Restocking Eel - an Appraisal of the Effects on Fish, Stock and Fishery

Restocking of young eel (Anguilla anguilla (L.)) - translocated within countries or imported from abroad - has been applied to enhance the stock and fishery since the mid 1800s. The ongoing decline of the stock to critical levels has drastically changed the context, recently. The European recovery plan (known as the EU Eel Regulation) emphasized the importance and use of restocking as a stock enhancement measure.

Past research focused on technical issues (transport, packaging and holding), on effectiveness of restocking (survival, growth), and on production maximisation (density, frequency, recipient habitats). Following the adoption of the Eel Regulation, the contribution of restocked eels to the spawning stock has been questioned, and research now focuses on the condition of silver eels and their ability to migrate successfully to the spawning place.

Our review of restocking and related research covers aspects of biological effectiveness and stock dynamics, both from a regional and a population-wide standpoint. Does restocking contribute to the local stock, to the spawning population, and what net benefit is obtained by relocation?

Our aim with this review is to provide a thorough basis for the heavily politicised discussions on restocking issues.