A Method to Measure Emergence Success of Westslope Cutthroat Trout Fry from Varying Substrate Compositions in a Natural Stream Channel

Abstract

This study developed a field method to examine emergence success of fry of westslope cutthroat trout Oncorhynchus clarki lewisi in relation to varying levels of fine substrate materials in a natural stream environment. We attempted to simulate natural incubation conditions in a stream by constructing cells with particle sizes and egg pockets characteristic of natural westslope cutthroat trout redds. We found a significant inverse relationship (r2 = 0.72, P < 0.005, N = 17) between fry emergence success, as measured by fry emergence traps, and the percentage of substrate materials less than 6.35 mm in diameter. Mean fry emergence success was 76, 55, 39, 34, 26, and 4%, respectively, in cells containing 0, 10, 20, 30, 40, and 50% substrate materials less than 6.35 mm. There were no significant differences in length or weight of fry emerging from the six gravel mixtures. Using the methods and results presented in this study, as well as previous laboratory results, resource managers could develop substrate quality guidelines for westslope cutthroat trout reproduction in streams affected by land management practices.

Dissolved oxygen concentration and emergence of sea trout fry from natural redds in tributaries of the River Rhine

“…In some field studies using artificial egg pockets, survival to emergence was correlated inversely with the amount of fines (Maret et al, 1993;Weaver & Fraley, 1993). While studying natural redds, Sowden & Power (1985) found no correlation between these factors soon after hatching in a groundwater discharge environment.…”

The Effects of Road Crossings on Prairie Stream Habitat and Function

“…Fish abundance and community composition may also be affected by road crossings, likely because fish cannot pass through crossings a s easily a s natural stream riffles (Warren andPardew 1998, Bouska andPaukert 2010). Alterations to substrate composition can affect the spawning success of stream fishes and other aquatic organisms, since many have specific requirements for spawning substrate (Weaver andFraley 1993, Pflieger 1997). Sedimentation can also decrease the density of benthic macroinvertebrates through habitat reduction or reduced foraging efficiency (Lenat et al 1981, Newcombe andMacDonald 1991).…”

Dissolved oxygen concentration and emergence of sea trout fry from natural redds in tributaries of the River Rhine

“…There are several laboratory studies relating sediment particle distribution to survival of salmonid eggs or fry (Chapman, 1988). In some field studies using artificial egg pockets, survival to emergence was correlated inversely with the amount of fines (Maret et al, 1993;Weaver & Fraley, 1993). While studying natural redds, Sowden & Power (1985) found no correlation between these factors soon after hatching in a groundwater discharge environment.…”