Strategic use of weed legislation to limit the spread of weeds in NSW

Although the NSW Noxious Weeds Act 1993 outlines a list of noxious weed species, these listings have not been used strategically to manage weed species from a state-wide perspective (i.e. to contain their spread). Using the following weed species: (1) cats claw creeper, (2) bridal creeper, (3) African olive and (4) fireweed, we illustrate how the declaration process, being a combination of the declared control areas (DCAs) and Control Classes (CCs) for individual species, can be used strategically to establish state-wide containment zones. Firstly, we overlaid the current distribution pattern for each taxa with the current DCA listings to highlight the degree of mismatch. Then, for each taxa, we systematically assigned each of the ‘unlisted’ DCAs with one of three CCs, being (i) eradication; (ii) suppression (containment) and (iii) asset protection, or left them as ‘unlisted’ for DCAs that are unlikely to be invaded. The selection of the CC for each DCA was based on its proximity to the current infestation, with DCAs covering core infestations assigned an asset-protection class, suppression assigned to those DCAs along the edge of the taxa’s distribution (i.e. with low density or scattered infestations), and eradication to all adjoining DCAs currently without the taxa or where it is scarce. The proposed approach will strategically limit the spread of listed weed species without the need for significant additional resources, simply by (i) raising awareness of the weed species with local stakeholders where it is absent or scarce, and (ii) ensuring that suppression and monitoring occurs in areas with low densities. Whilst the proposed change requires the support of local control authorities, we believe that a more comprehensive and strategic approach to containment of listed species will have direct benefits for all stakeholders. The underlying approach can also be applied to other jurisdictions.