What is the economic cost of biological invasions in our urban environments?

A recent study found an impressive economic impact of invasive species in urban areas, revealing a reported cost of US$ 326.7 billion between 1965 and 2021. The study, which found 61 invasive species across 24 countries, challenges our understanding of the true scale of the economic consequences of biological invasions in urban environments.

Invasive species encompass those with populations transported by humans beyond their natural biogeographic range and that can establish and spread in their introduced range. Hence, the environmental changes, and the high mobility of people and goods, facilitate the introduction of invasive species in urban areas where most of the human population lives.

These costs in urban areas represent approximately 15% of the total global economic impact of invasive species, estimated to be at least US$ 2.2 trillion. Urban areas, covering only between 0.6% and 3% of the Earth's surface, contribute significantly to the overall economic impact associated with biological invasions.

The study also reveals relevant gaps in our understanding of the economic impact of invasive species in urban areas. Most costs are strongly driven by a few species, such as Formosan subterranean termite, emerald ash borer, red imported fire ant, Mediterranean fruit fly, and feral pigeon. Other species probably have their costs underestimated, for example, Aedes mosquitoes. Moreover, most costs are concentrated in the United States of America, China, and Austria (respectively, US$ 261.5 billion, 518 million, and 169 million). 73 countries with occurrences of costly species in urban areas lack reported costs in the literature, implying a substantial underestimation of the global economic impact.

The management of invasive species in urban areas presents complex challenges, with costs frequently caused by damage rather than proactive management. The study underscores the importance of proactive measures to reduce and prevent future impacts associated with biological invasion in urban areas.

The study calls for stronger engagement with stakeholders, and more focused efforts to assess and report the costs related to the biological invasions in urban areas. Recognizing the financial drain caused by invasive species in urban environments enhances public and political awareness, fostering a collective effort to address this urgent global issue.

cite: Economic costs of invasive non-native species in urban areas: An underexplored financial drain. Gustavo Heringer, Romina D. Fernandez, et al. Science of the Total Environment, January 2024. DOI: https://doi.org/10.1016/j.scitotenv.2024.170336