Health, agriculture, fishing, real estate… Researchers point out the gigantic economic cost of invasive species

Almost 163 billion dollars in 2017. A sum twenty times greater than the cumulative annual budgets ofWorld Health Organization (WHO) and the UN. And which far exceeds the GDP of 50 of the 54 countries of the African continent.

Take the repository you want, the conclusion remains the same: the economic cost generated by invasive alien species, also called “invasive species”, is gigantic, point out scientists from the CNRS,
the Research Institute for Development (IRD) and
National Museum of Natural History in a study published this Wednesday in Nature. And these 163 billion are only for 2017. Since 1970, the economic losses related to invasive species amount to 1.288 billion dollars worldwide.

5,000 invasive species in Europe alone?

By exotic species, “we mean all those introduced by humans, voluntarily or not, into an environment where they had never lived until then, defines Franck Courchamp, CNRS research director and ecologist, co-author of the study. Their number is estimated at 14,000 in Europe, with some high estimates suggesting 20,000. “

Many do not adapt to their new environment, others do so without making waves. Still others become pests to the point of causing species extinctions and / or causing significant damage. These are what we call invasive alien species. The tiger mosquito, which came from Southeast Asia and is now present in a hundred countries on five continents, is undoubtedly the best known case. But it is also the
fire ant in the USA,
the zebra mussel in the great Canadian lakes, the
brown tree snake on the
guam island, the rabbit in Australia, the
jussie [une plante rampante] in Africa,
ambrosia in Western Europe … Or even
the cat on many islands.

We could go on with the list for a long time. “These invasive species come from all taxonomic groups (plants, fungi, invertebrates, vertebrates, etc.) and all environments (aquatic, terrestrial, etc.), recalls Franck Courchamp. In Europe alone, their number is estimated at 5,000. “

Talk in dollars to alert the public?

TheInternational Union for the Conservation of Nature (IUCN) makes these biological invasions the second factor in the loss of biodiversity in the world. However, they remain unknown to the general public and decision-makers. “One of the reasons is that these impacts on biodiversity are difficult to measure using meaningful indicators,” says Franck Courchamp.

This is the whole purpose of their work: to show that beyond the ecological consequences, these invasive species also generate heavy economic losses quantifiable in dollars, which speak this time to everyone. To arrive at their estimate, presented as the most complete to date, these researchers worked for five years from the InvaCost database *. Supplied since 2014 by an international network of economists and ecologists, Invacost compiles the various studies estimating the economic costs generated by invasive alien species.

“For this study, we focused on the most robust data recorded in Invacost, i.e. 2,419 for which we have developed an analysis tool making it possible to compare and classify them according to around forty variables (species, regions , type of environment, economic sector, etc.) ”, explains Christophe Diagne, researcher at Ecology, Systemics and Evolution laboratory, first author of this study.

Health, agriculture, tourism, real estate

These costs are already sanitary. Lethal diseases carried by insect vectors, such as dengue or chikungunya transmitted by the tiger mosquito, cause tens of thousands of deaths and millions of hospitalizations each year. The agriculture, fishing and forestry sectors are also hit hard. “Just for the asian longhorn beetle, a beetle [originaire de Chine ou de Corée] which destroys forests in the United States and arrives in Europe, the cost has amounted to 40 billion dollars over the last twenty years ”, illustrates Franck Courchamp.

These invasive species can also impact tourism and depreciate real estate. Like the coqui frog, arrived on the island of Hawaii and whose piercing song annoys the residents. Others cause significant damage to infrastructure. This is the case with zebra mussels in the great Canadian lakes, which
clog and damage subsea pipelines.

1.288 billion dollars, “a very underestimated figure”

Once again, we could go on with the damage list for a long time. Even this estimate of 1.288 billion dollars “remains very largely underestimated”, warns Christophe Diagne. “We have already taken into account only part of the InvaCost data,” he recalls. And there are biases. Only certain regions – North America, Oceania, a little less Europe – for example today have extensive research work on biological invasions and the estimation of their costs. “

One thing is certain, however: these economic costs are increasing as international trade and global warming [qui permet à des espèces de mieux s’acclimater aux milieux dans lesquels elles sont introduites] intensify. “The average annual cost over the period 1970-2017 that we took into account is $ 26.8 billion,” continues Christophe Diagne. But it has tripled each decade, reaching 162.7 billion dollars in 2017 alone. “

Soon a focus on France?

Another certainty pointed out for the researchers: “The amounts invested in the prevention, surveillance and fight against the spread of these invasive species remain marginal compared to the damage they can cause once they have established themselves in a territory. “

A call to decision-makers to act as early as possible, knowing that the European Union can do better in this area. ” The blacklist of invasive alien species considered to be of concern by the EU, there are only 66 to date, ”says Franck Courchamp. The ecologist announces a follow-up to this first estimate. It will be published in the coming months, and which will focus on France. “The figures are edifying,” he already announces.