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Title: Biological characteristics and exploitation of sea trout in the River Tywi during 1989
Author: D.M. Mee
Author: N. Stringer
Author: D. Clarke
Author: P. Wightman
Document Type: Monograph
This paper presents results from the first year (1989) of a two year project intended to assess the biology and legal exploitation of the R. Tywi sea trout stock. The study is an opportunistic exercise, taking advantage of significant sampling effort undertaken to provide both salmon and sea trout for radio tracking. Data were obtained from estuarial commercial seine nets, and from trap nets run by NRA staff. Catch per unit effort data were collected from direct observation of 213 seine net sampling tides (729 hauls) and from 160 trap net tides. A total of 934 sea trout were recorded during sampling operations, morphometric data were obtained from 398 fish and 369 were externally tagged vith floy tags. Based on these data, age structure, condition, length/weight relationships and timing of entry of various sea age classes are described, ranging from 2.0+ maiden fish to 2.2+4SM+, with mean lengths of 320mm to 820mm respectively. Average sea age and size declined as the season progressed, vith peak runs of previous spawners in April, and of maidens (mainly sea age 1+) in May.
Publisher: National Rivers Authority
Publication Date: 1989
Publication Place: Cardiff
Subject Keywords: RiversEstuariesTroutFishery managementFishery dataStock assessment
Geographic Keywords: WalesLoughor to Taf catchmentCeredigionPowys
Taxonomic Keywords: Salmo trutta
Extent: n.p. [30]
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