Suchergebnisse

We conducted comparisons for exotic mammal species introduced to New Zealand (28 successful, 4 failed), Australia (24, 17) and Britain (15, 16). Modelling of variables associated with establishment success was constrained by small sample sizes and phylogenetic dependence, so our results should be interpreted with caution. Successful species were subject to more release events, had higher climate matches between their overseas geographic range and their country of introduction, had larger overseas geographic range sizes and were more likely to have established an exotic population elsewhere than was the case for failed species. Of the mammals introduced to New Zealand, successful species also had larger areas of suitable habitat than did failed species. Our findings may guide risk assessments for the import of live mammals to reduce the rate new species establish in the wild.

Feral pig populations are expanding in many regions of the world following historically recent introductions. Populations are controlled to reduce damage to agriculture and the environment, and are also a recreational hunting resource. Knowledge of the area over which feral pigs may expand in the future could be used regionally to assist biosecurity planning, control efforts and the protection of biodiversity assets. The present study sought to estimate the future distribution of a recently introduced, expanding feral pig population in the remote Kimberley region of north-western Australia. An existing survey of feral pig distributions was enhanced and remote-sensing and weather data, reflecting or correlated with factors that may affect feral pig distributions, were collated and analysed. Relationships between feral pig distributions and these data were identified by using a generalised additive modelling approach. By the use of the model, the distribution of favourable habitat was estimated across the study region (89 125 km2). The potential future distribution of feral pigs in the Kimberley was then estimated, assuming only natural dispersal of feral pigs from areas of known feral pig status (cf. hunter-assisted movements or escape of domestic pigs). The modelling suggests that feral pigs could expand their distribution by realistic natural dispersal in the future (to 61 950 km2). This expansion possibility contains several strategically important areas (such as sea ports and biologically significant wetlands). This approach has the potential to improve biosecurity planning for the containment of the feral pig in the Kimberley and may have utility for other recently introduced invasive species in other regions. These results may also be used to improve pest-management programmes and contingency planning for exotic-disease incursions.

A risk assessment method was developed and applied to the Great Barrier Reef (GBR) to provide robust and scientifically defensible information for policy makers and catchment managers on the key land-based pollutants of greatest risk to the health of the two main GBR ecosystems (coral reefs and seagrass beds). This information was used to inform management prioritisation for Reef Rescue 2 and Reef Plan 3. The risk assessment method needed to take account of the fact that catchment-associated risk will vary with distance from the river mouth, with coastal habitats nearest to river mouths most impacted by poor marine water quality. The main water quality pollutants of concern for the GBR are enhanced levels of suspended sediments, excess nutrients and pesticides added to the GBR lagoon from the adjacent catchments. Until recently, there has been insufficient knowledge about the relative exposure to and effects of these pollutants to guide effective prioritisation of the management of their sources.