Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
River Basin ◽  
Chinook Salmon ◽  
Spatial Scales ◽  
Stream Temperature ◽  
Growth Potential ◽  
Main Stem ◽  
Field Observations ◽  
Habitat Types ◽  
Yukon River Basin ◽  
Freshwater Habitats

<i>Abstract.</i>—Climatic variation is a key driver of freshwater physical processes that in turn control stream fish growth and population dynamics at fine spatial scales and species distributions across broad landscapes. A recent downturn in Chinook Salmon <i>Oncorhynchus tshawytscha </i>returns across the Yukon River basin, Alaska, USA and Yukon Territories, Canada has led to hardship among user groups and increased interest in understanding how freshwater processes affect population persistence within this important commercial, recreational, and subsistence fishery. Here, we present results for the Chena River basin, interior Alaska, where we used field observations and riverscape-scale spatially explicit models to assess the influence of stream temperature on juvenile Chinook Salmon growth potential among years (2003–2015) and across 438 stream kilometers. We ran bioenergetic simulations for warm and cool year scenarios and contrasted temperature model precision and growth among different habitat types (small and large tributaries, main stem, and side channels) based on field estimates of growth, size, diet, and measured stream temperatures. Stream temperature regimes predicted from remotely sensed land surface temperatures were precise during the open water season (<I>R</I><sup>2</sup> > 0.87; root-mean-squared error < 1.1°C), although the relationship was weakest in groundwater-mediated tributary habitats. Field observations revealed salmon were 67% larger by mass (g) in September during a warm year versus a cool year from main-stem sites. Bioenergetic simulations predicted that, on average, growth potential was 42% higher in warm years, although growth potential varied across the riverscape as much as 60% between cool upstream and warm downstream habitats. Climate variability is clearly an important driver of freshwater habitat conditions and has a large role in controlling freshwater growth of juvenile salmon. A better understanding of how climate influences growth conditions in different habitat types and across broad landscapes will be critical for conservation and management of Alaskan Chinook Salmon stocks under an expected warmer and more variable climate.

Emigration of age-0 chinook salmon (Oncorhynchus tshawytscha) smolts from the upper South Umpqua River basin, Oregon, U.S.A.

1999 ◽  
Vol 56 (6) ◽  
pp. 939-946 ◽  
Author(s):  
Brett B Roper ◽  
Dennis L Scarnecchia
Keyword(s):  
River Basin ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Lunar Cycle ◽  
Stream Temperature ◽  
Spring Water ◽  
Day Length ◽  
The Moon ◽  
Moon Phases ◽  
Upper South

Two rotating smolt traps were used through 4 consecutive years to monitor emigrations of age-0 chinook salmon (Oncorhynchus tshawytscha) from two watersheds of the upper South Umpqua River basin, Oregon, U.S.A. The number of wild smolts moving past the mainstem South Umpqua River trap ranged from 26 455 in 1991 to less than 5000 in 1993. The number of wild smolts passing the Jackson Creek trap ranged from 13 345 in 1991 to 0 in 1993. Higher numbers of wild smolts were significantly (P = 0.003) correlated with higher numbers of prespawning adults counted in index reaches the preceding year. Timing of emigration of smolts was found to be significantly related to stream temperature (P < 0.05) and phase of the lunar cycle (P < 0.05) but not related to changes in discharge (P > 0.05). Median emigration dates, which varied over 9 weeks, were earlier when spring water temperatures were higher. On average, two thirds of yearly smolt runs occurred when the moon was either waning or new, even though these moon phases were present only about half of the time. Significantly (P < 0.05) more fish than expected emigrated past both traps when day length was increasing.

scholarly journals Caddisflies (Insecta: Trichoptera) of the Chipola River basin in Florida and southeast Alabama, USA: a faunistic survey

Check List ◽  
2016 ◽  
Vol 12 (4) ◽  
pp. 1936
Author(s):  
Dana R. Denson ◽  
Andrew K. Rasmussen ◽  
Steven C. Harris
Keyword(s):  
River Basin ◽  
Water Body ◽  
Field Survey ◽  
Main Stem ◽  
Habitat Types ◽  
Taxa Richness ◽  
Apparent Correlation ◽  
Habitat Specialists ◽  
Stream Size ◽  
State Records

A field survey of caddisflies of the Chipola River basin in Florida and Alabama was carried out from 2006 through 2012. Adults were collected at 54 sites. Most were stream collections, but three were lakes. In total, 122 samples were taken. Approximately 32,000 individuals were identified, comprising 143 species, 40 genera, and 18 families. Two species represent new Florida state records. Three species are new to science. The majority of species were Leptoceridae, Hydroptilidae, Hydropsychidae, and Polycentropodidae. Most abundant families were Hydroptilidae, Leptoceridae, Hydropsychidae, and Psychomyiidae. A few species/families were largely or entirely confined to specific water body and habitat types, but most were broadly distributed. There was no apparent correlation between stream size and taxa richness. Rarer habitat-specialists were more commonly found in small tributaries than main stem sites. In general, there was a decrease in taxa richness from upstream to downstream in the river’s main stem.

Advances in Fisheries Bioengineering

2008 ◽  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Spatial Scales ◽  
Habitat Type ◽  
Strain Rates ◽  
Habitat Types ◽  
Drift Feeding ◽  
Velocity Gradients ◽  
The Difference ◽  
Lateral Scale

Abstract<em>.</em>—Focal positions of drift-feeding salmonids are often proximate to higher velocities and may be characterized by velocity gradients. Velocity gradients result in distortion of the flow field through linear deformation and angular deformation, which are summarized as the normal and shear strain rates, respectively. The objective of our study was to use a metric termed the exposure strain rate to quantify velocity gradients used by juvenile spring Chinook salmon <em>Oncorhynchus tshawytscha </em>across habitat type, seasons, and spatial scales. Within a habitat type, focal and mean water column velocities were measured at the position of each fish. In addition, mean column velocities were measured 0.6 and 1.2 m laterally toward the center of the channel. Three exposure strain rates were calculated as the difference between focal and mean column velocity in the vertical scale and at 0.6 and 1.2 m lateral scale divided by the length of the smallest fish (0.4 cm) length scale for all seasons and habitat types. This allowed direct comparison of exposure strain rates for all sizes of fish. The data revealed that for Chinook salmon larger than 4 cm, the distribution of vertical exposure strain rates was similar across all habitat types by season. Exposure strain rates began to vary between habitat types for the lateral scale, reflecting hydraulic differences between reach-scale habitat features. We concluded that juvenile Chinook occupied a specific shear environment independent of reach-scale habitat. Exposure strain rates described microhabitat use in a manner reflecting the habitat occupancy model for drift-feeding salmonids. For this reason, exposure strain rates provide more specific information on habitat use than focal velocities alone.

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 &lt;500 fish), 2) radiotelemetry-based proportions of annual production (major producer if ≥1% of the run, minor producer if &lt;1% of the run), and 3) aerial survey index counts (major producer if ≥165 fish observed, minor producer if &lt;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.

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.

Mercury Export from the Yukon River Basin and Potential Response to a Changing Climate

2011 ◽  
Vol 45 (21) ◽  
pp. 9262-9267 ◽  
Author(s):  
Paul F. Schuster ◽  
Robert G. Striegl ◽  
George R. Aiken ◽  
David P. Krabbenhoft ◽  
John F. Dewild ◽  
...  
Keyword(s):  
River Basin ◽  
Potential Response ◽  
Changing Climate ◽  
Yukon River ◽  
Yukon River Basin

Western white pine development in relation to biophysical characteristics across different spatial scales in the Coeur d'Alene River basin in northern Idaho, U.S.A.

2002 ◽  
Vol 32 (7) ◽  
pp. 1109-1125 ◽  
Author(s):  
Theresa B Jain ◽  
Russell T Graham ◽  
Penelope Morgan
Keyword(s):  
River Basin ◽  
Spatial Scales ◽  
Pinus Monticola ◽  
White Pine ◽  
Basal Diameter ◽  
Landscape Characteristics ◽  
Coeur D'alene ◽  
Biophysical Factors ◽  
Western White Pine ◽  
Northern Idaho

Many studies have assessed tree development beneath canopies in forest ecosystems, but results are seldom placed within the context of broad-scale biophysical factors. Mapped landscape characteristics for three watersheds, located within the Coeur d'Alene River basin in northern Idaho, were integrated to create a spatial hierarchy reflecting biophysical factors that influence western white pine (Pinus monticola Dougl. ex D. Don) development under a range of canopy openings. The hierarchy included canopy opening, landtype, geological feature, and weathering. Interactions and individual-scale contributions were identified using stepwise log–linear regression. The resulting models explained 68% of the variation for estimating western white pine basal diameter and 64% for estimating height. Interactions among spatial scales explained up to 13% of this variation and better described vegetation response than any single spatial scale. A hierarchical approach based on biophysical attributes is an excellent method for studying plant and environment interactions.

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