Biosecurity and Regulation

BIOSECURITY AND REGULATION

invasive speciesPOSITION STATEMENT

Priority Declared Species- Agricultural Impact

Lead Author(s): / I-Lyn Loo, Senior Policy Officer, Invasive Species
Andrew Reeves, Development Officer, Invasive Species
Reviewed by: / Kay Bailey, Manager Priority Weed Response
Malcolm Kennedy, Research Officer, Invasive Species
Tim Thompson, A/Manager Engagement and Adoption
Richard Watkins, Manager Priority Pest Animal Response
Approved by: / Viv Read, Director Invasive Species
Kevin Chennell, Executive Director Biosecurity and Regulation
Rob Delane, Director General
Date approved: / 5 June 2015
Date for review: / 12 May 2016
Person responsible to keep and maintain this document: / Senior Policy Officer, Invasive Species
Position statement number: / 03
Version number: / v3_2015

Executive summary

In an environment of reducing resources, government resources must be targeted at activities that provide the greatest benefit or return in investment. This position statement identifies the priorities for activities of the Invasive Species Program in managing declared pests that are invasive species. Prioritisation is carried out based on their impact on agriculture. While all plants and vertebrate animals declared under the Biosecurity and Agriculture Management Act 2007(BAM Act) are considered during the prioritisation process, the key factor in determining the priorities is the species’ impact on agriculture to provide guidance on the resource allocation for the Invasive Species Program. This position statement excludes invasive species declared or prescribed under other legislation and the resource allocations of the relevant administering agencies.

The Invasive Species Plan for Western Australia identifies two groups of priority invasive species – high priority species and high profile species. High priority species are declared species that have the potential to cause the highest impact on agriculture while high profile species are species that biosecurity groups identified as their priority for control in the area.

High priority species

Responding to incursions of invasive species not known to be present in Western Australia is the highest priority for the Invasive Species Program.

The high priority list for declared plant species known to be present in Western Australia was developedthrough expert panels and economic analysis. The prioritisation process was carried out in two steps. Firstly, the species were ranked in accordance with their impact on agriculture in a nil management scenario. Next, an economic analysis was carried out on the top ten ranked declared plantspecies to determine their impact on agriculture based on a nil management scenario.

Table A provides the list of high priority declared plant species for Western Australia based on the two-step prioritisation process. An economic analysis has yet to be carried out on species ranked 11 to 15.

Table A: High priority declared plant species for Western Australia

Responding to incursions of invasive species not known to be present in Western Australia is the highest priority for the Invasive Species Program
Priority number / Declared plant species
1 / Gamba grass
Andropogon gayanus
2 / Rubber vine
Cryptostegia grandiflora
3 / Mesquites
Prosopis glandulosa x velutina, P. glandulosa and P. pallida
4 / Skeleton weed
Chondrilla juncea
5 / Hoary Cress
Lepidium draba
6 / Mimosa
Mimosa pigra
7 / Devil’s rope cactus
Cylindropuntiaimbricata
8 / Hudson pear
Cylindropuntiarosea
9 / Coral cactus
Cylindropuntiafulgida var. mamillata
10 / Three-horned bedstraw
Galium tricornutum
11 / Prickly pear
Opuntia spp.
12 / Prickly acacia
Acacia nilotica
13 / Two-leaf cape tulip
Moraea miniata
14 / Cane or Snake cactus
Austrocylindropuntiacylindrica
15 / Saffron thistle
Carthamus lanatus

Due to the inconsistency in the criteria applied for declared vertebrate animals during the ranking assessments and economic analysis, the prioritisation process applied to declared plant species cannot be applied to declared vertebrate animals. The prioritisation process for declared vertebrate animals was carried out using their location on the generalised invasion curve (Figure 1) as the first step.

A spatial differentiation was made for wild dogs (Canis lupus familiaris(feral), Canis lupus dingo x Canis lupus familiaris and Canis lupus dingo), feral goats (Capra hircus(feral), and water buffalo (Bubalusbubalis))as their presence are viewed differently in different areas of Western Australia. These three species were ranked in accordance with their earliest stage of invasion (e.g. feral goats are categorisedas stage 1 during the ranking process).

The second step ranks the species within each stage of invasion using its rank from the expert panel assessment. The ranking of declared vertebrate animals was carried out based on the impact of each species in the current management scenario.

The priority list is intended to guide operations of the Invasive Species Program. Therefore species with nil documented agricultural impact (such as geckos (Hemidactylusfrenatus) and flowerpot snakes (Ramphotyphlopsbraminus)) and species with management led by another government agency (such as cane toads (Bufo marinus)) are removed from the list.

Table B provides the list of high priority declared vertebrate animal species for Western Australia based on the prioritisation process for declared vertebrate animal species.

Activities of the Invasive Species Program will be focused on the management and control of these species. Compliance and enforcement activities through tools provided for under the BAM Act will be used to streamline the Program’s response to these species.

Table B: High priority declared vertebrate animal species for Western Australia

Responding to incursions of invasive species not known to be present in Western Australia is the highest priority for the Invasive Species Program
Priority number / Declared vertebrate animal species / Area
1 / European starling
Sturnus vulgaris / Whole of state
2 / Feral goat
Capra hircus / South-west Western Australia
3 / Sulphur-crested Cockatoo
Cacatuagalerita / Whole of state
4 / Northern Palm Squirrel
Funambuluspennantii / Whole of state
5 / Wild dogs
Canis lupus dingo, Canis lupus familiaris and Canis lupus dingo x Canis lupus familiaris / South-west Western Australia
6 / Rainbow lorikeet
Trichoglossushaematodus / Outside the containment line
7 / Fallow deer
Dama dama / Whole of state
8 / Wapiti, Red deer, elk
Cervuselaphus / Whole of state
9 / Feral pig
Sus scrofa / Whole of state
10 / Feral camel
Camelusdromedarius (feral) / Whole of state
11 / Red fox
Vulpesvulpes / Whole of state
12 / Feral donkey
Equusasinus (feral) / Whole of state
13 / Western corella (northern and central wheatbelt subspecies)
Cacatuapastinatorbutleri / Whole of state
14 / Feral horse
Equuscaballus (feral) / Whole of state
15 / Wild rabbit
Oryctolaguscuniculus / Whole of state

High profile species

The Invasive Species Program also recognises that there may be declared invasive species that are not considered high priority species in terms of their impact on agriculture but are of importance and significance to “eligible”[1]biosecurity and community groups. The BAM Act provides the recognised biosecurity group framework to underpin the response to these species, termed high profile species. The Invasive Species Program will respond to the management of these species through the community coordinated approach. The Program will support the community coordinated approach with compliance and enforcement activities within its resource capability.

Table C: High profile species in Western Australia

Species name / Declared plant or declared vertebrate animal / Region
Coral cactus[2]
Cylindropuntiafulgida var. mamillata / Plant / Pilbara and Southern Rangelands
Prickly pear[3]
Opuntia spp. / Plant / Pilbara and Southern Rangelands
Prickly acacia[4]
Acacia nilotica / Plant / Kimberley
Rubber vine[5]
Cryptostegia grandiflora / Plant / Kimberley
Mesquites[6]
Prosopis glandulosa, Prosopis pallida, Prosopis glandulosa x velutina / Plant / Pastoral region
Parkinsonia
Parkinsonia aculeata / Plant / Pastoral region
Narrow leaf cotton bush
Gomphocarpus fruticosus / Plant / South-west
Paterson’s curse
Echium plantagineum / Plant / South-west
Apple of Sodom
Solanum linnaeanum / Plant / South-west
Blackberry
Rubus spp. / Plant / South-west
Cape tulips
Moraea miniata,Moraea flaccida / Plant / South-west
Wild dogs (including dingoes, feral dogs and dingo-dog hybrids)
Canis lupus familiaris(feral), Canis lupus dingo, Canis lupus familiaris x Canis lupus dingo / Vertebrate animal / Pastoral region
Rainbow lorikeet
Trichoglossushaematodus / Vertebrate animal / Perth metropolitan area
Feral camel
Camelusdromedarius(feral) / Vertebrate animal / Pastoral regions
Feral pig
Sus scrofa / Vertebrate animal / South-west land division
Feral donkey
Equusasinus (feral) / Vertebrate animal / Pastoral regions
Feral horse
Equuscaballus (feral) / Vertebrate animal / Pastoral regions

1.Background

Government agencies are continually challenged to demonstrate value for money and to show that they are meeting the needs of their clients and stakeholders.

Invasive species management requires an investment by the community in the exclusion, eradication or management of a pest species that has the potential to cause significant economic damage to agricultural enterprises by impacting upon production, productivity and in some cases disrupting export markets.

In an environment of reducing resources, it becomes more essential for those resources to be targeted towards management of declared invasive species that yields the most benefits to the agriculture sector in Western Australia.

2.Purpose and scope

Purpose of this position statement:This position statement provides strategic direction and clarity to the Invasive Species Program through the identification of high priority and high profile declared invasive species in Western Australia based on their impact on agriculture. It also outlines the Program’s general approach to management of these high priority and high profile species.

Scope of this position statement: The declared pests covered under this position statement include plants and vertebrate animals declared under the Biosecurity and Agriculture Management Act 2007 (BAM Act). The statement excludes invasive species declared or prescribed under other legislation and the resource allocations by the relevant administering agencies.It also does not cover diseases or invertebrate organisms.

3.Relevant Legislation

The BAM Act and its regulations took full effect on 1May 2013 replacing the Agriculture and Related Resources Protection Act 1976. Under the BAM Act, organisms can be declared as:

Permitted under section 11;
Prohibited under section 12; or
Declared pests under section 22(2).

Organisms that are not on any of these lists are known as unlisted organisms under section 14 of the BAM Act.

The declaration of organisms under one of the three categories is based on its likely adverse impacts on another organism, human beings, the environment or part of the environment or agricultural activities, fishing or pearling activities or related commercial activities in Western Australia. Declaration can be for the whole or part of the state.

Prohibited organisms and section 22(2) declared pests can be assigned to control categories based on the extent of their presence in Western Australia. Three control categories exist under the BAM Act:

Category 1 – Prevention (C1)
Category 2 – Eradication (C2)
Category 3 – Management (C3)

Prohibited organisms and section 22(2) declared pests can also be assigned to keeping categories, which determines the keeping permit requirements for each of these species.

The draft BAM Act Policy BAM1.0 Declaring the status of organismsprovides further information on the process and criteria for declaring organisms under the BAM Act.

4.Link to the Invasive species plan for western australia

The Invasive Species Plan for Western Australia 2015-2019 (State IS Plan) outlines Western Australia’s approach to managing existing and potential invasive species that can harm the state’s economy, environment and people. The State IS Plan identifies two groups of priority invasive species – high priority species and high profile species.

High priority invasive species are defined in the State IS Plan as high risk species that can establish widely and if so cause the most undesirable impact. These species are also likely to be feasibly prevented, eradicated and contained or controlled. For the purposes of this position statement, impact on agriculture will be the primary consideration when determining high priority invasive species.

High profile invasive species are defined in the State IS Plan as declared species assessed by the community – normally already widely established – as being major problems. This definition will be applied in this position statement.

5.Developing the list of priority species

5.1Invasive species not known to be present in Western Australia

The Invasive Species Program’s approach to managing declared invasive species aligns with the generalised invasion curve (Figure 1). This approach is consistent with that taken in the State IS Plan.

In general, the most cost effective actions are in preventing a new invasive species entering or eradicating it before it becomes widely established. At this stage, government intervention is most needed and often delivers the greatest return on investment. Responding to the presence of invasive species that are not known to be present in Western Australia[7] is considered to be the highest priority for the Invasive Species Program. These species are not ranked or prioritised in this position statement as all incursions are treated as highest priorities for the Program.

Figure 1 Generalised Invasion Curve

Source: Victoria Department of Environment and Primary Industries

5.2High priority declared species known to be present in Western Australia

Declared invasive species that are known to be present in Western Australia are typically categorised in the C2 (eradication) and C3 (management) control categories. Management of these species form the bulk of activities within the Invasive Species Program.

5.2.1Declared plants

The prioritisation process for declared plants known to be present in Western Australia was carried out in two steps. The first step was a declared pest ranking assessment and the second step was an economic analysis of the top ten declared plant species as ranked in the first step.

Declared pest ranking assessment

Declared species that are known to be present in Western Australia were ranked by an expert panel based on the species’ impacts on agriculture. The ranking of declared plants was carried out based on the impact of each species in a nil management scenario. Appendix 1 provides the details of the method for ranking declared plants.

The ranking of a species is based on the average score from the panel. The score takes into account the invasiveness of the species and its capacity to change its surrounding.

The ranked list of plant species based on their impacts on agriculture is at Appendix 2.

Economic analysis

For the top ten ranked declared plant species from the declared pest ranking assessment, an economic impact assessment was conducted. This assessment built on the ranking of the expert panels and provided a quantitative estimated cost to the impact of each species to agriculture.

A model was constructed to calculate the potential impact of the top ten ranked declared plants on agricultural production over time (Cook, 2014a). The model allowed species to be prioritised in two different ways using two scenarios:

Management scenario - in which an eradication or a ‘slow-the-spread’ policy is either in place or intended;
Nil management scenario - where minimal effort is made to control a pest, providing an indication of the natural capacity of the pest to inflict damage on Western Australia’s (WA) agricultural economy.

The resultant list from the first scenario provided the benefits in economic terms of the current or proposed management strategies of the IS Program. The quantitative benefits of from this list were used to calculate the cost-benefit ration of management actions and to determine the maximum amount of expenditure for any current or proposed management actions.

The list from the second scenario provided the quantitative cost to Western Australian agriculture with no intervention or management of the species. This list was used as the basis for determining the priorities for Western Australia and is shown in Table 1. The cost presented against each species represents the potential damage to Western Australia due to the unmanaged spread of each species.

5.2.2Declared vertebrate animals

Analysis and categorisation of the stage of invasion

The generalised invasion curve (Figure 1) shows that the indicative economic returns are higher when intervention is applied at the earlier stages of invasion. This provides a rationale for government intervention in prevention of new invasive species and eradication of small populations.

The prioritisation process for declared vertebrate animals was carried out using their location on the generalised invasion curve (Figure 1) as the first step. Each of the declared pest animals were categorised into four categories based on its stage of invasion (from 1 to 4), from the earliest stage (stage 1) to widespread and well established (stage 4).

A spatial differentiation was also made for wild dogs (Canis lupus familiaris(feral), Canis lupus dingo x Canis lupus familiaris and Canis lupus dingo) and feral goats (Capra hircus(feral)) as their presence are viewed differently in the south-west as opposed to across the whole of the state. A similar approach was taken for water buffalo (Bubalusbubalis)as the species is categorised at the earliest stage of invasion north of the 20th parallel and widespread and established south of the 20th parallel. These three species were ranked in accordance with their earliest stage of invasion (e.g. feral goats are categorised as stage 1 during the ranking process).

Declared pest ranking assessment