Mail order, the Internet, and invasive aquatic weeds.

Aquatic and wetland weeds pose serious threats to the freshwater resources of the United States. Essentially unregulated sale of plants for aquarium and ornamental pool use has resulted in the recent introduction and spread of several highly invasive weeds, including giant salvinia. This problem has been exacerbated during the past few years by mail-order and e-commerce. The objective of this study was to examine mail order and the internet as sources for sale of invasive aquatic weeds, with primary emphasis on the Internet. An online search was conducted using the search engine Yahoo™. Data were collected on twelve of the most common and highly invasive weeds sold by the industry. The data from the first 100 hits were grouped into regulatory, educational, commercial, hobbyist, and foreign sites. Essentially every aquatic or wetland plant listed in the United States as either a Federal Noxious Weed or as a noxious weed in one or more states was found. Twelve highly invasive plants intentionally sold by the wetland nurseries and water garden dealerships were found listed for sale by sites throughout the United States and internationally. This study shows that stronger enforcement of laws and regulations and an intensive education and outreach effort are needed to prevent further introductions of invasive