scholarly journals Characterization of spawning habitat, incubation environment and early growth and development in bull trout (Salvelinus confluentus ) from pristine streams of northern British Columbia.

2007 ◽  
Author(s):  
Cory John Williamson
Keyword(s):  
British Columbia ◽  
Growth And Development ◽  
Early Growth ◽  
Bull Trout ◽  
Spawning Habitat ◽  
Salvelinus Confluentus

scholarly journals Seasonal timing of reproductive migrations in adfluvial bull trout: an assessment of sex, spawning experience, population density, and environmental factors

2018 ◽  
Vol 75 (12) ◽  
pp. 2172-2183 ◽  
Author(s):  
R. Niloshini Sinnatamby ◽  
Madalena C. Pinto ◽  
Fiona D. Johnston ◽  
Andrew J. Paul ◽  
Craig J. Mushens ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Upstream Migration ◽  
Swimming Ability ◽  
Bull Trout ◽  
Spawning Habitat ◽  
Salvelinus Confluentus ◽  
Intrinsic Factors ◽  
Migration Timing ◽  
First Time ◽  
Experienced Female

Using individual tags combined with a fish fence operated at the mouth of Smith-Dorrien Creek, the primary spawning habitat for Lower Kananaskis Lake bull trout (Salvelinus confluentus), we approximated a complete census of the spawning population from 1996 to 2000 to assess whether timing of upstream and downstream spawning migrations varied with extrinsic and intrinsic factors. The timing of both upstream and downstream migrations varied with sex, previous spawning experience, density, and temperature. Inferred spawning duration based on the predicted upstream and downstream migration dates indicated that experienced female spawners spent the least amount of time upstream and first-time spawners spent the most time upstream. No consistent differences in upstream migration timing were observed between non-repetitive and repetitive spawners. We suggest that variations in spawning migration timing observed in Lower Kananaskis Lake may be linked to environmental factors that influence upstream swimming ability and acquisition and expenditure of energy with respect to reproduction.

Microsatellite DNA analysis of coastal populations of bull trout (Salvelinus confluentus) in British Columbia: zoogeographic implications and its application to recreational fishery management

2006 ◽  
Vol 63 (5) ◽  
pp. 1157-1171 ◽  
Author(s):  
Eric B Taylor ◽  
A B Costello
Keyword(s):  
British Columbia ◽  
Microsatellite Dna ◽  
Fishery Management ◽  
Dna Analysis ◽  
Population Subdivision ◽  
Fraser River ◽  
Bull Trout ◽  
Salvelinus Confluentus ◽  
Recreational Fishery ◽  
Skeena River

Microsatellite DNA variation was assayed among 383 bull trout (Salvelinus confluentus) from 20 Pacific coastal localities from the Skeena River (central British Columbia) to the Olympic Peninsula (western Washington State). An average of 1.7 alleles was resolved per population and heterozygosity averaged 0.35. Twenty-six fish were identified as bull trout × Dolly Varden (Salvelinus malma) hybrids. Population subdivision was substantial (θ = 0.33), but subdivision was higher (θ = 0.46) when interior populations (N = 37) were included, indicating a major genetic distinction between "coastal" and "interior" bull trout. Bull trout populations north of the Squamish River were genetically more similar to interior bull trout than to other more southern coastal populations, suggesting that they had been founded by headwater transfers from interior populations. Individual assignment of bull trout averaged 53.4% correct assignment among populations (range: 12%–95%). Mixture analysis indicated that most fish from the lower Fraser River recreational fishery originated from major nearby tributaries (e.g., Pitt, upper Lillooet, and Chilliwack rivers). Our results substantiate the existence of two major evolutionary lineages of bull trout and highlight the importance of tributary habitats for the persistence of local populations, as well as for those that forage in downstream areas on the lower Fraser River.

Geomorphology, hyporheic exchange, and selection of spawning habitat by bull trout (Salvelinus confluentus)

2000 ◽  
Vol 57 (7) ◽  
pp. 1470-1481 ◽  
Author(s):  
Colden V Baxter ◽  
F Richard Hauer
Keyword(s):  
Spatial Scale ◽  
Stream Water ◽  
Spatial Scales ◽  
Hyporheic Exchange ◽  
Bull Trout ◽  
Spawning Habitat ◽  
Alluvial Valley ◽  
Salvelinus Confluentus ◽  
Multiple Spatial Scales ◽  
Swan River

The distribution and abundance of bull trout (Salvelinus confluentus) spawning were affected by geomorphology and hyporheic groundwater - stream water exchange across multiple spatial scales in streams of the Swan River basin, northwestern Montana. Among spawning tributary streams, the abundance of bull trout redds increased with increased area of alluvial valley segments that were longitudinally confined by geomorphic knickpoints. Among all valley segment types, bull trout redds were primarily found in these bounded alluvial valley segments, which possessed complex patterns of hyporheic exchange and extensive upwelling zones. Bull trout used stream reaches for spawning that were strongly influenced by upwelling. However, within these selected reaches, bull trout redds were primarily located in transitional bedforms that possessed strong localized downwelling and high intragravel flow rates. The changing relationship of spawning habitat selection, in which bull trout selected upwelling zones at one spatial scale and downwelling zones at another spatial scale, emphasizes the importance of considering multiple spatial scales within a hierarchical geomorphic context when considering the ecology of this species or plans for bull trout conservation and restoration.

Multiscale hydrogeomorphic influences on bull trout (Salvelinus confluentus) spawning habitat

2015 ◽  
Vol 72 (4) ◽  
pp. 514-526 ◽  
Author(s):  
Jared R. Bean ◽  
Andrew C. Wilcox ◽  
William W. Woessner ◽  
Clint C. Muhlfeld
Keyword(s):  
Stream Water ◽  
Spatial Scales ◽  
Hydraulic Modeling ◽  
Considerable Proportion ◽  
Shear Stresses ◽  
Bull Trout ◽  
Spawning Habitat ◽  
Alluvial Valley ◽  
Salvelinus Confluentus ◽  
Spawning Period

We investigated multiscale hydrogeomorphic influences on the distribution and abundance of bull trout (Salvelinus confluentus) spawning in snowmelt-dominated streams of the upper Flathead River basin, northwestern Montana. Within our study reaches, bull trout tended to spawn in the finest available gravel substrates. Analysis of the mobility of these substrates, based on one-dimensional hydraulic modeling and calculation of dimensionless shear stresses, indicated that bed materials in spawning reaches would be mobilized at moderate (i.e., 2-year recurrence interval) high-flow conditions, although the asynchronous timing of the fall–winter egg incubation period and typical late spring – early summer snowmelt high flows in our study area may limit susceptibility to redd scour under current hydrologic regimes. Redd occurrence also tended to be associated with concave-up bedforms (pool tailouts) with downwelling intragravel flows. Streambed temperatures tracked stream water diurnal temperature cycles to a depth of at least 25 cm, averaging 6.1–8.1 °C in different study reaches during the spawning period. Ground water provided thermal moderation of stream water for several high-density spawning reaches. Bull trout redds were more frequent in unconfined alluvial valley reaches (8.5 versus 5.0 redds·km−1 in confined valley reaches), which were strongly influenced by hyporheic and groundwater – stream water exchange. A considerable proportion of redds were patchily distributed in confined valley reaches, however, emphasizing the influence of local physical conditions in supporting bull trout spawning habitat. Moreover, narrowing or “bounding” of these alluvial valley segments did not appear to be important. Our results suggest that geomorphic, thermal, and hydrological factors influence bull trout spawning occurrence at multiple spatial scales.

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