Section 72 Analysis for 5-year Review Results Canterbury Regional Pest Management Strategy 2005- 2015 Report No. U10/3 ISBN 978-1-877574-29-0 (hard copy) ISBN 978-1-877574-30-6 (electronic) R Maw June 2010 Section 72 Analysis for 5-year Review Results Canterbury Regional Pest Management Strategy 2005-2015 ii Section 72 Analysis for 5-year Review Results Canterbury Regional Pest Management Strategy 2005-2015 Table of Contents PART 1: INTRODUCTION ................................................................................................. 1 PART 2: CHILEAN NEEDLE GRASS ............................................................................... 3 2.1 BACKGROUND ........................................................................................................... 3 2.2 DISTRIBUTION ........................................................................................................... 3 2.3 IMPACTS ................................................................................................................... 3 2.4 EFFECTS SUMMARY ................................................................................................... 4 2.5 ANALYSIS ................................................................................................................. 4 2.6 SECTION 72 CONCLUSIONS ....................................................................................... 8 2.7 FUNDING RATIONALE ................................................................................................. 8 2.8 ANNEX 1: MAIN ASSUMPTIONS ................................................................................. 10 2.9 ANNEX 2: TABLES OF RESULTS ................................................................................ 11 2.10 ANNEX 3 CURRENT AND POTENTIAL DISTRIBUTION OF NASSELLA NEESIANA ................. 19 PART 3: PLANTS FOR POSSIBLE INCLUSION IN A RPMS ........................................ 25 3.1 INTRODUCTION ....................................................................................................... 25 3.2 BACKGROUND ......................................................................................................... 26 3.3 EVALUATION ........................................................................................................... 27 3.4 ACKNOWLEDGEMENTS ............................................................................................. 99 3,5 REFERENCES ......................................................................................................... 99 3.6 OTHER SOURCES OF INFORMATION: ........................................................................ 100 PART 4: ANIMALS FOR POSSIBLE INCLUSION IN A RPMS .................................... 103 4.1 EUROPEAN HEDGEHOG (ERINACEUS EUROPAEUS) ................................................... 103 4.2 SHIP RAT (RATTUS RATTUS), NORWAY RAT (RATTUS NORVEGICUS) .......................... 104 4.3 ARGENTINE ANT ................................................................................................... 105 iii Section 72 Analysis for 5-year Review Results Canterbury Regional Pest Management Strategy 2005-2015 iv Section 72 Analysis for 5-year Review Results Canterbury Regional Pest Management Strategy 2005-2015 Part 1: Introduction Environment Canterbury has undertaken a 5-year review of the Canterbury Regional Pest Management Strategy 2005-2015 (RPMS). Feedback from interested parties suggested that various plants and animals should be considered for inclusion in the RPMS. The Biosecurity Act 1993 prescribes an analysis test be undertaken in accordance with section 72 the Act in order to justify inclusion. The section states: (1) A regional council may notify, in accordance with section 78 of this Act, a proposal for a regional pest management strategy only if it is of the opinion that— (a) The benefits of having a regional pest management strategy in relation to [each organism to which the strategy would apply] outweigh the costs, after taking account of the likely consequences of inaction or alternative courses of action; and (b) The net benefits of regional intervention exceed the net benefits of an individual's intervention; and [(ba) Where funding proposals for the strategy require persons to meet directly the costs of implementing the strategy— (i) The benefits that will accrue to those persons as a group will outweigh the costs; or (ii) Those persons contribute to the creation, continuance, or exacerbation of the problems proposed to be resolved by the strategy; and (c) each organism in respect of which the strategy is under consideration is capable of causing at some time a serious adverse and unintended effect in relation to the region on one or more of the following: (i) Economic wellbeing; or (ii) The viability of threatened species of organisms, the survival and distribution of indigenous plants or animals, or the sustainability of natural and developed ecosystems, ecological processes, and biological diversity; or (iii) Soil resources or water quality; or (iv) Human health or enjoyment of the recreational value of the natural environment; or (v) The relationship of Maori and their culture and traditions with their ancestral lands, waters, sites, waahi tapu, and taonga. The information included in Parts 2-4 is a compilation of the material used to guide Council’s opinion regarding the proposed inclusion of Chilean needle grass in the RPMS and the changes to the site-led biodiversity programmes. The information is the work of the authors who have produced the reports, papers or publications referenced. 1 Section 72 Analysis for 5-year Review Results Canterbury Regional Pest Management Strategy 2005-2015 2 Section 72 Analysis for 5-year Review Results Canterbury Regional Pest Management Strategy 2005-2015 Part 2: Chilean Needle Grass Environment Canterbury commissioned the following report into Chilean needle grass. Meeting the requirements of the biosecurity act 1993: economic evaluation of regional pest management strategy for plant pests, Harris Consulting May 2010. 2.1 Background Chilean needle grass is an erect, tufted perennial grass, which can grow up to one metre high in the absence of grazing. It originates from South America, and has naturalized in New Zealand in Hawke’s Bay, Marlborough, and Auckland. Plants form dense clumps, which exclude preferred pasture species and are unpalatable to stock during the flowering period. Chilean needle grass flowers between November and April and produces sharp tipped seeds, which can bore into the eyes and pelts of grazing animals. The seeds can be moved by stock, waterways, feral animals, machinery, hay, grain and to some extent, by wind. 2.2 Distribution Chilean needle grass is recognised as a weed of national significance in Australia. In New Zealand, there are localised infestations in Auckland and Hawke’s Bay in the North Island and more extensive infestations in Marlborough. Until recently Canterbury was thought to be free of Chilean needle grass. However an infestation was discovered recently in a vineyard in Spotswood, and the current infestation is estimated to be approximately 80 ha, with a nil to isolated plant infestation across approximately 95% of the area and 5% scattered to dense. Marlborough is the likely source of the infestation in Canterbury. In Marlborough, ninety-six properties are known to have an infestation of Chilean needle grass in 2005. Infestations there range from isolated patches to widespread infestations and cover an estimated area of 4300 hectares (Bell, 2005)1. The areas in Marlborough increased from ~1500 ha in 1987 to 4300 ha in 2005, showing its potential for rapid increase and spread. Table 1: Areas of Chilean needle grass infestation in Marlborough, 2005 survey Classification Area (ha, 2005) Fringe (<5% ground cover of CNG2) 1346 (31%) Core (5-50% ground cover of CNG 2106 (49%) Nucleus (>50% ground cover CNG) 859 (20%) Total 4311 (100%) 2.3 Impacts The impacts of Chilean Needle grass are summarised in the table below. Economic Impacts Conservation Values Soil resources or water Human Health or quality recreational values Current Potential Current Potential Current Potential Current Potential Low High Nil Medium Nil Nil Nil Nil 1 Bell, M.D. 2006 “Spread of Chilean Needlegrass (Nasella neesiana) in Marlborough, New Zealand”. NZ Plant Protection 59:266 – 270 (2006) 3 Section 72 Analysis for 5-year Review Results Canterbury Regional Pest Management Strategy 2005-2015 The Esler2 weediness rating for Chilean needlgrass is 11/40, and the Biological Success and Environmental Impact Rating is 18/60, which indicates a reasonably significant weed potential. The economic impacts of Chilean needle grass are likely to occur to pastoral landholders throughout Canterbury over time from exclusion of palatable grazing species and disruption to the farm operations. Typically farmers have to keep stock of infested paddocks for a period of 3 months in summer while the plant seeds. Chilean needle grass is a difficult weed to control and is not readily killed by approved herbicides. Chilean needle grass also impacts on animal welfare, as sheep, cattle and dogs can be affected by the sharp seeds. These are known to burrow through skin and into muscle tissue, entering eyes, and causing severe pain and infection. This can also cause economic damage through downgrading of pelts. Chilean needle grass has an impact on biodiversity through exclusion. It has been shown to form very dense stands, excluding all other material, thus reducing