A flurry of articles in influential scientific journals in recent months has questioned the urgency to address the growing threat to biodiversity from invasive species. The assertion is that the concern with invasive species derives from an unreasonable desire to maintain pristine ecosystems and exclude all alien species. Such criticism is, in fact, unfounded.
Conservationists recognize that ecosystems are dynamic, that alien species enter and are introduced into natural communities, and that modified (and even degraded) ecosystems have conservation value. In certain cases, alien species may prove beneficial to human wellbeing; examples of this include corn and potato crops, which were introduced to Europe and have become staple dietary components for millions of people. But, crucially, conservationists also recognize an important distinction between alien species in general—which are introduced outside their natural range by humans, but in many cases are harmless—and invasive species, which are not only introduced outside their range but also cause substantial harm to biodiversity and human livelihoods. Invasive species, not alien species, are indeed a major cause of biodiversity loss, implicated in the majority of extinctions recorded to date, and deserve aggressive intervention.
A letter published in Science today aims to highlight the growing threat to biodiversity from invasive species and addresses some of the dangerous mischaracterizations of the issue. The letter is signed by several leaders of well-established and respected conservation organizations, including IUCN’s Director General, Julia Marton-Lefèvre; the Chair of the Species Survival Commission (SSC), Simon Stuart; and the Chair of SSC’s Invasive Species Specialist Group, Piero Genovesi. The authors highlight that threats from invasive species can be mitigated and that biodiversity can be protected through decisive conservation interventions.
“Tackling invasive species also addresses the economic damage they cause and the serious threats that they pose to human health and livelihoods,” says Julia Marton-Lefèvre. “Attempts to remove the most harmful invasive species are proving to be increasingly successful, with more than 1,000 eradications completed worldwide to date.”
The letter concludes by noting that, at the Convention on Biological Diversity meeting in Nagoya, Japan in October 2010, 193 countries agreed, as part of a historic Strategic Plan for Biodiversity for 2011–2020, an explicit target to prevent, control and eradicate the most harmful invasive species by 2020.
In speaking out, the authors of the letter have demonstrated their clear commitment to the fight against invasives, and now call upon academics for support and, above all, action.