Dugong Management Plan - GREEN COAST RESOURCES
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GREEN COAST January 2015
Hey Point Bauxite Project
RESOURCES
Dugong
Management Plan
Dugong Management Plan
Hey Point Bauxite Project
This report has been prepared solely for the benefit of Green Coast Resources. MET Serve Pty Ltd
accepts no liability for the use or interpretation of any information contained in this report for any
other purpose other than intended, or for its use by any party other than the above named Client.
Document History and Status
Issue Revision Issued to Date Reviewed by
1 Draft METServe 8/1/2015 Chris Wiley
2 Draft METServe 9/1/2015 Michael Correll
Green Coast
3 Draft 13/1/2015 Hugh Simmons
Resources
4 Final Draft MET Serve 14/1/2015 Dave Moss
Green Coast
5 Final 22/1/2015 Michael Correll
Resources
MET Serve Project Delivery System
Printed: 22 January 2015
Last saved: 22 January 2015
File ID: 00223246
Project Manager: Michael Correll
Name of Organisation: MET Serve Pty Ltd
Name of Project: Hey Point Bauxite Project
Name of Document: Dugong Management Plan
Document Version: 002
Project Number: CL003
PO Box 306
Fortitude Valley Post Office
Fortitude Valley
QLD 4006
ABN 94 143 463 316
Radix Doc ID: 00223246
Dugong Management Plan
Hey Point Bauxite Project
Declaration of Accuracy by Green Coast Resources
In making this declaration, Green Coast Resources is aware that section 491 of the Environment
Protection and Biodiversity Conservation Act 1999 (EPBC Act) makes it an offence in certain
circumstances to knowingly provide false or misleading information or documents to specified persons
who are known to be performing a duty or carrying out a function under the EPBC Act or the
Environment Protection and Biodiversity Conservation Regulations 2000. The offence is punishable on
conviction by imprisonment or a fine, or both.
I am authorised to bind Green Coast Resources to this declaration and I have no knowledge of that
authorisation being revoked at the time of making this declaration.
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Dugong Management Plan
Hey Point Bauxite Project
TABLE OF CONTENTS
EXECUTIVE SUMMARY ..................................................................................................... 1
1 INTRODUCTION ................................................................................................... 2
2 PROJECT DESCRIPTION ....................................................................................... 3
3 OVERVIEW OF THE PROJECT ................................................................................ 4
3.1 LOCATION ................................................................................................................................4
3.2 ACTIVITIES...............................................................................................................................7
3.2.1 Construction, operation and rehabilitation phases ..................................................................7
3.2.2 Panel Mining Methodology .....................................................................................................7
3.2.3 Mine Sequencing ...................................................................................................................8
3.3 SCHEDULE OF ACTIVITIES ..........................................................................................................13
3.4 CONTINGENCY SCHEDULES ........................................................................................................13
4 OBJECTIVES ....................................................................................................... 14
5 ENVIRONMENTAL MANAGEMENT ROLES AND RESPONSIBILITIES ..................... 15
5.1 SITE MANAGER .......................................................................................................................15
5.2 PERSONNEL ............................................................................................................................15
6 REPORTING........................................................................................................ 16
6.1 REQUIRED REPORTS .................................................................................................................16
6.1.1 Daily reports ........................................................................................................................16
6.1.2 Monthly reports ...................................................................................................................16
6.1.3 Incident reports ...................................................................................................................16
6.1.4 Non-conformance reports ....................................................................................................16
6.1.5 EMP audit report ..................................................................................................................16
6.2 SCHEDULE FOR REPORTING ........................................................................................................16
6.3 DOCUMENT CONTROL ...............................................................................................................16
7 ENVIRONMENTAL TRAINING .............................................................................. 17
8 EMERGENCY CONTACTS AND PROCEDURES ....................................................... 18
9 DUGONG............................................................................................................. 19
9.1 ECOLOGY OF THE SPECIES .........................................................................................................19
9.2 HABITAT REQUIREMENTS ..........................................................................................................19
9.3 LOCAL POPULATION .................................................................................................................19
9.4 THREATS ...............................................................................................................................20
9.5 CONSERVATION STATUS ............................................................................................................20
9.6 POTENTIAL ENVIRONMENTAL IMPACTS AND MANAGEMENT MEASURES .................................................20
9.7 POTENTIAL IMPACTS ................................................................................................................22
9.7.1 Construction Phase ..............................................................................................................22
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9.7.2 Operation Phase ..................................................................................................................22
9.7.3 Rehabilitation Phase.............................................................................................................23
9.8 ENVIRONMENTAL MANAGEMENT MEASURES ...................................................................................23
9.8.1 Changes in Turbidity ............................................................................................................23
9.8.2 Direct Mortality from Boat Strikes.........................................................................................24
9.8.3 Acoustic Pollution and Disturbance.......................................................................................25
10 RESIDUAL RISK ASSESSMENT ............................................................................ 26
10.1 CHANGE IN TURBIDITY ..............................................................................................................26
10.2 DIRECT MORTALITY FROM BOAT STRIKES ......................................................................................27
10.3 ACOUSTIC POLLUTION AND DISTURBANCE.....................................................................................27
11 AUDIT AND REVIEW ........................................................................................... 28
11.1 ENVIRONMENTAL AUDITING .......................................................................................................28
11.2 MANAGEMENT PLAN REVIEW ......................................................................................................28
12 GLOSSARY .......................................................................................................... 29
13 REFERENCES ...................................................................................................... 30
FIGURES
Figure 1 Project Location.............................................................................................................5
Figure 2 Mining lease and disturbance footprint ..........................................................................6
Figure 3 Panel mining methodology ............................................................................................8
Figure 4 2015 disturbance footprint area...................................................................................10
Figure 5 2016 disturbance footprint area...................................................................................11
Figure 6 2017 disturbance footprint area...................................................................................12
Figure 7 Potential habitat for the Dugong in proximity to the HPBP mining lease .......................21
TABLES
Table 1 Schedule of activities ...................................................................................................13
Table 2 Control measures for managing risk of elevated turbidity impacting seagrass beds ......23
Table 3 Control measures for managing risk of direct mortality from boat strikes for the Dugong
...................................................................................................................................24
Table 4 Control measures for managing risk of acoustic pollution and disturbance for the Dugong
...................................................................................................................................25
Table 5 Qualitative risk assessment definitions .........................................................................26
Table 6 Risk rating methodology ..............................................................................................26
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Dugong Management Plan
Hey Point Bauxite Project
EXECUTIVE SUMMARY
This Dugong Management Plan has been developed to manage potential risks to the Dugong (Dugong
dugon) during activities associated with the Hey Point Bauxite Project (HPBP). The Hey Point Bauxite
Project (HPBP) is a proposed small-scale open cut bauxite mining operation located 10 km south of
Weipa.
The Dugong is listed as migratory under the Environmental Protection and Biodiversity Act 1999 and
vulnerable under the Queensland Nature Conservation Act 1992. It is also listed as a Back on Track
critical priority species for the Cape York Peninsula region. Dugongs are large marine mammals that
forage as individuals or pairs on seagrasses. They inhabit sheltered coastal waters and estuaries
where seagrasses form extensive colonies. Shallow waters, such as sand banks and estuaries are used
for calving. Dugongs are highly mobile, moving daily with the tides and executing long migrations
(100-600 km) in response to seasonal conditions. Potential seagrass beds are mapped within the
Embley River; therefore, it is possible for the species to be affected by activities associated with the
HPBP.
Three potential impacts of the HPBP on the Dugong have been identified, which include:
• changes to turbidity
• direct mortality from boat strikes
• acoustic pollution and disturbance.
A set of management measures is proposed to specifically address each of these impacts, and by
applying these, the HPBP aims to meet the following performance targets:
• compliance with the Mine Rehabilitation Plan
• compliance with the Erosion and Sediment Control Plan and the Waste Management Plan
• compliance with speed limits specified in this Dugong Management Plan
• no direct mortality of Dugong from boat strike
• no boating traffic within 100 m of seagrass beds.
The likelihood and potential consequences of each potential impact, once mitigation measures were
accounted for, were assessed using qualitative risk assessment methodology as per The Australian
Government’s Environmental Management Plan Guidelines 2014. The risk assessment identified a low
residual risk to the Dugong for each of the potential impacts identified.
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1 INTRODUCTION
The Dugong (Dugong dugon) has been identified by the Minister for the Environment as a species
that is likely to be impacted upon by the activities associated with the Hey Point Bauxite Project
(HPBP). This Dugong Management Plan provides a detailed analysis of the Dugong, identifies the
potential impacts that may occur in the context of the HPBP and proposes management strategies to
mitigate the potential impacts identified.
This Dugong Management Plan has been prepared to provide HPBP personnel with appropriate
management strategies to minimise potential impacts to the Dugong. Based on the Department of the
Environment (DoTE) Environmental Management Plan Guidelines 2014, it is one of several species
management plans documented for the HPBP and forms part of the HPBP Environmental Management
Plan (EMP).
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2 PROJECT DESCRIPTION
The HPBP will produce approximately 4 million tonnes (Mt) of product bauxite over the course of its
life and export up to 1.6 Mt of bauxite per year. Minimal processing (dry screening) is required and in
most areas the run-of-mine bauxite tonnes are equivalent to the product bauxite tonnes. The HPBP
has an optimal mine life of 3 years based on a dry season operation only. An additional year may be
required subject to weather conditions limiting the length of the operating dry season.
The key elements of the HPBP are outlined below:
• Open cut mining will involve conventional panel bauxite mining methods, including truck and
shovel operations with a mobile screening unit being utilised to separate bauxite from dry
screening material when necessary.
• Mining will only be undertaken during the dry season. Appropriate erosion and sediment control
measures will be utilised to stabilise areas of disturbance prior to the wet season shut down.
• The shallow mine pit (maximum depth of 4.5 m) is not predicted to interact with the regional
groundwater table during dry season operations.
• Due to site climate conditions, landform characteristics and geological properties, no overland
flow is anticipated during the dry season; however, in keeping with standard erosion and
sediment control principles, clean water drainage will be diverted away from mining areas and
mine-affected water will be captured and contained within the mine workings for reuse.
• A mobile conveyor (approximately 320 m long) will be used to move product bauxite from the
product stockpile to a barge moored in the Embley River. The 2,000 t barge will be loaded by a
radial stacker positioned at the end of a floating pontoon.
• Product bauxite will be transported via barge to a bulk vessel moored approximately 3.5 km
downstream in the Embley River (within the Port of Weipa waters) ready for export. The barge
will require three movements per day, over a ten day period to fill the bulk vessel.
• Power will be supplied from a combination of diesel-fuelled generators and renewable energy
(solar panels). A 30,000 litre diesel tanker (self-bunded) will be positioned on-site to refuel
plant and equipment.
• Staff will access the Project daily via road from Aurukun or via a small boat from Weipa. All
plant and equipment will be brought in via the road network from Weipa as required.
Mining activities will be conducted seven days a week, with one 12 hour shift per day. Loading of
product bauxite into the bulk vessel for export will be conducted for a total of six hours over a 24 hour
period in three two hour intervals.
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3 OVERVIEW OF THE PROJECT
3.1 LOCATION
The HPBP is located on freehold land, approximately 10 km south of the township of Weipa. Weipa is
located approximately 700 km north-west of Cairns and 1200 km east of Darwin as presented in
Figure 1. Figure 2 presents the proposed area of disturbance within the mining lease application
boundary (MLA 20611).
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3.2 ACTIVITIES
3.2.1 Construction, operation and rehabilitation phases
This management plan is structured on three project phases which include construction, operation
and rehabilitation. These phases are consistent with the panel mining methodology described below
and upon commencement of bauxite extraction activities, will occur concurrently as the mine
progresses. The activities within each phase are listed below:
• Construction phase: mobilisation to site, site preparation and infrastructure establishment,
construction of roads and tracks, progressive clearing of vegetation throughout life of mine.
• Operation phase: extraction of bauxite, potential screening, transportation and loading
product.
• Rehabilitation phase: progressive through life of mine, placing of fill, moving of topsoil,
final profiling, revegetation, removal of site infrastructure, final rehabilitation of mine.
3.2.2 Panel Mining Methodology
The mining activities have been designed to minimise movement and handling of topsoil, subsoil
(overburden) and screening waste, maximising the efficiency of the whole of life mining process by
directly placing waste materials and topsoil in excavated areas. The aim of the mining process is to
facilitate rehabilitation that closely follows the progression of the active mining pit, with only two
hectares actively disturbed by mining (excluding rehabilitation activities) at any one point in time. The
implementation of panel mining methodology can be seen in Figure 3.
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1 hectare (ha) panels 1 ha panels
Step Description Step Description
1 Topsoil moved from panel A to stockpile 9 Topsoil from panel E moved to panel C; panel D mined
2 Subsoil from panel A and topsoil from panel B moved to stockpile 10 Subsoil from panel E moved to panel D
3 Panel A mined 11 Topsoil from panel F moved to panel D; panel E mined
4 Subsoil from panel B moved to panel A 12 Subsoil from panel F moved to panel E
5 Topsoil from panel C moved to panel A; panel B mined 13 Topsoil from stockpile moved to panel E; panel F mined
6 Subsoil from panel C moved to panel B 14 Soil from stockpile moved to panel F
7 Topsoil from panel D moved to panel B; panel C mined 15 Topsoil from stockpile moved to panel F
8 Subsoil from panel D moved to panel C 16 Ready for rehabilitation prior to start of wet season
Figure 3 Panel mining methodology
3.2.3 Mine Sequencing
The main features of the proposed mining sequence are outlined below:
• Vegetation will be cleared, mulched and stockpiled. Some of the larger trees will be felled and
placed in the rehabilitation area for fauna habitat.
• A two-stage stripping process will be implemented. Topsoil will be stripped, followed by the
subsoil, leaving exposed bauxite to be mined. The topsoil and subsoil will be placed directly into
the previously mined panel commencing the rehabilitation process.
• Cap rock will be broken by deep ripping with a bulldozer if required to expose the bauxite ore
body. No explosives will be required.
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• Exposed bauxite will be pushed up into windrows with a bulldozer.
• The majority of windrowed bauxite will be loaded into rear dump trucks and transported to the
product stockpile area where it will be either stockpiled prior to load out or dumped straight into
the receivable hopper. Windrowed bauxite containing sufficient impurities will be processed
through a mobile screening unit prior to transportation to the product stockpile.
• Screening waste will be placed behind the screening unit by a loader and then later used for
backfilling purposes.
The optimal three year mining sequence is presented in Figure 4, Figure 5, and Figure 6. The
respective figures are based on the mine plan at a specific time in each year. For example Figure 4
presents the mine progression in September, 2015.
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The key feature of the mining sequence is that all mining panels will have commenced rehabilitation
activities prior to the cessation of operations each year. It is expected that vegetation will be
established during the subsequent wet season. Access tracks for the management of the rehabilitation
along with haul routes (if required) through the rehabilitated areas will be retained.
The infrastructure, plant and equipment selected for the HPBP is reflective of the small scale and
nature of the operation. Based on the optimal three-year life of mine, infrastructure has been
designed to be mobile, with minimal construction and decommissioning requirements.
3.3 SCHEDULE OF ACTIVITIES
The schedule (Table 1) presented below provides an overview of key activities for the life of the
HPBP, along with anticipated timeframes.
Table 1 Schedule of activities
Time Activity
Mobilise to site (plant and equipment/temporary office and workshops etc)
April 2015 Commence vegetation clearing and early works
Establish haul roads and access tracks
Floating pontoon positioned in place
May 2015 – June 2015
Construction of mobile conveyor
Commencement of panel mining sequence,
June 2015 – November 2015 Implementation of rehabilitation management plan (progressive rehabilitation
through life of HPBP)
November 2015 – April 2016 Shut down for wet season
Commencement of panel mining sequence,
April 2016-November 2016 Implementation of rehabilitation management plan (progressive rehabilitation
through life of HPBP)
November 2016 – April 2017 Shut down for wet season
Commencement of panel mining sequence,
April 2017 – November 2017 Implementation of rehabilitation management plan (progressive rehabilitation
through life of HPBP)
November 2017 Shut down for wet season
November 2017 – November 2027 Ongoing rehabilitation to meet objectives of the Rehabilitation Management Plan
November 2027 Lease relinquishment and financial close
3.4 CONTINGENCY SCHEDULES
Contingency schedules will be prepared based on weather conditions for each calendar year. For
example, a particularly wet year may reduce the period of time during the year when efficient mining
can be conducted. The planned area of disturbance for each calendar year will be adjusted
accordingly.
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4 OBJECTIVES
The objective of this Dugong Management Plan is to provide the HPBP with sufficient controls and
management strategies to minimise any potential impacts to Dugong as far as reasonably practicable.
To achieve this objective, a rigorous impact assessment has been undertaken. The impact assessment
proposed a number of potential impacts. To reduce the risk of the potential impacts occurring, a
series of control measures appropriate to the nature, size and scale of the impact are proposed. A
residual risk assessment was then conducted based on likelihood and consequence analysis.
Further to the impact assessment, this management plan provides a complete management
framework which includes:
• a description of the HPBP
• project timeframes
• roles and responsibilities
• monitoring requirements
• auditing and reporting requirements.
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5 ENVIRONMENTAL MANAGEMENT ROLES AND RESPONSIBILITIES
The number of employees working at the HPBP will be limited to a maximum of 20 on a rostered
basis. A single rostered ‘crew’ will be on site at any one time, supervised by a Site Manager. The Site
Manager, reporting directly to the Green Coast Resources Managing Director, will be responsible for
the management and performance of the staff across all management disciplines including operations,
safety and environment. The two-tiered structure requires all HPBP employees to demonstrate
responsible environmental stewardship.
5.1 SITE MANAGER
The Site Manager is the most senior member of staff on site. The Site Manager will be responsible for
the implementation of the HPBP Environmental Management Plan (EMP), of which this Dugong
Management Plan forms part. To maximise the effective implementation of the EMP, the Site Manager
will be responsible for:
• providing resources and equipment to meet objectives
• initiating reviews of EMP when required
• reporting non-compliances
• reporting environmental incidents
• implementing monitoring programs
• maintaining site records
• daily/monthly reporting.
The Site Manager is responsible for identifying training needs so that all HPBP personnel receive an
appropriate level of training to understand and implement the requirements of the EMP. To achieve
this, the Site Manager will use a combination of training and communication tools including:
• Site induction: this will provide staff with a thorough understanding of the environmental
values of the site, the EMP framework and a general overview of the objectives of the EMP.
The induction will provide staff with an understanding of the general environmental duty,
incident reporting requirements and set standards of environmental performance required.
• Toolbox talks: the toolbox talks will provide specific aspects of the EMP relevant to the
activities being undertaken that day. They will inform the operational methodology and
provide staff with appropriate management strategies to manage potential environmental
impacts.
• Reference hard copies of the EMP available in the crib hut and main office.
• Environmental alerts.
5.2 PERSONNEL
The Environmental Protection Act 1994 states that all staff have a general environmental duty. This
means that all staff are responsible for the actions they take that affect the environment.
Staff will be responsible for:
• carrying out environmental management activities as directed by the Site Manager
• observing and informing the Site Manager regarding general environmental performance of
the HPBP
• notifying the Site Manager of any environmental incidents
• notifying the Site Manager of any non-conformances
• participating in induction processes and daily tool box talks to build a suitable understanding
of site environmental values.
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6 REPORTING
Reporting will consist of both internal and external reports. Internal reports will make up the majority
of the reporting requirements and include daily and monthly reporting.
External reports will be required as a condition of approval, at the specific request of a key
stakeholder, or after a notifiable environmental incident.
6.1 REQUIRED REPORTS
6.1.1 Daily reports
The daily environmental checklist will be completed by the Site Manager. The environmental checklist
is integrated into a standard daily report (operational requirements) for the HPBP.
6.1.2 Monthly reports
The monthly report will provide a summary of environmental performance including but not be limited
to:
• summary of weather conditions
• a summary of construction activities undertaken through the month
• environmental incidents
• number of non-conformances
• corrective actions implemented
• area (ha) of clearance for the month
• area (ha) of rehabilitation
• environmental training
• a summary of community complaints (legitimate complaints) and how they were managed
• any environmental initiatives
6.1.3 Incident reports
Environmental incidents will be documented in accordance with the HPBP Environmental Incident
Reporting Procedure.
6.1.4 Non-conformance reports
Non-conformance reports will be documented in accordance with the HPBP Incident reporting
procedure.
6.1.5 EMP audit report
Audits will be undertaken annually or in accordance with the HPBP Environmental Authority
conditions.
6.2 SCHEDULE FOR REPORTING
A reporting schedule will be documented to include any conditions of approval requiring reporting
prior to activities commencing at the HPBP.
6.3 DOCUMENT CONTROL
Green Coast Resources have a document control system that will be implemented for the HPBP.
All environmental documentation is to be managed by the Green Coast Resources Managing Director.
No other staff are authorised to make changes to HPBP environmental documentation.
Hard copies of EMP will be kept onsite. It is the responsibility of the Site Manager to ensure that the
latest plans are being implemented.
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7 ENVIRONMENTAL TRAINING
Environmental training will be facilitated through site inductions and tool box talks. The site induction
will be provided to all staff and include the following:
• identification of site environmental values
• an understanding the requirements of the EMP
• roles and responsibilities
• environmental emergency response procedures
• site environmental controls
• environmental incident identification and response
• potential consequences of not meeting environmental responsibilities.
The management controls presented in this Dugong Management Plan will be included in daily toolbox
talks whilst vegetation clearance is occurring.
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8 EMERGENCY CONTACTS AND PROCEDURES
Emergency contacts and procedures are found in the following HPBP documents:
• Plan of Operations
• Health and Safety Management Plan
• Emergency response plan.
Where required, specialist advice will be sought by a recognised Dugong specialist.
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9 DUGONG
9.1 ECOLOGY OF THE SPECIES
The Dugong (Dugong dugon) is a large herbivorous mammal that forages in small to large herds on
seagrasses. The species inhabits sheltered coastal waters and estuaries, where seagrasses form
extensive colonies (DoTE 2014).
Dugongs are long-lived (beyond 70 years of age) with a slow reproductive rate, long generation time
and a high investment in each offspring (Marsh et al. 1999; DoTE 2014). Breeding seasons for the
Dugong vary, but in North Queensland breeding commences in August through to December (Marsh
et al. 1984). Females do not bear their first calf until at least the age of 10 and the gestation period is
approximately 1 year with a usual litter size of one calf (Marsh et al. 1984).
Dugongs have highly specialised dietary requirements with only certain seagrasses suitable as food
(Preen 1995). The preferred species of seagrass in the diet of Dugongs in North Queensland are the
small pioneering genera Halophila and Halodule (Marsh et al. 1982), but also Thlassia, Cymodocea
and Syringodium (André et al. 2005). They will often uproot whole plants; however, if this is not
possible, Dugongs will target only the leaves (Marsh et al. 1982). It is estimated that Dugongs
consume between 21-36 kg of seagrass each day (DoTE 2014).
Dugongs are highly mobile, and move constantly in a search of seagrass beds and warm waters
(Marsh et al. 2002). They move daily with the tides and can execute long migrations (100-600 km) in
response to seasonal conditions (Gales et al. 2004; Marsh et al. 2002). Such migrations are more
common in southern waters, where cool sea temperatures may make shallow waters less favourable
for Dugongs in winter. In contrast to southern populations, Dugongs in the Gulf of Carpentaria do not
exhibit major seasonal changes in distribution or abundance (Bayliss and Freeland 1989). Dugongs
tend to move on from any one foraging area after five or six days, when 30% of the area has been
grazed (Anderson and Birtles 1978).
9.2 HABITAT REQUIREMENTS
Habitats suitable for Dugong are found in north Australian waters from Shark Bay in Western Australia
to Moreton Bay in Queensland.
Dugongs are seagrass specialists and selectively forage for early pioneer species, especially species of
the genera Halophila and Halodule (Marsh et al. 1982; André et al. 2005; Lanyon et al. 2005). Feeding
aggregations tend to occur in wide, shallow protected bays, wide mangrove channels and in the lee of
large inshore islands, all of which have the common attribute of extensive seagrass colonies (DoTE
2014).
Although Dugongs mainly inhabit coastal waters, they have also been tracked travelling several
kilometres up estuarine creeks and streams (Lawler et al. 2002). Dugongs can also occur offshore in
deeper waters where the continental shelf is wide, shallow and protected (Marsh et al. 2002).
Dugongs sometimes use specialised habitats for various activities such as calving which might be a
strategy used to minimise predation from sharks (Anderson 1981). These specialised habitats include
tidal sand flats and estuaries (Marsh et al. 2002).
9.3 LOCAL POPULATION
A significant proportion of the world’s Dugong populations occur in the coastal waters of Northern
Australia. It is estimated that Queensland’s third-largest population (up to 7,000 Dugongs) inhabit the
eastern Gulf of Carpentaria, particularly the Wellesley Island area, which is one of the most important
Dugong habitats in Australia (DoTE 2012). The Wellesley Islands lie 490 km SSW of Hey Point.
Dugongs are known to inhabit the Embley River (Port of Weipa 2009), although sightings are
infrequent (RTA Weipa 2011). The Embley River estuary is considered to have ‘medium’ densities of
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Dugongs, and is not a recognised as an important refuge for the species (Cape York Turtle and
Dugong Taskforce 2013).
Within the HPBP mining lease, there are extensive seagrass beds along the shore northwest from Hey
Point, which extend almost to the mouth of the Embley River (RTA Weipa 2011). These are dominated
by the seagrass Enthalus acoroides, but contain a number of other seagrass species (RTA Weipa
2011). Enthalus acoroides is not a favoured food of Dugongs (Erftemeijer et al. 1993; André et al.
2005). Despite this, during an ecological survey of the HPBP in April 2013, one Dugong was observed
in the vicinity of this seagrass bed north of Hey Point.
The seagrass beds adjacent to Hey Point are likely to support small numbers of Dugongs transiently,
but are not expected to sustain important populations of the species.
9.4 THREATS
Population simulations indicate that even with the most optimistic combinations of life-history
parameters, and no human-induced mortality, a dugong population is unlikely to increase by more
than 5% per year (Marsh et al. 1999). This makes Dugongs particularly vulnerable to impacts; even a
slight reduction in adult survivorship can cause a chronic decline in a Dugong population (Marsh et al.
1999). For example, populations can take more than 25 years to recover from cyclones and floods
that damage seagrass beds (Preen and Marsh 1995).
A number of activities can lead to reduced adult survivorship. The main current threats to Dugongs
across Australian waters are:
• global warming, which changes sea temperatures, sea levels and frequency of storms
• unsustainable harvesting through indigenous hunting (Heinsohn et al. 2004)
• bycatch by commercial fisheries or shark netting around recreational beaches (Marsh et al.
2002).
Other threats to Dugongs at certain locations (usually those with high boating traffic such as in
southeast Queensland) may also include (DoTE 2014):
• collision with boating vessels
• dredging of estuaries
• acoustic pollution, caused by vessel traffic, low flying aircraft, seismic surveys and Defence
Force activities
• chemical pollution, such as oil spills, heavy metals at mining ports, and pesticides.
9.5 CONSERVATION STATUS
The Dugong is listed as migratory under the Environmental Protection and Biodiversity Conservation
Act 1999 and vulnerable under the Queensland Nature Conservation Act 1992. It is also listed as a
Back on Track critical priority species for the Cape York Peninsula region (DERM 2010).
9.6 POTENTIAL ENVIRONMENTAL IMPACTS AND MANAGEMENT MEASURES
For each phase (construction, operation and rehabilitation) of the HPBP, potential risks to Dugongs
are identified in the following sub-sections. Control measures to avoid and mitigate these risks are
specified. Figure 7 illustrates the locations of seagrass beds used by Dugongs, with respect to the
disturbance footprint of the HPBP, and is used as a reference throughout this section.
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Hey Point Bauxite Project
9.7 POTENTIAL IMPACTS
9.7.1 Construction Phase
9.7.1.1 Changes in turbidity impacting health of seagrass beds
Without appropriate sediment controls, vegetation clearing during the construction phase of the HPBP
could lead to elevated levels of turbidity in the Embley River. Elevated turbidity may impact the health
of seagrass eaten by Dugongs through smothering and lack of light (Marsh et al. 2002).
The Embley, Mission, Hey and Pine Norman Rivers, which all discharge into Albatross Bay, experience
large natural fluctuations in turbidity. Large amounts of suspended material are washed into the Gulf
of Carpentaria during the wet season, causing Albatross Bay to experience high levels of turbidity on a
seasonal basis (Port of Weipa, 2009). Seagrasses rapidly recolonise after the seasonal damage
caused by wet season runoff (Plus et al. 2003), and any changes to seagrass health caused by
increased turbidity through the HPBP are expected to be short-term. Nevertheless, any changes in
turbidity directly attributable to activities of the HPBP could potentially impact upon the health of
seagrass.
9.7.2 Operation Phase
9.7.2.1 Direct mortality from vessel strikes
During the operational phase of the HPBP a barge will be operating in the Embley River to transfer
product bauxite from the HPBP to a bulk vessel anchored 3.5 km north within the Port of Weipa.
Barge movements will be limited to three return trips over each 24 hr period. A small water craft
(small fishing boat) may also be utilised to transport HPBP personnel from Weipa to the floating
pontoon at Hey Point (one 8.5 km return trip per day).
Dugongs usually inhabit waters less than 2 m deep (Maitland et al. 2006), and are not susceptible to
collisions with watercraft in deep water. As a result, there have been few documented Dugong deaths
due to boat strikes, even though boat traffic is heavy in some parts of their range (e.g., Moreton Bay
and Hervey Bay) (Marsh et al. 2002). Nevertheless, any increase in boat traffic in the Dugong’s range
could potential elevate the risk of a boat strike, even though this risk is expected to remain low.
9.7.2.2 Acoustic pollution and disturbance
Dugongs have poor vision but an acute sense of hearing within narrow sound thresholds (Lawler et al.
2002). Anthropogenic acoustic pollution can be caused by activities such as water vessel traffic.
During the operational phase of the HPBP up to three return trips per day by the barge and one return
trip by a small water craft are expected.
Boat traffic is believed to cause disturbance to Dugongs in surrounding waters and may prevent them
from accessing potential seagrass habitats (Marsh et al. 2002). There is evidence to suggest that
there is some disturbance to Dugong feeding when boats pass nearby, although this is short in
duration (duration of response was approximately 100 seconds per pass of a small boat: Hodgson and
Marsh 2007). Boats further than 50 m from Dugongs generally do not elicit a disturbance response
(Hodgson and Marsh 2007).
By not employing the use of pile-driving (produces sound levels damaging to many marine mammals:
Southall et al. 2007; Popper and Hastings 2009) when installing the pontoon, and by ensuring boat
transit routes are >100 m from seagrass beds potentially used by Dugongs, the overall impacts of the
HPBP on Dugongs will be minimal.
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9.7.3 Rehabilitation Phase
9.7.3.1 Changes in turbidity impacting health of seagrass beds
Poor cover of vegetation caused by ineffective rehabilitation of mined areas have the potential to lead
to elevated levels of soil erosion from rehabilitation sites. If reporting to the Embley Reiver, this may
elevate levels of turbidity impacting the health of seagrass beds.
The rehabilitation methods proposed for the HPBP have high rates of success elsewhere (refer to the
HPBP Mine Rehabilitation Plan), and the risk of erosion during the rehabilitation is therefore expected
to be minimal.
9.8 ENVIRONMENTAL MANAGEMENT MEASURES
9.8.1 Changes in Turbidity
9.8.1.1 Environmental Management Activities, Controls and Performance Targets
Controls and performance targets to manage the potential risk of increased turbidity affecting
seagrass beds for Dugongs are listed in Table 2.
Table 2 Control measures for managing risk of elevated turbidity impacting
seagrass beds
Risk Control Measures Timing Performance Target
Implementation of the Mine Rehabilitation Plan: staged clearing will
remove vegetation in 1 ha blocks, which will then be progressively
Construction, operation Compliance with the
rehabilitated to limit the amount of time bare earth is exposed
and rehabilitation phases Mine Rehabilitation Plan
(reducing the risk of sediment laden water reporting to the Embley
River)
Surface runoff from disturbed areas (HPBP activities) will be treated Compliance with the
Construction, Operation
through sediment basins and retention of a buffer of remnant Erosion and Sediment
and Rehabilitation
vegetation along the coastline. Risk control measures will be detailed Control Plan and the
phases
within an Erosion and Sediment Control Plan Waste Management Plan
Compliance with speed
Barge speed limits will be restricted to 6 knots to limit wash Operation phase
limit
9.8.1.2 Environmental Monitoring
Environmental monitoring will prioritise the point source of pollution. This will direct monitoring efforts
to the vegetation clearing activities including the implementation of the Erosion and Sediment Contorl
Plan. Monitoring will include:
• Weekly inspection of erosion and sediment controls: to assess adequate implementation and
effective control.
• Inspection of erosion and sediment controls immediately after rainfall events.
In the unlikely event that water is required to be discharged offsite from sediment basins, water
quality (turbidity) checks will be undertaken prior to discharge to meet water discharge compliance
requirements. Failure to comply with the Erosion and Sediment Control Plan will trigger correction
actions.
9.8.1.3 Corrective Actions
Failure to comply with the Erosion and Sediment Control Plan and/or the Mine Rehabilitation Plan will
trigger corrective actions outlined in the Erosion and Sediment Control Plan and Mine Rehabilitation
Plan. Corrective actions may include repairs and maintenance of erosion and sediment control
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structures and re-educated of personnel about their environmental obligations and requirement to
adhere with the Erosion and Sediment Control Plan and Mine Rehabilitation Plan.
9.8.2 Direct Mortality from Boat Strikes
9.8.2.1 Environmental Management Activities, Controls and Performance Targets
The risk of Dugong mortality from boat strikes is considered a low risk (DoTE 2012). However, the
HPBP will increase the amount of boating traffic in the Embley River, which may increase the risk.
Controls to minimise this risk are listed in Table 3.
Table 3 Control measures for managing risk of direct mortality from boat strikes for
the Dugong
Performance
Risk Control Measures Timing
Target
Vessel movements will be confined to predetermined transit routes that avoid Construction,
known sea grass beds operation and
rehabilitation
phases
Barge speed will be confined to a maximum of 4 knots when loaded and 6 knots Construction,
when unloaded operation and
rehabilitation
phases
The crew on the Barge will observe the area for Dugong prior to the barge Before and during
leaving the floating pontoon and during its voyage to and from the bulk vessel. vessel movements
If a Dugong is sited, the Barge will slow down to 4 knots (if empty) within 50 m
of the Dugong.
No direct mortality
If the Dugong is moving within 50 m of the vessel, the vessel will slow down to from boat strikes
4 knots until the Dugong has moved beyond 50 m
If a Dugong is sighted, it will be recorded in the species observation register Construction,
operation and
rehabilitation
phases
All boat strike incidents will be reported to DEHP within 24 hours Construction,
operation and
rehabilitation
phases
HPBP employees and contractors will be made aware of environmental Prior to
obligations and compliance requirements through the site induction program commencing work
9.8.2.2 Environmental Monitoring
All sightings of Dugongs made during barge and passenger boat movements will be recorded in the
species observation register. Any boat strike incidents or near misses will be recorded in the incident
register, and will trigger corrective actions.
9.8.2.3 Corrective Actions
Any injury /mortality of wildlife through boat strike will be recorded and submitted to the Queensland
Marine Wildlife Stranding and Mortality database. Data collected will inform the need for further
restrictions to boat traffic in the Embley River. An incident investigation will be carried out and this
management plan may be revised (e.g. lowered speed limits) if required.
Other corrective actions will be determined based on the size, nature and scale of the incident
reported.
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9.8.3 Acoustic Pollution and Disturbance
9.8.3.1 Environmental Management Activities, Controls and Performance Targets
A list of the control measures and performance targets to reduce the risk of acoustic pollution and
disturbance can be found in Table 4.
Table 4 Control measures for managing risk of acoustic pollution and disturbance
for the Dugong
Performance
Risk Control Measures Timing
Target
Construction,
To minimise disturbance to sensitive species and seagrass beds inhabiting No boating traffic
operation and
shallow waters, boat traffic will be confined to predetermined transit routes within 100 m of
rehabilitation
following the deepest sections of the Embley River seagrass beds.
phases
The crew on the Barge will observe the area for Dugong prior to the barge Construction,
leaving the floating pontoon and during its voyage to and from the bulk vessel. operation and 100% adherence
If a Dugong is sighted, the Barge must reduce speed to 4 knots (if within 50 m rehabilitation to speed limits
of the Dugong) and maintain a safe distance of 20 m phases
9.8.3.2 Environmental Monitoring
Dugongs sighted during barge movements will be recorded in the species observation register.
Information to be included will be:
• approximate location
• distance to barge
• any corrective actions taken by barge to maintain a 20 m clearance zone (speed limit
reduction)
• general description of Dugong behaviour.
Failure of barge crew to adjust speed limits or maintain transit routes according to this Dugong
Management Plan will trigger corrective actions.
9.8.3.3 Corrective Actions
In the event that performance targets fail to be met, all staff will be re-educated on their
responsibilities under the Dugong Management Plan. Ongoing failure by certain persons to meet
performance targets may trigger disciplinary actions based on Green Coast Resources’ policies.
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10 RESIDUAL RISK ASSESSMENT
The likelihood and potential consequences of each impact, once mitigation measures are accounted
for, were assessed using qualitative risk assessment methodology recommended by DoTE’s
Environmental Management Plan Guidelines (2014) as shown in Table 5. These were used to
generate a risk rating using Table 6.
Table 5 Qualitative risk assessment definitions
Qualitative measure of likelihood after control strategies have been put in place
Highly likely Is expected to occur in most circumstances
Likely Will probably occur during the life of the project
Possible Might occur during the life of the project
Unlikely Could occur but considered unlikely or doubtful
Rare May occur in exceptional circumstances
Qualitative measure of consequences if this issue does occur
Minor Minor incident of environmental damage that can be reversed
Moderate Isolated but substantial instances of environmental damage that could be reversed with intensive efforts
High Substantial instances of environmental damage that could be reversed with intensive efforts
Major Major loss of environmental amenity and real danger of continuing
Critical Severe widespread loss of environmental amenity and irrecoverable environmental damage
Table 6 Risk rating methodology
Consequence
Likelihood Minor Moderate High Major Critical
Highly likely Medium High High Severe Severe
Likely Low Medium High High Severe
Possible Low Medium Medium High Severe
Unlikely Low Low Medium High High
Rare Low Low Low Medium High
10.1 CHANGE IN TURBIDITY
In light of the avoidance measures and controls in place, as well as the small scale of the HPBP, the
likelihood that turbidity within the Embley River is increased by the HPBP to the point that seagrass
productivity is affected is unlikely.
Any incidence of increased turbidity is likely to be short-term and localised (e.g., only following
extreme rain events, and only during short phases of the mining operation when a large area of
ground is cleared and not yet rehabilitated). The rapid regeneration of seagrass following such events
implies that any environmental damage is reversible. This amounts to a minor consequence under the
risk assessment definitions in Table 5.
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The overall risk rating for the HPBP affecting turbidity levels that impact Dugongs is Low.
10.2 DIRECT MORTALITY FROM BOAT STRIKES
In light of the low propensity for Dugongs to be struck by boats and the low speed limits to be
enforced in the HPBP, the likelihood of boat strike to Dugongs is unlikely.
The death of a Dugong from boat strike fulfils the definition of a moderate consequence; it is an
isolated environmental incident that is reversible through natural recruitment. Given the long
generation times and slow reproductive output of Dugongs, this recruitment is expected to be slow
(an ‘intensive effort’).
In light of the likelihood and consequences scores, the overall risk of the HPBP towards direct
mortality to Dugongs from boat strikes is considered to be low.
10.3 ACOUSTIC POLLUTION AND DISTURBANCE
With respect to the positioning of the pontoon away from key Dugong habitat, the restricted speed of
the barge and transit routes to be adopted by the HPBP, acoustic pollution and disturbance to
Dugongs will be limited. Nevertheless, disturbance is considered likely to occur at least once during
the three-year life of the HPBP.
Based on past studies, and the tendency of Dugongs to return to foraging within minutes of the
passing of boats (Hodgson and Marsh 2007), any disturbance caused by the HPBP is expected to be
minor.
The overall risk rating of acoustic pollution and disturbance from the HPBP activities upon Dugongs is
low.
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11 AUDIT AND REVIEW
11.1 ENVIRONMENTAL AUDITING
The implementation and effectiveness of this Dugong Management Plan will be internally audited on
an annual basis. The Site Manager will be responsible for coordinating this audit.
11.2 MANAGEMENT PLAN REVIEW
This management plan, in its current state, is to remain in place throughout the three-year duration of
the HPBP, unless:
• the conservation status of Dugong under the EPBC Act or the NC Act changes
• annual audits reveal a failure to meet one or more of the performance targets.
If a review is required, it will take into account environmental monitoring records, corrective actions
and results of audits. The Site Manager will be responsible for coordinating reviews, which should be
undertaken by qualified ecologists, in consultation with the Queensland DEHP and the Commonwealth
DoTE.
In the event that the management plan is altered, the revised plan will be submitted to the DoTE.
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12 GLOSSARY
Construction Phase: The phase of the HPBP that involves the mobilisation to site, site preparation
and infrastructure establishment, construction of roads and tracks, progressive clearing of vegetation
throughout life of mine.
Herbivorous Mammal: An animal which is anatomically and physiologically adapted to eating plant
material, for example foliage, for the main component of its diet.
Operation Phase: The phase of the HPBP that involves the extraction of bauxite, potential
screening, transportation and loading product.
Pioneer Species: Species which are first to colonise previously disrupted ecosystems.
Rehabilitation Phase: The phase of the HPBP that involves the placement of fill, movement of
topsoil, final profiling, revegetation, removal of site infrastructure and final rehabilitation of mine.
Significant Impact: as defined under Commonwealth Government’s Significant Impact Guidelines
1.1 – Matters of National Environmental Significance.
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13 REFERENCES
Anderson, P.K. (1981). The behaviour of the Dugong (Dugong dugon) in relation to conservation and
management. Bulletin of Marine Science. 31, 640-647.
Anderson, P.K. and A. Birtles (1978). Behaviour and ecology of the dugong, Dugong dugon (Sirenia):
observations in Shoalwater and Cleveland Bays, Queensland. Australian Wildlife Research 5, 1-23.
André, J., E. Gyuris and I.R. Lawler (2005). Comparison of the diets of sympatric dugongs and green
turtles on the Orman Reefs, Torres Strait, Australia. Wildlife Research 32, 53-62.
Bayliss, P. and W.J. Freeland (1989). Seasonal distribution and abundance of dugongs in the western
Gulf of Carpentaria. Australian Wildlife Research 16, 141-149.
Cape York Turtle and Dugong Taskforce (2013). Cape York Turtle and Dugong Regional Plan.
Environmental Legislation Amendment Bill 2013, Submission 16 – Attachment 1.
Department of Environment and Resource Management (DERM) (2010). Cape York Peninsula Natural
Resource Management Region Back on Track Actions for Biodiversity. Department of Environment and
Resource Management, Brisbane.
DoTE, (2012). Species group report card – Dugong, Commonwealth of Australia.
DoTE (2014). Dugong dugon in Species Profile and Threats Database, Department of the
Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed 8 Jan
2015.
Department of the Environment (2014). Environmental Management Plan Guidelines . Commonwealth
of Australia, Canberra.
Erftenmeijer, P.L.A., Djunarli and W. Moka (1993). Stomach content analysis of a Dugong ( Dugong
dugon) from South Sulawesi, Indonesia. Australian Journal of Marine and Freshwater Research 44,
229-233.
Gales, N., R.D. McCauley, J. Lanyon, D. Holley (2004). Change in abundance of dugongs in Shark Bay,
Ningaloo and Exmouth Gulf, Western Australia: evidence for large scale migration. Wildlife
Research 31, 283-290.
Heinsohm, R., R.C. Lacy, D.B. Lindenmayer, H. Marsh, D. Kawm and I.R. Lawler (2004).
Unsustainable harvest of dugongs in Torres Strait and Cape York (Australia) waters: two case
studies using population viability analysis. Animal Conservation 7, 417-425.
Hodgson, A., & H. Marsh (2007). Response of dugongs to boat traffic: The risk of disturbance and
displacement. Journal of Experimental Marine Biology and Ecology. 340, 50-61.
Lanyon, J.M., T. Johns and H.L. Sneath (2005). Year-round presence of dugongs in Pumicestone
Passage, south-east Queensland, examined in relation to water temperature and seagrass
distribution. Wildlife Research 32, 361-368.
Lawler, I., H. Marsh, B. McDonald & T. Stokes (2002). Current State of Knowledge: Dugongs in the
Great Barrier Reef. CRC Reef Research Centre, Townsville.
Marsh, H. (1995). The Life History, pattern of breeding and population dynamics of the
Dugong. In: T. J. O'Shea, B. B. Ackermann & H. F. Percival, eds. Population Biology of the Florida
Manatee'. Page(s) 75-83. US Department of the Interior, National Biological.
Marsh, H., P.W. Channells, G.E. Heinsohn and J. Morrissey (1982). Analysis of stomach contents of
dugongs from Queensland. Australian Wildlife Research 9, 55-67.
Marsh, H., G. E. Heinsohn & L. M. Marsh (1984). Breeding cycle, life history and population dynamics
of the Dugong Dugong dugon (Sirenia: Dugongidae). Australian Journal of Zoology. 32, 767-788.
Marsh, H., C. Eros, P. Corkeron and B. Breen (1999). A conservation strategy for dugongs:
implications of Australian research. Marine and Freshwater Research 50, 979-990.
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