Illegal, unreported and unregulated (IUU) fishing is a widely used designation for a broad range of fishing practices with a common theme: whether illegal or not, they cause damage to marine fish stocks and the human communities that depend on them. Yet, when subjected to thorough analysis, this pragmatic governance tool is revealed in a light that calls for caution against uncritical application. Unwrapping its uneasy relationship with international law, this study is ultimately a qualified defence of the IUU fishing paradigm, but also a practical proposal for its reform. This original book makes a genuine contribution to the international fisheries law and policy literature.