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W.A. Hubert

Publications and source records attributed to W.A. Hubert.

44 records · Page 3Linked to original sources
USGS1999

Standards for assessment of age and growth data for channel catfish

Standards for the assessment of age and growth data for channel catfish ( Ictalurus punctatus ) were developed using published data. A representative set of 102 studies of individual populations from across the geographic range of channel catfish was selected. Percentile values (5, 10, 25, 50, 75, 90, and 95th) were computed from the distribution of estimated mean total lengths for fish three to ten years old. This approach for development of standards to assess data from age and growth studies of fish is proposed for consideration in development of standards for other species in addition to channel catfish.

Journal of Freshwater Ecology↗
USGS1998

Relative abundance and lengths of Kendall Warm Springs dace captured from different habitats in a specially designed trap

A trap was designed to capture endangered Kendall Warm Springs dace Rhinichthys osculus thermalis (a subspecies of speckled dace Rhinichthys osculus ) without being destructive to the habitat of the fish in Kendall Warm Springs Creek, Wyoming. Four experiments were conducted to determine differences in catch per unit effort (CPUE) and length frequencies of fish among differing habitat types. The CPUE was highest in channel habitats with current, and one experiment indicated that it was particularly high at vertical interfaces with vegetation. Longer fish were captured in channel habitats away from vegetation than in vegetated areas. The CPUE was significantly greater during the day than at night during one experiment, but no significant differences were observed among the other three experiments. The traps were easy and inexpensive to construct, could be used in a variety of stream habitats, and may have applications in other small streams for sampling small, benthic fishes.

Wyoming↗
USGS1998

Relationships between Boron concentrations and trout in the firehole river, Wyoming: Historical information and preliminary results of a field study

The Firehole River (FHR) in Yellowstone National Park (YNP) is a world- renowned recreational fishery that predominantly includes rainbow trout (RBT, Oncorhynchus mykiss) and brown trout (BNT, Salmo trutta). The trout populations apparently are closed to immigration and have been self- sustaining since 1955. Inputs from hot springs and geysers increase the temperature and mineral content of the water, including elevating the boron (B) concentrations to a maximum of ~1 mg B/L. Both RBT and BNT reside in warm-water reaches, except when the water is extremely warm (???~25??C) during midsummer. They spawn in late fall and early winter, with documented spawning of BNT in the cold-water reach upstream from the Upper Geyser Basin and of RBT in the Lower Geyser Basin reach, where water temperatures presumably are the warmest; however, successful recruitment of RBT in waters containing ~1 mg B/L has not been demonstrated conclusively. Thus, we began investigating the relationships among temperature, B concentrations, other water-quality parameters, and the distribution and reproduction of trout in the FHR in spring 1997. However, atypical high water flows and concomitant lower than historical temperatures and B concentrations during summer 1997 preclude conclusions about avoidance of high B concentrations.

Conference Paper↗
USGS1997

Geomorphic influences on the distribution of Yellowstone cutthroat trout in the Absaroka Mountains, Wyoming

Influences of large‐scale abiotic, geomorphic characteristics on distributions of Yellowstone cutthroat trout Oncorhynchus clarki bouvieri are poorly understood. We sampled 151 sites on 56 perennial streams in the Greybull–Wood river drainage in northwestern Wyoming to determine the effects of geomorphic variables on Yellowstone cutthroat trout distributions. Channel slope, elevation, stream size, and barriers to upstream movement significantly influenced the presence and absence of Yellowstone cutthroat trout. Wild populations of Yellowstone cutthroat trout were not found upstream of barriers to fish migration, at sites with channel slopes of 10% or greater, or at elevations above 3,182 m. Based on channel slope alone, logistic regression models correctly classified presence or absence of Yellowstone cutthroat trout in 83% of study sites. The addition of elevation and stream size in the models increased classification to 87%. Logistic models tested on an independent data set had agreement rates as high as 91 % between actual and predicted fish presence. Large‐scale geomorphic variables influence Yellowstone cutthroat trout distributions, and logistic functions can predict these distributions with a high degree of accuracy.

Wyoming↗
USGS1996

Sources of variation in counts of meristic features of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri)

We determined variability in counts of meristic features (pyloric caceae, vertebrae, pelvic fin rays, gill-rakers, basibranchial teeth, scales above the lateral line, and scales in the lateral series) of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) by 3 independent readers, by the same reader on 3 different occasions, and among fish from 12 sampling sites within a 650-km2 watershed. Genetic purity of the cutthroat trout was determined by electrophoretic analysis. Significant differences in meristic counts were observed among 3 readers and among sampling sites, but not among 3 occasions by a single reader. Scale counts were within the reported range for Yellowstone cutthroat trout, but counts of other structures (pyloric caceae, gillrakers, vertebrae) were as similar to rainbow trout as to Yellowstone cutthroat trout. Meristic counts identified the fish as cutthroat trout; however, variation among readers and sampling sites as well as within the species, limits their use when identifying genetically pure cutthroat trout or assessing possible integration with rainbow trout.

Great Basin Naturalist↗