Appendix D Terrestrial and Aquatic Biodiversity - Environment ...

Gulf Coastal Bioregion
This bioregion includes two large reserves – Barranyi (North Pellew Island) and the recently declared
Limmen NP and Limmen Gate Marine Park. The Gulf Coastal bioregion comprises gently undulating coastal
plains with scattered rugged areas of sandstones and sediments. The Pellew islands are an important
refuge area, containing populations of many species which have declined or become regionally extinct from
the adjacent mainland. The islands are relatively undisturbed and in unusually good condition. The islands,
and some mainland coastal areas, are also nationally significant as nesting sites for marine turtles and
colonial seabirds, and as feeding sites for migratory shorebirds.
Much of the bioregion is in reasonably good condition, although this is being destabilised by increasing
impacts of weeds, feral animals, changed fire regimes and grazing. There are also more localised impacts
from mining and exploration. Condition is generally better on the islands than on the mainland
Three nationally significant wetlands are recognised from this bioregion:
• Borroloola bluebush swamps (NT006: wetland types B14 and B13),
• Limmen Bight (Port Roper) tidal wetlands system (NT007: wetland types A7, A8, A9, A6 and A2),
and
• Port McArthur tidal wetlands system (NT008: wetland types A1, A7, A8, A6, A2, A9 and B5).
These are generally in good condition, but are affected by feral animals, and have occasional or potential
threats from commercial fishing and/or pollution associated with mining.
The main rivers include the lower reaches of the Roper, McArthur, Calvert, Robinson, Limmen Bight,
Wearyan, Foelsche and Towns Rivers. Riparian areas are generally in reasonably good condition, but are
suffering some degradation from uncontrolled livestock, other feral animals (buffalo, horses, pigs and
donkey). More localised conservation issues include weed infestations, pollution associated with mining, and
altered fire regimes.
No ecosystems are formally recognised as threatened, however rainforest patches, riparian areas and some
wetlands hold high conservation value and are sensitive to disturbance.
This bioregion includes 16 species listed as threatened at national of Territory level. This includes a six
marine turtles, of which at least 4 have significant populations and/or nesting sites within this bioregion. Two
of the listed threatened mammal species – Carpentarian Antechinus (Pseudantechinus mimulus) and
Canefield Rat (Rattus sordidus) occur in the Northern Territory but only within this bioregion. The Canefield
Rat is only known to occur on the Pellew Islands but the Carpentarian Antechinus has recently been
recorded on the mainland. The significant seabird breeding colonies are currently unreserved and warrant
formal protection.
(Source: NRETAS website)
Client: Western Desert Resources Ltd Page 37 of 150
Doc No. DW120004-C0302-EIA-R-0036
Doc Title: Appendix D – Terrestrial Biodiversity Technical Report