1. Welcome to MAF Biosecurity New Zealand’s Didymo Science Seminar Welcome to MAF Biosecurity New Zealand’s Didymo Science Seminar 24 July 2007, Wellington Christina Vieglais, Didymo Science Programme Leader

2. 2 Introductions MAFBNZ Didymo Response Team ( Chris Bicknell, Frances Velvin, Jan Amann, Lesley Wilson, Judith Hamblyn, Jeff Donaldson, Fleur Petricevich, Matt Thorpe) Our Sponsor –Andrew Harrison, Chief Technical Officer and Acting Director of Post Border

3. 3 MAF BNZ Post Border Group Committed to developing a programme with partners to manage didymo into the future Knowledge gained during the incursion response can enable partners to make well- informed decisions Sharing of knowledge, skills and resources is vital to effective long term management

4. 4 Sharing for Science

5. 5 Didymo Incursion Response Science Programme

6. 6 New Arrivals Investigate Initial Response Eradicate Control Manage Assessment Criteria Detect

7. 7 Incursion Response Policy Key criteria to determine an appropriate response The technical feasibility of achieving the response objectives using the measures proposed; and The costs and benefits associated with the response objectives and measures proposed (including social, environmental, cultural costs and benefits)

8. 8 Assessment Criteria Technical feasibility←science Practical Benefit – cost Strategic Acceptable Priority Resource availability

9. 9 Required Burden of Proof 100 80 60 40 20 >95% = significant <95% = not significant >90% = beyond reasonable doubt >75% = compelling evidence >51% = preponderance of evidence <51% = not guilty Source: Haas, Glen, E., Journal of Forestry Sept 2003 Science Judiciary

10. 10 Didymo Response Challenges Absence of basic information Potential for economic, environmental, cultural and social impacts No known methods for control or eradication Can’t control natural pathways of spread Requires change in human behavior to reduce spread

11. 11 SCIENCE

12. 12 Didymo Science Programme Objectives To provide validated information on identification, detection, distribution, impacts, containment, control To Inform decision-making on response options What are the impacts and risks? Can we contain, control or eradicate???

13. 13 Need validated information Questions Studies What harm will it cause? Where else is it? How will we know if it has spread? Can we keep it from spreading? Can we reduce the pop / impacts? DISTRIBUTION IMPACTS CONTROL

14. 14 Didymo Science / Technical Studies – Ecology I and II – Trout Impacts – Likely Environments Map – Sampling Methods – Delimiting Surveys – Molecular Detection – Decontamination – Survival – Control Methods – Spring-fed Creeks DISTRIBUTION IMPACTS CONTROL

15. 15 What Are The Impacts? Mararoa River, Southland, Dec 2005 Photo courtesy Fish & Game New Zealand

16. 16 Trophic Cascade Carnivore Herbivore Producer

17. 17 Initial anecdotal observations included: -Environmental (other algae, insects, fish) -Health (itchy eyes & skin) -Water Quality (taste and odour) -Recreational (fishing, boating etc) -Aesthetic (unattractive) -Economic (clogging water intakes, fishing) Potential Impacts in Nov 2004

18. 18 Didymo Organism Impact Assessment What are the impacts to values not easily measured? Delphic Study – perceived impacts Current Assessment: High to extreme impacts on all core values (environmental, economic, social and cultural) Can we measure any quantitative impacts? Science Studies: Ecology and Trout Studies

19. 19 Didymo Economic Impact Assessment Assessment of potential economic impacts if didymo spreads provides a baseline relative to which to assess incursion response options avoidance of or reduction in impacts comprises the benefits of intervention, for comparison with control costs Potential present value impact over eight years est. $57 to 285 million

20. 20 Impact Study Outputs Ecology I - algae, benthic inverts ( completed Dec 2005) Ecology II – plus drift inverts, native fish, pH, DO (today) Trout Impacts - (today) Eco study results used in conjunction with LEM may reduce uncertainty about potential ecological impacts to specific sites Transfer to Partners

21. 21 Where Else Is It ? Mararoa River, Southland, Dec 2005 Photo courtesy Fish & Game New Zealand

22. 22 High Low Habitat Suitability Potential distribution - South Island

23. 23 High Low Suitable habitats in NZ Potential distribution - North Island

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25. 25 Gomphoneis (60-100  m) Gomphoneis Navicula (20-70  m) Gomphonema (up to ~100  m) Frustulia (50-60  m) Achnanthidium (5-25  m) Epithemia (20-60  m) Tabellaria (30-50  m) Encyonema (20-40  m) Cymbella (25-35  m) Diatoma (15-40  m) Synedra (up to ~200  m) Didymosphenia (80 – 130  m) 50  m

26. 26 Distribution Study Outputs Delimiting Surveys ( ongoing since Dec 04 ) Likely Environments Map I (completed Mar 05) Sampling Methods Study (completed Sep 06) DNA Detection Study (today) Sampling and Analysis Protocols (in use) Updated LEM (today) Transfer to Partners

27. 27 How Do We Control It? Mararoa River, Southland, Dec 2005 Photo courtesy Fish & Game New Zealand

28. 28 Didymo Control – Preliminary lit review : No proven control methods – Decontamination methods showed promise – RFP notified to trial control methods – Efficacy, impacts, feasibility, duration, and costs – Nine proposals received; NIWA commissioned – Chemical control most likely solution, if any

29. 29 Control Study Outputs Decontamination Study (completed Feb 05) Survival Study (completed Dec 06) Control Trials (today) Spring-fed Creek Study (today) Cleaning Methods (completed) Potential Control Tools (dependent on results) Transfer to Partners

30. 30 Purpose of Seminar facilitate technical knowledge transfer assist partners in making technical decisions bring closure to the 2006/07 scientific research programme update partners on the 2007/08 operational programme.

31. 31 Collective Effort Biosecurity New Zealand Didymo Incursion Response Team Didymo Technical Advisory Group – expert objective advice Didymo Science Providers – desktop, laboratory and field studies Didymo LTM Partners – skills, experience, wisdom

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37. 37 Didymo Response and LTM Objectives slow the spread of didymo and other freshwater pests throughout New Zealand protect valued sites and at risk species mitigate the impacts of didymo on affected sectors maintain the North Island free of didymo for as long as possible

38. 38 Didymo Affects Invert Communities Increased invertebrate numbers (No. per 6 sq m) Decreased proportion of “good” inverts DidymoSites Inverts UnaffectedAffected Total45615289271 EPT875120528 Proportion0.190.07