FISHERIES SOCIETY OF THE BRITISH ISLES BRIEFING PAPER 5 NON-NATIVE FRESHWATER FISH INTRODUCTIONS1,2 Table of Contents EXECUTIVE SUMMARY 3 1 INTRODUCTION 7 1.1 Aims and intended audience 7 1.2 Why is the introduction of non-native freshwater fishes a concern? 7 1.3 Definition of terms 8 2 ENTRY ROUTES AND MECHANISMS 11 2.1 The drivers of freshwater fish introduction 11 2.1.1 Fisheries activities 12 2.1.2 Bioengineering and biological actions 13 2.1.3 The role of the ornamentals trade 14 2.1.4 The role of research activities 14 2.1.5 Accidental introductions 15 2.1.6 The role of aquaculture 15 2.2 Colonisation and invasion routes 16 3 ECOLOGICAL IMPACT ASSOCIATED WITH THE INTRODUCTION OF NON-NATIVE FRESHWATER FISHES 18 3.1 What does ecological impact mean in the context of fish introduction? 18 3.1.1 Impact through predation 19 3.1.2 Impact through competition 20 3.1.3 Impact through hybridisation 23 3.1.4 Impact through habitat modification 24 3.1.5 Impact through disease transmission 25 1 Prepared by Rudy Gozlan (University of Bournemouth;
[email protected]), Rob Britton (University of Bournemouth), Gordon H. Copp (Centre for Environment Fisheries and Aquaculture Science and Bournemouth University) and Ian Cowx (University of Hull). Thanks to Karensa Lawrie for the collection and organisation of the scientific literature. 2 Cite as: FSBI (2010). Non native freshwater fish introductions. Briefing Paper 5, Fisheries Society of the British Isles, , Martineau Solicitors, No. 1 Colmore Square Birmingham, B4 6AA, Tel.