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

2.4.2        Australian lungfish

2.4.2.1      Ecological background
The Australian lungfish is a long, heavy-bodied, primitive freshwater fish that has five pairs of gills and its fins
resemble flippers. They have large, overlapping scales and a small mouth with large, crushing teeth on the
palate and lower jaw. Adult Australian lungfish can weigh up to 48 kg and grow to around 2 m, but commonly
reach 1.3 m and are dark brown or olive brown on the back and pink on the belly, with some whitish colour
on the belly and underside of the head (DAWE 2020e). Juveniles are dark olive, brown or yellow with a
mottled pattern above and a dull pink belly. The species is able to breathe aquatically using its gills, and
aerially using its single lung. It usually uses its gills, but surfaces to breathe when it is active and requires
more oxygen (DAWE 2020e).
The Australian lungfish is endemic to Australia and restricted to south-eastern Queensland. The species'
natural distribution is the Mary, Burnett and Brisbane River systems. However, the species has been
translocated to many other locations, with translocated populations persisting in the Coomera, Condamine,
Albert and Logan Rivers (DAWE 2021e). Within the Mary River system, the distribution of the Australian
lungfish within the Mary River is from the Mary River Barrage (59.3 km from the mouth of the river) to the
town of Conondale (220 km from the mouth of the river). It also occurs in large tributaries of the Mary River,
including Yabba Creek, Tinana Creek, Coondoo Creek, Wide Bay Creek, Obi Obi Creek, and Munna Creek
(DAWE 2021e).
The Australian lungfish inhabits still or slow-flowing, shallow, vegetated pools with clear or turbid water
where they feed on vegetation and invertebrates (the species is considered to be a low-level benthic
carnivore) which they ingest through a suctorial feeding method. They cannot live in saline waters or migrate
through sea water and are restricted to areas of permanent water. In order to spawn, the Australian lungfish
requires emergent or submerged vegetation which allows for successful deposition of eggs. These structures
also provide refuges for juveniles (DAWE 2021e).
The Australian lungfish are long lived (life spans ranging from 50 to 100 years), and mature very slowly, with
males reaching sexual maturity at 15 years of age, while females become sexually active at 20 years.
(DAWE 2021e). Whilst adult Australian lungfish are largely free of predation, eggs and juveniles are
susceptible to predation by insect larvae, shrimp and fish (DAWE 2021e).
The main threats to the Australian lungfish are impoundment of streams, erratic recruitment rates, recreation
anglers (caught as bycatch), exotic or translocated native fish, widespread clearing of aquatic vegetation
(particularly Vallisneria sp), and low genetic diversity (i.e. for populations in the Mary and Brisbane River
systems) resulting in decreased overall resilience (DAWE 2021e).


2.4.2.2      Potential impact
Whilst the Australian lungfish was not identified within or adjacent to the area of the proposed action, habitat
for the species (i.e. Six Mile Creek) has been identified as present (refer Figure 2.4). However, the proposed
action will not result in alteration or obstruction of the Six Mile Creek channel, or result in the loss of in-
stream aquatic vegetation (refer Section 1.3, Figure 1.2, Figure 1.3 and Figure 1.4). The structural integrity of
the channel will be maintained as part of the proposed action. Whist it is noted that the existing Six Mile
Creek bridge structures will be removed as part of the proposed action, instream structures will remain insitu,
thus avoiding disturbance to existing habitat for this species.
An assessment of significance related to potential impacts upon the Australian lungfish, 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 6.1.6 - Table 39).
In consideration of the absence of direct impacts and the proposed mitigation measures (refer Section 3),
and in consideration of Significant impact guidelines 1.1, the proposed action will not result in a significant
impact to the Australian lungfish.


                             Project number 511784 File Six Mile Creek - Matters of National Environmental Significance Report 2021-12-03 Revision 1   29