Threats to biodiversity

Biodiversity loss affects most areas of the region to varying levels. The primary driver is use of natural resources by humans for economic and social development.

An indicator of the health of biodiversity is the status of its ecosystems and species, many of which are now threatened. A range of threatening processes are implicated in observed reductions in the size and extent of more sensitive fauna and flora populations within the region.

The single most significant cause of biodiversity decline is loss of habitat, particularly through the clearing, fragmentation, and degradation of native vegetation. Weeds and feral animals are highly prominent throughout the entire region. Their impact can be diverse and severe - affecting primary production, biodiversity, downstream systems and landscape health. The impact of altered fire regimes is complex and affects various vegetation communities differently. Other impacts on biodiversity occur due to predation and competition with exotic and domestic species, pollution, climate change and unsustainable hunting and harvesting, land use intensification and coastal development.

Modified catchment hydrology, degraded water quality, and degradation of wetlands and riparian zones is also causing significant loss of biodiversity. The Burdekin floodplain was once teeming with productive wetlands. Most have been destroyed or filled. In the coastal floodplains, drainage in adjacent cane land often lowers water tables in remnant wetlands, in many cases eventually leading to a complete loss of the wetland.

The remaining wetlands suffer a variety of serious problems such as loss of their riparian zone, very poor water quality, significantly altered faunal communities, and infestation by terrestrial or aquatic weeds. In many areas, especially the Burdekin flood-plain, riparian vegetation is also seriously degraded.

Other important threats are direct access of stock into the wetlands, causing disturbances to water quality (turbidity, nutrient enrichment), trampling of banks and vegetation, changes to flow regime, weeds, lost connectivity with estuarine habitats, construction of fish passage barriers, irrigation tail water, and impacts of ferals such as pigs and brumbies.

These threats are listed by the Australian Government as Key Threatening Processes under the EPBC Act (1999).