Using thalweg profiling to assess and monitor juvenile salmon (Oncorhynchus spp.) habitat in small streams

2006 ◽  
Vol 63 (7) ◽  
pp. 1515-1525 ◽  
Author(s):  
Brent Mossop ◽  
Michael J Bradford
Keyword(s):  
Chinook Salmon ◽  
Stream Flow ◽  
Gold Mining ◽  
Oncorhynchus Tshawytscha ◽  
Fish Habitat ◽  
Juvenile Chinook Salmon ◽  
Yukon River ◽  
Small Streams ◽  
Longitudinal Profiles ◽  
Small Tributary

Thalweg profiles are longitudinal profiles of the streambed elevation measured along the deepest portion of the stream. This technique has recently been advocated as a tool to assess and monitor fish habitat in streams because metrics calculated from thalweg profiles can provide useful information on habitat quality, and measurements are both repeatable and independent of stream flow. Relations between thalweg metrics and land use have also been documented. However, a relation between fish abundance and thalweg metrics has not been established. To develop this relation, we surveyed thalweg profiles and sampled juvenile Chinook salmon (Oncorhynchus tshawytscha) density in 14 reaches of small tributary streams of the upper Yukon River. Chinook salmon density was correlated with three thalweg metrics. Two of these metrics — length in residual pool and mean maximum residual pool depth — provided useful measures of pool extent and quality and useful information on Chinook salmon habitat. Thalweg metrics differed between these undisturbed streams and reaches in streams affected by placer gold mining. These results suggest that thalweg profiling provides a useful tool to assess and monitor fish habitat in small streams.

A Predation Bioassay to Quantify the Ecological Significance of Sublethal Responses of Juvenile Chinook Salmon (Oncorhynchus tshawytscha) to the Antisapstain Fungicide TCMTB

1994 ◽  
Vol 51 (8) ◽  
pp. 1780-1790 ◽  
Author(s):  
G. M. Kruzynski ◽  
I. K. Birtwell
Keyword(s):  
Chinook Salmon ◽  
Stream Flow ◽  
Oncorhynchus Tshawytscha ◽  
Treated Wood ◽  
Control Group ◽  
Fraser River ◽  
Ecological Significance ◽  
Flow Conditions ◽  
Juvenile Chinook Salmon ◽  
Marine Predator

The lumber protection antisapstain fungicide 2-(thiocyanomethylthio)benzothiazole (TCMTB) is leached by rainfall from treated wood awaiting shipment from outdoor lumber storage facilities. Stormwater discharges of this pesticide into estuarine reaches of the Fraser River, British Columbia, have raised concern about toxic effects on juvenile salmon rearing in this habitat. Simulated stream flow conditions were used to expose underyearling chinook salmon (Oncorhynchus tshawytscha) to a sublethal (10 μg∙L−1) concentration of TCMTB. Equal numbers of fin-clipped control and exposed fish were subsequently transferred to a vertically stratified (fresh over seawater) 15 500-L outdoor tank where they were challenged with the combined stressors of salinity and the presence of a marine predator (yellowtail rockfish (Sebastes flavidus)). After 5 d under these simulated estuarine conditions, survivors were enumerated. Chinook salmon that had been exposed to the toxicant were consumed in preference to the control group by a factor of 5.5:1. Inasmuch as predator avoidance represents the successful integration of appropriate biochemical, physiological, and behavioural responses, the predator bioassay provides an ecologically relevant technique to determine the significance to survival of the complex multifactorial interactions of individually "sublethal" stressors.

Ecology of juvenile chinook salmon in a small non-natal stream of the Yukon River drainage and the role of ice conditions on their distribution and survival

2001 ◽  
Vol 79 (11) ◽  
pp. 2043-2054 ◽  
Author(s):  
Michael J Bradford ◽  
Jeff A Grout ◽  
Sue Moodie
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Thick Layer ◽  
Average Density ◽  
Yukon River ◽  
Small Streams ◽  
Mean Size ◽  
Ice Conditions ◽  
Stream Type

We investigated the ecology of juvenile stream-type chinook salmon (Oncorhynchus tshawytscha) in Croucher Creek, a small non-natal tributary of the upper Yukon River, in 1998 and 1999. Underyearling (age 0+) salmon enter Croucher Creek from the Yukon River in June, and by midsummer reached an average density of >0.5/m2. Fish were most commonly found in small pools. Their mean size increased until the end of August, but growth virtually ceased after that, when water temperatures fell. Juveniles remained in the stream through winter, and their distribution and survival were strongly influenced by aufeis, a thick layer of ice that develops from the freezing of groundwater. Over-winter survival was not dependent on fish size. Those fish that survived the winter grew rapidly and doubled in body mass in the spring. About 900 yearling fish emigrated from Croucher Creek in late June and early July at a mean length of 89 mm and mass of 7.2 g. Most of the migrants overwintered in a 700 m long reach of the creek that was downstream from groundwater sources and did not experience severe icing conditions. We suggest that small streams may be important habitats for juvenile salmon in the Yukon drainage, especially if there is a year-round source of groundwater flow that creates conditions suitable for overwintering.

scholarly journals Managed Wetlands Can Benefit Juvenile Chinook Salmon in a Tidal Marsh

2021 ◽  
Author(s):  
Nicole M. Aha ◽  
Peter B. Moyle ◽  
Nann A. Fangue ◽  
Andrew L. Rypel ◽  
John R. Durand
Keyword(s):  
San Francisco ◽  
Growth Rates ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Nursery Habitat ◽  
San Francisco Estuary ◽  
Rice Fields ◽  
Fish Growth ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

AbstractLoss of estuarine and coastal habitats worldwide has reduced nursery habitat and function for diverse fishes, including juvenile Chinook salmon (Oncorhynchus tshawytscha). Underutilized off-channel habitats such as flooded rice fields and managed ponds present opportunities for improving rearing conditions and increasing habitat diversity along migratory corridors. While experiments in rice fields have shown enhanced growth rates of juvenile fishes, managed ponds are less studied. To evaluate the potential of these ponds as a nursery habitat, juvenile Chinook salmon (~ 2.8 g, 63 mm FL) were reared in cages in four contrasting locations within Suisun Marsh, a large wetland in the San Francisco Estuary. The locations included a natural tidal slough, a leveed tidal slough, and the inlet and outlet of a tidally muted managed pond established for waterfowl hunting. Fish growth rates differed significantly among locations, with the fastest growth occurring near the outlet in the managed pond. High zooplankton biomass at the managed pond outlet was the best correlate of salmon growth. Water temperatures in the managed pond were also cooler and less variable compared to sloughs, reducing thermal stress. The stress of low dissolved oxygen concentrations within the managed pond was likely mediated by high concentrations of zooplankton and favorable temperatures. Our findings suggest that muted tidal habitats in the San Francisco Estuary and elsewhere could be managed to promote growth and survival of juvenile salmon and other native fishes.

A New Multilocus Probe for DNA Fingerprinting in Chinook Salmon (Oncorhynchus tshawytscha), and Comparisons with a Single-Locus Probe

1993 ◽  
Vol 50 (7) ◽  
pp. 1559-1567 ◽  
Author(s):  
T. A. Stevens ◽  
R. E. Withler ◽  
S. H. Goh ◽  
T. D. Beacham
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Polymorphic Locus ◽  
Pedigree Analysis ◽  
Single Locus ◽  
Dna Fingerprint ◽  
Dna Fragments ◽  
Banding Patterns ◽  
Discriminatory Ability ◽  
Juvenile Chinook Salmon

A multilocus DNA probe, B2-2, isolated from chinook salmon (Oncorhynchus tshawytscha) and a single-locus Atlantic salmon (Salmo salar) probe, 3.15.34, were examined for discriminatory ability among seven parents and 33–37 juveniles from five families of chinook salmon. DNA fingerprint patterns were observed in Hae III-digested chinook salmon DNA probed with B2-2. Between 8 and 20 fragments, from 2.20 kilobase pairs (kbp) to 19.0 kbp, were detected in each individual. The level of band sharing among unrelated parents was 0.18. Probe 3.15.34 hybridized with a total of nine DNA fragments, from 3.35 to 6.00 kbp, in the chinook salmon parents and progeny. One or two fragments were detected in each individual. Pedigree analysis confirmed that 3.15.34 detected both alleles of a single polymorphic locus whereas B2-2 detected autosomal, unlinked, predominantly heterozygous DNA fragments that were inherited in a Mendelian fashion at a minimum of 10 polymorphic loci. Among juvenile chinook salmon, levels of band sharing detected with probe B2-2 increased with increasing relatedness, and clustering based on differences in banding patterns distinguished unrelated progeny, half sibs, and full sibs even in the absence of parental genotypic data.

Predator avoidance ability of juvenile chinook salmon (Oncorhynchus tshawytscha) subjected to sublethal exposures of gas-supersaturated water

1997 ◽  
Vol 54 (4) ◽  
pp. 757-764 ◽  
Author(s):  
M G Mesa ◽  
J J Warren
Keyword(s):  
Chinook Salmon ◽  
Predator Avoidance ◽  
Oncorhynchus Tshawytscha ◽  
Control Fish ◽  
Dissolved Gas ◽  
Juvenile Chinook Salmon ◽  
Unexposed Control ◽  
Lateral Lines ◽  
Gill Filaments ◽  
Juvenile Chinook

To assess the effects of gas bubble trauma (GBT) on the predator avoidance ability of juvenile chinook salmon (Oncorhynchus tshawytscha), we created groups of fish that differed in prevalence and severity of gas emboli in their lateral lines, fins, and gills by exposing them to 112% total dissolved gas (TDG) for 13 days, 120% TDG for 8 h, or 130% TDG for 3.5 h. We subjected exposed and unexposed control fish simultaneously to predation by northern squawfish (Ptychocheilus oregonensis) in water of normal gas saturation in 6, 18, and 10 tests using prey exposed to 112, 120, and 130% TDG, respectively. Only fish exposed to 130% TDG showed a significant increase in vulnerability to predation. The signs of GBT exhibited by fish sampled just prior to predator exposure were generally more severe in fish exposed to 130% TDG, which had the most extensive occlusion of the lateral line and gill filaments with gas emboli. Fish exposed to 112% TDG had the most severe signs of GBT in the fins. Our results suggest that fish showing GBT signs similar to those of our fish exposed to 130% TDG, regardless of their precise exposure history, may be more vulnerable to predation.

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