Bias and significance of relative reproductive success estimates based on steelhead trout (Oncorhynchus mykiss) data: a Bayesian meta-analysis

Abstract

The evaluation of the reproductive success (RS) of hatchery fish in the wild is one of the most important issues in hatchery supplementation, aquaculture, and conservation. Estimates of the relative reproductive success (RRS) have been used to evaluate RS. Because RRS may vary greatly depending on cross, years of release, and environmental conditions, we introduced a log-normal distribution to quantify the variation. The classical estimator of RRS based on multiple measurements is contrasted with the mean of this distribution. We derived the mean, variance, and relative bias and applied our Bayesian hierarchical model to 42 empirical RRS estimates of steelhead trout ( Oncorhynchus mykiss ) in the Hood River, Oregon, USA. The RRS estimate generally had an upward bias. Although the average level of RRS implied the reproductive decline of hatchery fish and wild-born hatchery descendants, we could not reject the null hypothesis that hatchery fish and their descendants have the same chance of having smaller RS than wild fish as they do of having larger RS than wild fish.

Genetic effects of marine stock enhancement: a case study based on the highly piscivorous Japanese Spanish mackerel

“…A second concern is the potential for a reduction in fitness of the stocked population. A number of empirical studies have documented a decrease in reproductive success (RS) in hatchery salmon and trout in the wild (for a review see Araki and Schmid 2010), although there is significant variation in the RS (Anderson et al 2013) and relative RS (Kitada et al 2011). If hatchery fish with lower RS mate with wild fish, the total number of progeny born in the stocked population could be reduced after several generations.…”

Economic, ecological and genetic impacts of marine stock enhancement and sea ranching: A systematic review

“…I estimated the posterior probability distribution of RRS using the steelhead data (F1 fish) from the Hood River (Araki, Ardren, Olsen, Cooper, & Blouin, ; Araki, Cooper, et al., ), which were analysed in a previous study (Kitada, Kishino, & Hamasaki, ), and Chinook salmon from the Johnson Creek, Idaho, USA, using the data given in table 3 of the original study of Hess et al. ().…”

“…The lifetime RRS estimates for naturally spawning F1 Chinook salmon were close to 1.0, ranging from 0.72 to 1.31 with a mean (SD) of 0.98 (0.17) (Hess et al, 2012). I estimated the posterior probability distribution of RRS using the steelhead data (F1 fish) from the Hood River (Araki, Ardren, Olsen, Cooper, & Blouin, 2007;, which were analysed in a previous study (Kitada, Kishino, & Hamasaki, 2011), and Chinook salmon from the Johnson Creek, Idaho, USA, using the data given in table 3 of the original study of Hess et al (2012). In the latter analysis of Chinook salmon, three estimates for males (H × -vs. W × -) were excluded because of the small sample sizes with one missing estimate out of three.…”

Strategies for the conservation and management of isolated salmonid populations: lessons from Japanese streams

“…, 2011). Domestication even in the juvenile stage has implications for subsequent adult reproductive performance (Fleming, Lamberg & Jonsson, 1997), with only a few generations of domestication resulting in negative effects on natural reproduction (Araki, Cooper & Blouin, 2007; but see Kitada, Kishino & Hamasaki, 2011).…”

“…The frequency of local adaptation is estimated to be between 55 and 70% in salmonids, with local populations having c. 1.2 times the average fitness of non-native populations (Fraser et al, 2011). Domestication even in the juvenile stage has implications for subsequent adult reproductive performance (Fleming, Lamberg & Jonsson, 1997), with only a few generations of domestication resulting in negative effects on natural reproduction (Araki, Cooper & Blouin, 2007; but see Kitada, Kishino & Hamasaki, 2011).…”