Recently Declared Aquatic Pest Plants

Recently a new initiative, the National Pest Plant Accord (NPPA), was introduced by the Ministry of Agriculture and Forestry, Regional Councils, the Department of Conservation, and other government agences with biosecurity responsibility regarding the sale of invasive plants. The NPPA directly affects a number of aquarium species.

The introduction of the National Pest Plant Accord has resulted in a number of species being declared as unwanted organisms under the Biosecurity Act 1993. As such they are banned from sale, propagation, distribution or commercial display. These species include:

Hornwort (Ceratophyllum demersum), Water hyacinth (Eichhornia crassipes), Egeria oxygen weed (Egeria densa), Caulerpa (Caulerpa taxifolia), Water poppy (Hydrocleys nymphoides), Lagarosiphon (Lagarosiphon major), Primrose willow (Ludwigia peploides), Water primrose (Ludwigia peruviana), Bogbean (Menyanthes trifoliata), Parrots feather (Myriophyllum aquaticum), Eurasian milfoil (Myriophyllum spicatum), Southern naiad (Najas guadalupensis), Sawtooth (Najas marina), Yellow water lily (Nuphar lutea), Entire marshwort (Nymphoides peltata), Fringed waterlily (Nymphoides geminata), Water lettuce (Pistia stratoides), Giant Arrowhead (Sagittaria montevidensis), Delta Arrowhead (Saggitaria platyphylla), Arrowhead (Sagittaria sagittifolia), Salvinia (Salvinia molesta), Water soldier (Stratiotes aloides), Water Chestnut (Trapa natans), Giant reedmace (Typha latifolia), Bladderwort (Utricularia gibba)

Also banned are the marginal aquatic plants Senegal tea (Gymnocoronis spilanthoides), Manchurian wild rice (Zizania latifolia) and phragmites (Phagmites australis).

The focus of the National Pest Plant Accord is to ban these plants from sale, distribution, propagation and commercial display, and to educate nursery growers and the public about the potential impacts of these species on the environment. The declaration of the plants as unwanted organisms also means that if it appears in an area where it is not previously known, control work can be carried out very quickly to remove the infestation under section 100 of the Act. As well, several of the plants have further rules that apply to them, for example water hyacinth, salvinia and water lettuce are nationally declared pest plants that must be reported to MAF if found.

Regional councils may also include a number of these plants in Regional Pest Management Strategies. For example, senegal tea, Manchurian wild rice, giant arrowhead, marshwort, fringed water lily, sagittaria and water poppy are all declared as "Total Control Pest Plants" within the Auckland region. This means that the Auckland Regional Council will undertake control work on any infestations of these plants. Regional Pest Management Strategies may also include rules regarding additional plant species. Within the Auckland region, for example, reed sweet grass (Glyceria maxima), Nardoo (Marsilea mutica) and yellow flag (Iris pseudacorus) are also banned from sale, distribution, propagation and commercial display. To find out more about which plants are declared pests within your region, contact your local Regional Council.

More information on the National Pest Plant Accord, and the plants that are included in it, can be found on the ProtectNZ website (http://www.protectnz.org.nz). Additional information on invasive aquatic species can also be found on NIWA's National Centre for Aquatic Biodiversity and Biosecurity website (http://www.niwa.co.nz/ncabb/).

Mike Harre
Biosecurity Officer (Response)
Auckland Regional Council