The New Zealand Institute
| Grade | NZ Rank | Trend | Latest Value | 2015 Target | |
|---|---|---|---|---|---|
| C | Not applicable | - | 3.3b cost | Reduced annual cost | Special but vulnerable |
New Zealand’s islands have been isolated from the rest of the world for tens of millions of years and until recently its flora and fauna have evolved with relatively little influence from the arrival of species from other places. Most of the rest of the world has been exposed to invasions of predators and parasites as climate changes have led to migrations and sea level falls have created land bridges.
The arrival of humans in New Zealand has led to importation of predators such as rats and stoats, parasites such as the varroa mite, and other species that harm our natural environment such as possums and didymo. New Zealand’s history of relative isolation means that invasive species that become established in New Zealand may have few natural predators, and local ecologies may not be well-equipped to adapt to the invasions.
One important consequence of invasive species is the potential extinction and decline of native species, given their experience of only a limited range of predators. For example, if left unmanaged, possums would eventually eat their way through our natural forests and stoats would consume most of our native birds. Extinctions and declines reduce ecological resilience and preclude future benefits from products and services that might be derived from the species. Most of these native species losses and declines have limited short term impact on environmental productivity, though they have large detrimental effects on environmental quality.
Invasive pests also have negative impacts on economic productivity. Pests cause economic damage when they become established with material costs for surveillance, prevention and response.
The long term outcomes from these invasions will depend on how well they are managed. Efforts to contain possums and stoats are ongoing with technological advances likely to improve outcomes provided the effort is sustained. It is expected that many weeds are becoming established in the wild but are not yet widespread. These weeds will have important future environmental costs. Climate change may help many of these weeds to flourish.
The output loss in 2008 from invasive species is estimated at almost $1.3 billion per annum, mostly in agriculture and forestry. A further $836 million was spent on pest management with 45% of that spent by central government or regional councils. Central government spending is concentrated in two areas: biosecurity (e.g. quarantine activities, pest surveillance and response) and Department of Conservation pest control on the conversation estate which is around 30% of New Zealand’s land area.
Combining these costs and taking account of consequential losses to the economy, Figure 1 shows the estimated total economic cost of pests in 2008 was $3.3 billion, or almost 2% of GDP. Without effective biosecurity management these costs could be much higher. The cost estimates do not include costs of environmental degradation such as loss of habitat and the decline and extinction of native species.
The table in Figure 2 shows that some individual invasive species can impose significant costs.
Outside of the economic costs, New Zealanders have a responsibility to manage the country’s native species and endemic species (those found only in New Zealand and uniquely ours) endowment. The estimated total number of threatened native species identified in the New Zealand listing carried out in 2004-05 was 2,788, up by 416 since the 2002 listing. Twenty-four percent (668) of the species were classified as acutely threatened i.e. nationally critical, endangered or vulnerable.
Figure 3 shows most of the acutely threatened species are plants and invertebrates. The Parliamentary Commissioner for the Environment identified that around 90% of New Zealand’s birds and insects are found nowhere else in the world, along with 80% of our plants, all of our 60 reptiles, four frogs and three bats. Furthermore in a study of 179 countries, New Zealand was ranked as having the highest proportion of threatened species (Bradshaw, Giam & Sodhi, 2010).
Birds are associated in special ways with New Zealand. Based on 2011 data a large number of New Zealand’s native bird species are threatened. Figure 4 compares New Zealand’s native bird populations to that of other countries, and shows how many of these species are threatened. Over half (56%) of New Zealand’s native bird species are classified as threatened (ICUN Red List).
New Zealand is recognised as one of a handful of countries that have invested in coordinated policies to manage invasive species. The Biosecurity Act of 1993, was a world first; a law specifically to support systematic protection of all our valued biological systems – introduced and indigenous – from the harmful effects of exotic pests and diseases (John Hellström, Biosecurity Council chair 2003). Amendments to this Act, and a range of other Acts, are currently proposed in the Biosecurity Law Reform Bill, which is an omnibus bill with the purpose of updating the biosecurity system to enable it to respond to increasing challenges. Included in the bill are proposals to transfer biosecurity costs to landowners and primary industries rather than importers. Federated Farmers, the Soil and Health Association of New Zealand, and others have expressed concerns about this and other proposals in the bill. After considering submissions, the Primary Production Committee reported back to Parliament for a Second Reading of the Bill on 16 August 2011.
There are many activities that impact the introduction and management of invasive species, which means that there are many organisations which influence how successful New Zealand is in protecting native species. Since 2003 the Ministry of Agriculture and Forestry (MAF) has had overall leadership responsibility for implementing the Biosecurity Strategy published in 2003. One of the tasks of MAF Biosecurity New Zealand is coordinating efforts across various government agencies including the Department of Conservation, Ministry of Fisheries, Ministry of Health, Ministry of Science and Innovation, and more. The coordination is primarily through the Biosecurity Council.
The 2003 Biosecurity Strategy identified issues that were to be addressed in order to improve processes and manage risks. While a comprehensive review of the strategy has not yet taken place a new Biosecurity Surveillance Strategy 2020 was launched in February 2010 to help meet the expectations set out in the overarching strategy. The Surveillance Strategy provides a common vision and long-term direction and approach for all the agencies and organisations involved in biosecurity surveillance. It also established the underlying principles and identified the most important actions to realise the vision. Implementation is now being progressed and has included establishing two advisory groups to ensure change is implemented.
In February 2011, the Pest Management National Plan of Action 2010-2035 was published. Its purpose is to make it easier for everyone involved in pest management to act collectively in New Zealand’s best interests. It sets out changes agreed by central and regional government and identifies four improvement areas: clarify roles and accountabilities; improve and simplify processes; develop better and more accessible tools; improve capacity for collective action. A series of actions are set out that are to be delivered within, two, five and 25 years. The plan of action and progress on it is to be reviewed by 31 December 2015.
Two national pest programmes operate. The National Interest Pests Response (NIPR) aims to eradicate eleven established pests from New Zealand (see http://www.biosecurity.govt.nz/pests/surv-mgmt/mgmt/prog/nipr). The National Pest Plant Accord (NPPA) is a cooperative agreement between the Nursery and Garden Industry Association, regional councils and government departments to ensure plants that are unwanted organisms cannot be sold, propagated or distributed in New Zealand (see http://www.biosecurity.govt.nz/pests/surv-mgmt/mgmt/prog/nppa).
Focus on the potential economic impact of invasive species is relevant, but effort and investment are also required to understand the state of native species. Funding for research to assess the level of threat and endangerment of New Zealand’s native species is sporadic, and annual updates of statistics are not available.
Preventing the extinction of New Zealand’s unique plant and animal species is a critical element in the government’s New Zealand Biodiversity Strategy adopted in February 2000. New Zealand is a biodiversity hotspot - one of the world’s treasure chests of unusual life forms, many of which are found nowhere else. While evidence points to the continued decline of biodiversity and only one eighth of the conservation estate has any pest control at all, over the past decade there has been some progress and greater participation in protection activities. Protected areas free of predators have increased, allowing populations of kiwi and other native species to re-establish. Many of these programmes depend on local action, but are supported by government funding as well.
In October 2010 the government committed $4 million to enable a three-year testing programme of innovative self-resetting traps that can kill up to 12 pests before needing to be set again by hand. Two different types of traps will be trialled from September 2011, one for rats and stoats and another for possums. Although more expensive than current traps, using 10,000 of these automatic traps could save $800,000 in labour costs annually and, if successful, provide a significant boost in protection for New Zealand’s forests and native species. Research into the biological control of possums is expected to result in effective biological bait in the next 5 -10 years.
While traps and other poisons assist in controlling pests, based on a careful analysis of the evidence, the Parliamentary Commissioner for the Environment concluded in June 2011 that not only should the use of 1080 continue (including aerial operations) to protect the country’s forests but more of it should be used. Possums, rats and stoats are devastating national parks and other conservation land and the creatures that live within them. These predators are widespread and are the greatest threat to the continued survival of many native birds. All three predators eat eggs and young birds, while rats and possums have a huge effect on plant life.
In January 2011 the government released a Proposed National Policy Statement on Indigenous Biodiversity to provide clearer direction to local authorities on their responsibilities for managing indigenous biodiversity under the Resource Management Act. A report on public submissions along with Ministry for the Environment recommendations is being prepared. Before finalising the NPS the Government intends to consider the Waitangi Tribunal’s report on claim 262 which relates to rights in respect to indigenous flora and fauna.
New Zealand faces a unique challenge to protect its environment because it does not have many of the species that cause harm in other countries and because local ecosystems are especially vulnerable to invasive species. Past decisions to deliberately import damaging species and international connectedness mean the challenge is large.
Assigning a grade is difficult because international comparisons are not meaningful and objective trend data is not available for important metrics. New Zealand scores poorly on established invasive species, with high economic and environmental quality costs. New Zealand scores well for having developed strategies and action plans for biosecurity and biodiversity. Vigorous and largely effective efforts on biosecurity, together with progress to protect habitats, threatened species and eradicate established invasive species, have occurred over recent years. On balance a grade of C.
Assessing progress is likely to involve substantial judgement. The data that is gathered to estimate annual costs due to invasive species is collected over several years and not comprehensively updated each year. Unpredictable events like new introductions can radically change the expected cost of invasive species.
Successful performance would be reducing the ongoing costs of species already introduced, while making reasonable investments to avoid further introductions.
Assuming no serious events, the target is to reduce the cost of invasive species, through efficient investment in eliminating or controlling established species and avoiding further introductions.
Figure 1: MAF Biosecurity New Zealand (2009, September) Economic costs of pests to New Zealand, a report prepared by Giera, Nick & Bell, Brian from Nimmo-Bell, retrieved on 21 January 2010 from http://www.biosecurity.govt.nz/files/pests/surv-mgmt/economic-costs-of-pests-to-new-zealand.pdf. The cost estimates on p.3 are in 2008 dollars and were obtained by collecting information on economic costs from previous studies, from 1999 or later, rather than conducting new analyses on individual pest species. Annual defensive expenditure is $836.4 million. Losses in upstream and downstream services and industries is calculated from Production losses with multiplier ($2,454) less Total output losses ($1,292).
Figure 2: Same as for Figure 1. Table 4.6: List of common invasive species and associated annual production loss, pp 39-40.
Figure 3: Hitchmough, R., Bull, L., & Cromarty, P. (2007, January). New Zealand Threat Classification Systems List 2005, Department of Conservation. Table 1 Distribution of Threat Rankings by Taxonomic Group, p13. Retrieved on 22 March 2010 from http://www.doc.govt.nz/publications/conservation/new-zealand-threat-classification-system-lists-2005/.
A Department of Conservation Factsheet on The New Zealand Threat Classification System is available from http://www.doc.govt.nz/publications/conservation/nz-threat-classification-system/nz-threat-classification-system-lists-2005/.
Figure 4: The International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species provides taxonomic, conservation status and distribution information on plants and animals that have been globally evaluated using the IUCN Red List Categories and Criteria. This system is designed to determine the relative risk of extinction, and the main purpose of the IUCN Red List is to catalogue and highlight those plants and animals that are facing a higher risk of global extinction (i.e. those listed as Critically Endangered, Endangered and Vulnerable).
Data was sourced from the IUCN Red List version 2011.2, Table 8: Total endemic and threatened endemic species in each country (totals by taxonomic group), retrieved on 23 November 2011 from http://www.iucnredlist.org/about/summary-statistics. The table focuses on endemic species only (i.e., species occurring naturally within one country only) and only presents figures for species groups that have been completely assessed.
Further information links for invasive species
Parliamentary Commissioner for the Environment (2011, June) Evaluating the use of 1080: Predators, poisons and silent forests available at http://www.pce.parliament.nz/publications/all-publications/evaluating-the-use-of-1080-predators-poisons-and-silent-forests.
Bradshaw, C.J.A., Giam, X. and Sodhi, N.S. (2010, May) Evaluating the relative environmental impact of countries available at http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010440.
Biosecurity Council (2003, August) Tiakina Aotearoa Protect New Zealand: The Biosecurity Strategy for New Zealand and associated documents are available at http://www.biosecurity.govt.nz/biosec/sys/strategy/biostrategy.
MAF Biosecurity New Zealand (2009, November) Biosecurity Surveillance Strategy 2020 is available at http://www.biosecurity.govt.nz/strategy-and-consultation/strategy/strategy/pest-management/surveillance.
MAF Biosecurity New Zealand (2011, February) Pest Management National Plan of Action available at http://www.biosecurity.govt.nz/pests/surv-mgmt/mgmt/future-project.
An interactive key for the identification weed species in New Zealand is available at http://www.landcareresearch.co.nz/research/biosystematics/plants/weedskey/index.asp.
The Department of Conservation is coordinating implementation of The New Zealand Biodiversity Strategy (2000, February). Seven other government agencies are involved in implementing parts of the strategy which is available at http://www.biodiversity.govt.nz/picture/doing/nzbs/index.html.
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