terrestrial vertebrate fauna assessments for ecological ...8.13 exploration impacts 42 8.14 mining...
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Scott A ThompsonGraham G Thompson
Terrestrial Vertebrate Fauna Assessments for Ecological Impact Assessment
TERRESTRIAL ECOSYSTEMS
Published by Terrestrial Ecosystems
First published in 2010
10 Houston Place
Mt Claremont, Western Australia, 6010.
This text can be freely downloaded from: http://www.terrestrialecosystems.com/faunabook.htm
Designed and typeset by Swish Design West Perth - www.swishdesign.com.au
ISBN – 978-0-646-53015-4
Notice
No responsibility is implicitly or explicitly assumed or accepted by the authors or publisher for any injury and / or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein.
ABOUT THE AUTHORS
Dr Scott Thompson is a Senior Environmental Scientist (Zoology) with an environmental consulting firm. He has a long standing interest in the vertebrate ecology of terrestrial fauna in Western Australia. His PhD focussed on developing a bio-index that measured the extent to which rehabilitated sites had returned to supporting near-natural, self-sustaining, functional ecosystems or the degradation of habitat by a development.
Scott has particular expertise in undertaking vertebrate fauna surveys and has undertaken fauna surveys in many of the Western Australia’s bioregions. He has a particular focus on the Goldfields, Pilbara and the Swan Coastal Plain.
Dr Graham Thompson is a Senior Lecturer at Edith Cowan University, a member of the Centre for Ecosystem Management, and a partner of Terrestrial Ecosystems. He has many years experience in terrestrial ecosystems and animal biology. Initially, his research on vertebrates focussed on ecophysiology, morphology and performance traits of reptiles and frogs. In more recent years his research has focussed on improving terrestrial fauna surveys to improve environmental impact assessments.
He has undertaken field research projects in most parts of the state, including the goldfields, Pilbara, Kimberley, Great Victoria and Gibson Deserts, south-west, mid-western and northern wheatbelt.
ACKNOWLEDGMENTS
The contents of this book were significantly improved by the comments and ideas of a number of people who read a draft copy, including Mary Aerts, Dr Mike Bamford, Belinda Bastow, Dr Susan Campbell, Harold Ehmann, Graeme Finlayson, Eileen Thompson, Chris Mayberry, Dr Paul Mitrovski, Dr Dorian Moro, Mark Robertson, Sarah Thompson, Dr Alex Watson and Dr Andrew Woolnough.
We often discussed alternative methods and better ways of undertaking fauna surveys and assessments with colleagues, other researchers and environmental scientists. We gleaned a lot of useful information from these discussions which has influenced what we do and the way in which we do it. Many of these ideas have found their way into this book; however, we are unable to give credit to just one person for initially giving us the idea. The contributions of all of the above people are appreciated.
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CONTENTS PAGE
CHAPTER 1 - PURPOSE 9
CHAPTER 2 - INTRODUCTION 132.1 EcIA AND EIA PROCESSES 132.2 ROLE OF THE ENVIRONMENTAL CONSULTANT 15
CHAPTER 3 - LEGISLATIVE AND POLICY FRAMEWORK FOR FAUNA SURVEYS AND ASSESSMENTS 17
CHAPTER 4 - PRINCIPLES 214.1 PRECAUTIONARY PRINCIPLE AND OTHER ISSUES 214.2 ETHICAL CONSIDERATIONS 22
CHAPTER 5 - OBJECTIVES AND FOCUS OF A FAUNA ASSESSMENT 255.1 OBJECTIVES AND PURPOSE 255.2 FOCUS 26
CHAPTER 6 - GEOGRAPHICAL CONTEXT 29
CHAPTER 7 - RISK ASSESSMENT 31
CHAPTER 8 - FACTORS AFFECTING FAUNA ASSESSMENTS 378.1 HABITAT CONDITION AND QUALITY 388.2 SIZE 398.3 AVAILABILITY OF HABITAT TYPES 398.4 PROPORTION OF ORIGINAL HABITAT REMAINING 398.5 NATURE OF THE DEVELOPMENT 398.6 EXISTING KNOWLEDGE 408.7 LOCAL KNOWLEDGE 408.8 CONSERVATION SIGNIFICANT SPECIES OR ECOSYSTEMS 408.9 DISJUNCT HABITAT AND FAUNA ASSEMBLAGES 408.10 RANGE RESTRICTED POPULATIONS 418.11 HABITAT CONNECTIVITY AND CORRIDORS 418.12 INCREMENTAL CHANGES 418.13 EXPLORATION IMPACTS 428.14 MINING IN ENVIRONMENTAL SENSITIVE LANDS 42
CHAPTER 9 - STAGES OF A FAUNA ASSESSMENT 459.1 STAGE 1 FAUNA ASSESSMENTS 469.2 STAGE 2 FAUNA ASSESSMENTS 48
CHAPTER 10 - FAUNA SURVEYS FOR ‘SPECIAL’ CASES 5110.1 LINEAR CORRIDORS 5110.2 ISOLATED AND REMNANT PATCHES OF VEGETATION 5310.3 ISLANDS 5410.4 OTHER SPECIAL CASES 55
CHAPTER 11 - SURVEY DESIGN 6111.1 CLARITY OF SURVEY PURPOSE AND OBJECTIVES 6111.2 SOURCES OF ERROR AND BIAS 6211.3 SAMPLING AND INFERENCE TO THE POPULATION 6311.4 RANDOM SAMPLING VS. ADAPTIVE SAMPLING 6411.5 SAMPLING UNITS 6511.6 DEFINING FAUNA HABITATS 6711.7 SPATIAL VARIABILITY 6911.8 TEMPORAL VARIATION 7111.9 EDGE EFFECTS AND TRANSITION ZONES 7311.10 ESTIMATES OF DENSITY 7411.11 ADEQUACY OF SURVEY EFFORT 7511.12 TRAPPING EFFORT PER SITE 8111.13 TRAPPING ISSUES 8211.14 TRAP TYPES AND DETECTION METHODS USED IN GENERIC SURVEYS FOR TWO OR MORE TAXA 8511.15 OBSERVATIONAL SURVEYS 94
CHAPTER 12 - VOUCHERING SPECIMENS 101
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CHAPTER 13 - SURVEYING TAXONOMIC GROUPS 10313.1 AMPHIBIANS 10313.2 REPTILES 10513.3 NON-VOLANT MAMMALS 11413.4 BATS 11713.5 BIRDS 124
CHAPTER 14 - MARKING ANIMALS 13514.1 BIRDS 13614.2 AMPHIBIANS 13614.3 REPTILES 13814.4 MAMMALS 139
CHAPTER 15 - OBSERVATION SIGNIFICANT FAUNA 14115.1 MALLEEFOWL (LEIPOA OCELLATA) 14115.2 WESTERN RINGTAIL POSSUM (PSEUDOCHEIRUS OCCIDENTALIS) 14615.3 BILBY (MACROTIS LAGOTIS) 14815.4 MULGARA (DASYCERCUS CRISTICAUDA; D. BLYTHI) 15015.5 SOUTHERN BROWN BANDICOOT (ISOODON OBESULUS FUSCIVENTER) 15215.6 CHUDITCH (DASYURUS GEOFFROII) 15315.7 NORTHERN QUOLL (DASYURUS HALLUCATUS) 15415.8 BLACK COCKATOOS (CALYPTORHYNCHUS LATIROSTRIS, C. BAUDINII, C. BANKSII NASO) 15615.9 WESTERN SPINY SKINK (EGERNIA STOKESII BADIA) 15915.10 GHOST BAT (MACRODERMA GIGAS) 16015.11 PILBARA LEAF-NOSED BAT (RHINONICTERIS AURANTIA) 16115.12 MARSUPIAL MOLES (NOTORYCTES CAURINUS, N. TYPHLOPS) 16215.13 SANDHILL DUNNART (SMINTHOPSIS PSAMMOPHILA) 164
CHAPTER 16 - REPORTING FAUNA ASSESSMENTS AND SURVEYS 16716.1 REPORTING METHODS 16716.2 REPORTING RESULTS 17016.3 DISCUSSION OF RESULTS AND POTENTIAL IMPACTS 17116.4 RECOMMENDATIONS 175
CHAPTER 17 - FAUNA DATABASES 17917.1 NATUREMAP 17917.2 CONSULTANT AND RESEARCH DATA 180
CHAPTER 18 - FIELD DATA RECORDING SYSTEMS 183
CHAPTER 19 - FAUNA MANAGEMENT PLANS 18519.1 INTRODUCTION TO THE FAUNA MANAGEMENT PLAN 18619.2 FAUNA 18719.3 OBJECTIVES AND KEY PERFORMANCE INDICATORS 18719.4 MANAGEMENT STRATEGIES AND ACTIONS 19019.5 MANAGEMENT PLAN REVIEW 19319.6 SUMMARY OF ACTIONS 19319.7 FAUNA MANAGEMENT PROCEDURES 193
CHAPTER 20 - EVALUATING IMPACTS 19520.1 ISSUES WITH SINGLE SITE AND QUASI-EXPERIMENTAL DESIGNS 19620.2 PURPOSE, OBJECTIVES, KEY PERFORMANCE INDICATORS AND TRIGGERS 19920.3 EVALUATION PROTOCOLS 20020.4 BASELINE DATA 20020.5 ADEQUACY OF SAMPLING 20120.6 POWER AND THE PRECAUTIONARY PRINCIPLE 20220.7 BIO-INDICATORS 20220.8 REHABILITATION AND DEGRADATION INDEX 20320.9 SITE SELECTION 203
CHAPTER 21 - REFERENCES 205
CHAPTER 22 - APPENDICES - EXAMPLE REPORT 223
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PURPOSE
This book sets out to suggest ‘appropriate practice’ for:
i. terrestrial vertebrate fauna assessments to support EcIAs or EIAs in Western Australia; and
ii. fauna management plans and the subsequent evaluation of the effectiveness of these plans.
This text is relevant to anyone who commissions, undertakes or reviews terrestrial vertebrate fauna assessments to support an EcIA. Although our book focuses on Western Australia, the principles and many of the suggested assessment and survey protocols will be applicable in other states of Australia.
The requirements for fauna assessments to support an EcIA in Western Australia are unclear, and the standard of assessments undertaken by consultants and the quality of work accepted by the EPA varies. The EPA (2002) commented that there were ‘insufficient resources allocated by proponents for appropriate surveys’, there was ‘uncertainty about the validity of using and/or interpreting the
results of previous surveys and thus their adequacy for a current assessment’, there was ‘insufficient reference to available databases and current literature’, there was an ‘absence of a consolidated database’ and ‘inappropriate timing of surveys’, there was ‘insufficient information on condition of the vegetation and the absence of common standards for assessment of that condition’ and ‘the absence of documented general requirements for surveys and the pressure of time constraints for project approval provides little encouragement to improve the quality of surveys’ (p. 4). Many of these shortcomings can be improved by better guidelines.
There have been numerous meetings and publications in Australia to discuss fauna survey
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methodology (e.g. Myers et al., 1984, Margules and Austin, 1991, Owens, 2000, Murray et al., 2002) stretching back more than two decades and there is recent reference material on fauna census techniques that has more universal application (Wilson et al., 1996, Sutherland, 2006, Bibby et al., 2007). However, much of this information was not designed to support EcIAs. Almost two decades ago, Braithwaite (1991) suggested typical fauna surveys provided useful but relatively trivial information on the distribution and abundance of vertebrate fauna. It is our view also that this is largely the current situation for many fauna surveys undertaken to support EcIAs in Western Australia (Thompson, 2007).
It is necessary for government assessors to have a good knowledge of the vertebrate fauna assemblage to adequately assess potential impacts of a development on vertebrate biodiversity and the adequacy of mitigation strategies and fauna management plans. Inadequate knowledge increases the risk of unknown or unintended impacts and implementing ineffective mitigation and management strategies. The proponent has a responsibility to provide this information.
It is intended that this book will lead to a more scientifically robust approach in the assessment of impacts on terrestrial vertebrate fauna in Western Australia. Although we generally support current practices in EcIA in Western Australia, we believe there are some areas that can be improved. Too many fauna surveys have been undertaken unnecessarily, have not been cost-effective and have not provided assessors with either sufficient or appropriate information upon which to make an adequate assessment of potential impacts on the vertebrate fauna or how these might best be managed. If this book leads to better outcomes for the vertebrate fauna of Western Australia and the EcIA process, then we will have achieved our goal.
When describing appropriate fauna survey protocols we have endeavoured to cite the appropriate literature that supports our recommendations, as this provides the reader with the opportunity to determine the reasonableness and appropriateness of what we are suggesting. There is often no ‘correct’ method or approach for undertaking a
particular survey. Similarly, the extent and intensity of the survey effort required cannot be mandated as it is dependent on numerous considerations. In many circumstances where the literature is either silent or ambiguous on what is appropriate, we have indicated our considered assessment of what appropriate practice should be. We would welcome comment, discussion and feedback on what we have suggested. Similarly, there is an enormous volume of published literature on the issues that we have addressed and we have only reviewed a small proportion of this information. If you are aware of particular publications or data that we should consider for a future edition, then we would appreciate the feedback.
This text starts with a brief overview of the most relevant legislation and is followed by a discussion of the principles, objectives and purpose of a fauna assessment to support an EcIA. A risk assessment framework is provided and this is followed by a discussion of the factors that affect a risk assessment. A two stage assessment process is then explained. This is followed by a discussion of issues and considerations related to undertaking fauna surveys. There is a section on trapping strategies for various taxonomic groups and species-specific searches for some Western Australia’s conservation significant species. Comments are provided on writing reports and the importance of developing and maintaining a database of fauna survey records. We also provide comment on the use of PDAs to collect data in the field. The text concludes with a section on preparing fauna management plans and evaluating impacts of a development on the fauna in adjacent areas.
We have enclosed in boxes our suggested appropriate practice and important comments. These boxes have been placed at the beginning of the relevant sections, but are based on the information that is discussed and summarised in the paragraphs that follow.
This text does not cover fish or invertebrates, although, they should be considered in any ecological impact assessment.
Dr Scott Thompson
Dr Graham Thompson
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2.1 EcIA AND EIA PROCESSES
Suggested appropriate practice
• Where a Scoping Document indicates that fauna surveys are required; then the specific objectives and protocols for those surveys should be provided in that document.
• Fauna assessments and fauna survey objectives and protocols provided in Scoping Documents should be independently peer reviewed, and reviewers’ names and qualifications included in that report.
An EcIA is about identifying and evaluating potential impacts on biodiversity associated with a proposed development, and then developing effective mitigation and ongoing evaluation strategies to minimise biodiversity loss. EIA incorporates EcIA plus it addresses a wide range of other issues. If properly implemented, an EIA provides a scientifically defensible approach to ecosystem management (Treweek, 1999). The generally accepted process is shown in Figure 2.1.
Fauna assessments or surveys can assist in the screening process (i.e. deciding whether an
EcIA is required, and what level of assessment is appropriate). This will be influenced by issues such as the size and scale of the proposed development, availability of existing information, potential impacts, and the nature and abundance of the ecosystems to be disturbed. The primary outcome of the screening process is to classify the project’s environmental sensitivity (i.e. referral and level of assessment stage; see Section 38 of the EP Act). Scoping is the stage in the process of identifying and assigning priority to potential impacts, and detailing what additional information is necessary to adequately assess potential impacts. At this stage the
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proponent / environmental consultant will develop a good appreciation of the proposed development and potential impacts. To assist in developing this understanding, the consultant would normally review the available literature and databases on fauna in the bioregion and undertake a site visit. If a field survey is required, then the objectives and protocols for this survey should be defined in the Scoping Document.
The scoping process is important for EcIAs, as it helps clarify the issues and is an opportunity to ensure that the subsequent work is focussed and appropriate to the task (EPA, 2009). The EPA (2009) indicated that a Scope of Works outlining proposed studies and investigations is an integral component of a Scoping Document. The scoping process also ensures that a scientifically robust assessment of the risks associated with the impacts of a proposed development on the fauna is presented to the assessors. All too often, the objectives and protocols for a fauna assessment and survey are vague and do not provide sufficient guidance to the environmental consultant on desired outcomes. Specific objectives will reduce the number of expensive terrestrial fauna surveys that have little biological / ecological value, where they are not required because adequate information is already available, where the area of impact is small and any loss of habitat is unlikely to have a significant impact on the fauna in the area, or where the proposed protocol is unlikely to provide sufficient information to adequately assess impacts.
If it is likely that fauna survey data are to be used for monitoring and evaluation purposes once the development becomes operational (e.g. monitoring impacts on adjacent habitat), then this needs to be clearly stated in the Scoping Document, as it will affect the design of the fauna surveys (see Chapter 20). The fauna survey protocols to support impact evaluations may be quite different to those used to support an EcIA, but there is always going to be considerable overlap. As a consequence, it is cost effective to plan both together at an early stage in the process.
An independent peer review of the fauna assessment and survey objectives and protocols that are contained in Scoping Documents should lead to enhanced outcomes. The EPA (2009) encourages proponents to incorporate a peer review in defining and assessing a project. Peer review reports by appropriately qualified and experienced practitioners should be included in Scoping Documents when they are made available for public comment, to provide readers and assessors with a level of comfort about the quality of the work. The qualifications and experience of reviewers should be included in the report. It is also suggested that details of the protocols and methods to be used in fauna surveys be peer reviewed prior to their implementation. The opportunity to redesign a survey based on a peer review report should be available to the proponent along with the capacity to negotiate an agreed survey protocol.
Figure 2.1. EcIA process showing where fauna assessments and surveys, and monitoring data contribute to the outcome
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2.2 ROLE OF THE ENVIRONMENTAL CONSULTANT
It is the role of the environmental consultant undertaking fauna assessments and surveys to support EcIAs to provide a scientifically robust, objective and transparent assessment of the potential risks associated with a proposed development on the fauna assemblage. The proponent / environmental consultant has a responsibility to obtain, actively seek out and provide sufficient information so that assessors and the public can make an informed decision about potential impacts of a development on the vertebrate biodiversity and the extent to which mitigation strategies and management plans will avoid or minimise these impacts.
In an ideal world, environmental consultants should remain impartial to the client and maintain
a commitment to the maintenance of biodiversity and ecosystem function. However, consultants can be compromised as they are selected by proponents and their future income and livelihood often depends on them producing a report that meets the proponents’ objectives, which most often is to clear or disturb the environment. Therefore, the scientific rigor of all EcIAs should be independently examined and tested. This is a primary reason for a strong recommendation that all fauna assessment and survey reports be peer reviewed.
Ideally, environmental consultants should be independently appointed to projects, so that their loyalty to the client does not comprise the quality of their assessments.
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LEGISLATIVE AND POLICY FRAMEWORK FOR FAUNA SURVEYS AND ASSESSMENTS
This section draws the reader’s attention to Commonwealth and State legislation that are particularly relevant to fauna assessments and surveys, and to policy documents that provide direction and guidance on why and how fauna assessments and surveys should be undertaken. The relevant legislation includes:
• Environment Protection and Biodiversity Conservation Act 1999.
• Wildlife Conservation Act 1950.• Wildlife Conservation Regulations 1970.• Environmental Protection Act 1986.• Animal Welfare Act 2002.
Some of the more relevant documents that provide guidance and direction on how and why fauna surveys and assessments might be conducted based on the above are:
• EPBC Act Policy Statement 1.1 Significant Matters of National Environmental Significance.
• EPBC Act Policy Statement 1.2 Significant Impact Guidelines.
• Australian Code of Practice for the Care and Use of Animals for Scientific Purposes 7th Edition.
• A Guide to the Exemption and Regulations
for Clearing Native Vegetation under the Environmental Protection Act 1986.
• EPA (2002) Terrestrial Biological Surveys as an Element of Biodiversity Protection Position Statement No. 3. Environmental Protection Authority, Perth.
It is not our intention to summarise or paraphrase the legislation, but the following points are particularly relevant:
• If a proposed action will significantly impact on a species that is critically endangered, endangered or vulnerable or if a proposed action will significantly impact on a critically endangered or endangered ecological community as listed under the EPBC Act 1999, then a referral is required. A fauna assessment or survey will generally be required to determine whether this impact will occur and would be significant.
• Some of the legislative objectives of the Environmental Protection Act 1986 are particularly relevant as they provide the basis for why fauna assessments are undertaken. The EPA in Western Australia is required to consider the following principles in its assessment of development applications:
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° The precautionary principle - such that a careful evaluation to avoid serious or irreversible damage to the environment and a risk-weighted assessment of the consequences of the various options should be undertaken;
° The principle of intergenerational equity - such that the existing environment should be maintained or enhanced for future generations; and
° The principle of the conservation of biological diversity and ecological integrity - such that the biological diversity and ecological integrity of the State should be conserved.
• One of the objectives of the EPA is to protect the environment and to prevent and control environmental harm. The Environmental Protection Act 1986 gives the EPA a broad range of functions and authorities. One of these is to assess the impact of proposals on the environment, including vertebrate fauna, and to advise and recommend a suitable course(s) of action to the Minister.
• Issues to do with clearing native vegetation are also addressed under the Environmental Protection Act (Part V, Division 2). There are specific regulations relating to the clearing of
native vegetation – Environmental Protection (Clearing of Native Vegetation) Regulations 2004. Appropriate fauna assessments and surveys are required to enable government assessors to determine whether the proposed clearing of native vegetation will compromise:° a high level of biological diversity;° the whole or a part of, or a part necessary for
the maintenance of a significant habitat for fauna indigenous to Western Australia; and
° the whole or a part of, or a part necessary for the maintenance of a threatened ecological community.
• The Wildlife Conservation Act 1950 prohibits the taking of fauna without an appropriate licence. To ‘take’ in relation to fauna includes to kill or capture, to disturb or molest. People wishing to undertake fauna assessments or surveys that will ‘take’ fauna are required to obtain a Regulation 17 licence from the DEC.
• The Animal Welfare Act 2002 stipulates that a person must not use animals for scientific purposes unless that person is from a scientific establishment that has a licence authorising that use. Scientific establishments are required to have an animal ethics committee that approves of the use of animals. ‘Use’ is not defined in the Act, but ‘scientific establishment’ is defined as a legal person who uses, or whose staff or students use animals for scientific purposes. Scientific purpose includes research. Currently, there is no mechanism in Western Australia for environmental consultants to obtain ethics approval for fauna assessments and surveys that they might undertake unless they are linked with a university or government agency that has such an ethics committee. It is unclear whether fauna assessments and surveys are deemed as research under the Animal Welfare Act and whether environmental consultants require ethics approval for their activities. Environmental consultants are required to obtain ethics approvals for their fauna surveys in other Australian states.
• The Animal Welfare Act 2002 relies heavily on the Australian Code of Practice for the Care and Use of Animals for Scientific Purposes, which has a section on wildlife studies. This section addresses issues to do with the capture / trapping, handling, release and transport of fauna. It also provides advice on identification and vouchering of specimens.
• The EPAs Position Statement No. 3 Terrestrial Biological Survey as an Element of Biodiversity Protection (2002) provides a useful overview of the purpose of fauna surveys, namely ‘the EPA expects proponents to ensure that terrestrial biological surveys provide sufficient information to address both biodiversity conservation and ecological functional values within the context of the type of proposal being considered and the relevant EPA objectives for the protection of the environment.’
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4.1 PRECAUTIONARY PRINCIPLE AND OTHER ISSUES
PRINCIPLES
Protection and conservation of biodiversity is best achieved in the context of all available information. In circumstances where insufficient is known about the fauna, the precautionary principle should be adopted. Kriebel et al. (2001) suggested there are four components to the precautionary principle:
• Taking preventive action in the face of uncertainty;
• Shifting the burden of proof to the proponent of the activity;
• Exploring a wide range of alternatives to the possible harmful actions; and
• Increasing public participation in the decision making.
From a regulator’s perspective, it is the proponent’s responsibility to demonstrate the extent to which a development is likely to impact on the biodiversity. In the absence of adequate data to predict and describe potential impacts of a proposed action or development, then the worst case scenario should be presumed if the precautionary principle is adopted. Worst case in this context is the highest level of impact that is feasible within the constraints of what is known.
An absence of data increases uncertainty associated with the assessment of impacts. The
most environmentally responsible approach is to fully understand the fauna assemblage and ecosystems that are to be impacted. It is difficult to prepare cost-effective fauna management and mitigation plans in the absence of good information on species abundance and spatial distribution. In the long term, it is often a cheaper option to undertake a more detailed initial investigation than to implement mitigation and management plans that are ineffective and unwarranted.
The Environment Institute of Australia and New Zealand (2009) ecology group’s final draft discussion paper on biological diversity outlined two principles that are worthy of repeating here:
• Biodiversity management is not just about protecting particular species of flora and fauna (e.g. threatened species), it is about maintaining functioning ecosystems and processes; and
• It is essential that biodiversity outcomes are monitored and reported so that we can learn from past successes and failures.
Both of these principles underpin many of the appropriate practice suggestions that are included in this text.
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4.2 ETHICAL CONSIDERATIONS
There has been considerable discussion about the ethical standards associated with fauna assessments and surveys. In Western Australia the Animal Welfare Act 2002 controls what is acceptable and how animal research will be managed. Although it is currently unclear whether environmental consultants are required to obtain ethics approval for their fauna surveys, there is still an obligation on everyone to act in an ethical manner when undertaking fauna surveys.
What is ethical, acceptable and reasonable is not always clear. For example, Langkilde and Shine (2006) pointed out that animal ethics committees are required to assess the potential stress likely to be suffered by an animal during a procedure (e.g. being trapped), but stress is poorly defined, and animal ethics committees generally base their decisions on intuition, which can be an unreliable criterion. They illustrated this with evidence to indicate perceived stressful activities (such as handling and measuring, or toe-clipping of lizards) were often less stressful than placing animals in an unfamiliar enclosure. In addition, concern is sometimes expressed at the number of animals that die in traps, but in many cases the entire population from which these trapped animals were sampled will be killed during the vegetation clearing process.
The NSW Department of Primary Industry in its publication on ethical considerations for wildlife surveys (Department of Primary Industries and Animal Research Review Panel, 2009) made the point that a case needs to be presented for every survey to demonstrate that it is both necessary and justified which is partially determined on a review of existing data. This statement provided strong support for the two stage EcIA process that is advocated in this text.
The NSW Department of Primary Industry (2009) document suggested that the following issues need to be considered to reduce unnecessary stress on fauna during surveys:
• Survey staff should have practical training and be experienced and competent in all the techniques used;
• Methods that do not require animals to be caught are preferable to those that do (e.g. ultrasonic detectors are preferable to nets and traps when surveying bats);
• Fauna should be captured using the least stressful method(s), taking into account animal activity periods and release times;
• Animals that have to be handled should be gently restrained and the procedure completed as quickly as possible;
• Non-invasive approaches should be used in preference to those that might adversely interfere with the normal functioning of an animal;
• Vouchering of animals should be justified, and the number kept to a minimum;
• Euthanasia of animals to be vouchered must be done by approved methods;
• Protocols to deal with injured animals should be decided in advance of the survey; and
• Emergency procedures should be in place to address circumstances that might inhibit traps being cleared within a reasonable time due to weather, accidents, etc.
In addition, protocols to deal with introduced (e.g. Rattus rattus, Mus musculus) and pest species (Felis catus, Vulpes vulpes) should be decided in advance of the survey.
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5.1 OBJECTIVES AND PURPOSE
OBJECTIVES AND FOCUS OF A FAUNA ASSESSMENT
Terrestrial fauna assessments and surveys are undertaken to provide proponents, the EPA, stakeholders, other government agencies and the public with sufficient information to ensure:
• The environment, including functional ecosystems, conservation significant fauna and fauna assemblages, are adequately identified and protected;
• Ecosystem functional values of the disturbance area are identified and protected;
• Potential impacts on fauna are identified and effectively mitigated and managed;
• Survey data, where appropriate, are capable of being used to measure long term impacts on fauna in adjacent areas; and
• The community can be confident that the approval conditions and the implementation of management and mitigation plans will be sufficient to protect the vertebrate fauna and impacts will be equal to or less than those indicated as being acceptable.
In this context, the objectives of fauna assessments and surveys undertaken to support an EcIA fit into two categories; background and descriptive information about the fauna assemblage, and, most importantly, an assessment of the potential impacts of the proposed development on the fauna. A report should therefore provide the following information.
Background and descriptive information
• Describe the type and condition of major fauna habitats that will be impacted;
• Provide a description of the fauna assemblages (i.e. species richness and relative abundance) in each of the major habitats, including an indication of fauna of conservation significance;
• Describe ecological functional values for each of the major fauna habitats and indicate any that are of high ecological value or importance; and
• Compare fauna assemblages in major habitats with those elsewhere in the bioregion to determine the extent to which they are unique and therefore have high ecological value.
Impact, risk assessment and mitigation strategies
• Describe the potential impact(s) on vertebrate biodiversity and ecosystem function on-site, in adjacent areas and in a landscape and bioregional context;
• Describe potential impacts on species and ecosystems of conservation significance;
• Describe mitigation strategies and management plans that will effectively minimise impacts; and where appropriate provide baseline data to enable the ongoing evaluation of impacts in the longer term.
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of one habitat type merges with those in adjacent areas. In some areas (e.g. jarrah / wandoo forests, woodlands on the Swan Coastal Plain) there is often more of a continuum with boundaries between habitat types much less defined. A judgment is therefore required when defining major fauna habitats and survey sites should be located away from fauna habitat boundaries or ecotones so that the fauna survey data can be linked to particular characteristics associated with a particular fauna habitat type.
The focus for terrestrial fauna assessments should therefore be on:
• ‘Major’ fauna habitats (i.e. collection, collation, analysis and preparation of the information should be based on major habitat types);
• Fauna assemblages and ecosystem function (i.e. describing species richness and assemblage structure and how this is integrated with other biotic and non-biotic variables on and off-site); and
• Potential for the development to impact on conservation significant species or ecologically significant communities.
Fauna habitats can be defined at various geographic scales. For example, at a micro-scale, a spinifex hummock can be the habitat for a small community of geckos and pygopods; and at the landscape scale, the red sand ridge-swale system of interior deserts can be the habitat for a complex fauna assemblage. The term ‘major fauna habitat’ discussed here lies between these two ends of a continuum. It is an area that supports a recognised and relatively cohesive vertebrate fauna assemblage that is associated with the terrain, soils and vegetation in that area. Typically, a major fauna habitat might be a sparsely vegetated mulga woodland, ephemeral drainage lines, wetlands, gorges, stony ridges in a sand plain, low heath scrubland, relatively flat spinifex plain or riverine edges of a permanent or semi-permanent waterway. What is defined as a ‘major fauna habitat’ will also be influenced by the scale of the proposed disturbance footprint.
Currently, there is an emphasis and focus on species of conservation significance in the EcIA process. Possingham et al. (2002) made an interesting observation about the use of threatened species lists that is relevant here. Because a species is legislated as being conservation significant, its presence within a development site can curtail that development even when the impacts are potentially low, whereas projects with large impacts that do not directly impact on species of conservation significance are often allowed to proceed without mitigation requirements. It is our view that a higher weighting should be applied in the EcIA process to the scale of the impact and the potential impact on functioning ecosystems than is the current practice.
The protection of conservation significant species and ecosystems is important, however, the authors believe that there should be a greater emphasis and focus on maintaining and protecting functioning ecosystems of which conservation significant fauna are an important component. The EPA’s Position Statement No 3 (2002) focuses on biodiversity value at the genetic, species, and ecosystem levels and ecological functional value at the ecosystem level. The EIANZ (2009) suggested focus on maintaining functioning ecosystems is strongly supported as the basis for EcIA assessments.
The approach adopted here is to gather sufficient information to be able to describe, with a reasonable degree of confidence, vertebrate species richness and assemblage structure for each of the major fauna habitats that will be impacted (i.e. this may include areas outside the development footprint), so that impacts might be adequately described and mitigation and management measures developed to protect the fauna.
Defining what a major habitat is can be problematic. Sometimes it is obvious, as there are distinct variations in the soils, vegetation and topography that are then reflected in differences in the fauna assemblages. In some circumstances, the boundary of various fauna habitats can be defined as narrow bands on the ground, but more often the boundary
5.2 FOCUS
Suggested appropriate practice
• Fauna assessments should be based on major fauna habitat types.
• Fauna assessments should focus on how the proposed development will impact on the fauna assemblage and ecological functional values of the area, as well as on conservation significant species.
Comment
• Fauna survey data should be reported based on relative abundance and not as ‘presence-only’.
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All too often fauna survey data are presented for the whole of the site, and no attempt is made to describe species richness or assemblage structure for each of the major habitat types. The composition of fauna assemblages can vary appreciably within what is often perceived to be a uniform fauna habitat (i.e. spatial variability), among seasons and from year-to-year (i.e. temporal variability), and even more so for sites that contain multiple and diverse habitat types. To aid the interpretation of fauna survey information, survey data should be collected, collated, analysed and presented on the basis of fauna habitats.
Vertebrate fauna density and relative species abundance are important considerations when assessing potential impacts on ecosystem function whether it is at the local or regional scale and when comparing a development site with similar habitats in the bioregion. Presenting ‘presence-only’ data is therefore of little value in fauna assessment reports, as this information gives the same value to species that are abundant, rare or vagrants, which is clearly inappropriate (Denny, 1984). For example, if we compare two habitats in which we caught only
species A and B. In habitat X we caught 1 species A and 99 species B, and in habitat Y we caught 50 species A and 50 species B. When assessed on a presence-only basis, these two fauna assemblages are incorrectly considered identical. To determine the uniqueness of a fauna assemblage or ecosystem more information about the assemblage structure is required than a species inventory. High species richness or diversity may, in some circumstances, be important and indicate high ecological value. However, fauna habitats supporting low species richness or diversity but containing a unique assemblage, conservation significant species, species that have a limited geographic range or a geographically disjunct population, can also be of high ecological value.
An impact assessment on the fauna of an area can only be adequately undertaken by comparing its fauna assemblage with others in the bioregion (Denny, 1984). Sufficient data are therefore required on a habitat basis to make meaningful comparisons among fauna assemblages in the same and other biogeographical regions.
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GEOGRAPHICAL CONTEXT
For the purposes of this text and providing a context for a fauna assessment at a particular site, there are three geographical scales. A site is located within the:
• Local area• Landscape• Bioregion (Figure 6.1)
The local area is the area around the impact site that has similar geology, topography, soils and
Figure 6.1. Three geographic
scales for reporting fauna
assemblages at a particular
development site
vegetation and probably similar fauna assemblages. Landscape scale is defined more broadly by the geology and topography (e.g. flood plain, ranges, undulating mulga woodland).
Bioregional scale is most often defined as the Interim Biogeographic Regionalisation for Australia (IBRA). Australia has 85 bioregions, and 403 subregions. Most often fauna survey data are best analysed in the IBRA subregion context.
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RISK ASSESSMENT
Suggested appropriate practice
• An assessment of potential impacts on the vertebrate fauna of a proposed development should be undertaken in the context of the likelihood and consequence of an event occurring (i.e. a risk assessment).
• A risk assessment should be undertaken with and without the implementation of proposed management and mitigation strategies.
Comment
• A risk assessment undertaken in a Stage 1 fauna assessment should be used to provide guidance on what additional information should be collected in a Stage 2 assessment.
• A risk assessment undertaken in a Stage 2 fauna assessment should clearly define potential impacts and be used to develop more effective management and mitigation strategies.
A risk assessment based on adequate data will provide a succinct summary of the level of risk for conservation significant species, fauna assemblages and ecosystems within and adjacent to the proposed development and how effective the proposed mitigation or management strategies might be in reducing that risk.
Risk is generally assessed in the context of a matrix of ‘likelihood’ verses ‘consequences’. Where the consequence of a particular action is assessed as low or very low, then there is little point in collecting a lot of data to determine the likelihood of the event occurring. The converse is also true, that is, high quality data should be collected to describe likelihood and consequences where the risk is high, as this will improve decisions on mitigation and management plans should the development proceed.
Consequence in the context of a risk assessment is defined as an outcome or impact of an event (Standards Australia International and Standards New Zealand, 2009). There can be more than one consequence from an event.
Consequences can be positive or negative and can be expressed in a qualitative or quantitative format (Standards Australia International and Standards New Zealand, 2009). Likelihood is the probability of an event happening and can be expressed in a qualitative or quantitative format (Standards Australia International and Standards New Zealand, 2009). In the simplest qualitative form, a risk assessment matrix would look like the one shown in Table 7.1 (Standards Australia International and Standards New Zealand, 2009).
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Table 7.1. A simple qualitative risk assessment matrix
Figure 7.1. Species accumulation curve indicating that most of the species have been detected after about 5,000 individuals have been recorded and about 87 species were present at the time of the survey
Figure 7.2. Relationship between survey effort (i.e. number of sites) and the confidence associated with estimating species density
Co
nseq
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e Likelihood
Improbable Probable
Minor Low risk Medium risk
Major Medium risk High risk
Increasing the survey effort to more adequately assess likelihood and consequence has diminishing returns. For example, the relationship between survey effort and proportion of species recorded is curvilinear (Figure 7.1), with a high proportion of the
species recorded for a small number of individuals caught or seen, but a rapidly reducing number of additional species recorded for a much higher survey effort. Similarly, to determine the species density for a particular habitat, and thus the potential impact and
consequences of a development, multiple sites will need to be surveyed in that habitat type. Precision in estimating density is improved with additional sites being surveyed, but the rate of improvement generally diminishes quickly with the addition of more survey sites (Figure 7.2).
A framework for assessing potential risks to the fauna assemblage associated with a proposed development is provided below. This framework makes provision for adjusting the risk, based on proposed management and mitigation strategies. Descriptors for various levels of likelihood and consequence are provided in Table 7.2. The acceptable level of risk based on
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Table 7.2. Fauna impact
risk assessment descriptors
Table 7.3. Levels of
acceptable risk
these descriptors is provided in Table 7.3. Data from these two tables are then used to assess the risk associated with a potential development based on the data collected during a fauna assessment or survey. An example of the output for such an assessment is shown in Table 7.4. Most often, based on the fauna assessment, a series of recommendations are made
on how to mitigate or manage potential impacts, that is, to either reduce the likelihood of the occurrence or the consequence of an occurrence. Extra columns are added to the risk assessment matrix to indicate how the risk is altered with the implementation of those strategies (Table 7.4).
Likelihood
Level Description Criteria
A Rare The environmental event may rarely occur.
B Unlikely The environmental event is unlikely to occur.
C Moderate The environmental event could occur.
D Likely The environmental event should occur.
E Almost certain The environmental event will occur.
Consequences
Level Description Criteria
1 InsignificantNo loss of conservation significant fauna or regional biodiversity and an insignificant impact on non-conservation significant fauna.
2 MinorNo loss of conservation significant fauna or the localised loss of individuals and species in a regional context.
3 ModerateLoss of an individual from a conservation significant species or a moderate loss of non-conservation significant fauna in a regional context.
4 MajorSignificant loss of conservation significant fauna as defined in the DEH (2006) publication or a loss of a significant number of non-conservation significant fauna at landscape scale.
5 CatastrophicLoss of a population of conservation significant at a local scale or loss of a significant number of non-conservation significant fauna at regional scale.
Acceptability of Risk
Level of risk Management Action Required
Low No action required.
ModerateAvoid if possible, routine management with internal audit and review of monitoring results annually.
HighExternally approved management plan to reduce risks, monitor major risks annually with external audit and review of management plan outcomes annually. Will probably require a referral to the Commonwealth under the EPBC Act 1999.
Extreme Unacceptable, project should be redesigned or not proceed.
Any risk assessment is a product of the likelihood of an event or impact occurring and the consequences of that event or impact. Likelihood and consequence are categorised and described below. The assessed risk level (likelihood x consequence) is then calculated as the overall risk for the development. This is followed by an assessment of the acceptability of the
Likelihood
Con
sequ
ence
s
Rare (A) Unlikely (B) Moderate (C) Likely (D) Almost certain (E)
Insignificant (1) Low Low Low Low Low
Minor (2) Low Low Low Moderate Moderate
Moderate (3) Low Moderate Moderate High High
Major (4) Moderate Moderate High High Extreme
Catastrophic (5) Moderate High High Extreme Extreme
risk associated with each of the events or impacts. Disturbances and vegetation clearing have an impact on the fauna at multiple scales – site, local, landscape and regional. Each of these is considered in the risk assessment. This assessment should be considered in the context of the summary in Table 7.4
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Table 7.4. An example of a risk assessment of the impact of ground disturbance activity on fauna
Before Management With Management
Factor Potential Impact Inherent Risk Risk Controls / Management Residual Risk
Like
lihoo
d
Con
sequ
ence
Sig
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ance
Like
lihoo
d
Con
sequ
ence
Sig
nific
ance
Inadequate fauna survey data.
Unknown loss of fauna, fauna of conservation significance or fauna assemblage(s) in
development site.
B 2 Low
Inadequate knowledge of potential
impacts.
Unknown or poorly assessed impact(s) on fauna assemblage and conservation
significant species.
B 2 Low
Inadequate bioregional data
for contextual purposes.
Incomplete analysis and appreciation of impacts on
biodiversity values in a regional context.
B 2 Low
Removal of habitat – site
scale.
Almost complete loss of terrestrial fauna in cleared
areas, severe impact on local fauna assemblage in the development footprint.
E 3 High
Reduce by 75% the proposed clearing of vegetation along
ephemeral creek lines, realign transport corridors between
the mine and the plant, and the camp and access to the public
road so that they are along fauna habitat boundaries.
E 2 Moderate
Significant reduction of
habitats – local scale.
Loss of fauna and fauna habitat and impacts on local fauna assemblage (excluding
conservation significant species).
A 1 Low
Significant reduction of habitats –
landscape scale.
Loss of fauna and fauna habitat and impacts on
fauna in a landscape context (excluding conservation
significant species).
A 1 Low
Significant reduction of habitats –
bioregional scale.
Loss of fauna and fauna habitat and impacts on fauna
in a bioregional context (excluding conservation
significant species).
A 1 Low
Impact on resident
conservation significant terrestrial species.
Loss of conservation significant species – Bilby.
D 4 High
Search for and close all Bilby burrows and translocate all
Bilbies to another site. Monitor the success of translocations.
A 2/3 Low
Resident avian species.
Loss of conservation significant species.
A 3 Low
Migratory avian species.
Loss of conservation significant species.
A 3 Low
Habitat fragmentation.
Isolation of fauna assemblages.
C 3 Moderate
Roads and conveyor belt re-routed to eliminate remnant
vegetation patches on the mine site.
A 1 Low
Lowering of the water table.
Loss of vegetation along ephemeral creek lines.
E 3 High50% of the water sourced from
another location.E 1 Low
Death of aquatic vertebrates in the permanent pools along
the creek.E 2 Moderate
50% of the water sourced from another location to maintain permanent surface water in
the creek
E 1 Low
Loss of fauna corridors.
Loss of vegetation corridors in valleys that are to be mined.
E 3 High
Site redesigned so that the location of infrastructure
maintains vegetation corridors along the valley floor and ephemeral creek lines.
E 1 Low
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FACTORS AFFECTING FAUNA ASSESSMENTS
Suggested appropriate practice
• Environmental consultants should collect sufficient data to be able to predict, with a relatively high degree of confidence, the consequences and significance of the impact of the proposed development on the vertebrate fauna and the ecosystems. Factors to be considered when determining the approach and intensity of the assessment should include:
° Existing habitat condition and quality;
° Size of the area to be impacted;
° Proportion of the original habitat that is still largely intact in a bioregional context;
° Nature of the proposed development;
° Knowledge of fauna assemblages for the various fauna habitats in that bioregion;
° Potential presence of conservation significant species and / or ecosystems in the area;
° Extent to which the area supports disjunct habitats and fauna assemblages;
° Presence of range restricted populations;
° Prior ‘natural’ or human induced disturbance (e.g. fire);
° Extent to which the site provides ecological linkages that might facilitate the movement of fauna through the landscape;
° Incremental changes;
° Exploration impacts; and
° Environmental sensitive lands.
There are a variety of factors associated with a potential development that will alter the nature, extent and intensity of a fauna assessment and the survey effort. Some of these are discussed overleaf.
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8.1 HABITAT CONDITION AND QUALITY
Prior land use (e.g. cattle grazing, mining exploration, pasture, forestry, residential development) can alter and denude habitat and therefore negatively impact on the fauna assemblage. Areas that have been used for anthropogenic activity often have lower ecological value than they did prior to the disturbance. This will most often mean an altered fauna assemblage which could result in reduced species richness and / or lower abundance and more feral animals. It is acknowledged that some conservation significant fauna are able to survive and even thrive in some degraded areas (e.g. Pseudocheirus occidentalis, Isoodon obesulus fusciventer, Calyptorhynchus latirostris). Large scale and extensive fauna surveys are generally not necessary or appropriate in highly degraded areas. However, where these areas have the potential to support conservation significant fauna or a unique fauna assemblage, then it is important that potential impacts on these fauna are adequately assessed and addressed.
Descriptors of habitat quality should be clearly
defined and it is preferable that they are standardised across the industry. Habitat quality descriptors that can be used are shown in Table 8.1. A distinction is required between anthropogenic induced disturbance and a ‘natural’ disturbance when assessing habitat quality. For example, a wild fire can destroy and diminish the vegetation in an area and can be a major disturbance. Natural wild fires are part of the Australian landscape and in some areas play an important role in maintaining the long term health of functional ecosystems. Human induced wild fires have the potential to either replicate nature or to upset or destroy functional ecosystems. A discussion of the source and nature of the impact is often necessary. Long-term burning practices of indigenous people have shaped the vertebrate fauna assemblages in many Australian environments (Burbidge et al., 1988). The effects of this anthropogenic activity is probably different to that of fires started by pastoralists to stimulate plant growth for stock feed or by government agencies reducing the fuel load to inhibit future fires.
Table 8.1. Habitat condition descriptors of anthropogenic origin
Habitat condition label Condition description
High quality fauna habitat:
These areas closely approximate the vegetation mix and quality that would have been in the area prior to any human induced disturbance. The habitat has connectivity with other habitats and is likely to support the most natural vertebrate fauna assemblage.
Very good fauna habitat:
These areas show minimal signs of human induced disturbance (e.g. grazing, clearing, fragmentation, weeds) and retain almost all of the characteristics of the habitat had it not been disturbed. The habitat has connectivity with other habitats, and fauna assemblages in these areas are likely to be minimally effected by disturbance.
Good fauna habitat:
These areas show signs of human induced disturbance (e.g. grazing, clearing, fragmentation, weeds) but generally retain many of the characteristics of the habitat had it not been disturbed. The habitat still retains some connectivity with other habitats but fauna assemblages in these areas are likely to be affected by disturbance. Fauna assemblages in these areas are likely to be similar to what might be expected in this habitat.
Disturbed fauna habitat:
These areas show signs of human induced significant disturbance (e.g. mining, clearing, tracks and roads). Many of the trees, shrubs and undergrowth have died or have been cleared. These areas may be in the early succession and regeneration stages. Areas may show signs of significant grazing, contain an abundance of weeds or have been damaged by vehicles or machinery. Habitats are fragmented or have limited connectivity with other fauna habitats. Fauna assemblages in these areas are likely to differ significantly from what might be expected in the area had the disturbance not occurred.
Highly degraded fauna habitat:
These areas often have a significant human induced loss of vegetation, and / or a large number of vehicle tracks and / or have been completely cleared, and / or areas have been heavily grazed or farmed. There is limited or no fauna habitat connectivity. Fauna assemblages in these areas are likely to differ significantly from what existed prior to the disturbance, and are often depleted compared to what existed prior to the disturbance.
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8.2 SIZE
The size and scale of a potential development is of primary importance in determining the extent and nature of a fauna assessment or survey. If an area to be disturbed is small, and adjacent to an area that has already been disturbed (e.g. an extension to a
residential subdivision), or is in a habitat type that is abundant in adjacent areas, then the approach and effort applied will generally be considerably less than it would be for a large development or in a habitat that is poorly represented in the bioregion
8.3 AVAILABILITY OF HABITAT TYPES
At a landscape scale, Western Australia has an abundance of the inland dune-swale system on red soil that is vegetated with spinifex and scattered trees and shrubs (e.g. Great Victoria Desert, Little Sandy Desert or Gibson Desert). Much of the habitat in these desert systems is in very good condition and has been subject to low levels of anthropogenic induced disturbance. Clearing small sections of these habitats for a development, although it will result in the loss of most vertebrates in the cleared area, is unlikely to have a significant impact on ecosystem function or result in the loss of an important ecosystem when considered in a bioregional context. There are many areas and habitats in Western Australia’s interior that fit into
this category. Although the loss of small sections of this type of habitat is regrettable, it is much less significant than impacting on habitat that has become scarce.
In contrast, a proposed development might be adjacent to an isolated marsh (e.g. Mandora Marsh in the Kimberley) that is an important stop over for migratory birds moving south from the northern hemisphere, in which case, the investigation should be detailed and thorough. The scale and intensity of a fauna assessment or survey needs to be adjusted according to the availability of the habitat in the bioregion.
8.4 PROPORTION OF ORIGINAL HABITAT REMAINING
Large proportions of some habitat types have been degraded or cleared over many years resulting in small and often fragmented remnants remaining. On a bioregional scale, the Western Australian wheatbelt is an example of habitat fragmentation. Farmers have selected most of the ‘best’ land for agriculture and land suitable for agriculture is often the more productive areas for native fauna, so there is already a high loss of important fauna habitat in this bioregion.
Proposed developments in remnant areas, where much of the original habitat has been lost and that contain high quality habitat, will require a relatively intensive investigation of potential impacts that will probably require extensive surveys at the proposed site and in adjacent areas to define the extent to which the proposed development will impact on a scarce resource.
8.5 NATURE OF THE DEVELOPMENT
The impact of some developments is contained within the nominated vegetation clearing footprint, whereas, other developments can impact on fauna over a much larger area. For example, clearing and developing sites that alter stream flow can have significant downstream implications on the vertebrate fauna, as it can change both soil moisture content and the vegetation assemblage.
The extent of the disturbance footprint and the nature of the development are important considerations
in determining the size and scale of the fauna assessment and areas that should be surveyed. It is therefore important that at an early stage in the assessment process the scale and nature of the development is known so that the potential impact area can be determined, as it may go well beyond the cleared area.
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8.6 EXISTING KNOWLEDGE
Habitats that have been comprehensively surveyed and for which there is substantial and robust published data are likely to require either no additional survey or a focussed survey to address gaps in existing knowledge. For example, if the available vertebrate fauna data for the Swan Coastal Plain or the avifauna data for the Jarrah forest was collated and made available in a manner that linked fauna assemblages to habitat types, then there would be little need for any additional generic fauna surveys to be undertaken in these areas.
However, currently the available data for these two example habitats are fragmented, dispersed and of varying quality. The consequence is that for most development proposals in these areas, further surveys will need to be undertaken to adequately describe extant fauna.
Currently, there are only three fauna survey databases (i.e. NatureMap, Birds Australia and Terrestrial Ecosystems fauna database) that have collated information about fauna assemblages over a wide area or for multiple surveys that could be used to adequately represent the fauna likely to be found in most habitats in Western Australia. A number of environmental consultants maintain databases of surveys that they have undertaken, but few of these are in a form that enables the collation of information across sub-bioregions, bioregions or at a landscape scale.
An added complication is that many of the fauna surveys undertaken to support EcIA are of such low intensity or were undertaken in an inappropriate season, that the data are of limited value as they fail to provide a comprehensive appreciation of the fauna assemblage (How, 1998, Thompson, 2007).
8.7 LOCAL KNOWLEDGE
Most often, fauna surveys to support an EcIA are a snapshot of what exists at a particular time and place. Surveys are often repeated in another season to detect species or variations in relative abundance due to seasonal differences. Abbott (2001) and Burbidge et al. (1988) ably demonstrated the value of local knowledge in determining the presence of vertebrate fauna that had become locally extinct or may be difficult to detect.
Our experience is that much can be gleaned about the fauna assemblage in an area from talking with the ‘locals’. For example, information about birds
that are only seasonally present in an area (e.g. Merops ornatus) or the presence of relatively rare species (Leipoa ocellata) can often be obtained from people that live or work in an area. People who have lived in an area for many years and have an interest in the vertebrate fauna are often willing to share their knowledge about the relative abundance of fauna in past years. These data can be very useful in developing a more complete understanding of the vertebrate fauna assemblage for a potential impact site.
8.8 CONSERVATION SIGNIFICANT SPECIES OR ECOSYSTEMS
The possible presence of a conservation significant species (or ecosystem) in a development site will most often require specific and targeted searches to confirm its presence, its relative abundance and spatial distribution. In the absence of substantial and robust data it can be a high risk to presume that because there is no record of a particular conservation significant species in an area, that it is not present. Similarly, excluding the possible
presence of a conservation significant species from a particular site because it does not contain its preferred habitat type, as described in the literature, can also be a high risk. There are multiple examples of detecting conservation significant species in areas where they were not detected during earlier fauna assessments because of a lack of ‘suitable’ or ‘preferred’ habitat.
8.9 DISJUNCT HABITAT AND FAUNA ASSEMBLAGES
Geological processes have often separated fauna habitats and in turn isolated fauna assemblages that may contain important genetic diversity. As some of
these disjunct populations can have high ecological value, they should be preserved and may require particular attention in fauna assessments.
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8.10 RANGE RESTRICTED POPULATIONS
Western Australia has numerous vertebrate species that have a restricted geographical range. These species may be locally abundant but have a very small geographic distribution (e.g. Ctenotus nigrilineatus, C. lancelini, Lerista viduata). In some cases, their current known limited distribution is an artefact of a lack of surveys, but for others there is a genuine restricted range. Species with a limited geographic distribution are more susceptible to becoming endangered, particularly if they are in low abundance, and therefore require particular attention in fauna assessments.
Knowledge of the reason for the localised distribution is often poor (e.g. particular habitat requirements, predator pressure, diet or resource specialist). In this context, translocating individuals away from a proposed development area can often result in the individuals suffering the same fate as if they stayed in the development area. So the translocation option may not be a reasonable alternative for protecting locally important species.
8.11 HABITAT CONNECTIVITY AND CORRIDORS
Linkages and corridors that enable fauna to move among habitats, and over an extended period, to facilitate gene flow and recruitment among extant populations should be maintained and enhanced to return linkages to what might have existed prior to the disturbance.
For avifauna and some mammals (e.g. Pseudocheirus occidentalis), isolated plots of remnant vegetation may provide an opportunity for individuals to move through the landscape in a series of small hops from one remnant to the next. The presence and functionality of corridors and remnants requires particular attention in a fauna assessment.
8.12 INCREMENTAL CHANGES
Small but progressive changes and disturbances to the environment over a period of time can manifest themselves as major impacts. There are multiple examples in the Western Australian landscape of approvals for relatively limited and small scale discharges of mine waste water into salt lakes, small mining footprints, limited vehicle traffic on unsealed roads or limited utilisation of underground water sources that have been progressively and
subsequently expanded and the development has grown to result in a much more significant impact than was initially envisaged.
Often, proponents will take into account previous damage and impact on the environment to suggest that the impact of further expansion plans will be less than would have been the case because the environment is already disturbed.
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8.14 MINING IN ENVIRONMENTAL SENSITIVE LANDS
Exploration and mining can occur on crown land that is deemed environmentally sensitive. This includes national parks and conservation reserves, which include, but are not limited to:
• Nature reserves• Conservation parks• State forests• Timber reserves
In addition, there are other environmentally sensitive areas (ESAs) that may be explored or mined that the DMP and DEC have agreed warrant environmental protection. These include some rainforests, areas containing declared rare flora, mangroves and wetlands.
Figure 8.1. Exploration impact prior to environmental approvals for two mine sites
8.1a
8.1b
8.13 EXPLORATION IMPACTS
Existing legislation and regulations in WA enables mining companies to undertake significant exploration activity prior to obtaining formal approval from the Minister for Environment to proceed with the development and sometimes before a fauna assessment has been undertaken.
This exploration can result in cleared exploration tracks, cleared drilling pads, cleared camp sites, drill holes, plastic sample bag storage areas, grid pegs, water storage dams, small waste dumps, costeans, and sumps being left in the environment. Often the fauna assessment is undertaken after much of the exploration activity has occurred and the environment is already seriously disturbed and degraded (Figure 8.1).
It is not clear whether the EcIA should be undertaken based on what existed prior to exploration or as the site was found during the assessment. In many cases, much of the damage has already been done before the proponent has received Ministerial approval to proceed to develop the mine.
Environmental consultants should indicate pre-exploration and the current condition and quality of the fauna habitats in their assessment.
A memorandum of understanding (MOU) agreed in 1995 between the EPA and DMP clarifies government arrangements for referral of mineral exploration and mining proposals to the EPA and DEC where they occur on conservation reserves and other environmental sensitive lands.
Where a proposed development is likely to impact on environmentally sensitive lands, then the proponent should refer to the DMPs Mineral Exploration and Mining within Conservation Reserves and other environmentally sensitive Lands in WA (1998) guidelines.
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STAGES OF A FAUNA ASSESSMENT
Suggested appropriate practice
• A two stage data collection process should be used in fauna assessments to support an EcIA.
• The first stage is a desk top assessment with a site visit to verify information collected during the desktop review and to describe fauna habitats.
• A second stage, if that is required, can include:
° Targeted species searches; and / or
° Fauna survey(s) focusing on fauna assemblages; and / or
° Fauna survey(s) to establish baseline evaluation data.
A two-staged approach to the data collection phase of a fauna assessment is strongly recommended. The outcome of a desktop assessment (i.e. Stage 1) can often reveal that little new information is likely to be gained from a generic survey, but it may suggest that a targeted species-specific survey is required. This approach also enables environmental consultants to determine whether a survey is necessary and can be justified on animal ethics grounds. Field surveys that trap animals should only be undertaken if they are necessary.
Figure 9.1 outlines a two stage process for collecting data to support an EcIA. The first stage in the process is to undertake a desktop study and reconnaissance visit to the site (Stage 1). Based on these data and analysis, the proponent can determine what type and scale of additional assessment or survey is required or can argue that no additional survey work is required, as:
• Sufficient information is known about the area to provide an adequate assessment of potential impacts;
• The area is of little biological value;• The potential impacts are of a small scale; or • The scale of the potential impact is relatively
insignificant (i.e. low likelihood or low consequence) in the context of available similar fauna habitat in adjacent areas.
Information collected during a Stage 1 assessment will be used to write up the results of fauna surveys undertaken as part of Stage 2, so the effort in undertaking a Stage 1 assessment is not wasted if it is followed by more extensive field surveys. If a Scoping Document is required, then based on the Stage 1 assessment, details of any further survey work can be drafted for inclusion in this document.
If the area is known to contain conservation significant species or a conservation significant community, or little is known about the area, then the proponent may wish to go straight to a Stage 2 assessment. This is often resolved in the screening / scoping process discussed in Chapter 2.
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Figure 9.1. Two stage process for undertaking a fauna assess-ment
Stage 2
Stage 1
Desktop study and reconnaissance survey to assess:
Extent to which the site is already degraded.Size of the area to be impacted. Size of the habitats that are currently available in reasonable condition. Proportion of the original habitat that is still largely intact. Nature of the proposed development. Knowledge of fauna assemblages for the various fauna habitats in that bioregion. Potential presence of conservation significant species in the area. Potential presence of conservation significant ecosystems in the area. Extent to which the area supports disjunct habitats and fauna assemblages. Range restricted populations. Extent to which the site provides an ecological linkage that facilitates the movement of fauna through the landscape.
Decide on whether a field survey is necessary and its purpose.
Sufficient information is known about the area. Area is of little biological value. Potential impact very localised. The scale of the potential impact is insignificant in the context of the available habitat and fauna assemblages.
Targeted species searches.
Fauna survey focusing on fauna assemblages.
Fauna survey to establish baseline monitoring data.
No additional field survey required.
Draft fauna report based on a Stage 1 or 2 assessment.
Independent peer review.
Final fauna assessment report.
9.1 STAGE 1 FAUNA ASSESSMENTS
There are two components of a Stage 1 assessment:
• A desktop review of all available published and unpublished literature, and databases; and
• A reconnaissance visit to the site to verify the information collected during the desktop review and to describe fauna habitat types and condition. The reconnaissance visit can also be used to specifically look for habitat suitable for or evidence of conservation significant species.
Data from this assessment should then be used to provide background and descriptive information and
to interpret, assess the risk and develop mitigation strategies. A report should therefore provide the following information.
Background and descriptive information
• Describe the type and condition of major fauna habitats that will be impacted;
• Describe the size of the area to be impacted;• Indicate the proportion of the original habitats
that are still largely intact;• Indicate the extent of knowledge about vertebrate
fauna in major fauna habitats on-site and in the bioregion;
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Interpret, risk assessment and mitigation strategies• Assess the potential impact of a proposed
development on the vertebrate fauna at the local, landscape and bioregional scales;
• Assess existing knowledge of fauna assemblages for the various fauna habitats on-site and in a bioregional context;
• Assess the potential for conservation significant species and / or ecosystems to be present on-site or in the adjacent area;
• Assess the extent to which the site is likely to support disjunct or unique habitats and fauna assemblages;
• Assess the potential for the site to support a population of a range restricted or ecological specialist species;
• Describe the extent to which the site provides an ecological linkage that facilitates the movement of fauna through the landscape; and
• Assess the potential risks associated with the proposed development to the vertebrate fauna.
When we have prior knowledge of the fauna assemblage for a particular site / area a generic fauna survey may not be required, however, a species-specific targeted search may be required to identify the presence and / or abundance of conservation significant species (e.g. Pseudocheirus occidentalis, nesting sites for Calyptorhynchus latirostris or C. baudinii). This targeted assessment can (and often is) combined with a reconnaissance site visit.
Often it is fruitful to seek out ‘locals’ that have an interest in fauna, as they can provide useful data on fauna and fauna habitat that may not be obvious during a reconnaissance site visit (Abbott, 2001).
The desktop review should assess all available published and unpublished fauna data for a development site. This will include a search of the available zoological and environmental databases (e.g. Zoological Records, Pilbara Biological Survey
Database, EPA Environmental Protection Bulletins, EPA reports, DMP mining proposals). It is possible that the proponent will have copies of previous reports for the development site. Most environmental consultants maintain a library of their own reports and some also keep copies of other reports that have been made public.
Searches of the EPBC online database on matters of national environmental significance and the DEC threatened and priority species database to determine the potential presence of conservation significant species and ecosystems are also necessary.
9.1.1 Stage 1 Report
A detailed discussion is provided on reporting requirements in Chapter 16. The following provides a brief overview of the reporting requirements for a Stage 1 report so that it enables a Stage 2 assessment to be placed into context. A Stage 1 report should provide the following information:
• Background on the project;• Scope of the report;• Fauna assessment objectives;• An indication of the extent and sources of fauna
information for the site and the adjacent areas;• A succinct summary of the findings and
recommendations of any earlier fauna survey reports for this site and adjacent areas;
• A summary of fauna survey data for the site and adjacent areas (details of what was caught in other surveys in similar habitats should be appended to the report);
• A description of major fauna habitats, including an assessment of their current condition and the level of disturbance;
• A list and an assessment of the potential for conservation significant fauna and ecosystems to be found on-site, with an indication of their location and relative abundance;
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9.2 STAGE 2 FAUNA ASSESSMENTS
If the Stage 1 assessment indicates that additional information is required to make an informed and adequate assessment of potential impacts, then it is suggested that one or more of the following key focus areas should be used as the basis for developing and implementing that survey(s). The decision as to which of the following key focus areas are selected will largely be determined by the adequacy of information that you have been able to be gleaned from other sources during Stage 1 and your assessment of the potential risk of impacts in the absence of a more detailed understanding of the vertebrate fauna in the proposed impact area.
• Targeted species searches; and / or• Fauna survey(s) focusing on fauna assemblages;
and / or• Fauna survey(s) to establish baseline evaluation
data.
The Stage 1 assessment or Scoping Document should clearly indicate those taxonomic groups to be the focus of any field survey. The following list is provided as a guide:
• Small mammals (including bats);• Large mammals (e.g. wallabies, kangaroos,
cats, dingoes, etc);• Reptiles (including turtles);• Birds;• Fish;• Amphibians; • Invertebrates, including short range endemics;
and• Conservation significant fauna – provide a list of
species.
9.2.1 Targeted Species Searches
Targeted species-searches normally focus on species that are considered threatened, vulnerable or approaching extinction [i.e. listed under the EPBC Act or the most recent Wildlife Conservation (Specially Protected Fauna) Notice under the Wildlife Conservation Act]. Search strategies adopted will be based on the ecology of the species and an understanding of their preferred habitat types. Caution must be exercised in deciding not to search for particular conservation significant species based on the lack of ‘suitable’ habitat, as there are numerous examples of conservation significant species being found outside commonly considered or ‘textbook’ preferred habitat types. Chapter 15 discusses a range of strategies that might be used to detect the presence of conservation significant species, their relative abundance and spatial distribution.
Sufficient survey effort should be applied to convince assessors that if a conclusion is reached that the targeted species is not present, then there is a high probability that this is true, particularly if it is a vulnerable, endangered or critically endangered species.
9.2.2 Fauna Survey Focusing On Fauna Assemblages
The suggested effort and approach for a survey that focuses on providing a near complete species list and a good indication of their relative abundance is as follows. This survey should be limited to a set group(s) of taxa (see list above).
• Records of any conservation significant species detected on-site during the reconnaissance site visit;
• A discussion that addresses biodiversity values of the site, including comments on issues such as:° Condition of fauna habitat and extent of
habitat degradation;° Any incremental and long-term changes and
effects;° Ecological linkages;° Size and scale of the proposed disturbance
and potential impacts;° Abundance and distribution of similar habitat
in the adjacent areas and the bioregion; ° An indication of the gaps in knowledge that
will impact on the assessment;° Ecological functional value of the site;° Potential impacts on ecosystem function;° Potential impacts on conservation significant
species, range restricted and ecological specialist species and conservation significant ecosystems;
° Potential for the proposed development to be further expanded and the impact to be extended beyond the proposed boundaries;
• A risk assessment using the matrix discussed in Chapter 7;
• A discussion of potential impacts, mitigation and management strategies and fauna management plans that are recommended;
• Recommendations to minimise impacts on the fauna and additional surveys necessary to adequately assess potential impacts. Where additional field survey work is required, a brief overview of what is required and the protocols that should be adopted should be provided;
• If additional surveys are not required, then recommendations to minimise impacts (e.g. mitigation and fauna management strategies) should be provided; and
• A description of the constraints and limitations on the assessment, including an assessment of the adequacy of the available data to assess potential impacts.
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• Minimum of two surveys (all taxa);• Survey in each major habitat type, with a
minimum of five replicate sampling sites in each habitat type;
• Number of individuals to be trapped in each major habitat type to be determined from Figure 11.5 for reptiles and small mammals;
• A minimum of five replicate line transects or area searches for birds in each of the major habitat types;
• Species-specific targeted searches, if identified as a focus;
• Sand pads and sand tracks to be used for detecting medium and large mammals, if these were identified as a focus;
• Spotlighting searches, focussing on areas that are not trapped to increase the species inventory;
• Trap types to be used:° Bucket pit traps;° Pipe pit traps;° Funnel traps;° Aluminium box traps;° Cage traps (where appropriate);
• Echolocation detectors used to determine the presence of bats, for four nights in each habitat type;
• Suggested survey periods:° Kimberley – early part of the wet season and
the dry season;° Pilbara – one in summer and the other in
spring or autumn;° Mid-west, Goldfields and Sandy Deserts –
one in summer and the other in late spring or early autumn;
° Swan Coastal Plain – one in late spring or summer and the other in spring or autumn; and
° South-west – summer and late spring.
9.2.3 Fauna Surveys To Establish Baseline Evaluation Data
Data collected during this survey can be subsequently used to evaluate impacts of the development on adjacent fauna assemblages. Sometimes this evaluation will focus on a single species that is of particular concern (e.g. Leipoa ocellata), in which case adequate data will need to be gathered on its relative abundance in predetermined ‘impact’ and ‘control’ areas. These data should be of sufficient quality to determine development impacts on the adjacent fauna assemblage or targeted species where those impacts exist to a predetermined level of confidence and to separate these from normal spatial and temporal variations.
When the evaluation focuses on the fauna assemblage, then an a priori decision will be required on which taxonomic groups should be included (e.g. small or large mammals; reptiles, birds, amphibians).
Impact assessments are typically a single season survey in control and impact sites, which are
replicated at appropriate periods in the future.
Loss of individuals due to trap deaths from control and impact sites is undesirable, so consideration should be given to the timing of surveys to minimise the impact of extreme hot and cold temperatures.
Surveys for evaluation purposes should avoid fauna breeding periods, except for birds.
When the focus is on the fauna assemblage then there are a range of indices that can be used to evaluate impacts. For example, Thompson et al. (2008) provided an index to measure impacts or rehabilitation success based on the reptile assemblage. A similar index was used by O’Connell et al. (1998) based on bird assemblages, but there are many such indices (Karr et al., 1986, Majer and Beeston, 1996, Bradford et al., 1998). A much simpler approach might only consider the range of species and their relative abundance. However, in all cases sufficient data should be collected to detect changes and to be able to differentiate impacts from natural temporal and spatial variability.
If, for example, there was an intention to use the Rehabilitation and Degradation Index (RDI; Thompson et al., 2008) and mammals were to be used along with reptiles, then the following data should be collected:
• Single season survey for reptiles and small mammals;
• Surveys in selected major habitat types, with a minimum of five replicate sampling sites in each habitat type for both ‘control’ and ‘impact’ areas;
• The trapping effort would be determined based on catching 90% of the species in each habitat type (see Figure 11.5);
• Trap types to be used:° Bucket pit traps;° Pipe pit traps;° Funnel traps;° Aluminium box traps;
• Suggested survey periods:° Kimberley – early part of the wet season;° Pilbara – late spring;° Mid-west, Goldfields and Sandy Deserts –
late spring;° Swan Coastal Plain– late spring; and° South-west – summer.