Importance of large woody debris for juvenile chinook salmon habitat in small boreal forest streams in the upper Yukon River basin, Canada

2004 ◽  
Vol 34 (9) ◽  
pp. 1955-1966 ◽  
Author(s):  
Brent Mossop ◽  
Michael J Bradford
Keyword(s):  
Boreal Forest ◽  
River Basin ◽  
Chinook Salmon ◽  
Woody Debris ◽  
Large Woody Debris ◽  
Juvenile Chinook Salmon ◽  
Yukon River ◽  
Yukon River Basin ◽  
Juvenile Chinook ◽  
Forest Streams

The importance of large woody debris (LWD) in forested stream ecosystems is well documented. However, little is known about LWD in northern boreal forest streams. We investigated the abundance, characteristics, and function of LWD in 13 small tributary streams of the upper Yukon River basin, Yukon Territory, Canada. LWD abundance was similar to values reported from temperate regions, whereas LWD size and total volume were well below values for the Pacific Northwest. LWD formed 28% of the pools, which provide important habitat for juvenile chinook salmon (Oncorhynchus tshawytscha Walbaum). The median diameter of pool-forming pieces was 17 cm, and ring counts on fallen riparian trees indicated that pool-forming pieces were likely 70–200 years old when downed. Juvenile chinook salmon density was correlated with LWD abundance in our study reaches. We conclude that despite differences in climate and forest type, LWD in Yukon streams and LWD in temperate regions appear to perform a similar function in creating fish habitat. Resource managers should consider the relatively slow tree growth and thus potentially long recovery times following human disturbances in these watersheds.

Spatially explicit estimation of aboveground boreal forest biomass in the Yukon River Basin, Alaska

2015 ◽  
Vol 36 (4) ◽  
pp. 939-953 ◽  
Author(s):  
Lei Ji ◽  
Bruce K. Wylie ◽  
Dana R. N. Brown ◽  
Birgit Peterson ◽  
Heather D. Alexander ◽  
...  
Keyword(s):  
Boreal Forest ◽  
River Basin ◽  
Forest Biomass ◽  
Spatially Explicit ◽  
Yukon River ◽  
Yukon River Basin

scholarly journals Juvenile Chinook Salmon abundance in the northern Bering Sea: Implications for future returns and fisheries in the Yukon River

2017 ◽  
Vol 135 ◽  
pp. 156-167 ◽  
Author(s):  
James M. Murphy ◽  
Kathrine G. Howard ◽  
Jeanette C. Gann ◽  
Kristin C. Cieciel ◽  
William D. Templin ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Bering Sea ◽  
Juvenile Chinook Salmon ◽  
Northern Bering Sea ◽  
Yukon River ◽  
Juvenile Chinook

Catalog of Chinook Salmon Spawning Areas in Yukon River Basin in Canada and United States

2017 ◽  
Vol 8 (2) ◽  
pp. 558-586 ◽  
Author(s):  
Randy J. Brown ◽  
Al von Finster ◽  
Robert J. Henszey ◽  
John H. Eiler
Keyword(s):  
United States ◽  
River Basin ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
The United States ◽  
Maximum Effect ◽  
Yukon River ◽  
Spawning Areas ◽  
Yukon River Basin ◽  
Major Producer

Abstract Chinook Salmon Oncorhynchus tshawytscha return to the Yukon River in northwestern North America each summer, migrating to spawning destinations from the lower river to more than 3,000 km upstream. These returns support numerous fisheries throughout the basin. Despite a long history of fisheries research and management, there is no comprehensive account of Chinook Salmon spawning areas in the basin. To address this issue, we cataloged, summarized, and mapped the known spawning areas of Yukon River Chinook Salmon by using a variety of sources including published articles, gray literature, and information archived in agency databases. Most of our sources were published within the past 30 y, but some refer to observations that were recorded as long ago as the late 1800s. We classified spawning areas as major or minor producers with three indicators of abundance: 1) quantitative estimates of escapement (major producer if ≥500 fish, minor producer if <500 fish), 2) radiotelemetry-based proportions of annual production (major producer if ≥1% of the run, minor producer if <1% of the run), and 3) aerial survey index counts (major producer if ≥165 fish observed, minor producer if <165 fish observed). We documented 183 spawning areas in the Yukon River basin, 79 in the United States, and 104 in Canada. Most spawning areas were in tributary streams, but some were in main-stem reaches as well. We classified 32 spawning areas as major producers and 151 as minor producers. The Chinook Salmon spawning areas cataloged here provide a baseline that makes it possible to strategically direct abundance, biological sampling, and genetics projects for maximum effect and to assess both spatial and temporal changes within the basin.

Assessment of boreal forest historical C dynamics in the Yukon River Basin: relative roles of warming and fire regime change

2012 ◽  
Vol 22 (8) ◽  
pp. 2091-2109 ◽  
Author(s):  
F.-M. Yuan ◽  
S.-H. Yi ◽  
A. D. McGuire ◽  
K. D. Johnson ◽  
J. Liang ◽  
...  
Keyword(s):  
Boreal Forest ◽  
River Basin ◽  
Regime Change ◽  
Fire Regime ◽  
Yukon River ◽  
C Dynamics ◽  
Yukon River Basin

scholarly journals Effects of Disturbance and Climate Change on Ecosystem Performance in the Yukon River Basin Boreal Forest

2014 ◽  
Vol 6 (10) ◽  
pp. 9145-9169 ◽  
Author(s):  
Bruce Wylie ◽  
Matthew Rigge ◽  
Brian Brisco ◽  
Kevin Murnaghan ◽  
Jennifer Rover ◽  
...  
Keyword(s):  
Climate Change ◽  
Boreal Forest ◽  
River Basin ◽  
Yukon River ◽  
Yukon River Basin

Fine-scale taxonomic and temporal variability in the energy density of invertebrate prey of juvenile Chinook salmon Oncorhynchus tshawytscha

2020 ◽  
Vol 655 ◽  
pp. 185-198
Author(s):  
J Weil ◽  
WDP Duguid ◽  
F Juanes
Keyword(s):  
Energy Density ◽  
Chinook Salmon ◽  
Temporal Variability ◽  
Energy Content ◽  
Single Point ◽  
Single Species ◽  
Fine Scale ◽  
Temporal Differences ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

Variation in the energy content of prey can drive the diet choice, growth and ultimate survival of consumers. In Pacific salmon species, obtaining sufficient energy for rapid growth during early marine residence is hypothesized to reduce the risk of size-selective mortality. In order to determine the energetic benefit of feeding choices for individuals, accurate estimates of energy density (ED) across prey groups are required. Frequently, a single species is assumed to be representative of a larger taxonomic group or related species. Further, single-point estimates are often assumed to be representative of a group across seasons, despite temporal variability. To test the validity of these practices, we sampled zooplankton prey of juvenile Chinook salmon to investigate fine-scale taxonomic and temporal differences in ED. Using a recently developed model to estimate the ED of organisms using percent ash-free dry weight, we compared energy content of several groups that are typically grouped together in growth studies. Decapod megalopae were more energy rich than zoeae and showed family-level variability in ED. Amphipods showed significant species-level variability in ED. Temporal differences were observed, but patterns were not consistent among groups. Bioenergetic model simulations showed that growth rate of juvenile Chinook salmon was almost identical when prey ED values were calculated on a fine scale or on a taxon-averaged coarse scale. However, single-species representative calculations of prey ED yielded highly variable output in growth depending on the representative species used. These results suggest that the latter approach may yield significantly biased results.

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