A New Code of conduct on aquatic plants in the Netherlands
After 3 years of negotiations, a Code of conduct on aquatic plants was signed on the 2010-02-23 at the botanical garden of the Leiden University (NL). This Code of conduct was signed in a very appropriate setting: the tropical greenhouse adorned by luxurious palms, orchids, impressive lianas and some very ornamental tropical aquatic plants. Partners signing the Code of conduct represented both public and private sectors: management authorities suffering from the prolific growth of invasive aquatic plants, as well as stakeholders having an economic interest in the sale of these plants. Signatories are: the “Unie van Waterschappen” on behalf of all 26 local water boards of the Netherlands, the Ministry of Agriculture, Nature and Food safety, as well as umbrella organisations and various associations representing producers, importers, retailers and garden centres such as DIBEVO, Tuinbranche Nederland, De Nederlandse Bond van Boomkwekers, De Vereniging van Vasteplantenkwekers. Several individual importers and producers of aquatic plants also signed the Code of conduct.
As of 2011-01-01, the signatories of the Code of conduct should stop selling the following 6 species in the Netherlands as they are considered to be invasive: Crassula helmsii (Crassulaceae, EPPO A2 List), Hydrilla verticillata (Hydrocharitaceae, EPPO Alert List), Hydrocotyle ranunculoides (Apiaceae, EPPO A2 List - prohibited since 2010 in the Netherlands), Ludwigia grandiflora (Onagraceae, EPPO List of IAP), Ludwigia peploides (Onagraceae, EPPO List of IAP) and Myriophyllum aquaticum (Haloragaceae, EPPO List of IAP).
An additional 7 species will be on sale only accompanied by recommendations on the appropriate use and disposal of the plants. These species are: Azolla spp. (Salviniaceae), Cabomba caroliniana (Cabombaceae, EPPO List of IAP), Egeria densa (Hydrocharitaceae, EPPO List of IAP), Eichhornia crassipes (Pontederiaceae, EPPO A2 List), Myriophyllum heterophyllum (Haloragaceae, EPPO Alert List), Pistia stratiotes (Araceae, EPPO Alert List) and Salvinia molesta (Salviniaceae, EPPO Alert List).
A communication campaign is part of the implementation of the Code of conduct, and several documents are produced for a vast audience. A leaflet for the general public providing information on how to use the plants wisely will be available in garden centres and pet shops selling aquatic plants. It can also be downloaded from the website of the Dutch Plant Protection Service. A similar leaflet to raise awareness among land managers will be launched in May 2010. This leaflet will be completed with a field guide to assist field staff in the identification of the 20 most troublesome aquatic alien plants.
The Dutch Plant Protection Service will closely monitor the compliance with the Code of conduct and the effects of the communication campaign.
Sources
The website of the Dutch Plant Protection Service: www.minlnv.nl/invasieve-waterplanten (at present in Dutch only)
Personal communication with Johan van Valkenburg, Dutch Plant Protection Service, J.L.C.H.van.valkenburg@minlnv.nl