Transcript Document
Control of Aquatic Invasive Species and Restoration of Natural Communities in Ireland Dr Joe Caffrey Central Fisheries Board QUB, Belfast – 7th April 2009 Scope High impact aquatic invasive species in Ireland Case study Lagarosiphon major (Curly Waterweed) Future work and funding High Impact Aquatic Invasive Species Curly Waterweed Lagarosiphon major Nuttall’s Waterweed Elodea nuttallii Dace Leuciscus leuciscus Zebra Mussel Dreissena polymorpha New Zealand Pigmyweed Crassula helmsii Parrot Feather Myriophyllum aquaticum Fringed Water lily Nymphoides peltata Water Fern Azolla filiculoides Potentially High Impact Aquatic Invasive Species Chinese Mitten Crab Eriocheir sinensis Chub Leuciscus cephalus Bloody Red Shrimp Hemimysis anomala Floating Pennywort Hydrocotyle ranunculoides Lagarosiphon near Kilmeaden, Waterford 2005 Nuttall’s Waterweed (Elodea nuttallii) in Carrigadrohid Reservoir New Zealand Pigmyweed (Crassula helmsii) Emergent and submerged Parrot’s Feather (Myriophyllum aquaticum) Fringed Water lily (Nymphoides peltata) Water Fern (Azolla filiculoides) Azolla in River Barrow and Limerick Canal Chinese Mitten Crab (Eriocheir sinensis) - 2005 Chub (Leuciscus leuciscus), River Inny – 2006 Bloody Red Shrimp (Hemimysis anomala) Photo - Dan Minchin (2008) Floating Pennywort (Hydrocotyle ranunculoides) INVASIVE SPECIES CONTROL Case Study Lagarosiphon major in Lough Corrib Curly Waterweed (Lagarosiphon major) Submerged aquatic ‘Oxygenating weed’ Artificial watercourses ~ Only natural habitat is Lough Corrib Rinerroon Bay, Lough Corrib pre-Lagarosiphon major Rinerroon Bay, Lough Corrib post-Lagarosiphon major (2005) Why is Lagarosiphon a Problem? No natural enemies in Ireland Rapid growth rate Dispersal through fragmentation Actively grows in winter Canopy forming – excludes indigenous macrophytes Alters macroinvertebrate community structure Creates improved conditions for coarse fish No legislation to prohibit its sale and distribution Lagarosiphon Control Methods Currently Employed Hand removal using Scuba Mechanical cutting and harvesting Herbicides Light exclusion Life cycle studies [Biological control] Hand Removal using Scuba Lagarosiphon in low abundance - recently colonised sites - edge of large stands - following other treatment methods Herbicides for Lagarosiphon Control Lough Corrib is a SAC and drinking water supply !!! Only one approved herbicide to treat submerged weeds Lagarosiphon is susceptible to dichlobenil Applied locally in upper lake Mechanical Cutting in Lough Corrib Deep cut with trailing knives (V-blades) 10 infested sites treated in 2008 4,700 tonnes of Lagarosiphon removed 29.2 hectares of infested lake bed cleared Light Exclusion using Biodegradable Geotextile - 2008 Trials commenced in August 2008 1,750 sq m at 4 sites treated Early indications positive Life Cycle Studies as an Aid to Lagarosiphon Control Little is known about the life cycle strategies or adventive traits of Lagarosiphon under Irish conditions Less is known about the factors that influence its growth in Irish waters This information is vital if potential weak links in Lagarosiphon’s life cycle are to be identified and targeted for specific control Restoration of Natural Communities Natural recolonisation of indigenous species from spores, seeds, fragments Transplant indigenous species Create conditions favourable for indigenous species Funding & Future Research Primary source of funding for 2009 - 2013 is Life+ (EU & NPWS) €1.5 million 2 Projects Lagarosiphon control in Lough Corrib Invasive species in Grand Canal / Barrow corridor Worth approx. €180k per annum per project (vs c. €200k for 6 months on Lagarosiphon in 2008) Strategic Control of Lagarosiphon in 2009 Clearance of sites from all upstream sites Strategic Control of Lagarosiphon in 2009 Mechanical cutting of sites on north-western shore Strategic Control of Lagarosiphon in 2009 Apply geotextile to all sites in the middle lake Road Map for Lagarosiphon Control in Lough Corrib 2009 Q2 2009 Q3 2009 Q4 2010 Q1 2010 Q2 2010 Q3 2010 Q4 2011 Q1 2011 Q2 2011 Q3 2011 Q4 Recruit & Train Research Implementation Eradication Monitoring Program Review & Report Review & Report Education and awareness Biocontrol Literature review 2012 Q1 2012 Q2 2012 Q3 Experiments in Quarantine 2012 Q4 2013 Q1 Eradication Monitoring Program Education and awareness Final Report Biocontrol Controlled Experiments in Corrib Report Controlled Experiments under licence Report Road Map for Lagarosiphon Control in Lough Corrib Biocontrol PhD to be funded – commencing in summer 2009 Collaboration with University of Grahamstown in SA No. of candidate species already identified Photos J-R Baars Can We Eradicate Lagarosiphon in Lough Corrib? Enormous task – using traditional methods Best expertise available will be utilised Biocontrol may provide the ‘silver bullet’