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37,000 cataloged alien species cost humans $423 billion a year: report

37,000 cataloged alien species cost humans $423 billion a year: report

The number tends to increase and the claims bill quadruples. (Representative)


Invasive species that are wiping out crops, devastating forests, spreading disease and upending ecosystems are spreading around the world at an accelerating rate, and mankind has been unable to stem the tide, a major scientific review says Monday.

The failure costs well over $400 billion a year in damage and lost income – the equivalent of the GDP of Denmark or Thailand – and that’s likely a “gross underestimate,” according to the Intergovernmental Scientific Advisory Body to the UN Convention on Biological Diversity (IPBES).

From water hyacinths choking Lake Victoria in East Africa, to rats and brown snakes wiping out bird species in the Pacific, to mosquitoes introducing new regions to Zika, yellow fever, dengue and other diseases, the report cataloged more than 37,000 so-called alien species – often in the truest sense of the word – have taken root far away from their places of origin.

That number is trending sharply upwards, and the bill for damages has quadrupled on average every decade since 1970.

Economic growth, population growth and climate change “will increase the frequency and magnitude of biological invasions and the impact of invasive alien species,” the report says.

Only 17 percent of countries have laws or regulations to deal with this onslaught, it said.

Accidental or intentional, when alien species end up on the other side of the world, it’s man’s fault.

The spread of species is clear evidence that the rapid expansion of human activity has changed natural systems so radically that Earth has entered a new geological epoch, the Anthropocene, scientists say.


The hyacinth, which once covered 90 percent of Lake Victoria — crippling transportation, smothering aquatic life, blocking water intake from dams and breeding mosquitoes — is thought to have been introduced by Belgian colonial officials in Rwanda as an ornamental garden flower before they established their way down the Kagera River in the 1980s.

The Florida Everglades teem with destructive offspring of once-pets and houseplants, from fifteen-foot Burmese pythons and migrating catfish to Old World climbing ferns and Brazilian pepper.

In the 19th century, English settlers brought rabbits to New Zealand for hunting and food. When they bred like, well, rabbits, officials imported wild little carnivores called stoats to reduce their numbers.

But the stoats hunted easier prey: dozens of endemic bird species that were soon decimated, from young kiwis to crooked beaks.

New Zealand and Australia – where a similar bad-to-bad saga unfolded with rabbits – are “case studies” of how not to fight one imported pest with another, Elaine Murphy, a scientist at New Zealand’s Department of Conservation, told AFP.

More common, however, are invasive species arriving by accident, hitchhiking in the ballast water of cargo ships, in the containers in their holds, or in a tourist’s suitcase.

The Mediterranean Sea is teeming with non-native fish and plants like lionfish and killer algae that arrived from the Red Sea through the Suez Canal.

Vulnerable small islands

Killer hornets, which can wipe out entire colonies of bees in a single attack, are thought to have stowed away in cargo from Asia to the United States.

As the IPBES report shows, Europe and North America have the world’s highest concentrations of invasive species, defined as those that are non-native, harmful and have been relocated due to human activity, primarily due to the enormous volume of trade.

According to the results, invasive species are a major cause of 60 percent of all documented plant or animal extinctions and one of the top five causes alongside habitat loss, global warming and pollution.

These drivers work together: Climate change has pushed alien species into newly warmed waters or areas where native species are often vulnerable to invaders they’ve never encountered.

The deadly blaze that burned the Hawaiian town of Lahaina, Maui last month was fueled in part by bone-dry grass imported decades ago to feed cattle that has spread across abandoned sugar plantations.

A global treaty to protect biodiversity negotiated in Montreal last December sets the goal of reducing the rate at which invasive alien species spread by half by 2030.

The IPBES report sets out general strategies to achieve this goal, but does not assess the chances of achieving this goal.

According to the report, there are three main lines of defense: prevention, eradication, and failing that, containment.

In large bodies of water and open waterways, as well as on large contiguous tracts of land, attempts at eradication generally failed. The places with the highest success rate in removing unwanted guests — particularly rats and other vertebrates — are also those that have proven to be the most vulnerable: small islands.

(This story was not edited by NDTV staff and is auto-generated from a syndicated feed.)

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