Condition, impacts and threats to aquatic biodiversity

[Extract] The aquatic systems that support the distinctive and diverse biodiversity of northern Australia are in relatively good ecological condition because of the region's low population density and limited land and water use (NLWRA 2002, Woinarski et al 2007). Nonetheless, a range of existing and potential threats impinge on the natural values of these ecosystems and may reduce their future capacity to sustain aquatic biodiversity. In this chapter, we first evaluate and discuss the known current condition of aquatic ecosystems of northern Australia. We then discuss the current condition of different catchments in the region and identify a broad range of potential threats. Next, we elaborate on the nature of these threats and describe the manner in which future human activities and climate change may intensify and multiply the range of threats. It needs to be stressed that, although there are currrent threats to the rich aquatic biodiversity of northern Australia, they are frequently diffuse in distribution and intensity. Such a situation may not continue into the future, however. Remediation or control of these threats is needed now to prevent more widespread damage