Growth and Production of Sympatric Brook and Rainbow Trout in an Appalachian Stream
作者:
WilburE. Whitworth,
RichardJ. Strange,
期刊:
Transactions of the American Fisheries Society
(Taylor Available online 1983)
卷期:
Volume 112,
issue 4
页码: 469-475
ISSN:0002-8487
年代: 1983
DOI:10.1577/1548-8659(1983)112<469:GAPOSB>2.0.CO;2
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
A small, second-order stream in the southern Appalachians was sampled every 2 months from September 1978 to October 1979. The 1.5-km study segment was divided into 50, 30-m sections grouped into three areas: A downstream area with only rainbow trout Salmo gairdneri; a middle, mixed-trout area; an upstream area with predominantly brook trout Salvelinus fontinalis. Although a few fish of both species exhibited substantial movements, the majority of fish moved less than 30 m either upstream or downstream. Growth rates of both species were approximately equal until the spring of their second year, when rainbow trout outgrew brook trout and thereafter maintained a size-at-age advantage. Rainbow trout, particularly the 1978 cohort, dominated trout production in the stream. Even in the brook trout area, where the density of 1978 cohort brook trout was twice that of 1978 cohort rainbow trout, rainbow trout outproduced brook trout by 1.20 g/m2to 1.14 g/m2. Declining mean biomass of older fish of both species indicates high winter mortality. This, accompanied by slow growth of older fish, resulted in very few fish of either species entering the legal fishery.
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