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Self‐sustaining Rainbow Trout (Salmo gairdneri) Population in McConaughy Reservoir, Nebraska
Author(s) -
Van Velson Rodney C.
Publication year - 1974
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1974)103<59:srtsgp>2.0.co;2
Subject(s) - rainbow trout , tributary , salmo , fishery , spring (device) , population , streams , hatchery , environmental science , trout , geography , biology , fish <actinopterygii> , mechanical engineering , computer network , demography , cartography , sociology , computer science , engineering
A self‐sustaining rainbow trout population has developed in the North Platte River drainage. This population inhabits McConaughy Reservoir and reproduces successfully in tributary streams of the North Platte River located approximately 113 to 145 km above the reservoir. Fall and spring spawning populations migrate from the reservoir. Scale analysis indicated 92% of the juveniles had spent 1 yr and 8% had spent 2 yr in the stream before the spring migration to the reservoir as 175–250 mm smolts. In the 1965–1969 spawning populations 13 life history categories were present. The spawning runs were composed of 76% maiden spawners, 22% second‐year spawners and 2% third‐year spawners. The sex ratio of the spawning runs ranged between 2.0–2.2 females per male. The rainbow trout population is subjected to a variety of conditions in tributary streams of the North Platte during summer including flooding, irrigation return water and high water temperatures. However, spawning rainbow trout utilize these groundwater streams from November through April. In addition the coldwater habitat in the reservoir is restricted throughout the summer, especially during August. The established rainbow trout population survived better in this environment than hatchery rainbow trout.