Effects of Logging on Size and Age Composition of Juvenile Coho Salmon (Oncorhynchus kisutch) and Density of Presmolts in Southeast Alaska Streams

1989 ◽  
Vol 46 (8) ◽  
pp. 1383-1391 ◽  
Author(s):  
John F. Thedinga ◽  
Michael L. Murphy ◽  
Jonathan Heifetz ◽  
K V. Koski ◽  
Scott W. Johnson
Keyword(s):  
Coho Salmon ◽  
Condition Factor ◽  
Oncorhynchus Kisutch ◽  
Buffer Strips ◽  
Short Term ◽  
Old Growth ◽  
Age Composition ◽  
Southeast Alaska ◽  
Clear Cut ◽  
Northern Regions

Short-term effects of logging on age composition and size of juvenile coho salmon (Oncorhynchus kisutch) were studied in 18 streams in Southeast Alaska in 1982 and 1983; studies were in old-growth and clear-cut reaches with or without buffer strips. The number of fry (age 0) in summer and winter was proportionately higher in buffered and clear-cut reaches than in old-growth reaches, and all treatments averaged a 20% decrease in fry from summer to winter. Fry length and condition factor were greater for buffered and clear-cut reaches than for old-growth reaches, whereas parr (age 1 and older) size did not differ among treatments. Fry and parr were larger in the southern than in the northern regions and their length and weight were directly related to peripbyton biomass and benthos density. A higher percentage of large [Formula: see text] fry remained in buffered reaches than in clear-cut and old-growth reaches; therefore, the density of fry that were potentially large enough to become smolts the next spring (presmolts) was greater in buffered reaches. The larger fry in buffered and clear-cut reaches compared with old-growth reaches was probably due to earlier fry emergence that resulted from increased water temperature.

Emigration and Production of Hatchery Coho Salmon (Oncorhynchus kisutch) Stocked in Streams Draining an Old-growth and a Clear-cut Watershed

1987 ◽  
Vol 44 (8) ◽  
pp. 1397-1407 ◽  
Author(s):  
Robert E. Bilby ◽  
Peter A. Bisson
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Old Growth ◽  
Trophic Conditions ◽  
Temperature Changes ◽  
Gross Photosynthesis ◽  
Clear Cut ◽  
Salmon Fry ◽  
Streamflow Change ◽  
Downstream Movement

Downstream movement of coho salmon fry (Oncorhynchus kisutch) stocked in old-growth and clear-cut watersheds occurred in three phases: (1) a brief period of heavy emigration immediately after stocking, (2) relatively little movement throughout most of the summer, and (3) intermittent heavy emigration during early autumn freshets. Coho emigrated whenever a streamflow change ≥ 3%∙d−1 occurred, but movement nearly ceased at flows above a certain level. Temperature changes were less important than discharge in triggering movement. When high densities were stocked, emigrant fry were smaller than residents. When low densities were stocked, emigration after the initial pulse of downstream movement was generally lower and there were no size differences between emigrants and residents. Production in the clear-cut was greater than in the old-growth watershed. Proportionately fewer fish emigrated from the old-growth stream, but when population densities were high, mortality in the old-growth exceeded the clear-cut. Greater emigration from the clear-cut site was possibly related to a scarcity of pools. Although the old-growth stream possessed better rearing habitat, less food may have been available, as suggested by gross photosynthesis rates 50% lower than in the clear-cut stream. Coho production therefore appeared to be most strongly influenced by trophic conditions, while volitional residency was most strongly influenced by habitat quality.

Effects of Clear-cut Logging with and without Buffer Strips on juvenile Salmonids in Alaskan Streams

1986 ◽  
Vol 43 (8) ◽  
pp. 1521-1533 ◽  
Author(s):  
Michael L. Murphy ◽  
Jonathan Heifetz ◽  
Scott W. Johnson ◽  
K V. Koski ◽  
John F. Thedinga
Keyword(s):  
Primary Production ◽  
Coho Salmon ◽  
Woody Debris ◽  
Salmo Gairdneri ◽  
Buffer Strips ◽  
Channel Stability ◽  
Old Growth ◽  
Clear Cut ◽  
Clear Cutting ◽  
Old Growth Forest

To assess short-term effects of logging on juvenile Oncorhynchus kisutch, Salvelinus malma, Salmo gairdneri, and Salmo clarki in southeastern Alaska, we compared fish density and habitat in summer and winter in 18 streams in old-growth forest and in clearcuts with and without buffer strips. Buffered reaches did not consistently differ from old-growth reaches; clear-cut reaches had more periphyton, lower channel stability, and less canopy, pool volume, large woody debris, and undercut banks than old-growth reaches. In summer, if areas had underlying limestone, clear-cut reaches and buffered reaches with open canopy had more periphyton, benthos, and coho salmon fry (age 0) than old-growth reaches. In winter, abundance of parr (age > 0) depended on amount of debris. If debris was left in clear-cut reaches, or added in buffered reaches, coho salmon parr were abundant (10–22/100 m2). If debris had been removed from clear-cut reaches, parr were scarce (< 2/100 m2). Thus, clear-cutting may increase fry abundance in summer in some streams by increasing primary production, but may reduce abundance of parr in winter if debris is removed. Use of buffer strips maintains or increases debris, protects habitat, allows increased primary production, and can increase abundance of fry and parr.

Winter Distribution of Juvenile Coho Salmon (Oncorhynchus kisutch) Before and After Logging in Carnation Creek, British Columbia, and Some Implications for Overwinter Survival

1983 ◽  
Vol 40 (4) ◽  
pp. 452-461 ◽  
Author(s):  
P. J. Tschaplinski ◽  
G. F. Hartman
Keyword(s):  
Survival Rate ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Habitat Characteristics ◽  
Main Stream ◽  
Low Velocity ◽  
Tree Roots ◽  
Apparent Survival ◽  
Winter Habitat ◽  
Clear Cut

Numbers of juvenile coho salmon (Oncorhynchus kisutch) in streams are reduced substantially in winter compared to those that occur in summer. Most of this reduction occurs early in autumn with the onset of the first seasonal freshets. Stream sections containing adequate winter habitat in the form of deep pools, log jams, and undercut banks with tree roots and debris lost fewer fish during freshets and maintained higher numbers of coho in winter than sections without these habitat characteristics. These features provide shelter and reduce stream velocities. Microhabitats occupied by coho juveniles in winter after logging were unchanged from those described before logging — all microhabitats were characterized by low water velocities (≤ 0.3 m/s). Up to 48% of the coho population inhabiting stream sections with adequate shelter remained there by midwinter (Jan. 3). This percentage was typical of stream sections where at least some trees remained after logging. Streamside trees stabilized the banks and prevented their collapse. In contrast, two of three study sections that had been clear-cut logged had unstable banks which collapsed during winter freshets. Almost no coho remained in these sections in winter. Many coho emigrate from the main stream to seek the shelter of low-velocity tributaries and valley sloughs concurrent with the decline of coho populations in Carnation Creek during autumn and early winter. This seasonal shift in distribution reverses in the spring when large numbers of coho reenter the main stream. Fish overwintering in these sites have a high apparent survival rate. Before logging a 4-yr mean of 169 ± 44 coho entered one tributary (a slough called 750-m site) in autumn. Of these numbers entering, 72.2% came out in spring. During and after logging, an annual mean of 288 coho entered the same site. The apparent survival rate during and after logging was 67.4%, essentially unchanged from the prelogging value. Logging has neither reduced the numbers of coho juveniles that enter such sites in autumn to overwinter, nor reduced the numbers leaving these sites to reenter Carnation Creek in spring.

Predation by River Otters (Lutra canadensis) on Juvenile Coho Salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) in Southeast Alaska

1993 ◽  
Vol 50 (2) ◽  
pp. 312-315 ◽  
Author(s):  
C. Andrew Dolloff
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
River System ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Southeast Alaska ◽  
River Otters ◽  
Juvenile Salmonids ◽  
Dolly Varden Salvelinus Malma ◽  
Lutra Canadensis

The effect of predation by river otters (Lutra canadensis) on juvenile coho salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) in a Southeast Alaska watershed was inferred by examining the number and size distribution of sagittal otoliths that were found in otter scats. Individual scats contained up to 408 otoliths, indicating that at least 200 fish had been eaten between defecations. Otoliths from juvenile salmonids outnumbered those from coastrange sculpins (Cottus aleuticus) by about six to one. Based on examination of over 8000 otoliths found in otter scats, at least 3300 juvenile salmonids were eaten by two river otters and their two young in the Kadashan River system during a 6-wk period in late spring 1985.

Review and synthesis of Carnation Creek herbicide research

1993 ◽  
Vol 69 (3) ◽  
pp. 323-330 ◽  
Author(s):  
P. E. Reynolds ◽  
J. C. Scrivener ◽  
L. B. Holtby ◽  
P. D. Kingsbury
Keyword(s):  
Rain Forest ◽  
Environmental Fate ◽  
Coho Salmon ◽  
Aquatic Organisms ◽  
Buffer Strips ◽  
Short Term ◽  
The West ◽  
Winter Storms ◽  
Biological Studies ◽  
Autumn And Winter

Carnation Greek Watershed (48°54′N,125°01′W), located on the west coast of Vancouver Island, was aerially treated with glyphosate (ROUNDUP1) in September 1984. Various chemical and biological studies were conducted for up to 3 years after the treatment in order to study the environmental fate and impacts of the herbicide in a temperate coastal rain forest. In tributaries oversprayed with the herbicide, impacts on coho salmon (Oncorhynchus kisutch) and other aquatic organisms were short-term, and the impacts were considered to be acceptable. Residue movements within the watershed and residue inputs into the aquatic ecosystem were monitored in relation to autumn and winter storms. Glyphosate residues rapidly dissipated and degraded in the natural environment. After 1 year, remaining residues were strongly adsorbed to organic matter, soil particles, and/or stream bottom sediments, where they appeared to be inactivated and immobilized. Key words: ROUNDUP, glyphosate, environmental fate, aquatic impacts, herbicide efficacy, residues, coho salmon, buffer strips.

Changes in Territorial, Gill-flaring, and Feeding Behavior in Juvenile Coho Salmon (Oncorhynchus kisutch) following Short-term Pulses of Suspended Sediment

1985 ◽  
Vol 42 (8) ◽  
pp. 1410-1417 ◽  
Author(s):  
L. Berg ◽  
T. G. Northcote
Keyword(s):  
Feeding Behavior ◽  
Suspended Sediment ◽  
Brine Shrimp ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Turbid Water ◽  
Short Term ◽  
Dominance Hierarchies ◽  
Short Term Exposure ◽  
Laboratory Stream

The territorial, gill-flaring, and feeding behavior of juvenile coho salmon (Oncorhynchus kisutch) in a laboratory stream was disrupted by short-term exposure to suspended sediment pulses. At the higher turbidities tested (30 and 60 nephelometric turbidity units (NTU)), dominance hierarchies broke down, territories were not defended, and gill flaring occurred more frequently. Only after return to lower turbidities (0–20 NTU) was social organization reestablished. The reaction distance of the fish to adult brine shrimp decreased significantly in turbid water (30 and 60 NTU) as did capture success per strike and the percentage of prey ingested. Implications of these behavioral modifications suggest that the fitness of salmonid populations exposed to short-term pulses of suspended sediment may be impaired.

Allochthonous versus Autochthonous Organic Matter Contributions to the Trophic Support of Fish Populations in Clear-Cut and Old-Growth Forested Streams

1992 ◽  
Vol 49 (3) ◽  
pp. 540-551 ◽  
Author(s):  
Robert E. Bilby ◽  
Peter A. Bisson
Keyword(s):  
Organic Matter ◽  
Forest Canopy ◽  
Coho Salmon ◽  
Coniferous Forest ◽  
Fish Populations ◽  
Fish Production ◽  
Old Growth ◽  
Growth Site ◽  
Clear Cut ◽  
Autochthonous Organic Matter

Annual organic matter inputs and production of stocked coho salmon (Oncorhynchus kisutch), coastal cutthroat trout (O. clarki clarki), and shorthead sculpin (Cottus confusus) from spring through early autumn were monitored for 2 yr in two headwater tributaries of the Deschutes River, Washington. One site was bordered by old-growth coniferous forest; the other was an area clear-cut without buffer strips 7 yr before the study. Allochthonous organic matter (terrestrial origin) dominated inputs to the old-growth site and contributed ~300 g∙m−2∙yr−1, while autochthonous organic matter totaled ~100 g∙m−2∙yr−1. In the clear-cut site, autochthonous inputs contributed ~175 g∙m−2∙yr−1, but allochthonous inputs contributed only ~60 g∙m−2∙yr−1 owing to loss of riparian vegetation. Although combined allochthonous and autochthonous inputs were almost twofold greater in the old-growth site, fish production was greater in the clear-cut site. Production of coho salmon and shorthead sculpin during early summer was largely responsible for differences between sites. Fish populations appeared to depend upon food derived from autotrophic pathways during spring and summer in the presence or absence of forest canopy, a hypothesis supported by analysis of coho stomach contents and the similar ratios of autochthonous inputs and fish production between the two streams.

Short-term storage sperm of coho salmon (Oncorhynchus kisutch) at 4 °C: Effect of sperm: Extender dilution ratios and antioxidant butyl-hydroxytoluene (BHT) on sperm function

Cryobiology ◽  
2020 ◽  
Vol 95 ◽  
pp. 44-50 ◽  
Author(s):  
Osvaldo Merino ◽  
Kelly Dumorné ◽  
Sandoval-Vargas Leidy ◽  
Elías Figueroa ◽  
Iván Valdebenito ◽  
...  
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Sperm Function ◽  
Short Term ◽  
Short Term Storage ◽  
Term Storage

Geographic variation in environmental factors regulating outmigration timing of coho salmon (Oncorhynchus kisutch) smolts

2014 ◽  
Vol 71 (1) ◽  
pp. 56-69 ◽  
Author(s):  
Brian C. Spence ◽  
E.J. Dick
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Environmental Cues ◽  
Lunar Phase ◽  
Short Term ◽  
Migration Timing ◽  
Selection Processes ◽  
Favorable Conditions ◽  
Migration Probability ◽  
Downstream Movement

The environmental cues that regulate smoltification and trigger downstream movement by salmon should vary across space in response to differences in the predictability of favorable conditions for migration and ocean entry. To examine this, we modeled the short-term outmigration probability of four coho salmon (Oncorhynchus kisutch) populations in three distinct geographic regions in relation to photoperiod, temperature, streamflow, lunar phase, and interactions among these variables. For smolts in Deer and Flynn creeks, Oregon (1960–1972), migration probability was influenced by numerous factors, including photoperiod, temperature (absolute and change), flow (absolute and change), and lunar phase, with certain factors interacting. Smolts from Carnation Creek, British Columbia (1972–1986) responded to a similarly diverse suite of factors (excluding lunar phase), though in somewhat different ways. In contrast, migration timing of smolts in Sashin Creek, Alaska (1959–1969) was best explained by a model that included only photoperiod, temperature, and the interaction between these terms. These population differences suggest fundamental differences across regions in the selection processes operating in both marine and freshwater environments.

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