This section provides links to guidance documents that have been produced by a range of organisations. While this information should be a useful resource, the Non-native Species Secretariat cannot endorse any guidance. If you would like to recommend management information to include here please contact us.

On this page:

• Didemnum vexillum (Carpet Sea-squirt)
• Dikerogammarus spp (Killer shrimps)
• Dreissena polymorpha (Zebra Mussel)
• Non-native flatworms
• Pacifastacus leniusculus (Signal Crayfish) and other non-native crayfish

Didemnum vexillum (Carpet Sea-squirt)

• Good practice management guidance for carpet sea squirt (PDF) - RAPID LIFE (2018)
• First records in Great Britain of the invasive colonial ascidian Didemnum vexillum (external link).  Kate Griffith, Stephen Mowat, Rohan H.F. Holt, Kirsten Ramsay, John D.D. Bishop, Gretchen Lambert and Stuart R. Jenkins (2002).
• Didemnum vexillum – Feasibility of Eradication and/or Control in Holyhead Marina (PDF).  CCW Contract Science report No. 875 (2009).
• The carpet sea squirt Didemnum vexillum: eradication from Holyhead Marina (PDF). Progress to October 2009. Rohan Holt, CCW
• Survey of a non-native ascidian (sea squirt) Didemnum vexillum in Holyhead Harbour (PDF). CCW Marine Monitoring Report No (2009).
• Assessment of the impacts of Didemnum vexillum and options for the management of the species in England (PDF).  Project report for Defra (2010).
• Maps indicating potential spread of Didemnum vexillum in GB (PDF).  Developed with funding from Defra, CCW and SNH.  For information on methods refer to the above report ('Assessment of the impacts of Didemnum vexillum and options for the management of the species in England').
• Recommendations for Reducing the Rate of Spread and Potential Re-Invasion of Didemnum vexillum (PDF).  Report of the GB Working Group for D. vexillum (2011
• Initial response to the invasive carpet sea squirt, Didemnum vexillum, in Scotland (PDF).  Commissioned Report No. 413 (2011).
• Eradication of the non-native carpet ascidian (sea squirt) Didemnum vexillum in Holyhead Harbour: Progress, methods and results to spring 2011 (PDF)  Rohan Holt and Ashley Cordingley (2011).  CCW Marine Monitoring Report No. 90
• Denny, C. M. (2008) Development of a method to reduce the spread of the ascidian Didemnum vexillum with aquaculture transfers (external link). – ICES Journal of Marine Science, 65: 805–810.
• Switzer, S.E., Therriault, T.W., Dunham, A. & Pearce, C.M. (2011) Assessing potential control options for the invasive tunicate Didemnum vexillum in shellfish aquaculture (external link). Aquaculture, 318: 145-153
• Rolheiser, K.C., Dunham, A., Switzer, S.E., Pearce, C.M. & Therriault, T.W. (2012) Assessment of chemical treatments for controlling Didemnum vexillum, other biofouling, and predatory sea stars in Pacific oyster aquaculture (external link). Aquaculture, 364-365: 53-60
• Invasive Species Compendium: Didemnum vexillum (external link) - CABI website 
• Coutts, A.D.M. & Forrest, B.M. (2007) Development and application of tools for incursion response: Lessons learned from the management of the fouling pest Didemnum vexillum (external link). Journal of Experimental Marine Biology and Ecology 342(1): 154-162
• Nimmo, F., Cook, E. J., Moxey, A. P., Hambrey, J. and Black, K. (2011) Cost benefit analysis of management options for Didemnum vexillum (carpet sea squirt) in Scotland (PDF). Report by Hambrey Consulting in association with the Scottish Association for Marine Science and Poseidon Aquatic Resource Management to the Scottish Government Tender Ref: Cr/2011/16
• Carman, M.R., Allen, H.M. & Tyrrell, M.C. (2009) Limited value of the common periwinkle snail Littorina littorea as a biological control for the invasive tunicate Didemnum vexillum (PDF). Aquatic Invasions, 4(1): 291-294
• McCann, L.D., Holzer, K.K., Davidson, I.C., Ashton, G.V., Chapman, M.D. & Ruiz, G.M. (2013) Promoting invasive species control and eradication in the sea: Options for managing the tunicate invader Didemnum vexillum in Sitka, Alaska (external link) Marine Pollution Bulletin, 77(1-2): 165-171

Dikerogammarus spp (Killer shrimps)

Dikerogammarus villosus

• Evaluation of a number of treatments to be used as biosecurity measures in controlling the spread of the invasive killer shrimp (PDF) - Cefas 2011
• Invasive Species Factsheet (Dikerogammarus villosus) (PDF) - Environment Agency 2011
• Dikerogammarus villosus briefing notes - Killer Shrimp Task Group 2011 - 2012
  • briefing note 5 (PDF)
    
  • briefing note 4 (PDF)
    
  • briefing note 3 (PDF)
    
  • briefing note 2 (PDF)
  • briefing note 1 (PDF)
• Biosecurity best practice (poster) (PDF) - University of Leeds & Cefas 2014
• Effectiveness of hot water as a decontamination method to prevent the accidental movement of aquatic invasive species (external link) - Anderson et al 2014

Dikerogammarus haemobaphes

• Dikerogammarus haemobaphes briefing notes
  • briefing note 2
  • briefing note 1
• An investigation into the impacts of a non-native Gammarid on the benthic macroinvertebrate community and ecosystem function of the River Cherwell (PDF) - Hugh Graham 2014

Dreissena polymorpha (Zebra Mussel)

• Good practice management guidance for zebra mussel (PDF) - RAPID LIFE (2018)
• Durán, C., Lanao, M., Anadón, A. and Touyá, V. (2010) Management strategies for the zebra mussel invasion in the Ebro River basin (PDF). Aquatic Invasions (2010) Volume 5, Issue 3: 309-316
• Management Options for Quagga & Zebra Mussel Infestations (PDF) - U.S. Department of the Interior Bureau of Reclamation
• Maguire, C.M. and Sykes, L.M. (2004) Zebra Mussel Management Strategy for Northern Ireland 2004-2010 (PDF). Queens University Belfast
• Zebra Mussel Control (PDF)  - Missouri Department of Conservation website (4 March 2014)
• Invasive Alien Species Fact Sheet: Dreissena polymorpha
• Invasive Species Compendium: Dreissena polymorpha (zebra mussel) (external link) - CABI website 
• Aldridge, D.C., Elliott, P. & Moggridge, G.D. (2004) The recent and rapid spread of the zebra mussel (Dreissena polymorpha) in Great Britain. Biological Conservation, 119(2) 253-261
• Quagga and Zebra Mussel Eradication and Control Workshop (PDF).  February 1-2, 2012, San Diego, California
• Rapid Response Plan for the Zebra Mussel (Dreissena polymorpha) in Massachusetts (PDF). Report prepared by ENSR for the Massachusetts Department of Conservation and Recreation
• Zebra Mussels in Texas: Assessment of relative risks to fishery resources, recommendations for action, and expectations for the future (PDF). Texas Parks and Wildlife Department – Inland Fisheries Division (2010)
• Boelman, S.F., Neilson, F.M., Dardeau, E.A. & Cross, T. (1997) Zebra Mussel (Dreissena polymorpha) Control Handbook for Facility Operators, First Edition (PDF). US Army Corps of Engineers, Waterways Experiment Station
• Chemical Control Research Strategy for Zebra Mussels (PDF).  Zebra Mussel Research Technical Notes 1998. US Army Corps of Engineers, Waterways Experiment Station
• Wimbush, J., Frischer, M.E., Zarzynski, J.W. & Nierzwicki-Bauer, S.A. (2009) Eradication of colonizing populations of zebra mussels (Dreissena polymorpha) by early detection and SCUBA removal: Lake George, NY (PDF). Aquatic Conserv: Mar. Freshw. Ecosyst. 19: 703–713
• Coons, K., McCabe, D.J., Marsden, J.E. (2004) The Effects of Strobe Lights on Zebra Mussel Settlement and Movement Patterns (PDF). Journal of freshwater Ecology, 19(1)
• Costa, R., Elliott, P., Saraiva, P.M., Aldridge, D. & Moggridge, G.D. (2008) Development of Sustainable Solutions for Zebra Mussel Control Through Chemical Product Engineering (PDF). Chinese Journal of Chemical Engineering, 16(3) 435-440

Non-native flatworms

The New Zealand flatworm is a non-native species, first recorded in Great Britain in Edinburgh (1965), but now widely distributed throughout much of Scotland and, to a lesser extent, northern England.

A Code of Practice has been produced for this and other non-native flatworms in GB. This is a practical guide to help producers and traders of nursery stock detect and limit the spread of non-indigenous flatworms, notably the 'New Zealand' flatworm, Arthurdendyus triangulatus, and the 'Australian' flatworm, Australoplana sanguinea.

Non-native Flatworm Code of Practice (PDF)

Follow the links below for additional resources and information about these species:

• Information on 'New Zealand' flatworm, Arthurdendyus triangulatus
• Identification sheet for 'New Zealand' flatworm, Arthurdendyus triangulatus (PDF)
• Information on 'Australian' flatworm, Australoplana sanguinea
• Identification sheet for 'Australian' flatworm, Australoplana sanguine (PDF)
• Identification sheet for 'Kontikia' flatworms, Kontikia ventrolineata (PDF)

Invasive Alien Species Fact Sheet (PDF): Arthurdendyus triangulatus - NOBANIS

Invasive Species Compendium: Arthurdendyus triangulatus (New Zealand flatworm) (external link) - CABI website 

Pacifastacus leniusculus (Signal Crayfish) and other non-native crayfish

• Controlling invasive crayfish: Managing signal crayfish populations in small enclosed water bodies (PDF). Defra commissioned Cefas report, 2016.
• Holdich, D. M. & Sibley, P. J. (eds) (2003). Management & Conservation of Crayfish (PDF). Proceedings of a conference held on 7th November, 2002. Environment Agency, Bristol. 217 pp
• Peay, S., Hiley, P.D., Collen, P. & Martin, I. (2006) Biocide treatment of ponds in Scotland to eradicate Signal Crayfish (PDF). Bull. Fr. Pêche Piscic. 380-381: 1363-1379
• The Impact of Non-Native Species - Case Study: The Signal Crayfish (PDF) - Salmon & Trout Association (2009)
• Sibley, P. & Nöel, P. (2002) Control and Management of Alien Crayfish (PDF). Bull. Fr. Pêche Piscic. 367: 881-886
• Frings, R.M. Vaeßen, S.C.K., Groß, H., Roger, S., Schüttrumpf, H. & Hollert, H. (2013) A fish-passable barrier to stop the invasion of non-indigenous crayfish (PDF). Biological Conservation 159: 521-529
• Crayfish and River Users (PDF) - Hampshire & Isle of Wight Wildlife Trust in partnership with Environment Agency (2009)
• Peay, S. (2001) Eradication of alien crayfish populations (PDF). Environment Agency and English Nature, R&D Technical Report W1-037/TR1
• Sandodden, R. & Johnsen, S.I. (2010) Eradication of introduced signal crayfish Pasifastacus leniusculus using the pharmaceutical BETAMAX VET.® (PDF) Aquatic Invasions 5, 1: 75-81
• Invasive Alien Species Fact Sheet: Pacifastacus leniusculus (external link) - NOBANIS 
• Invasive Species Compendium: Pacifastacus leniusculus (American signal crayfish) (external link) - CABI website 
• Ribbens J.C.H. & Graham J.L. (2004). Strategy for the containment and possible eradication of American signal crayfish (Pacifastacus leniusculus) in the River Dee catchment and Skyre Burn catchment, Dumfries and Galloway (PDF). Scottish Natural Heritage Commissioned Report No. 014. (ROAME No. F02LK05) (downloaded from SNH website March 2014)
• Reeve, I D (2004). The removal of the North American signal crayfish (Pacifastacus leniusculus) from the River Clyde (PDF). Scottish Natural Heritage Commissioned Report No. 020 (ROAME No. F00LI12) (downloaded from SNH website March 2014)
• Peay, S. & Hiley, P. (2006). Biocide trial to eradicate signal crayfish in the North Esk catchment (PDF). Scottish Natural Heritage Commissioned Report No. 122 (Purchase Order No. 9725) (downloaded from SNH website March 2014)
• Evaluation of the capacity of pheromones for control of invasive non-native crayfish (part 1) (PDF) - English Nature Research Report 578, and (part 2) (PDF) - English Nature Research Report 633
• Dana, E. D., López-Santiago, J., García-de-Lomas, J., García-Ocaña, D. M., Gámez, V. & Ortega, F.(2010) Long-term management of the invasive Pacifastacus leniusculus (Dana, 1852) in a small mountain stream (PDF). Aquatic Invasions 5(3): 317-322
• Bills, T.D. & Marking, L.L. (1988) Control of Nuisance Populations of Crayfish with Traps and Toxicants (external link).  The Progressive Fish-Culturist 50(2): 103-106
• Gherardi, F., Aquiloni, L., Diéguez-Uribeondo, J. & Tricarico, E. (2011) Managing invasive crayfish: is there a hope? (external link) Aquatic Sciences 73(2): 185-200
• Freeman, M.A., Turnbull, J.F., Yeomans, W.E. & Bean, C.W.(2010) Prospects for management strategies of invasive crayfish populations with an emphasis on biological control (external link). Aquatic Conservation: Marine and Freshwater Ecosystems 20(2): 211-223