Degradation and rehabilitation of wetlands in the Alligator Rivers Region of northern Australia
The wetlands of the Alligator Rivers Region of northern Australia have been recognized as having high national and international conservation value. The diversity and productivity of these habitats is, however, under current and future threat from invasive feral animals (Asian water buffalo and pigs) and naturalized alien plants (mimosa, salvinia and para grass) and also from climate change and sea level rise. Some habitats have already been severely degraded and require rehabilitation. In response to this situation feral animal management has centered on eradicating the buffalo population and introducing measures to control pigs. Weed management has focused on control of mimosa and salvinia with an increasing emphasis on integrated control measures. The vulnerability of the freshwater wetlands to climate change and sea level rise is considerable, although the exact nature of environmental change has not been determined. Rehabilitation of the degraded wetlands has centered on controlling the cause of the problem (e.g., the invasive species) and allowing subsequent natural succession to occur. It is recommended that further monitoring and assessment of successional change is undertaken to ascertain if this is sufficient. An integrated monitoring program for detecting the extent and rate of ecological change because of climate change and sea level rise is also proposed. Specific management and research tasks for each of the major broad causes of wetland degradation within the region are made. It is then strongly recommended that all rehabilitation and monitoring activities, including related research, are conducted within a holistic management framework that takes into account the different land jurisdictions within the region and also within the broader landscape context. The utilization of existing management and research structures and processes is stressed as one means of achieving an integrated approach.