The emergence period of sea trout fry in a Lake District stream correlateswith the North Atlantic Oscillation

The date of fry emergence over 30 years in a sea trout nursery stream, pred icted by an individual-based model, correlated significantly (r=0.660, P<0. 001) with an index of the North Atlantic Oscillation. Water temperature is the main driving variable in the model and stream temperature also correlat ed significantly (r=0.662, P<0.001) with the index, providing a probable ca usal link. Therefore, the inter-annual variations in emergence may not be u nique to this one stream, but may be typical of other trout streams with si milar climatic conditions. (C) 2000 The Fisheries Society of the British Is les.