Sea-Trout from the Tidal Waters of the River Moy

Abstract

Sea trout from the tidal waters of the River Moy are described on the basis of life data and scales from 1,269 specimens collected during 1974 and 1975. The mean smolt age was 2.30 years. Lengths ranged from 16.4 cm for one-year-old A type smolts to 23.9 cm for four-year-old B type fish. Two-year-old smolts increased in length by 67% in their first summer at sea. Sixteen age categories were identified and 82 % of the first spawners were finnock. The proportion of 2. + fish increased throughout the season. Correlation between mean age at first maturation and coefficient of total mortality in British and Irish sea trout stocks was demonstrated. Moy trout are short-lived in the sea and this factor is identified as the most important of those influencing the population which is a typically westem seaboard Atlantic-feeding stock.