The Quantitative Importance of an Intermittent Stream in the Spawning of Rainbow Trout
- 1 November 1976
- journal article
- research article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 105 (6) , 675-681
- https://doi.org/10.1577/1548-8659(1976)105<675:tqioai>2.0.co;2
Abstract
From 1972 to 1975, an estimated 39–47% of the adult rainbow trout (Salmo gairdneri) in Sagehen Creek spawned in an intermittent stream—Kiln Meadow Tributary—while several permanently flowing tributaries attracted only 10–15% of the run. The balance of the fish presumably spawn in the upper reaches of the main stream. Kiln Meadow Tributary drains a south‐facing slope, and peak runoff from snow melt occurs early. This may be one factor that attracts spawning fish. The absence of competition from brook trout, which cannot spawn in Kiln Meadow Tributary in the fall, may enhance the value of this watercourse for rearing young rainbow trout. The number of spawning rainbows in Kiln Meadow Tributary declined from 707 in 1972 to 254 in 1975. Two large year classes were present in 1972 and 1973 following winter floods in preceding winters. Males matured a year earlier than females. Males outnumbered females in every year: the sex ratio in mature fish varied from 2.4:1 to 4.9:1. Repeat spawners to Kiln Meadow Tributary ranged from 25% to 28% of the run.This publication has 0 references indexed in Scilit: