Economic costs of invasive alien species in Mexico

Invasive alien species (IAS) are a leading driver of biodiversity loss worldwide, and have negative impacts on human societies. In most countries, available data on monetary costs of IAS are scarce, while being crucial for developing efficient management. In this study, we use available data collected from the first global assessment of economic costs of IAS (InvaCost) to quantify and describe the economic cost of invasions in Mexico. This description was made across a range of taxonomic, sectoral and temporal variables, and allowed us to identify knowledge gaps within these areas. Overall, costs of invasions in Mexico were estimated at US$ 5.33 billion (i.e., 10⁹) ($MXN 100.84 billion) during the period from 1992 to 2019. Biological invasion costs were split relatively evenly between aquatic (US$ 1.16 billion; $MXN 21.95 billion) and terrestrial (US$ 1.17 billion; $MXN 22.14 billion) invaders, but semi-aquatic taxa dominated (US$ 2.99 billion; $MXN 56.57 billion), with costs from damages to resources four times higher than those from management of IAS (US$ 4.29 billion vs. US$ 1.04 billion; $MXN 81.17 billion vs $MXN 19.68 billion). The agriculture sector incurred the highest costs (US$ 1.01 billion; $MXN 19.1 billion), followed by fisheries (US$ 517.24 million; $MXN 9.79 billion), whilst most other costs simultaneously impacted mixed or unspecified sectors. When defined, costs to Mexican natural protected areas were mostly associated with management actions in terrestrial environments, and were incurred through official authorities via monitoring, control or eradication. On natural protected islands, mainly mammals were managed (i.e. rodents, cats and goats), to a total of US$ 3.99 million, while feral cows, fishes and plants were mostly managed in protected mainland areas, amounting to US$ 1.11 million in total. Pterygopli-chthys sp. and Eichhornia crassipes caused the greatest reported costs in unprotected aquatic ecosystems in Mexico, and Bemisia tabaci to terrestrial systems. Although reported damages from invasions appeared to be fluctuating through time in Mexico, management spending has been increasing. These estimates, albeit conservative, underline the monetary pressure that invasions put on the Mexican economy, calling for urgent actions alongside comprehensive cost reporting in national states such as Mexico.