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 ( Tait
2004 ).
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( Tait
2004 ). Their impact can be diverse and severe - affecting
primary production, biodiversity, downstream systems and landscape
health ( Tait 2004 ). 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. In some cases this is compounded
by infilling of the wetland depressions to increase the area and
accessibility of cropping land ( Tait 2004 ).
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).