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Sea Trout of the North Esk
Author(s) -
Pratten D. J.,
Shearer W. M.
Publication year - 1983
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.1983.tb00056.x
Subject(s) - fishery , trout , biology , rainbow trout , population , fish <actinopterygii> , zoology , demography , sociology
The sea trout population of the River North Esk was sampled by means of a stationary trap situated on Kinnaber Mill Lade which drains its water from the main river. Commencing in 1971 the number of trout taken in the trap was noted daily, and from 1976 all stages of trout caught in the trap were tagged. The peak of the sea trout smolt migration was usually in May or June, and over the period of study exhibited a tendency to occur later each season. Two‐year‐old smolts comprised the largest age class in the smolt samples with 3‐year‐old fish being the other substantial age class. Samples of smolts taken for sex determination were found to be predominantly female. In 1979 and 1980 the sea trout smolt production of the North Esk was estimated from a mark‐recapture experiment to be 51,969 and 78,208 respectively. A proportion of finnock (post‐smolts) returned to fresh water in the year of their smolt migration and were taken moving upstream into the trap from July onwards, with a peak of movement occurring in the autumn. The main run of adult sea trout into the trap was found to take place at any time between July and October. The adult sea trout sampled were predominantly maiden spawners of ages 2.1+ and 3.1+ years. Both finnock and adult sea trout samples exhibited a similar freshwater age composition to that of the smolts.