2022-09-06 P&E Agenda - Item 5 - Attachment 1 - Six Mile Creek Bridge Replacement Offset Report - TMR

2.3.3        Giant barred frog

2.3.3.1      Ecological background
The Giant barred frog is a large, dark-olive green to black coloured frog that grows to 115 mm. The species
is characterised dark cross-bars on the hindlimbs, with dark thighs and yellow spots (DAWE 2021c).
The Giant barred frog occurs in southern Queensland and northern New South Wales. Within Queensland,
the Giant barred frog is known to occur from Doongul Creek in the Burrum River catchment, in scattered
locations in the Mary River catchment downstream to Kenilworth, the Upper Stanley River, the Caboolture
River and the Coomera River (DAWE 2021c).
The Giant barred frog occurs in rainforests and wet sclerophyll forests in upper to lower catchment areas, in
south-east Queensland, Giant barred frogs typically prefer a closed forest canopy with a relatively light cover
of vegetation at ground level (DAWE 2021c). The Giant barred frog is carnivorous as an adult and typically
feeds upon invertebrates. As a tadpole, the species typically feeds opportunistically upon biofilms, algae and
other organic material within the aquatic environment.
The Giant barred frog breeds in running water, such as streams. Eggs are laid out of water, in areas such as
bank overhangs or steep bank slopes, and upon hatching the tadpoles fall into the water. Clutch size for the
Giant barred frog is variable and may range from 1343 to 4184 with an egg diameter of between 1.7-1.8 mm
(DAWE 2021c). Giant barred frog tadpoles are large (i.e. over 100 mm in length) and are deep-bodied and
ovoid, with a tail length twice that of the body, with eyes that are located in a dorsolateral position. Tadpoles
are yellow-brown above with dark spots and a dark patch at the base of tail. The tadpole has a thick and
muscular tail, with fins that are opaque with dark flecking and low in profile (DAWE 2021c).
The main threats to the Giant barred frog include upstream clearing, changes in water flow regimes, declines
in water quality, disturbance to riparian vegetation, feral animals, domestic sock and weed invasion. In
addition, Chytridiomycosis (e.g. caused by the fungus Batrachochytrium dendrobaidis) has also been
identified as a threatening process for this species (DAWE 2021c).


2.3.3.2      Potential impact
Approximately 0.173 ha of the Giant barred frog habitat, which corresponds to the Lowland Rainforest of
Subtropical Australia TEC has been identified as being contained within the area of direct disturbance
associated with the proposed action (refer Figure 2.3). Analysis of this habitat against the conservation
advice for this species (DAWE 2021c) indicates that the identified Giant barred frog habitat constitutes
“habitat critical to the survival of the species”.
An assessment of significance related to potential impacts upon the Giant barred frog (and its habitat), as a
result of the proposed action, has been undertaken in accordance with the Significant impact guidelines 1.1
(DotE 2013) (refer Appendix A; Section 6.1.3 - Table 34).
In consideration of the relatively small area of disturbance (i.e. 0.173 ha), the localised nature of potential
impacts, the nature of disturbance, the proposed mitigation measures, and in consideration of Significant
impact guidelines 1.1, the proposed action is not likely to result in a significant impact to the Giant barred
frog.
Mitigation measures to reduce the severity of these impacts include the provision of voluntary direct, land-
based offsets (refer Section 3.2) for the Lowland Rainforest of Subtropical Australia TEC (noting that the
Giant barred frog habitat is synonymous with this TEC). In addition, clearing the minimum extent necessary
for the safe construction and operation of the proposed action, and management measures to reduce edge-
related impacts from degrading areas that have been retained will also reduce the severity of impact to this
species. Further detail related to mitigation measures to reduce the potential impacts associated with the
proposed action, are provided within Section 3.2.




                             Project number 511784 File Six Mile Creek - Matters of National Environmental Significance Report 2021-12-03 Revision 1   23