An Evaluation of the Effects of Conservation and Fishery Enhancement Hatcheries on Wild Populations of Salmon 1 Kerry A. Naish,* ,2 Joseph E. Taylor, III † PhillipS. Levin, ‡ Thomas P. Quinn,* James R. Winton, § Daniel Huppert, } and Ray Hilborn* Contents 1. Introduction 63 1.1.Scope of the review 65 1.2.Motivations and objectives of hatcheries 68 1.3.Content overview 70 2. Historical Overview of Hatchery Activities 71 3. Political Dynamics of Hatchery Programmes 78 4. Geographical Extent of Activities 84 4.1.Enhancement of indigenous salmonids: Conservation, production and mitigation hatcheries 84 4.2. Enhancement of non-indigenous salmon and trout: Introductions 99 5. Potential Consequences of Enhancement Activities 100 5.1.Genetic risks associated with salmon hatchery programmes 100 5.2.Behavioural and ecological interactions between wild and hatchery-produced salmon 127 5.3.The effects of harvest on wild salmon populations 133 5.4.Disease effects of salmonid enhancement 141 Advances in Marine Biology, Volume 53 # 2008 Elsevier Ltd. ISSN 0065-2881, DOI: 10.1016/S0065-2881(07)53002-6 All rights reserved. * School of Aquatic and Fishery Sciences, University of Washington, Washington 98195, USA { Departments of History and Geography, Simon Fraser University, British Columbia, Canada, USA { Northwest Fisheries Science Centre, NOAA Fisheries, Seattle, Washington 98122, USA } Western Fisheries Research Center, US Geological Survey, Seattle, Washington 98115, USA } School of Marine Affairs, University of Washington, Seattle, Washington 98195, USA 1 Lead authors of specific sections: K.A.N., genetics; J.E.T., historical and political perspectives; P.S. status; T.P.Q., competition; R.H., harvest; J.R.W., disease; D.H., economic analyses, USA 2 Corresponding author: Email Knaish@u.washington.edu 61