Invasive alien species are expensive

Posted in:

Invasive alien species are plants and animals that have become harmful to the ecosystems in which they have settled. Harmful to biodiversity, health, and the economy. Estimated cost: $1,300 billion in 50 years.

They are often stowaways. Asian hornets arrived in France in a shipment of Chinese pottery, before colonizing almost the entire country in a few years, unfortunately for bees attacked by this invasive alien species (IAS). The tiger mosquito, which carries tropical diseases such as dengue or chikungunya, reached Europe by landing in an Italian port under a tire.

These are only two of the 880 invasive alien species recorded worldwide. Animal or plant species that are voluntarily or involuntarily introduced into a territory and whose distribution and impact has proven to be problematic. The emergence of invasive alien species has accompanied the emergence of globalization. These plants, animals, and even fungi have benefited from the increased trade and infrastructure that humans built.

serpent breaker

This is the remarkable case of black rats and house mice, followers of food shipments. ” In some African or Asian countries, there is a gradual increase in paved roads during the 20th century Explains Christophe Diani, researcher at the IRD, Institute for Research and Development, in Montpellier, southern France. ” Rodents climb onto trucks in search of food, then are often taken down involuntarily throughout the journey, forming stable populations year after year that will favor inland invasion. »

In the face of these types of invasive alien species, the islands are particularly vulnerable. Such was the case on the island of Guam, the American Pacific territory invaded by the brown tree snake in the last century on the Pacific island of Guam. “ It had no natural predators on this island and its population was able to grow slowly until it exploded Christophe Diagne says. Then he wiped out a very large part of the native species of birds. Since he is in a new environment and cannot find the usual trees that he used to climb in his native habitat, he begins to climb on electricity poles, often causing them to fall, with great interruptions in running from several hours to several days. of these snakes. »

Invaders are expensive

Invasive alien species are defined according to their impact on biodiversity, but also on human health, agriculture or infrastructure. And the bill is salty, according to a French study by the IRD, CNRS and the National Museum of Natural History, published last year in the journal. temper nature. Between 1970 and 2017, the cost of the IAS was $1.288 billion. The figure indicated by the authors has been underestimated due to a lack of accurate data in certain regions and species. Nearly $1,300 billion in half a century, which is an average of $27 billion annually. But for 2017 alone, the most recent bill available, the bill came to more than 162 billion, more than the GDP of fifty African countries.

Evils are known: destruction of crops or electrical cables, spread of parasites or diseases, effects of multiple IAS. “ They are types of reservoirs for pathogensidentifies Christophe Diagne, first author of the study. Upon arrival in an environment where the pathogen is not present, both animals and humans can be affected, which are considered naïve for this type of pathogen. »

green cancer

Conversely, IAS can say thank you to humans, often directly or indirectly responsible for its spread. In Tahiti, we thought we were doing the right thing by planting a beautiful Latin American tree in a garden, Myconia calvescens. It did some great damage. Tahitians called it “green cancer”. “ More than half of the island has been invaded by this tree Christophe Diani says. Since it is a large tree that covers the other plants around it, it prevents light from reaching these plants. We started with a simple desire to introduce a very beautiful ornamental plant, only to end up with a dramatic result because some of the native species of Tahiti simply no longer exist. »

Biodiversity is collapsing everywhere, and it will be more profitable to fight invasions than to fight their effects. Christophe Diagne also called for more restrictive legislation as the disease worsens each year. We could also have talked about the world’s number one invasive species. The human race that colonized the planet is slowly destroying it.

“Rabbits, do they… really love rabbits?” »

In any case, this is what Australians were able to notice in the nineteenth century, with the explosion of rabbit numbers imported from Europe, thanks to the mild climate in Australia that allows for breeding all year round. The damage is great to agriculture and the environment. Then the Australians decided to introduce foxes to hunt them. But they attack marsupials, koalas and kangaroos. Later, in the twentieth century, myxomatosis will appear. It is present today on almost the entire planet.

Leave a Comment