in 86% of known extinctions on islands, according to UNESCO — a mere 30 invasive species have contributed to the extinction of some 738 animals worldwide.
In the Pacific island nation of Tonga, for instance, introduced rats have severely repressed or displaced seabird populations, in part by feasting on their eggs and chicks.
Seabirds spread essential nutrients that feed into reef ecosystems and healthy fish stocks. Government and local communities have responded by eradicating rats using poisoned baits on Late Island — home to one of the world's largest intact tropical broadleaf forests, and among the many Tongan island ecosystems to be invaded by rats.
Garcia-Berthou notes that IAS are the second largest cause of biodiversity loss after habitat destruction, and ahead of climate change.
He describes the impact of aggressive mosquitofish, introduced from North America, on freshwater ecosystems in southern Europe. The rapid decline of the Greek native Corfu toothcarp freshwater fish, for example, is partly due to the alien species known to consume the egg and larvae of local fish and outcompete them for food and space.
Climate is further exacerbating these impacts, with warming waters set to expand the reach of non-native mosquitofish in Europe from Mediterranean to northern waters, including Germany, according to the ecology researcher.
Invasive species and climate interlinked
The IPBES Invasive Alien Species Assessment Report has focused strongly on the interconnected impacts of IAS and climate change.
"IPBES has made it very explicit that their assessments are all intermingled with the IPCC (the UN's climate change body) assessments, because you can't really do one without the other," said Corey Bradshaw, professor of Global Ecology at the ARC Center of Excellence for Australian Biodiversity and Heritage in South Australia.
But though the simple metric of temperature rise can be used to measure climate change, Bradshaw has supported research efforts to create a benchmark to judge the impact of invasive species by estimating the cost of prevention and control.
The global economic cost of managing invasive alien species exceeded $423 billion (€391 billion) annually in 2019, with costs having at least quadrupled every decade since 1970, according to the IPBES assessment.
Funding solutions to biological invasions globally
Creating a clear benchmark to measure IAS damage is motivating governments in wealthier countries to fund solutions, said Bradshaw.
"People are more prone to want to invest," he said.
Australia, an island nation that has been highly vulnerable to introduced species, has spent the second highest on IAS management globally behind the US — and ahead of China and Canada.
Most recently, Australian political parties have promised significant funds to help eradicate gamba grass, which was introduced into northern Australia as cattle feed in the 1930s and is today fueling wildfires as it spreads across the region.
"They are highly flammable when they dry out," said Bradshaw of the noxious weed, "and massively increase the severity and the extent of fires across much of the semi-arid parts of Australia."
These feral weeds also crowd out native plant species and impact biodiversity, he added.
Meanwhile, Emili Garcia-Berthou says that prevention of the movement of IAS must be a higher priority than management and control — implemented too often once the alien "invasion curve" has already peaked.
The IPBES assessment acknowledges that alien species "preventions" is the most "cost-effective management option."
"There is a lot we can do to prevent new species arriving and establishing in countries or to relocate them when they just arrived," Garcia-Berthou said, describing a need for better biosecurity and monitoring of cross-border travel and transport.
Edited by: Tamsin Walker
No more honey, tequila or bird song — as species on the planet disappear at an alarming rate cartoonist Rohan Chakravarty (aka Green Humour) looks at some of the essential services and guilty pleasures we could miss.
9 CARTOONS
An unsweetened world without honey
Animals help pollinate about 88% of the world's flowering plants — and few are better known than the honeybee. Humans have managed these bees for centuries, harvesting their sweet honey and wax to make items like candles. While domesticated honeybees aren't at risk of extinction, beekeepers worldwide are reporting massive colony losses. Threats include pesticides, climate change
…Image: Rohan Chakravarty/DW