Weed wide web: characterising illegal online trade of invasive plants in Australia

Abstract

Invasive plants seriously impact our environmental, agricultural and forestry assets, and the ornamental plant trade is a major introduction pathway. The variety and extent of ornamental plant trade is growing in reach and is increasingly facilitated by the internet (i.e., through e-commerce). A lack of surveillance and regulation of e-commerce has resulted in invasive species being widely traded on these platforms. Here, we investigated the illegal trade in invasive plant species occurring in Australia by collecting advertisements found on a popular e-commerce website. Across a 12-month period we found 155 plant taxa advertised online that were prohibited to trade in Australian. From 10,000 advertisements (4.25% of total advertisements found), we found 1,415 instances of these invasive plants advertised, of which 411 breached local jurisdictional (i.e., State or Territory) laws. Opuntia cacti and invasive aquatic plants were traded in the greatest quantities. A variety of uses for plants prohibited to trade were purported by sellers, where aquatic uses were the most popular (i.e., water filtering and habitat for aquatic animals). Despite Australia’s strict internal biosecurity regulations, we found that trade prohibitions had no influence on the quantity and price of illegal invasive plants traded. Given this, and the extent of illegal invasive plants traded, we believe increased monitoring and regulation of online plant trade is warranted. However, to obtain the most optimal outcomes, regulations should be coupled with increased cooperation from e-commerce platforms and public awareness campaigns. Future weed risk assessments should consider online trade as a key factor in the long-distance dispersal and propagule pressure of a plant. Jurisdictions would also benefit from greater alignment on plant trade prohibitions and revision of associated compliance policies.