The black mimosa, Mimosa pigra, is a prickly shrub that forms impenetrable thickets up to six metres high. Native to America, this species has become invasive in several tropical regions of the world, including parts of Australia and Southeast Asia. In the Pacific, M. pigra is so far only known of in three localities in Papua New Guinea (PNG). One of these infestations is situated close to Madang in Northern PNG.
On PNG mainland Mimosa pigra especially threatens the wetlands of the Sepik and Ramu river basins. The successful invasion of M. pigra into the Sepik and Ramu River systems would endanger thousands of livelihoods in the floodplains where people depend on traditional fishing and agriculture as well as on tourism. The Sepik River, probably the largest unpolluted river in the Asia-Pacific region, hosts one of the world’s highest levels of biodiversity including many endemic species such as the Sepik Blue Orchid (Dendrobium lasianthera). In the Oro Province, PNG, M. pigra could displace, amongst others, the world’s largest butterfly, Ornithoptera alexandrae, which is currently classified as Endangered (IUCN Red List, 1996). The expected spread of M. pigra could threaten virtually all other plant species in wetland areas and would make infested areas inaccessible to animals and people.
This project has been proposed by the Secretariat of the Pacific Community (SPC) on behalf of The National Agricultural Quarantine and Inspection Authority, PNG, who will be leading the project. The aim of the project is to determine the feasibility of managing, through eradication or control, the M. pigra infestation at the site in Madang. It is anticipated that the project will increase public awareness of the negative affects of M. pigra on biodiversity and people. This in turn will help gain support from communities to contain the species within the site it is currently present. The project is funded by NZAID, New Zealand's International Aid and Development Agency. A feasibility team visited the Madang site in June 2006. A report is being written that will stipulate recommendations on future actions towards the management of M. pigra.
Several national agencies have agreed to support the eradication project:
- The National Agricultural Quarantine and Inspection Authority
- The Department of Environment and Conservation
- The National Agricultural Research Institute
Souad Boudjelas – (firstname.lastname@example.org)