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).
