Targeted Green and Golden Bell Frog Study · 05462 HWR ecological research & innovation Green &...

Appendix F

Targeted Green and Golden Bell Frog Study

05462

HWR ecological research & innovation

Green & Golden Bell Frog Assessment Proposed Upgrade of SH23 Shortland to Sandgate

Newcastle, Hunter Region

Report to Roads and Traffic Authority

Nigel Cooper & Geoff Winning

7 May 2006

Thornton Office

PO Box 229, THORNTON 2322

p 02 4966 0513

f 02 4966 0513

e [email protected]

Highfields Office

PO Box 55, KOTARA 2289

p 02 4942 4346

f 02 4947 8853

e [email protected] HW

R P

TY L

IMIT

ED

A

BN 7

1 09

4 28

6 14

7

GGBF Assessment – Proposed Upgrades of SH23 Shortland to Sandgate i

Document Control

Issue Date Purpose of Issue Changes from Previous

Issue Authors Checked Director

Authorisation

23 Dec 2005 Draft for client comment n/a NC, GW GW GW

7 May 2006 Final Minor corrections and edits. GW GW GW

GGBF Assessment – Proposed Upgrades of SH23 Shortland to Sandgate ii

Table of Contents

1. GENERAL INTRODUCTION ............................................................................................1

1.1 Background.........................................................................................................................1 1.2 Brief Description of the Proposal .......................................................................................1 1.3 Definition of Study Area ....................................................................................................1 1.4 Scope of Report ..................................................................................................................1 1.5 Description of Study Area ..................................................................................................2 1.6 Previous Flora & Fauna Studies .........................................................................................2

2. BACKGROUND INFORMATION.....................................................................................5 2.1 Historical Changes to Wetlands in the Study Area ............................................................5 2.2 The 2HD Swamp & GGBF Habitat....................................................................................5

3. DETAILED INVESTIGATIONS ........................................................................................7 3.1 Introduction ........................................................................................................................7 3.2 Methodology.......................................................................................................................7 3.2 Results ................................................................................................................................8

4. POTENTIAL IMPACTS ON GGBF .................................................................................10 4.1 Introduction ......................................................................................................................10 4.2 Potential Impacts on GGBF..............................................................................................10

5. LEGISLATIVE ASSESSMENTS......................................................................................13 5.1 Environmental Planning & Assessment Act 1979 ...........................................................13 5.2 Environment Protection & Biodiversity Conservation Act 1999.....................................14

6. CONCLUSIONS ................................................................................................................16 7. REFERENCES...................................................................................................................17

GGBF Assessment – Proposed Upgrades of SH23 Shortland to Sandgate 1

HWR Ecological

Specialist Consultancy Services in Wetland and Bushland Ecology

1. GENERAL INTRODUCTION

1.1 Background

The NSW Roads and Traffic Authority (RTA) proposes to upgrade of State Highway 23 (SH23) from Shortland to Sandgate (the Proposal). This study assesses the potential effects of the Proposal on Green and Golden Bell Frog (Litoria aurea), which is listed as endangered under the NSW Threatened Species Conservation Act 1995 (TSC Act) and as vulnerable under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). This study is part of a review of environmental factors (REF) being undertaken for the Proposal pursuant to Part 5 (s.111) of the Environmental Planning and Assessment Act 1979 (EPA Act), to take into account all matters affecting or likely to affect the environment as a result of the proposed action.

1.2 Brief Description of the Proposal

The Proposal comprises construction of a two-way median-separated dual carriageway highway commencing at the intersection of the existing SH23 and Sandgate Road, continuing north-northeast to link up with Maitland Road south of St Josephs Nursing Home. The proposed highway would be located to the east of Shortland Wetlands Centre before the Main Northern Railway, continuing west of Sandgate Cemetery before linking to Maitland Road at Sandgate. The northern end of the road would pass close to an unnamed wetland informally known as the ‘2HD Swamp’, in which a population of Green and Golden Bell Frog (GGBF) has been recorded.

1.3 Definition of Study Area

The following terms have been adopted in this report to describe different parts of the study area (Figure 1):

(i) proposal area -the area to be directly affected by the road construction (including embankments, etc.);

(ii) study area - all areas which are likely to be affected by the proposal, either directly or indirectly, including nearby water courses and wetlands that may be affected hydrologically, or which may provide habitat for GGBF;

(iii) investigation area - the area in the vicinity of the 2HD Swamp that has the potential to provide habitat for GGBF.

1.4 Scope of Report

The key objectives of the study were to: (i) provide information on the GGBF population in accordance with state and national

statutory legislative requirements; (ii) provide a habitat model to determine which areas are important to the GGBF; (iii) identify the likely effects of the Proposal on GGBF and their habitats, both direct and

indirect;


HWR Ecological


(iv) determine the most effective amelioration measures based on site-specific data, personal knowledge of the study area of the authors, and knowledge of GGBF ecology contained in the scientific literature;

(v) determine whether a species impact statement (SIS) is required and/or whether referral to the Commonwealth Minister for Environment is required.

1.5 Description of Study Area

The study area comprises low lying areas of Shortland and Sandgate which includes a mix of wastelands (i.e. previously cleared areas now dominated by weeds), remnant wetland areas, small patches of remnant forests and various infrastructure and land uses including minor roads, a railway line, a cemetery, industrial uses, residential areas and easements. The study area includes a number of wetland areas, including an unnamed wetland informally known as the ‘2HD Swamp’ in the northern part of the study area, Hexham Swamp and Shortland Wetlands Centre to the west and northwest of the study area, and Newcastle Wetlands Reserve and an unnamed wetland informally known as the ‘Market Swamp’ to the east and southeast (Figure 1). A number of larger remnant wetlands in the study area are covered by State Environmental Planning Policy 14 - Coastal Wetlands (SEPP 14), being Hexham Swamp and Shortland Wetlands Centre to the west and northwest, and Newcastle Wetlands Reserve and an unnamed wetland informally known as the ‘Market Swamp’ to the east and southeast. The gazetted boundaries of SEPP 14 provided on the official maps do not always coincide with the actual extent of wetlands (Winning, 1991). The Shortland Wetlands Centre wetlands and Hexham Swamp are listed as important wetlands in the Directory of Important Wetlands in Australia (Environment Australia, 2001), and are included on the Register of the National Estate as part of the ‘Hunter Estuary Wetlands’ (Australian Heritage Council, undated). In addition, the Shortland Wetlands Centre is included on the Convention of Wetlands of International Importance (the Ramsar Convention).

1.6 Previous Flora & Fauna Studies

The flora and fauna of Hexham Swamp and the Sandgate area has been well documented by many previous studies (Briggs 1978; Pressey 1981; Broadbent et al. 1984; McDonald and Winning 1986; Winning 1986; Gilligan et al. 1990; Winning 1993; Winning 1996; Morrison 2000; MacDonald 2001), as well as unpublished investigations (e.g. GGBF surveys in the 2HD Swamp by members of the Society of Frogs and Reptiles, and observations by members of Hunter Bird Observers Club in various wetlands over many years).


HWR Ecological



HWR Ecological


2. BACKGROUND INFORMATION

2.1 Historical Changes to Wetlands in the Study Area

At the time of European settlement, an arm of Hexham Swamp extended along a low-lying area where the railway now lies, and extended south to what is now Queen Street, Waratah West (Winning, 1996). A relatively narrow link across what is now Sandgate Road, connected the larger tidal part of Hexham Swamp with the part south of Sandgate Road which is inferred to have been non-tidal, or essentially so. The rail line at Sandgate was originally constructed in 1857, essentially along the centre of the drainage line that supported this arm of Hexham Swamp (Grgas, undated). Partial filling mainly during the 1960s and 1970s (extending into the early 1990s in some places) as part of the Lorna Street dump and the Astra Street dump, development of industrial land at Sandgate, the construction of the regional fruit markets and construction of the Kooragang rail link, left the present remnant wetlands. Most of the wetlands in the study area were historically subject to tidal inundation, but the construction of floodgates on Ironbark Creek in 1971 effectively prevented tidal inundation of the remnant wetlands. This combined with changes to hydrology resulting from filling and catchment development, has caused substantial changes in the wetlands (Winning, 1996). For example, much of the wetland area has been colonised by Common Reed (Phragmites australis), Swamp Oak (Casuarina glauca) and Broad-leaf Cumbungi (Typha orientalis), in place of the original mangroves and saltmarsh (Winning, 1996). Subsequent to the restriction of tidal inundation, placement of fill, deposition of sediment and growth of reeds have occluded many drainage lines, resulting in an increase in depth and permanence of inundation of many of the wetland areas, including the 2HD Swamp, the Shortland Wetlands, Newcastle Wetlands Reserve and the Market Swamp.

2.2 The 2HD Swamp & GGBF Habitat

A population of GGBF has previously been identified in the 2HD Swamp in the northern part of the study area, and individuals have been observed to disperse from this pond into adjoining wetlands (Winning, 2004). Based on data compiled by the Society of Frogs and Reptiles over several years, it is inferred that this pond is the core habitat for this local population of GGBF. Individuals have been recorded to disperse from this pond after good breeding seasons and occupy lower quality habitats in the surrounding area. After a series of poor seasons, the population contracts back to the core habitat (Winning, 2004). During the 2001/2002 breeding season, 100 frogs were captured in the 2HD Swamp. Although there have been no comprehensive surveys since then, observations suggest a decline in population size over the past three drought seasons (Society of Frogs and Reptiles, unpublished data). A tentative observation of a GGBF was made in the rail corridor in 2004 (Winning, 2004). Surveys of the 2HD swamp by various researchers this year have not recorded the presence of GGBF (Mike Mahony, University of Newcastle, pers. com., 2005).


HWR Ecological


The reason for the decline in the population is unknown at present and is assumed to be related to an outbreak of disease (Mike Mahony, pers. com., 2005) and a combination of other factors including habitat changes, low reproductivity rates, extreme weather conditions, and predation. As a result the 2HD Swamp is becoming increasingly poor habitat for GGBF, with Plague Minnow (Gambusia holbrooki) becoming an increasing problem within the pond. Plague Minnow predates on the tadpoles of GGBF and is negatively correlated with the presence of GGBF. The population dynamics of GGBF are yet to be fully understood, but like many frogs it has a boom and bust breeding cycle in response to seasonal conditions. It is probable that a large area of secondary habitat is required in addition to core breeding habitat to maintain a population of GGBF. While it remains unclear to what extent the secondary habitat is important, the precautionary principle requires that the secondary habitat be considered to be important. In relation to the investigation area, the main pond of the 2HD Swamp is assumed to be core habitat, with its large areas of open water and patches of reeds, especially Coastal Clubrush (Schoenoplectus littoralis) and Broad-leaf Cumbungi. Secondary habitat is assumed to comprise to mosaic of ponds, reedswamps and grasslands in the vicinity of the main pond, although these have been modified over recent years (this is discussed further, below).


HWR Ecological


3. DETAILED INVESTIGATIONS

3.1 Introduction

The area defined as the ‘investigation area’ was the target area for intensive investigations of GGBF habitat and for searches for GGBF. In addition to original investigations, reference is also made to results of other recent surveys of the investigation area. The results are discussed in detail in Section 4, below.

3.2 Methodology

Microhabitat Mapping Mapping of the microhabitat within the investigation area was undertaken during December 2005 to provide an indication of the actual habitat value of the existing resources at the 2HD Swamp for GGBF. The mapping comprised intensive qualitative field observations to act as ground-truthing of fine-scale aerial photograph interpretation. This information provided the preliminary data required to design suitable targeted surveys for GGBF within the investigation area. Nocturnal Transects Nocturnal walking transects were sampled during December 2005 to February 2006. Transects were based on the preliminary habitat mapping results and targeted areas of high habitat value, principally around the 2HD swamp. The survey effort is summarised below:

Date Weather Conditions Number of Observers

Number of Hours

9 Dec 05 temp 24.5C, rel hum 50%; wind 13k/h SE; rain last 24 hrs 0mm 1 2 19 Dec 05 temp 21.5C, rel hum 49%; wind 13k/h SE; rain last 24 hrs 0mm 2 2 20 Dec 05 temp 25.7C, rel hum 31%; wind 11k/h SE; rain last 24 hrs 0mm 2 2 2 Jan 06 temp 26.0C, rel hum 70%; wind 6k/h SE; rain last 24 hrs 0.4mm 1 2 27 Jan 06 temp 31.2C, rel hum 61%; wind 4k/h SE; rain last 24 hrs 10mm 1 2 27 Feb 06 temp 24.4C, rel hum 69%; wind 19k/h SE; rain last 24 hrs 35.2mm 1 2

Call Playback and Listening Points Call playback and listening points were haphazardly selected while conducting walking transects on 19 and 20 December 2005. The call playback period consisted of playing the call for 5-10 minutes and then listening for approximately 10 minutes for a response. This process was undertaken for approximately 30 minutes each evening. Opportunistic Searches Haphazard searches of likely amphibian habitat were conducted during field surveys when suitable habitat was encountered. Reference Sites A reference sites at Ash Island was surveyed for calling GGBF prior to sampling within the investigation area to determine if GGBF were actively calling during the survey period. This technique is used as a means of determining whether the surveys were conducted during good ‘frog weather’.


HWR Ecological


3.2 Results

No GGBF were heard calling nor observed during intensive surveys of the reference sites and the 2HD Swamp. The only frogs heard calling at the 2HD Swamp during the survey period were Litoria fallax, Litoria peronii and Litoria tyleri. Results of habitat mapping are presented in Figure 3, and the map units used are described in Table 1. Table 1. Description and evaluation of GGBF habitat within the investigation area.

Map Unit Description Area (ha) Habitat Value

A Open water with submerged macrophytes, such as Myriophyllum spp. And Potamogeton spp. This and the following map unit represent the main area of habitat occupied by GGBF.

4.4 Core

B ‘Islands’ of Schoenoplectus littoralis and Panicum repens, with some remnant mangroves. 0.3 Core

C1 Reed swamp dominated by Phragmites australis with patches of Typha orientalis. Generally not suitable for GGBF other than for potential transient use of edge areas.

4.8 Low quality

C2 Areas of lower and less dense reedswamp, with Isachne globosa. 0.3 Low quality

C3 Edge areas where weedy shrubland (e.g. Lantana camara) mixes with reedswamp. 0.6 Low quality

D1 Dense Panicum repens. This introduced grass species forms very dense stands up to a metre high. This grass has invaded areas that presumably provided foraging habitat previously.

1.6 Low quality

D2 Areas of Panicum repens mown to provide access to radio mast. The mowing makes this area more accessible as foraging habitat. 0.5 Moderate quality

D3 Edge areas where weedy shrubland (e.g. Lantana camara) mixes with Panicum repens. 0.3 Low quality

E

Areas of Juncus kraussii rushland, presumably remnants from the original estuarine vegetation. The inferred higher localised salinity of the soil in these areas appears to inhibit dense growth of grasses and maintains a more open structure, making these areas more accessible as foraging habitat.

0.1 Moderate quality

F

Low wet grassland dominated by Stenotaphrum secundatum, Cynodon dactylon and Hydrocotyle bonariensis. Presently low quality because of the density of the vegetation, but several small pondages in this area allude better quality habitat in the recent past. The proposal is likely to remove approximately 50% of this habitat in its current form.

1.1 Low quality

G Tall pasture (unmown, ungrazed). Stenotaphrum secundatum is the main grass species, but the weedy herb Verbena bonariensis is the visually dominant species.

0.7 Low quality

H Mown or grazed pasture and grasses. 3.0 Low quality

I Patches of Casuarina glauca forest and areas of plantings of Casuarina glauca, Melaleuca spp., and other species. 0.8 Low quality

J Remnant forest patches with eucalypt spp. and mesophyll trees such as Glochidion ferdinandi. 0.6 Low quality


HWR Ecological



HWR Ecological


4. Potential Impacts on GGBF

4.1 Introduction

The main purpose of this additional investigation was to provide information on the impact of the Proposal on GGBF. The main REF, to which this report will be appended, provided a general assessment of the likely impacts that the proposal would have on the GGBF. This assessment is reproduced in Table 2. Table 2. Potential impacts of the Proposal on GGBF and proposed mitigation measures.

Species Legal Status Potential Impacts Mitigation Measures Green and Golden Bell Frog Litoria aurea

E (TSC Act); V (EPBC Act)

- Loss of foraging habitat where grassy habitat adjoins known GGBF population.

- Potential runoff from road works into GGBF habitat.

- Potential changes to hydrological regime through infilling of land to raise height for road.

- Increased isolation of known GGBF population.

- Increased risk of collision with motor vehicles.

- Reduction in dispersal opportunities.

- Position highway on high ground as far north-east as possible to avoid habitat loss and minimise disturbance.

- Provide habitat augmentation (i.e. habitat ponds, movement corridors) to facilitate dispersal routes and improve habitat quality.

- Provide barriers to frog movement to reduce risk of collision with cars and direct dispersal.

* V = Vulnerable; E = Endangered; M = Migratory TSC Act = NSW Threatened Species Conservation Act (1995) EPBC Act = Commonwealth Environment Protection and Biodiversity Conservation Act (1999)

Due to the timing of the REF (winter), surveys for GGBF could not be undertaken and as such further surveys were required to determine if and how this species utilises the investigation area and to determine the extent of the habitat. This population of GGBF is relatively isolated from other populations in the local area and the proposed action could potentially contribute to some or all of the above factors in relation to this species. This report addresses these issues in light of further surveys within the investigation area focussing on GGBF. The following comments on likely effects on GGBF are based on the precautionary assumption that a population of GGBF persists in, or in the vicinity of the 2HD Swamp. As mentioned above, there is some doubt whether the population still survives but prudence suggests that a conclusion in this regard should not be reached until after several years of nil results for GGBF surveys.

4.2 Potential Impacts on GGBF

Within the study area, primary or ‘core’ habitat for GGBF comprises the areas of open water and ‘islands’ of reeds (habitat types A and B in Figure 3). Other adjoining wetland habitats, such as dense reeds and wet grasslands (habitat types C, D, E and F) are of minor value and would be expected to be used as secondary habitat and/or as part of dispersal movements.


HWR Ecological


Potential direct impacts of the Proposal include: (i) loss of habitat through clearing; (ii) potential disruption to the dispersal activities of the local population during the

construction phase of the activity; (iii) mortality of dispersing individuals as a result of construction activities; (iv) mortality on the constructed road; and (v) blocking of potential dispersal routes by the constructed road.

The Proposal could result in the following in-direct impacts: (i) potential chemical pollution of habitat (i.e. oil spills) both during the construction phase,

and the operation phase; (ii) potential changes to hydrology; and (iii) potential weed invasion of any created habitat.

The Proposal would require the removal of approximately 4.3 hectares of vegetation within the GGBF investigation area, part of which (approximately 0.4ha) is low-lying land adjacent to the 2HD Swamp which could provide potential foraging habitat (see Proposal area coverage in Figure 3). This study found that the majority of the habitats within the investigation were of poor quality due, mainly, to rank growth of reeds, introduced grasses and other weeds. Although wetland habitats will be lost as part of the Proposal, virtually all are of little value to GGBF as primary or secondary habitat. The original recommendation to push the road as far to the north-east as possible upon leaving the Sandgate Cemetery corridor is supported by these detailed investigations. It is also recommended that the RTA contribute to enhanced management of GGBF habitat at the 2HD Swamp site through measures such as land acquisition, ongoing maintenance, etc. Such measures would be investigated during the design process and should be developed in consultation with appropriate agencies (e.g. Department of Environment & Conservation) and other interested parties (e.g. University of Newcastle, Society for Frogs and Reptiles). The habitats to be removed could form part of dispersal corridors, and replacement of these with a road could interfere with any potential dispersal. The current upgrade of the Main Northern Railway at Sandgate was designed to include allowance for movement of GGBF from the vicinity of the 2HD Swamp south towards Wallsend Road. The construction of SH23 should make a similar allowance on a precautionary basis. This would include measures such as a barrier along the toe of the road embankment to discourage frogs from accessing the road, and use of culvert or piped underpasses to facilitate frog passage across the road corridor. A detailed design and management plan should be prepared supporting this recommendation. This plan should be prepared in consultation with appropriate agencies (e.g. Department of Environment & Conservation) and other interested parties (e.g. University of Newcastle, Society for Frogs and Reptiles). Potential indirect impacts would be mitigated through a comprehensive environmental management plan employing best practice design and management. The RTA has extensive experience in management of potential impacts in sensitive wetland areas (e.g. F3 Interim Connection, Five Islands Road Proposal), and experience from these Proposals should be applied to the SH23 Proposal. Design measures should include controls for sediments and other pollutants arising from construction activities and from long term operation, frog movement controls (as discussed above), etc.


HWR Ecological


Management measures should include, qualitative monitoring of erosion and pollutant controls, monitoring of condition of wetland habitats, searching construction areas for frogs prior to commencement of works, appropriate frog hygiene protocols for people and machinery accessing potentially sensitive areas (following Department of Environment & Conservation guidelines), etc.


HWR Ecological


5. Legislative Assessments

5.1 Environmental Planning & Assessment Act 1979

In assessing the potential effects of a proposed activity on threatened species, a proponent and/or a consent authority must have regard to the seven factors listed under s.5A(2) of the Environmental Planning & Assessment Act 1979 (EPA Act). These seven factors (which replaced the old ‘8-part test’ as of 31 October 2005) are:

(a) in the case of a threatened species, whether the action proposed is likely to have an adverse effect on the life cycle of the species such that a viable local population of the species is likely to be placed at risk of extinction,

(b) in the case of an endangered population, whether the action proposed is likely to have an adverse effect on the life cycle of the species that constitutes the endangered population such that a viable local population of the species is likely to be placed at risk of extinction,

(c) in the case of an endangered ecological community or critically endangered ecological community, whether the action proposed: (i) is likely to have an adverse effect on the extent of the ecological community such that

its local occurrence is likely to be placed at risk of extinction, or (ii) is likely to substantially and adversely modify the composition of the ecological

community such that its local occurrence is likely to be placed at risk of extinction, (d) in relation to the habitat of a threatened species, population or ecological community:

(i) the extent to which habitat is likely to be removed or modified as a result of the action proposed, and

(ii) whether an area of habitat is likely to become fragmented or isolated from other areas of habitat as a result of the proposed action, and

(iii) the importance of the habitat to be removed, modified, fragmented or isolated to the long-term survival of the species, population or ecological community in the locality,

(e) whether the action proposed is likely to have an adverse effect on critical habitat (either directly or indirectly),

(f) whether the action proposed is consistent with the objectives or actions of a recovery plan or threat abatement plan,

(g) whether the action proposed constitutes or is part of a key threatening process or is likely to result in the operation of, or increase the impact of, a key threatening process.

The assessment under s.5A should not be considered a “pass or fail” test as such, nor should it be the totality of threatened species assessment. The assessment is designed to allow the proponent and consent authority to undertake a qualitative analysis of the likely impacts and ultimately whether further assessment needs to be undertaken via a Species Impact Statement (SIS). Where the proponent or consent authority considers that there is likely to be a significant effect on threatened species, a SIS is required to be prepared. Where there is any doubt regarding the likely impacts, or where detailed information is not available, a SIS should be prepared. A detailed assessment pursuant to s.5A is presented in Appendix 1. This assessment concluded that the Proposal would not have a significant effect on GGBF provided appropriate mitigation


HWR Ecological


strategies are adopted. A proposal incorporating suitable mitigation measures, therefore, would not need to be supported by a SIS. Indeed, it is unlikely that a SIS would shed any further light on the issues relating to the effect of the Proposal on GGBF.

5.2 Environment Protection & Biodiversity Conservation Act 1999

The Commonwealth Environment Protection & Biodiversity Conservation Act 1999 (EPBC Act) provides for the need for the approval of the Commonwealth Environment Minister for all actions that will or are likely to have a significant impact on a matter of national environmental significance. Matters of national environmental significance are:

• World Heritage properties; • Ramsar wetlands of international importance; • listed threatened species and communities; • migratory species protected under international agreements; • nuclear actions; and • the Commonwealth marine environment.

The process established under the EPBC Act compels the person proposing the action to refer that action to the Commonwealth Environment Minister where that person thinks that the proposed action will or is likely to have a significant impact on a matter of national environmental significance. GGBF is listed as vulnerable under the EPBC Act is therefore considered a matter of national environmental significance which requires further assessment under the EPBC guidelines. According to the EPBC Act in order to decide whether an action is likely to have a significant impact, it is necessary to take into account the nature and magnitude of potential impacts. In determining the nature and magnitude of an action's impact, it is important to consider matters such as:

• all on-site and off-site impacts; • all direct and indirect impacts; • the frequency and duration of the action; • the total impact attributable to the action over the entire geographic area over time; • the sensitivity of the receiving environment; and • the degree of confidence with which the impacts of the action are known and understood.

Actions which contribute to any of the following factors needs to be considered:

• lead to a long-term decrease in the size of a population; • reduce the area of occupancy of the species; • fragment an existing population into two or more populations; • adversely affect habitat critical to the survival of a species; • disrupt the breeding cycle of a population; • modify, destroy, remove, isolate or decrease the availability or quality of habitat to the

extent that the species is likely to decline; • result in invasive species that are harmful to a critically endangered or endangered species

becoming established in the endangered or critically endangered species habitat; or • interferes substantially with the recovery of the species.


HWR Ecological


Details of the assessment under the EPBC Act for GGBF are presented in Appendix 2. The Proposal would potentially have an impact on the breeding population of Green and Golden Bell Frog known to occur within the 2HD Swamp. This impact is considered likely to be minor and would be mitigated by ameliorative measures, obviating the need to refer the matter to Commonwealth Minister of the Environment on a precautionary basis.


HWR Ecological


6. Conclusions

The assessment assumes that a population of GGBF is extant in the 2HD Swamp, despite no records of GGBF within the investigation area during this study, no records during the present season by other observers (G. Winning, pers. obs.; M. Mahony, pers. com.), and evidence that the population has been declining over recent years (M. Mahony, pers. com.). Habitat mapping indicated that while potential secondary foraging habitat occurs in the Proposal area, it is unlikely to be utilised by GGBF due to its overgrown nature and the energy costs required for movement. The proposal in its current form requires the removal of approximately 0.4 hectares of potential foraging habitat (among the approximately 4.3ha of wetland and other habitat to be removed for the proposal) which is not considered to be a significant impact. Indirect impacts (i.e. drainage and construction works) within the GGBF habitat would be monitored and controlled to mitigate any secondary impacts on GGBF. Ameliorative measures to be adopted by the proposal for mitigation of potential impacts on GGBF include:

• ensuring connectivity between habitats to the north of the proposed road and south of the road by:

- provision of an underpass north of the railway; - provision of frog exclusion fencing to limit frog access to the road (design details to be determined);

• modification of construction sediment basins after completion of works to provide frog habitat;

• provision of some foraging habitat north of the roadway (details to be determined); • revegetation of road batters and disturbed areas after construction.

Assessment under Part 5a of the EP&A Act found no significant impact for the proposal, and a similar assessment under the EPBC Act indicates that there is no need for referral to the Commonwealth Minister of the Environment.


HWR Ecological


7. References

Australian Heritage Council (undated) The Register of the National Estate.

http://www.ahc.gov.au/register/. Viewed on 24 December 2005. Briggs, S. V. (1978) Hexham Swamp - vegetation and waterbird habitats. NSW National Parks &

Wildlife Service. Unpublished. Broadbent, J. A., Carter, S., Rice, B., Shea, G. and Williams, R. (1984) Ecological study of State

Highway No. 23 (Shortland to Pacific Highway Corridor). Prepared for Department of Main Roads, by Macdonald Wagner. Unpublished.

Environment Australia (2001). A Directory of Important Wetlands in Australia, Third Edition. Environment Australia, Canberra.

Gilligan, B., Winning, G. and Markwell, K. (1990) Shortland - Waratah West catchment study. Prepared for Newcastle City Council, by Shortland Wetlands Centre. Unpublished.

Grgas, J. (undated) History of surveying in the Hunter. http://www.survsoc.newcastle.edu.au/hunterhistory.html, accessed 28/6/2004.

MacDonald, T. A. (2001) Investigating the estuarine wetlands of the lower Hunter River: rehabilitation potential of tidal reinstatement following degradation caused by tidal restriction. PhD thesis. The University of Newcastle. Unpublished.

McDonald, K. and Winning, G. (1986) Flora and fauna of the Shortland Wetlands. Hunter Wetlands Trust.

Morrison, D. (2000) Historical changes in land cover and predicted distribution of mangrove and saltmarsh in Hexham Swamp. BSc (Hons) thesis. The University of Newcastle. Unpublished.

Pressey, R. L. (1981) A survey of wetlands on the lower Hunter floodplain, New South Wales. Prepared for NSW National Parks & Wildlife Service. Unpublished.

Winning, G. (1986) Vegetation & flora of Shortland Wetlands. Hunter Wetlands Trust. Winning, G. (1991) Some problems in determining the boundaries of SEPP 14 wetlands., Wetlands

(Aust), 11(1), 10-20. Winning, G. (1993) University of Newcastle wetlands management plan. Prepared for The

University of Newcastle, by Shortland Wetlands Centre. Unpublished. Winning, G. (1996) Vegetation of Kooragang Nature Reserve and Hexham Swamp Nature Reserve

and adjoining land. Prepared for NSW National Parks & Wildlife Service, by Shortland Wetlands Centre. Unpublished

Winning, G. (2004) Ecological assessment for proposed Sandgate rail grade separation. Report to Australian Rail Track Corporation by HWR Ecological.


HWR Ecological


Appendix 1: EP&A Act s.5A Assessment


HWR Ecological


(a) in the case of a threatened species, whether the action proposed is likely to have an adverse effect on the life cycle of the species such that a viable local population of the species is likely to be placed at risk of extinction

General Habitat Requirements The habitat preference and requirements of the GGGBF are not well understood and difficult to define (Mahony, 1999), and it is often found in evidently unlikely locations. It would appear that the species makes use of a number of habitat components to fulfil its life-cycle requirements. These include breeding, foraging and refuge habitat, as well as suitable habitat to facilitate its movement patterns. The current general view of what constitutes the species habitat has emerged from the collective observations of habitat use by various authors but most of these observations have been heavily biased toward breeding habitat when the species is most obvious (see Pyke and White, 1996; Gillespie, 1996; Mahony, 1999; Pyke and White, 2002). GGBF utilises a wide range of waterbodies including natural and man-made structures (Pyke and White, 1996). For example GGBF has been recorded associated with coastal swamps, marshes, dune swales, lagoons, lakes and other estuary wetlands as well as riverine floodplain wetlands and billabongs. Constructed waterbodies such as stormwater detention basins, farm dams, bunded areas, drains, ditches and other excavations capable of capturing water such as quarries and brick pits are also known to be occupied. Even relatively minor structures such as tanks, safety bunds surrounding storage tanks, wells, cavitation pits, water troughs, old laundry tubs and baths have all been recorded as being utilised by the GGBF for breeding purposes. Utilised waterbodies are generally shallow, still or slow flowing, ephemeral and/or widely fluctuating, unpolluted and without heavy shading. There is still some debate as to the relative importance of some of these attributes (Gillespie, 1996; Patmore, 2001; Pyke and White, 2001; Hamer et al., 2002). Other associated terrestrial habitat attributes which are important include extensive grassy areas and an abundance of shelter sites such as rocks, logs, tussock forming vegetation and other cover adjacent to the investigation area (Pyke and White, 1996; Mahony, 1999; Patmore, 2001; Pyke and White, 2001). There is also a clear preference shown by GGBF for sites with a complexity of vegetation structure (Patmore, 2001; Hamer et al., 2002). Habitat features are often found peripheral to the breeding habitat and are considered foraging and/or refuge habitat. Refuge habitat is the least well understood component of this species’ lifecycle but it is considered to be important for the species especially during the cooler parts of the year (‘over-wintering’ habitat) when they are not metabolically efficient, but also at other times when they are seeking shelter from adverse conditions or predators. The range of habitat that has been recorded as being used for this purpose includes:

• dense tussock forming vegetation (Hamer, 1998 and pers. comm.; Patmore, 2001); • deep fissures in mud (R. Wells pers. comm.; M. Christy vide Patmore, 2001); • amongst rocks (White and Pyke, 1996; Hamer, 1998; Pyke and White, 2001; M. Christy

vide Patmore, 2001); • underground holes or burrows (Patmore, 2001); • within rotting logs or under embedded logs and timber piles (R. Wells pers. comm., R.

Wellington unpublished; Pyke and White 2001); and • other human refuse such as sheet iron, fibro, bricks etc (Pyke and White, 2001; R.Wells

pers. comm.); such shelter has been recorded utilised by aggregations of the GGBF (R. Wells pers. comm.; R. Wellington unpublished; Pyke and White, 2001; Patmore, 2001).


HWR Ecological


A population of GGBF resides in a wetland adjacent to the western side of the proposed highway in the northern section of the study area, informally known as 2HD Swamp. Based on data compiled by the Society of Frogs and Reptiles over several years, it is inferred that this pond is the core habitat for this local population of GGBF. Individuals have been recorded to disperse from this pond after good breeding seasons and occupy lower quality habitats in the surrounding area. After a series of poor seasons, the population contracts back to the core habitat. The size and viability of this population is not known although during the 2001/2002 breeding season, 100 frogs were captured within the 2HD Swamp. Although there have been no comprehensive surveys since then, observations suggest a decline in population size over the past two drought seasons (Society of Frogs and Reptiles, unpublished data). It is unknown how this species utilises the investigation area given that no individuals were recorded during the survey period. Micro-habitat mapping suggested that the core habitat which would be utilised included the ‘islands’ and the open water habitats in the 2HD Swamp. Surrounding habitat which would provide potential foraging habitat is overgrown by rank grass and weed growth, and is assumed to be of reduced value for GGBF. The Proposal would remove a small area of this habitat (approx. 0.4ha). Breeding Habitat: Breeding events and other associated reproductive behaviours have been recorded from late winter to early autumn but generally between September and February (Fletcher, 1889; Harrison, 1922; Barker et al., 1995; Pyke and White, 2001) with a peak around January-February after heavy rain/storm events, (White, 1995a; Daly, 1995a; Griffiths, 1997; Anstis, 2002). Reproductive events are however clearly influenced by the prevailing weather conditions from season to season and also appear to be influenced by geography. More southerly and higher altitude populations appear to have a narrower window of opportunity for breeding than more northerly and lower altitude populations. More northerly populations appear to more often commence breeding earlier and continue longer than southern and tableland populations which appear to have a much shorter breeding period (Humphries, 1979; Clancy, 1986; Daly, 1995a; Patmore, 2001; G. Daly pers. comm.; Wellington and Parsons, in prep.). The Green and Golden Bell Frog is a highly fecund species with average clutch size has also been estimated and in rounded figures is about 3700 eggs per clutch with 3-5 thousand apparently the norm (White, 1995; Daly, 1995a; Pyke and White, 2001; Anstis, 2002; Mahony, 2002). The spawn can be described as clear and gelatinous rather than foamy. The eggs are laid on the water surface where they float initially and then sink after 2-3 hours adhering to fringing vegetation (Harrison, 1922; Tyler and Davies, 1978; Barker, Grigg and Tyler, 1995; White, 1995). Dietary preference of tadpoles of the GGBF has been summarised in Pyke and White, (2001) where it is suggested that they predominantly graze on the algal or bacterial scum growing on submerged rocks and other substrata. More advanced tadpoles may show some preference for vegetable matter but also scavenge or become carnivorous on other aquatic organisms (Pyke and White, 2001). The behaviour of tadpoles is variable and is likely influenced by water depth, clarity, benthic vegetation and the presence of predators. The 2HD Swamp, adjacent to the proposed highway provides known breeding habitat for a local population of this species. The proposed action is unlikely to directly affect this habitat.


HWR Ecological


Regional habitat: There is evidence that GGBF can show strong site fidelity with individuals returning to or remaining at an identified site (Murphy, 1994; Patmore, 2001; Hamer, 1998; M. Christy pers. comm.; R. Wellington unpublished). The species is capable of making quite large movements in a single day/night up to 1-1.5 km (A. White, pers. comm; Pyke and White, 2001; R. Wellington unpublished). Of the 43 known key populations identified within the recovery plan for GGBF, only 12 are located predominantly within DEC estate equating to approximately 21%. Within the Hunter region there are a number of ‘key’ Green and Golden Bell Frog populations identified within the recovery plan for this species, although all are disjunct and isolated from each other. There are key populations at:

• Kooragang Island (>300); • Ravensworth Liddell area Singleton; and • Wentworth Swamps (Gillieston Heights)

(b) in the case of an endangered population, whether the action proposed is likely to have an

adverse effect on the life cycle of the species that constitutes the endangered population such that a viable local population of the species is likely to be placed at risk of extinction.

Not applicable. This population is not listed as being an endangered population (even though GGBF is listed as an endangered species). (c) in the case of an endangered ecological community or critically endangered ecological

community, whether the action proposed: (i) is likely to have an adverse effect on the extent of the ecological community such that its

local occurrence is likely to be removed or modified as a result of the action. (ii) is likely to substantially and adversely modify the composition of the ecological

community such that its local occurrence is likely to be placed at risk of extinction. Not applicable to GGBF (d) in relation to the habitat of a threatened species, population, or ecological community:

(i) the extent to which habitat is likely to be removed or modified as a result of the action proposed, and

The proposed action would result in the loss of approximately 0.4 hectares of potential foraging habitat, but in its current state this habitat is regarded as being of low quality given its overgrown condition. GGBF prefer foraging in open grassy areas where they can readily move without restriction, the current habitat contained within the investigation area is overgrown and would be cost inhibitive for foraging.

(ii) whether an area of habitat is likely to become fragmented or isolated from other areas of habitat as a result of the proposed action, and


HWR Ecological


Despite the presently fragmented character of habitats within the study area, there are still opportunities for GGBF to disperse from the 2HD Swamp both north towards Hexham Swamp, and south via the cemetery corridor towards Market Swamp and habitats between there and the cemetery corridor (Figure 2). Construction of the road through the cemetery corridor would effectively remove most of the existing habitat in this area, and potentially act as barrier to southern dispersal. This would be mitigated by providing for a movement corridor along the western edge of the road, with barriers to prevent frogs accessing the carriageways, and underpasses to facilitate dispersal to the southern side of the road. The design and management of these measures would be the subject of a detailed environmental management plan.

(iii) the importance of the habitat to be removed, modified, fragmented or isolated to the

long-term survival of the species, population or ecological community in the locality. As stated previously the habitat to be removed is considered to be of poor quality. The proposal would remove 0.4 hectares of rank grassland which is considered to provide potential foraging habitat, as well as the approximately 4 hectares of reedswamp and other habitat types that are considered to be generally unsuitable for GGBF. In its current state the habitat to be removed is not considered important to the long-term survival of the species. (e) whether the action proposed is likely to have an adverse effect on critical habitat (either

directly or indirectly)

There is a capacity for critical habitats to be gazetted under the Threatened Species Conservation Act 1995. No such habitats have yet been gazetted for Green and Golden Bell Frog. Therefore, the Proposal would not have an adverse effect on critical habitat. (f) whether the action proposed is consistent with the objectives or actions of a recovery or

threat abatement plan.

GGBF Recovery Plan The overall outcomes of the GGBF draft recovery plan are to:

• manage threats impacting on currently known populations of the Green and Golden Bell Frog, so as to stabilise and prevent further decline of the species;

• return the species to its former distribution, abundance and role in the ecosystem where-ever possible.

The GGBF recovery plan has specific objectives to achieve these two main outcomes, including:


HWR Ecological


• increasing the security of key GGBF populations by way of preventing the further loss of GGBF habitat at key populations across the species range and where possible secure opportunities for increasing protection of habitat areas;

• ensure extant GGBF populations are managed to eliminate or attenuate the operation of factors that are known or discovered to be detrimentally affecting the species;

• implement habitat management initiatives that are informed by data obtained through investigations into the general biology and ecology of the GGBF through a systematic and coordinated monitoring program;

• establish, within more than one institution, self sustaining and representative captive populations (particularly ‘at risk’ populations) of the Green and Golden Bell Frog for the primary purpose of maintaining ‘insurance’ colonies for re-establishment and supplementation of populations of the species; and

• increase the level of regional and local awareness of the conservation status of the Green and Golden Bell Frog and provide greater opportunity for community involvement in the implementation of this recovery plan.

The Proposal, incorporating mitigation measures, is consistent with the recovery planning objectives. The proposal seeks to manage any threats arising as a result of the action and minimise any impact on GGBF, and through improved management initiatives seeks to return the species to its former distribution. Threat Abatement Plans

• Plague Minnow (Gambusia holbrooki) Threat Abatement Program - DEC in collaboration with DPI (formerly NSW Fisheries) will develop strategies for the

control and/or eradication of Gambusia from specific Green and Golden Bell Frog sites, where appropriate.

- The DEC will, where possible, initiate installation of supplementary breeding habitat when other Gambusia control measures are not feasible or have failed, and where this is supported by trials and identified in relevant key population site management plans. The DEC will encourage investigations into the value of artificial pond structures as supplementary breeding habitat for the GGBF where Gambusia is identified as a threat to populations of the species (see research priorities, section 12.3.2).

- The DEC and NSW Fisheries will use the GGBF as a ‘flagship’ species to undertake a public awareness-raising program to alert the community of the pest status of Gambusia, and the impact it is having on the GGBF and other threatened and protected native frog and fish species. This program will seek to address the mosquito control issue, alternatives to Gambusia, and allay concerns regarding mosquitoes associated with GGBF habitat creation initiatives. (see section 14.2).

• Red Fox, Feral Cat, Cane Toad Threat Abatement Programs - DEC will promote the assessment of the impacts of predation by the Red Fox and the

Feral Cat at specific locations (see research priorities, section 12.3.2) and, if possible, conduct this as an adjunct to the relevant TAP.

- DEC will monitor possible interactions between the GGBF and the Cane Toad at sites in the vicinity of their current distributional contact zone (Yamba/Yuraygir NP and at Port Macquarie/Lake Innes NR).

- DEC will develop and implement control/management strategies where necessary and if possible in concert with existing control/management programs (eg Reserve PoMs, Red Fox TAP and Cane Toad 'Round Up' program).


HWR Ecological


• Other Threat Abatement Programs - Alteration to the natural flow regimes of rivers and streams and their floodplains and

wetlands. - Clearing of native vegetation - High frequency fire resulting in the disruption of life cycle processes in plants and

animals and loss of vegetation structure and composition - vegetation structure and composition

The proposal is consistent with Threat Abatement Programs relevant to GGBF, where appropriate management initiatives will be developed to address relevant issues. (g) whether the action proposed constitutes or is part of a key threatening process or is likely to

result in the operation of, or increase the impact of, a key threatening process. Infection of frogs by amphibian chytrid causing the disease chytridiomycosis Chytridiomycosis is a fatal disease of amphibians and is caused by the chytrid Batrachochytrium dendrobatidis (Longcore et al. 1999). The chytrid sporangia grow in the keratinised epidermis of amphibians and the waterborne zoospores remain viable for over 24 hours. The chytrid is virulent only to adult amphibians; however it has been found, and therefore may be carried, on the keratinised mouthparts of tadpoles (Berger et al. 1999). The chytrid does not appear to rely on susceptible (stressed) hosts for survival and persists in populations where the density of adults has been reduced (Daszak et al. 1999). Further, other poikilotherms with keratinised surfaces could harbour and help to spread the disease, although this has not yet been observed. Chytrid fungus is probably transferred by direct contact between frogs and tadpoles, or through exposure to infected water. The disease may not kill frogs immediately, and they can swim or hop to other areas before they die, spreading fungal spores to new ponds and streams. This means it's very important not to move frogs from one area to another. The proposed action is unlikely to result in an increase in the spread of chytrid fungus and as such is unlikely to contribute to this Key Threatening Process in relation to this species. Predation by the plague minnow (Gambusia holbrooki) Gambusia holbrooki Girard, 1859 (previously known as Gambusia affinis) (Plague Minnow, also known as Mosquito Fish) is a small freshwater fish originally introduced into Australia in the 1920s. The fish was imported as an aquarium fish but some were released into creeks around Sydney, Melbourne and Brisbane. Recent research has documented that Gambusia holbrooki preys upon eggs and tadpoles of the Green and Golden Bell Frog (Morgan and Buttermer 1996; White and Pyke 1998). Surveys by McPherson and McGrath (2004) within the study area identified G. holbrooki. Management strategies need to be implemented to ensure that the 2HD Swamp does not become invested with G. holbrooki as a result of the proposed action. Clearing of native vegetation


HWR Ecological


The proposed action would require the clearing of native vegetation and as such would to contribute to this process, even though a relative small area of native vegetation would be cleared (approximately 2.5ha of Phragmites reedswamp and approximately 0.4ha of remnant forest).


HWR Ecological


Appendix 2: EPBC Act Assessment


HWR Ecological


1. Whether the action would lead to a long-term decrease in the size of a population. No the action would not disrupt foraging habitat and dispersal abilities of the local GGBF population. Foraging habitat was found to be of low quality and unlikely to be utilised by GGBF. GGBF dispersal is more likely to be occur through a drainage channel between industrial estates in the northwest leading to the railway easement. The action would not result in a decrease in the size of the population. 2. Whether the action would reduce the area of occupancy of the species. The action would remove 0.4 hectares of potential foraging habitat, however the proposal would not result in the loss of any core habitat which would be retained, secondary impacts to this area will be controlled and improved management regimes implemented to improve secondary habitat. These management actions could potentially increase the area of occupied by the local population. 3. Whether the action would fragment an existing population into two or more populations. The action would not result in the fragmenting of an existing population. 4. Whether the action would adversely affect habitat critical to the survival of a species. Under the s.207A of EPBC Act, Critical Habitat may be registered for any nationally listed threatened species or ecological community. When adopting a Recovery Plan the Federal Minister for the Environment must consider whether to list habitat identified in the Recovery Plan as being critical to the survival of the species or ecological community. No such habitat has been listed for Green and Golden Bell Frog and as such the proposed action would not adversely affect critical habitat. 5. Whether the action would disrupt the breeding cycle of a population. The action would not disrupt the dispersal abilities of the local population and would not disrupt the demography and breeding dynamics of the local population. Microhabitat mapping indicated that GGBF dispersal is more likely to be occur through a drainage channel between industrial estates in the northwest leading to the railway easement. The proposal has the option of improving dispersal opportunities along the Sandgate Cemetery corridor through the creation of appropriate habitat which would provide a more direct route to GGBF habitat currently being created north of Market Swamp. The erection of a frog barrier would stop frogs dispersing onto the bypass. 6. Whether the action would modify, destroy, remove, isolate or decrease the availability or

quality of habitat to the extent that the species is likely to decline. The proposed action would remove 0.4 hectares of potential foraging habitat, although in its current state is considered poor quality and is not likely to be utilised. The proposal will not further isolate the 2HD swamp, as it is already isolated and through management initiatives will seek to improve


HWR Ecological


dispersal opportunities along the Sandgate Cemetery corridor. This would hopefully result in greater dispersal and recruitment into the population ultimately improving the fitness of the population. 7. Whether the action would result in invasive species that are harmful to a critically

endangered or endangered species becoming established in the endangered or critically endangered species´ habitat.

The action is unlikely to result in invasive species becoming established in ‘endangered’ species habitats. 8. Whether the action would interfere with the recovery of the species. The Draft Recovery Plan for Green and Golden Bell Frog advocates a program that: • increases the security of key GGBF populations by way of preventing the further loss and

favouring in-situ protection and management of GGBF habitat at key populations as well as secure opportunities for increasing the protection of these habitat areas;

• ensure extant GGBF populations are managed to eliminate or attenuate the operation of factors that are known or discovered to be detrimentally affecting the species;

• implement habitat management initiatives informed through a coordinated monitoring program;

• establish self sustaining and representative colonies of ‘at risk’ captive populations of the GGBF for the primary purpose of maintaining ‘insurance’ colonies for re-establishment and supplementation; and

• through educational programs and involvement increase the level of regional and local awareness of the conservation status of the GGBF and provide opportunity for community participation in the implementation of this recovery plan.

Only four populations of this species occur in the Hunter region. The proposed action could result in decreased security for the population occurring in the study area by potentially disrupt foraging habitat, dispersal ability and breeding dynamics. Therefore, it is important that comprehensive mitigation measures are implemented to ameliorate the potential impacts.

Targeted Green and Golden Bell Frog Study · 05462 HWR ecological research & innovation Green &...

Documents

Transcript of Targeted Green and Golden Bell Frog Study · 05462 HWR ecological research & innovation Green &...