Population dynamics of migratory trout, Salmo trutta, in a Lake District stream, 1966–83, and their implications for fisheries management

A short review summarises the chief conclusions of an 18‐year investigation of the population dynamics of migratory trout, Salmo trutta L., in a Lake District stream. The chief factors affecting growth, survival and production have been identified and their effects summarized in a series of mathematical models. The implications of this work are discussed in relation to long‐term investigations, data analysis and modelling, and the scientific management of trout populations. It is shown that mathematical models, based on long‐term investigations, can be used to assess the effects on a fish population of changes due to natural causes (e.g., droughts and spates) or human activities. One of the main objectives of future work should be the development and improvement of models that can be used as tools for the conservation and management of fish stocks.