Comparative Abundance, Survival, and Growth of One Wild and Two Domestic Brown Trout Strains Stocked in Michigan Rivers

Abstract

Abstract.-Stocking is commonly practiced to create, sustain, or enhance fisheries, but comprehensive evaluations of stocking success are rare. I assessed the relative abundance, survival, and growth of three strains of brown trout Salmo trutta that were stocked as sympatric populations into six rivers to evaluate relative stocking performance from 1997 to 2000. Stocked brown trout from wild broodstock were initially smaller but were more abundant and had higher survival and growth rates than fish from two domestic strains. However, on average, the densities and biomass of all stocked brown trout were lower than the densities and biomass of unclipped resident brown trout. Fisheries managers must consider the performance of individual stocked brown trout strains, as well as the performance of stocked brown trout in general, when implementing or reviewing brown trout stocking programs.

Genetic variation at the mtDNA ND-1 locus among North American wild and hatchery brown trout (Salmo trutta)

“…Wills (2005Wills ( , 2006 found that the Gilchrist strain, a relatively new hatchery strain, survives N100× better than the Seeforellen strain and 6× better than Wild Rose (Wills, 2006). Enhanced survival of wild brown trout versus domesticated hatchery strains also was reported in a longitudinal study in Wisconsin (Avery et al, 2001) as well as in several European studies (Hansen, 2002;Hansen et al, 2000).…”

“…The Wild Rose and Seeforellen strains used to stock Michigan waters, have been maintained in hatcheries for nearly two decades, are considered domesticated, and have been used in other hatcheries across the U.S. (Wills, 2006). The Seeforellen strain was originally brought to Michigan in 1989 as eggs from the Caledonia State Fish Hatchery in New York (Dan Sampson, MDNR, personal communication).…”

“…An additional haplotype was found in three Lake Michigan individuals, which may belong to the Seeforellen strain according to Michigan Department of Natural Resources (MDNR) stocking records (Tiano, 2005). Because the three strains differ substantially in survival and growth (Wills, 2006), further study of their mtDNA composition was undertaken here to evaluate their genetic basis.…”

Genetic identification of two putative world record Michigan salmonids resolves stakeholder and manager questions

“…Wills (2006) found Gilchrist Creek strain brown trout survived at a rate more than 100 times that of Seeforellen strain and more than six times greater than Wild Rose. The putative WRLAS functions as an example of how phenotypic plasticity can potentially misinform taxonomic classification based on traditional morphometric data; however, the individual's strain could not be determined conclusively.…”

“…The assignment of the WRBT to the Seeforellen strain was unexpected since relatively few fish from this strain were stocked in the Manistee River and the strain has exhibited reduced survivorship in Michigan waters (Wills, 2006). In the river of capture, Gilchrist…”