The interaction of low flow conditions and spawning brown trout (Salmo trutta) habitat availability

The analysis uses fuzzy logic to show how habitat availability changes for the three species over a 32 year period with detailed investigation of the role of hydrological extremes. Critical flows were determined below which habitat availability suffers. Results indicated that wet years provide increased habitat availability for spawning brown trout as an individual species, but when the results are combined with their biotic dependants it becomes clear that more habitat for these is available during drier years. The study highlights the importance of the natural flow regime to the dependent freshwater ecosystem components and understanding different species requirements.