Response of Young-of-the-Year Cutthroat Trout to Manipulation of Habitat Structure in a Small Stream

In a 112-ha bog lake on the Queen Charlotte Islands, British Columbia, small fish comprised the major element in the diet of cutthroat trout (Oncorhynchus clarki). Despite the presence of juvenile salmon and char in the lake, threespine stickleback (Gasterosteus aculeatus) was the most common fish in the diet (99.5%). Foraging activity appeared to be more frequent in littoral than in limnetic regions. Mark–recapture methods indicate an average population of 220 trout and 75 000 adult stickleback. Trout consumed an estimated 308 770 stickleback yearly (145 kg) of which 65% were taken during summer. Seventy-three percent of all fish consumed were young of the year and 2% were adults, the latter representing 4% of the adult population in the lake. There was a 75% reduction in total mortality between successive year classes of stickleback (0,1,2,3 +). This consumption curve, which resembles a typical survivorship curve of fish, is a function of the size-structure of the populations and includes interactions between size availability of stickleback, prey-size preferences of the trout, and length frequency distributions of trout. Total weight of stickleback consumed by trout comprised about 40% of that previously calculated for 16 species of avian piscivores in the lake.

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Fitness consequences of habitat use for juvenile cutthroat trout: energetic costs and benefits in pools and riffles

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f01-019 ◽

2001 ◽

Vol 58 (3) ◽

pp. 585-593 ◽

Cited By ~ 82

Author(s):

Jordan S Rosenfeld ◽

Shelly Boss

Keyword(s):

Growth Rates ◽

Habitat Preference ◽

Cost Benefit Analysis ◽

Cutthroat Trout ◽

Cost Benefit ◽

Invertebrate Drift ◽

Oncorhynchus Clarki ◽

Fitness Consequences ◽

Young Of The Year ◽

Bioenergetic Cost

To assess freshwater habitat requirements of juvenile anadromous cutthroat trout, Oncorhynchus clarki, we measured habitat preference and growth rates of young-of-the-year (YOY) and 1- to 2-year-old fish confined to either pools or riffles in Husdon Creek, British Columbia, during 1999. YOY preferred pools to riffles in habitat-preference experiments, despite normally occurring at lower densities in pools. YOY grew in both pools and riffles when experimentally confined to either habitat, but growth rates were higher in pools. Larger juvenile cutthroat trout, on average, grew in pools, but consistently lost weight in riffles, indicating that pools are a habitat preference for YOY but a requirement for larger fish. A bioenergetic costbenefit analysis (based on swimming costs and energy intake from invertebrate drift) indicates that energetics alone are sufficient to account for avoidance of riffles by larger cutthroat trout, without having to invoke greater predation risk in shallow habitats. Energetics modeling demonstrates that the smaller size and energetic needs of YOY allow exploitation of habitats (e.g., pocket pools in riffles) that are unavailable to larger fish.

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Absence of Autumnal Changes in Habitat Use and Location of Adult Colorado River Cutthroat Trout in a Small Stream

Transactions of the American Fisheries Society ◽

10.1577/1548-8659(1998)127<0147:aoacih>2.0.co;2 ◽

1998 ◽

Vol 127 (1) ◽

pp. 147-151 ◽

Cited By ~ 19

Author(s):

Michael K. Young

Keyword(s):

Habitat Use ◽

Colorado River ◽

Cutthroat Trout ◽

Small Stream ◽

Colorado River Cutthroat Trout

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Landscape Influences on Stream Habitats and Biological Assemblages

Landscape Influences on Stream Habitats and Biological Assemblages ◽

10.47886/9781888569766.ch22 ◽

2006 ◽

Keyword(s):

Spatial Scales ◽

Cutthroat Trout ◽

Suitable Habitat ◽

Physical Habitat ◽

Oncorhynchus Clarkii ◽

Small Stream ◽

Landscape Characteristics ◽

Small Streams ◽

Habitat Template ◽

Integrated Program

<em>Abstract.</em>—Small stream systems are complex networks that form a physicochemical template governing the persistence of aquatic species such as coastal cutthroat trout <em>Oncorhynchus clarkii clarkii</em>. To gain new insight into these interactions, we initiated an integrated program of landscape- scale sampling that is focused on fine- and broad-scale relationships among upslope landscape characteristics, physical stream habitat, and the spatial patterns of cutthroat trout abundance. Our sample of 40 catchments (500–1,000 ha) represented approximately 15% of the 269 barrier-isolated catchments in western Oregon that support populations of cutthroat trout. Because data were collected in a spatially contiguous manner throughout each catchment, it was possible to collect biological and geographic information necessary to assess the spatial structure of cutthroat trout abundance. Results underscore the influence of the physical habitat template at a variety of spatial scales. For example, cutthroat trout move throughout the accessible portions of small streams. Some cutthroat trout congregate in areas of suitable habitat and form local populations that may exhibit unique genetic attributes. At times, some cutthroat trout move into larger downstream portions of the network where they may contribute to the genetic character of anadromous or local potamodromous assemblages. Results underscore the advantages of viewing habitats that are critical to the fitness and persistence of cutthroat trout populations as matrices of physical sites that are linked by movement. It is apparent that human activities that impede movement among suitable habitat patches can have unanticipated consequences for metapopulations of cutthroat trout and may ultimately affect their persistence.

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Habitat factors affecting the abundance and distribution of juvenile cutthroat trout (Oncorhynchus clarki) and coho salmon (Oncorhynchus kisutch)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-010 ◽

2000 ◽

Vol 57 (4) ◽

pp. 766-774 ◽

Cited By ~ 97

Author(s):

Jordan Rosenfeld ◽

Marc Porter ◽

Eric Parkinson

Keyword(s):

Coho Salmon ◽

Woody Debris ◽

Oncorhynchus Kisutch ◽

Cutthroat Trout ◽

Habitat Associations ◽

Channel Width ◽

Oncorhynchus Clarki ◽

Small Stream ◽

Factors Affecting ◽

Small Streams

The distribution, abundance, and habitat associations of juvenile anadromous coastal cutthroat trout (Oncorhynchus clarki) and coho salmon (Oncorhynchus kisutch) were evaluated using survey data from 119 sites in coastal British Columbia. Both cutthroat and coho occurred at their highest densities in very small streams (<5 m channel width), and bankfull channel width was the single best predictor of cutthroat presence (p = 0.0001) and density (R2 = 0.55). Within a channel, densities of coho and larger (yearling and older) cutthroat parr were highest in pools, while densities of young-of-the-year cutthroat were significantly lower in pools and highest in shallower habitats. Abundance of larger cutthroat parr and pool habitat were positively correlated with large woody debris (LWD) within a subset of intermediate-gradient gravel-cobble streams, where pools appear to be limiting to larger cutthroat parr abundance. More than 50% of pools were formed by scour associated with LWD in streams ranging from 1.2 to 11 m channel width, and pools formed by LWD scour were on average 10% deeper than pools formed by other mechanisms. Disproportionate use of small streams by cutthroat indicates that protection of small stream habitat is important for long-term conservation of sea-run populations.

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A Prehistoric Ford near Rough Castle, Falkirk

Scottish Archaeological Journal ◽

10.3366/saj.2001.23.2.91 ◽

2001 ◽

Vol 23 (2) ◽

pp. 91-103

Author(s):

JAMIE HAMILTON ◽

CIARA CLARKE ◽

ANDREW DUNWELL ◽

RICHARD TIPPING

Keyword(s):

Coal Mining ◽

Pollen Analysis ◽

Site Formation ◽

Site Formation Processes ◽

Formation Processes ◽

Radiocarbon Dates ◽

Small Stream ◽

Mining Project ◽

First Millennium

This report presents the results of the excavation of a stone ford laid across the base of a small stream valley near Rough Castle, Falkirk. It was discovered during an opencast coal mining project. Radiocarbon dates and pollen analysis of deposits overlying the ford combine to indicate a date for its construction no later than the early first millennium cal BC. Interpreting this evidence was not straightforward and the report raises significant issues about site formation processes and the interpretation of radiocarbon and pollen evidence. The importance of these issues extends beyond the rarely investigated features such as fords and deserve a larger place in the archaeological literature.

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EFFECT OF VARIOUS HORMONES ON THE KIDNEY RESPIRATION RATES IN THE CUTTHROAT TROUT (SALMO CLARKI CLARKI)

Acta Endocrinologica ◽

10.1530/acta.0.xxxiii0428 ◽

1960 ◽

Vol XXXIII (III) ◽

pp. 428-436 ◽

Cited By ~ 4

Author(s):

W. N. Holmes

Keyword(s):

Single Dose ◽

Respiration Rate ◽

Cutthroat Trout ◽

Adaptive Mechanism ◽

Respiration Rates ◽

Salmo Clarki

ABSTRACT Relatively large doses of vasopressin administered intraperitoneally to the trout significantly enhanced the kidney respiration rate. In contrast to vasopressin a single dose of oxytocin depressed the kidney Qo2 value. This depression continued throughout the observed 24 hour period after injection. Cortisol enhanced the kidney Qo2 values significantly and to a greater extent than vasopressin. These results are discussed in relation to possible adaptive mechanism in euryhaline species of teleosts.

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