DEVELOPING AUGMENTATIVE BIOCONTROL TOOLS FOR MARINE PESTS

Transcript

1. DEVELOPING AUGMENTATIVE BIOCONTROL TOOLS FOR MARINE PESTS JAVIER ATALAH*, GRANT HOPKINS and BARRIE FORREST CAWTHRON INSTITUTE, NELSON, NEW ZEALAND 23 of August 2011
2. OUTLINE  Biocontrol background and introduction  Natural enemies caging experiment  Case study: Biocontrol of Undaria in Fiordland  Further research avenues
3. BIOCONTROL  Frequent practice in terrestrial and freshwater systems  Lack of research investigating the feasibility of biocontrol agents for the management of non-indigenous species (NIS) in marine habitats
4. • Classical – introduce natural enemy from the pest’s native range • Neoclassical – introducing a NIS to control native pest • Augmentative biocontrol – enhancing natural enemies to control pests TYPES OF BIOCONTROL
5. NATURAL ENEMY MECHANISMS  Predation  Grazing  Larval interception  Space preemption  Competition  Parasitism
6. IDEAL TRAITS  High consumption rate per capita  Rapid population growth  Generalist vs specialist  Potentially farmed and enhanced  Resistant to changing conditions  Minimal non-target effects
7. Spread Infested vector source Natural habitats Other values, e.g. shellfish aquaculture Adverse effects Biocontrol to reduce propagule pressure Biocontrol as mitigation tool
8. Biocontrol at Nelson marina
9.  Caging experiment in a marina  Target fouling assemblages, including several NIS  Four biocontrol agent tested:  Sea urchin (Evechinus chloroticus)  Cushion star (Patiriella regularis)  Cat’s eye (Turbo smaragdus)  Limpets (Cellana radians)  Monthly photo quadrat sampling METHODS Nelson
10. EXPERIMENTAL DESIGN n = 3 Control Cage Control Control Cage Control Fouled structures Defouled structures
11. Time (month) 0 1 2 3 Mean fouling % cover (±SE) 0 20 40 60 80 100 Control EFFECT ON DEFOULED STRUCTURES (PREVENTION)
12. DEFOULED PRINCIPAL RESPONSE CURVES 0 1 2 3 -2 -1 0 1 2 Time (month) Effect Red filamentous Erect bryozooan Undaria pinnatifida Rhodymenia sp. Hydroides elegans Hydroids Colonial ascidean Green algae Red foliose Ciona spp. Solitarian ascidean Watersipora subtorquata Bare space Control
13. BEGINNING OF EXPERIMENT
14. CONTROL AFTER 3 MONTHS
15. TURBO EFFECT AFTER 3 MONTHS
16. PATIRIELLA EFFECT AFTER 3 MONTHS
17. Time (month) 0 1 2 3 Total Cover (%) 0 20 40 60 80 100 Control EFFECT ON ESTABLISHED FOULING
18. 0 1 2 3 -4 -2 0 2 4 6 8 Time (month) Effect Bryozoan Colonial ascidean Ciona spp. Solitarian ascidean Red filamentous Hydroids Red foliose Watersipora subtorquata Undaria pinnatifida Green algae Hydroides elegans Perna canaliculus Bare space Control FOULED PRINCIPAL RESPONSE CURVES
19. EVECHINUS BEGINNING OF EXPERIMENT
20. EVECHINUS EFFECT AFTER 3 MONTHS
21. PATIRIELLA BEGINNING OF EXPERIMENT
22. PATIRIELLA EFFECT AFTER 3 MONTHS
23. SUMMARY AND DIRECTIONS  All tested agents were effective, except limpets  Sea urchins and starfish are generalists, hence useful for artificial structures  High cushion star escape rate, especially on defouled  Sea urchins cannot stay upside down for long periods  Cat’s eye had excellent prevention and retention rates  What are the optimal densities?  Combined control agents for higher pest mortality?
24. A real world application: Undaria invasion in Fiordland
25. BACKGROUND  Undaria incursion during vector management strategy development process  Remoteness implies manageable vectors, but difficult response  A government joint-agency response was activated  Sea urchins as part of integrated pest management 1987
26. INTEGRATED PEST RESPONSE  Six weekly surveillance  Manual removal  Encapsulation of target areas of seabed (with bleach added)  Sea urchin biocontrol of target areas (< 2 ha)
27. ASSOCIATED RESEARCH  Biocontrol efficacy  Urchin persistence at release sites  Colonization of adjacent areas  Assess non-target effects
28. CONCLUSIONS AND FUTURE RESEARCH  Augmentative biocontrol a promising tool, with application for natural and artificial habitats  Many issues remaining to address, including non-target effects  Eco-engineering design of marina and aquaculture farms  Effectiveness of anemones as biocontrol on shellfish aquaculture  Not a panacea, perhaps more useful as part of integrated pest management
29. ACKNOWLEDGEMENTS • New Zealand Ministry of Science and Innovation • Joint agency response team:  Environment Southland (ES)  Ministry of Agriculture and Forestry (MAF)  Department of Conservation (DoC)  Nelson Marina