PRIORITISING PESTS FOR COORDINATED CONTROL PROGRAMS: THE SOUTH AUSTRALIAN APPROACH

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1 PRIORITISING PESTS FOR COORDINATED CONTROL PROGRAMS: THE SOUTH AUSTRALIAN APPROACH John Virtue, Mark Williams and David Peacock Biosecurity SA, Department of Primary Industries and Regions South Australia (PIRSA), GPO Box 1671 Adelaide SA 5001 ABSTRACT Faced with an increasing diversity of pests at various stages of invasion across a range of land uses, plus a general trend of declining resources for natural resources management, managers have to prioritise pests for control programs. South Australia (SA) developed the SA Weed Risk Management System (SAWRMS) to assist prioritisation of weed management at the state and regional levels. In essence, the SAWRMS compares a score for Weed Risk (derived from criteria of Invasiveness, Impacts and Potential Distribution) with a score for Feasibility of Containment (derived from criteria of Control Costs, Current Distribution and Persistence) to determine the most appropriate management action (e.g. prevention, eradication or containment). The principles, logic and methodology established in the SAWRMS have been adapted to an equivalent SA Pest Animal Risk Management System, which is being used at regional levels to drive planning and on-ground programs. Both of these systems have fundamentally improved weed and pest animal management in SA, with a cultural shift in recognising the benefits of early intervention and in being driven by economic, environmental and/or social outcomes rather than simply pest control activity. Keywords: risk assessment, prioritisation, feasibility of control INTRODUCTION South Australia has 35 exotic vertebrates (excluding fish) known to have established in the wild. These include widespread species (e.g. rabbit, fox, house mouse and starling), species well established in some regions but with potential to expand (e.g. goat and camel), and species with limited distribution (e.g. pig, deer and peacock). South Australia is also at risk of incursions from interstate (e.g. cane toad and Indian myna) and from captive pets, both illegal (e.g. red eared slider turtle) or legal (e.g. Indian ringneck). Vertebrate pests (non-native mammals, birds, reptiles and amphibia) are managed as declared animals under the Natural Resources Management Act 2004 (NRM Act), with regionally led programs by eight Natural Resources Management Boards and state coordination through Biosecurity SA. Non-native fish are managed under separate fisheries legislation through Biosecurity SA. Declaration places legal obligations on persons to not import, transport and/or sell, to contain (where held as domesticated animals or under permit) and/or to control such animals. Declaration is based on an animal being a threat to primary industries, natural ecosystems and/or public amenity and safety. The challenge of managing vertebrate pests in South Australia is similar to other jurisdictions. All face a diversity of vertebrate pests at various stages of invasion across a range of land uses, coupled with a general trend of declining government resources for natural resources management. It is simply not feasible to prevent the

2 establishment and spread, and minimise the impacts, of all vertebrate pests. Managers have to prioritise their actions. The basis of this prioritisation needs to be transparent and defensible, given that pest control is a considerable cost to land and water managers, including the use of government funds for incentive and compliance actions in relation to declared pests. Such prioritisation needs to be based on two, separate considerations; does the vertebrate pose a significant pest risk and is control feasible? South Australia developed the SAWRMS to assist prioritisation of weed management at state, regional and local levels (Virtue 2010). The system was derived from criteria developed to determine Weeds of National Significance (Virtue et al. 2001) and from further criteria defined in the national post-border weed risk management protocol (Anon. 2006). In essence, the SAWRMS compares a score for Weed Risk (derived from criteria of Invasiveness, Impacts and Potential Distribution) with a score for Feasibility of Containment (derived from criteria of Control Costs, Current Distribution and Persistence) to determine the most appropriate management action (e.g. prevention, eradication and containment). The principles, logic and methodology established in the SAWRMS have been adapted to pest animal management in SA for use in strategic planning. THE SOUTH AUSTRALIAN PEST RISK MANAGEMENT SYSTEM (SAPARMS) Comparative Pest Animal Risk (CPAR) A score for CPAR is generated by multiplying separate scores (each ranging between 0 and 10) for the three criteria of Invasiveness, Impacts and Potential Distribution. Hence CPAR has a minimum of 0 and a maximum of Assessments are done on a land use basis. Invasiveness considers the establishment, reproductive and dispersal abilities of vertebrate species, providing an indicator for rate of spread. Impacts considers the types and magnitude of economic, environmental and social effects that the species could have as pests. Potential distribution considers the geographic area that could be invaded by the pest. For each criterion a score is generated from a series of multiple-choice questions (e.g. high/medium/low) with clear definitions for each of the multiple answer options to help make assessments more consistent (Biosecurity SA 2012). In summary, questions are as follows: Invasiveness 1. Reproductive ability of the pest animal in the land use? (a) Time to reproductive maturity? (b) Reproductive cycles? (c) Reproductive output? (d) Offspring survival? (e) Reproductive lifespan?; and 2. How likely is long-distance dispersal (>3 home ranges)? (a) Animals walking, flying or swimming? (b) Water or wind? (c) Deliberate or accidental by people?

3 Impacts 1. Pest animal reduces reproductive output, and/or establishment, of desired plants?; 2. Pest animal reduces numbers or reproductive output of desired animals?; 3. Pest animal reduces the quality of products, services or natural resources obtained from the land use?; 4. Pest animal indirectly impacts desired animals (e.g. harass domestic livestock or native animals, prevent access to water or feed, or transmit disease)?; and 5. Pest animal has major, positive or negative effects on environmental health? Potential Distribution 1. In the Management Area, what percentage area of the land use is suitable for the pest animal? Feasibility of Containment (FoC) A score for FoC is generated by multiplying separate scores (each ranging between 0 and 10) for the three criteria of Control Costs, Current Distribution and Persistence. Control Costs considers the pest management costs of detection, onground control and enforcement/education needs. Current distribution considers how widespread the vertebrate pest is at present. Persistence refers to the expected duration of a control program. In summary, questions are as follows: Control Costs 1. How easy is it to detect and identify the pest animal?; 2. General accessibility of known infestations?; 3. How expensive is control of the pest animal, using techniques which both maximise efficacy and minimise off-target damage? (a) vertebrate pesticides, fuel, equipment, disposal operating costs? (b) labour costs?; 4. Likely level of cooperation from landholders within the land use at risk?; 5. Negative impacts of control?; and 6. Animal welfare impacts of control? Current Distribution 1. What percentage area of the land use does the pest currently infest?; and 2. Pattern of the pest animal s distribution across the management area? Persistence 1. How effective are targeted control treatments applied to the pest animal?; 2. Does the life history of the pest animal make it susceptible to control?; 3. Potential for the pest animal to re-colonise land use area after control through dispersal or escape from domestic or captive populations?; and 4. Potential for the pest animal to persist in the land use due to some landholders desiring or tolerating a low population of the species? Pest Animal Management Action Matrix Species scores for CPAR and FoC are categorised into five levels (ranging from negligible to very high), which enables pests to be placed on a simple prioritisation matrix for a land use in the management area of interest (Figure 1). The matrix indicates the most appropriate management action for each pest species with guiding principles for such actions detailed in Biosecurity SA (2012). However, a final

4 ALERT decision on what level of regional control is required for a particular species needs to weigh up its allocated management actions across different land use matrices. For example, a pest may rank as destroy infestations in one land use and limited action in others. In this case coordinated control may still be required in the latter land uses to enable prevention of spread to the former land use. PEST RISK Negligible >98 FEASIBILITY OF CONTAINMENT Low Medium High Very High <12 Negligible <11 LIMITED ACTION LIMITED ACTION LIMITED ACTION LIMITED ACTION MONITOR Low LIMITED ACTION LIMITED ACTION LIMITED ACTION MONITOR MONITOR Medium MANAGE SITES MANAGE SITES MANAGE SITES PROTECT SITES CONTAIN SPREAD High PROTECT SITES CONTAIN SPREAD DESTROY INFESTATIONS Very High >173 PROTECT SITES & CONTAIN SPREAD DESTROY INFESTATIONS ERADICATE Figure 1. Pest animal management action matrix. DISCUSSION The SAPARMS is now routinely used by Natural Resources Management (NRM) Boards in SA to determine pest animal priorities in regional management plans and to drive on-ground coordinated control programs. For example, the South East NRM Board (2009) assessed 25 vertebrates (including fish) across eight land uses. Species ranking highest for regional eradication were wild dogs and feral goats, with the mallard duck a priority for destruction. Deer species and rabbits ranked as priorities to contain further regional spread. Ongoing programs and competitively funded projects reflect this prioritisation. Both the weed and pest animal systems have fundamentally improved weed and pest animal management in SA with a cultural shift in recognising the benefits of early intervention and with management now being driven by economic, environmental and/or social outcomes rather than simply pest control activity. The systems are being used to justify investments in surveillance for new pests and regional containment and eradication programs and to target programs on widespread species to those land uses and localities where most benefits can be gained.

5 The SAPARMS is not the only assessment system that has been developed to prioritise vertebrate pests for control programs. Walton (2005) developed a Queensland risk assessment system that included consideration of the benefits of a species (and not just their pest impacts). Victoria is also in the process of developing a pest animal system to complement their pest plant prioritisation model (John Weiss pers. comm. June 2012). In selecting a system one needs to consider the operational needs, knowledge base and resources of the organisation in both undertaking the assessment process and implementing coordinated control programs based on the assessment results. There has been no comparison of the accuracy of such systems. Pest risk assessment systems are tools to assist decision-making and the limits of the models (including uncertainty in species assessments) and additional policy considerations need to be recognised in deciding on a particular course of action for a pest. For weeds, the use of risk assessment systems has been much improved by applying them within a standard risk management framework (anon. 2006), which can be applied regardless of the particular system being used. REFERENCES Anonymous (2006). 'HB National Post-Border Weed Risk Management Protocol' (Standards Australia International Ltd., Sydney, Standards New Zealand, Auckland and CRC Australian Weed Management, Adelaide). Biosecurity SA (2012). SA Pest Animal Risk Management Guide. al_risk_assessment (Primary Industries and Regions South Australia). South East Natural Resources Management Board (2009). South East Pest Management Strategy Part 2: Pest Management Plan. Virtue, J.G., Groves, R. H. and Panetta, F.D. (2001). Towards a system to determine the national significance of weeds in Australia. In 'Weed Risk Assessment', eds R. H. Groves, F. D. Panetta and J. G. Virtue, pp (CSIRO Publishing, Collingwood). Virtue, J.G. (2010). South Australia s Weed Risk Management System. Plant Protection Quarterly 25(2): Walton, C. (2005). Assessment of pests in Queensland. unpublished report (Department of Natural Resources and Mines, Brisbane).